1CHANGES - changes for libpng
2
3version 0.1 [March 29, 1995]
4  initial work-in-progress release
5
6version 0.2 [April 1, 1995]
7  added reader into png.h
8  fixed small problems in stub file
9
10version 0.3 [April 8, 1995]
11  added pull reader
12  split up pngwrite.c to several files
13  added pnglib.txt
14  added example.c
15  cleaned up writer, adding a few new transformations
16  fixed some bugs in writer
17  interfaced with zlib 0.5
18  added K&R support
19  added check for 64 KB blocks for 16 bit machines
20
21version 0.4 [April 26, 1995]
22  cleaned up code and commented code
23  simplified time handling into png_time
24  created png_color_16 and png_color_8 to handle color needs
25  cleaned up color type defines
26  fixed various bugs
27  made various names more consistent
28  interfaced with zlib 0.71
29  cleaned up zTXt reader and writer (using zlib's Reset functions)
30  split transformations into pngrtran.c and pngwtran.c
31
32version 0.5 [April 30, 1995]
33  interfaced with zlib 0.8
34  fixed many reading and writing bugs
35  saved using 3 spaces instead of tabs
36
37version 0.6 [May 1, 1995]
38  first beta release
39  added png_large_malloc() and png_large_free()
40  added png_size_t
41  cleaned up some compiler warnings
42  added png_start_read_image()
43
44version 0.7 [June 24, 1995]
45  cleaned up lots of bugs
46  finished dithering and other stuff
47  added test program
48  changed name from pnglib to libpng
49
50version 0.71 [June 26, 1995]
51  changed pngtest.png for zlib 0.93
52  fixed error in libpng.txt and example.c
53
54version 0.8 [August 20, 1995]
55  cleaned up some bugs
56  added png_set_filler()
57  split up pngstub.c into pngmem.c, pngio.c, and pngerror.c
58  added #define's to remove unwanted code
59  moved png_info_init() to png.c
60  added old_size into png_realloc()
61  added functions to manually set filtering and compression info
62  changed compression parameters based on image type
63  optimized filter selection code
64  added version info
65  changed external functions passing floats to doubles (k&r problems?)
66  put all the configurable stuff in pngconf.h
67  enabled png_set_shift to work with paletted images on read
68  added png_read_update_info() - updates info structure with transformations
69
70Version 0.81 [August, 1995]
71  incorporated Tim Wegner's medium model code (thanks, Tim)
72
73Version 0.82 [September, 1995]
74  [unspecified changes]
75
76Version 0.85 [December, 1995]
77  added more medium model code (almost everything's a far)
78  added i/o, error, and memory callback functions
79  fixed some bugs (16-bit, 4-bit interlaced, etc.)
80  added first run progressive reader (barely tested)
81
82Version 0.86 [January, 1996]
83  fixed bugs
84  improved documentation
85
86Version 0.87 [January, 1996]
87  fixed medium model bugs
88  fixed other bugs introduced in 0.85 and 0.86
89  added some minor documentation
90
91Version 0.88 [January, 1996]
92  fixed progressive bugs
93  replaced tabs with spaces
94  cleaned up documentation
95  added callbacks for read/write and warning/error functions
96
97Version 0.89 [June 5, 1996]
98  Added new initialization API to make libpng work better with shared libs
99    we now have png_create_read_struct(), png_create_write_struct(),
100    png_create_info_struct(), png_destroy_read_struct(), and
101    png_destroy_write_struct() instead of the separate calls to
102    malloc and png_read_init(), png_info_init(), and png_write_init()
103  Changed warning/error callback functions to fix bug - this means you
104    should use the new initialization API if you were using the old
105    png_set_message_fn() calls, and that the old API no longer exists
106    so that people are aware that they need to change their code
107  Changed filter selection API to allow selection of multiple filters
108    since it didn't work in previous versions of libpng anyways
109  Optimized filter selection code
110  Fixed png_set_background() to allow using an arbitrary RGB color for
111    paletted images
112  Fixed gamma and background correction for paletted images, so
113    png_correct_palette is not needed unless you are correcting an
114    external palette (you will need to #define PNG_CORRECT_PALETTE_SUPPORTED
115    in pngconf.h) - if nobody uses this, it may disappear in the future.
116  Fixed bug with Borland 64K memory allocation (Alexander Lehmann)
117  Fixed bug in interlace handling (Smarasderagd, I think)
118  Added more error checking for writing and image to reduce invalid files
119  Separated read and write functions so that they won't both be linked
120    into a binary when only reading or writing functionality is used
121  New pngtest image also has interlacing and zTXt
122  Updated documentation to reflect new API
123
124Version 0.89c [June 17, 1996]
125  Bug fixes.
126
127Version 0.90 [January, 1997]
128  Made CRC errors/warnings on critical and ancillary chunks configurable
129  libpng will use the zlib CRC routines by (compile-time) default
130  Changed DOS small/medium model memory support - needs zlib 1.04 (Tim Wegner)
131  Added external C++ wrapper statements to png.h (Gilles Dauphin)
132  Allow PNG file to be read when some or all of file signature has already
133    been read from the beginning of the stream.  ****This affects the size
134    of info_struct and invalidates all programs that use a shared libpng****
135  Fixed png_filler() declarations
136  Fixed? background color conversions
137  Fixed order of error function pointers to match documentation
138  Current chunk name is now available in png_struct to reduce the number
139    of nearly identical error messages (will simplify multi-lingual
140    support when available)
141  Try to get ready for unknown-chunk callback functions:
142    - previously read critical chunks are flagged, so the chunk handling
143      routines can determine if the chunk is in the right place
144    - all chunk handling routines have the same prototypes, so we will
145      be able to handle all chunks via a callback mechanism
146  Try to fix Linux "setjmp" buffer size problems
147  Removed png_large_malloc, png_large_free, and png_realloc functions.
148
149Version 0.95 [March, 1997]
150  Fixed bug in pngwutil.c allocating "up_row" twice and "avg_row" never
151  Fixed bug in PNG file signature compares when start != 0
152  Changed parameter type of png_set_filler(...filler...) from png_byte
153    to png_uint_32
154  Added test for MACOS to ensure that both math.h and fp.h are not #included
155  Added macros for libpng to be compiled as a Windows DLL (Andreas Kupries)
156  Added "packswap" transformation, which changes the endianness of
157    packed-pixel bytes (Kevin Bracey)
158  Added "strip_alpha" transformation, which removes the alpha channel of
159    input images without using it (not necessarily a good idea)
160  Added "swap_alpha" transformation, which puts the alpha channel in front
161    of the color bytes instead of after
162  Removed all implicit variable tests which assume NULL == 0 (I think)
163  Changed several variables to "png_size_t" to show 16/32-bit limitations
164  Added new pCAL chunk read/write support
165  Added experimental filter selection weighting (Greg Roelofs)
166  Removed old png_set_rgbx() and png_set_xrgb() functions that have been
167    obsolete for about 2 years now (use png_set_filler() instead)
168  Added macros to read 16- and 32-bit ints directly from buffer, to be
169    used only on those systems that support it (namely PowerPC and 680x0)
170    With some testing, this may become the default for MACOS/PPC systems.
171  Only calculate CRC on data if we are going to use it
172  Added macros for zTXt compression type PNG_zTXt_COMPRESSION_???
173  Added macros for simple libpng debugging output selectable at compile time
174  Removed PNG_READ_END_MODE in progressive reader (Smarasderagd)
175  More description of info_struct in libpng.txt and png.h
176  More instructions in example.c
177  More chunk types tested in pngtest.c
178  Renamed pngrcb.c to pngset.c, and all png_read_<chunk> functions to be
179    png_set_<chunk>.  We now have corresponding png_get_<chunk>
180    functions in pngget.c to get information in info_ptr.  This isolates
181    the application from the internal organization of png_info_struct
182    (good for shared library implementations).
183
184Version 0.96 [May, 1997]
185  Fixed serious bug with < 8bpp images introduced in 0.95
186  Fixed 256-color transparency bug (Greg Roelofs)
187  Fixed up documentation (Greg Roelofs, Laszlo Nyul)
188  Fixed "error" in pngconf.h for Linux setjmp() behavior
189  Fixed DOS medium model support (Tim Wegner)
190  Fixed png_check_keyword() for case with error in static string text
191  Added read of CRC after IEND chunk for embedded PNGs (Laszlo Nyul)
192  Added typecasts to quiet compiler errors
193  Added more debugging info
194
195Version 0.97 [January, 1998]
196  Removed PNG_USE_OWN_CRC capability
197  Relocated png_set_crc_action from pngrutil.c to pngrtran.c
198  Fixed typecasts of "new_key", etc. (Andreas Dilger)
199  Added RFC 1152 [sic] date support
200  Fixed bug in gamma handling of 4-bit grayscale
201  Added 2-bit grayscale gamma handling (Glenn R-P)
202  Added more typecasts. 65536L becomes (png_uint_32)65536L, etc. (Glenn R-P)
203  Minor corrections in libpng.txt
204  Added simple sRGB support (Glenn R-P)
205  Easier conditional compiling, e.g.,
206    define PNG_READ/WRITE_NOT_FULLY_SUPPORTED;
207    all configurable options can be selected from command-line instead
208    of having to edit pngconf.h (Glenn R-P)
209  Fixed memory leak in pngwrite.c (free info_ptr->text) (Glenn R-P)
210  Added more conditions for png_do_background, to avoid changing
211    black pixels to background when a background is supplied and
212    no pixels are transparent
213  Repaired PNG_NO_STDIO behavior
214  Tested NODIV support and made it default behavior (Greg Roelofs)
215  Added "-m" option and PNGTEST_DEBUG_MEMORY to pngtest (John Bowler)
216  Regularized version numbering scheme and bumped shared-library major
217    version number to 2 to avoid problems with libpng 0.89 apps
218    (Greg Roelofs)
219
220Version 0.98 [January, 1998]
221  Cleaned up some typos in libpng.txt and in code documentation
222  Fixed memory leaks in pCAL chunk processing (Glenn R-P and John Bowler)
223  Cosmetic change "display_gamma" to "screen_gamma" in pngrtran.c
224  Changed recommendation about file_gamma for PC images to .51 from .45,
225    in example.c and libpng.txt, added comments to distinguish between
226    screen_gamma, viewing_gamma, and display_gamma.
227  Changed all references to RFC1152 to read RFC1123 and changed the
228    PNG_TIME_RFC1152_SUPPORTED macro to PNG_TIME_RFC1123_SUPPORTED
229  Added png_invert_alpha capability (Glenn R-P -- suggestion by Jon Vincent)
230  Changed srgb_intent from png_byte to int to avoid compiler bugs
231
232Version 0.99 [January 30, 1998]
233  Free info_ptr->text instead of end_info_ptr->text in pngread.c (John Bowler)
234  Fixed a longstanding "packswap" bug in pngtrans.c
235  Fixed some inconsistencies in pngconf.h that prevented compiling with
236    PNG_READ_GAMMA_SUPPORTED and PNG_READ_hIST_SUPPORTED undefined
237  Fixed some typos and made other minor rearrangement of libpng.txt (Andreas)
238  Changed recommendation about file_gamma for PC images to .50 from .51 in
239    example.c and libpng.txt, and changed file_gamma for sRGB images to .45
240  Added a number of functions to access information from the png structure
241    png_get_image_height(), etc. (Glenn R-P, suggestion by Brad Pettit)
242  Added TARGET_MACOS similar to zlib-1.0.8
243  Define PNG_ALWAYS_EXTERN when __MWERKS__ && WIN32 are defined
244  Added type casting to all png_malloc() function calls
245
246Version 0.99a [January 31, 1998]
247  Added type casts and parentheses to all returns that return a value.(Tim W.)
248
249Version 0.99b [February 4, 1998]
250  Added type cast png_uint_32 on malloc function calls where needed.
251  Changed type of num_hist from png_uint_32 to int (same as num_palette).
252  Added checks for rowbytes overflow, in case png_size_t is less than 32 bits.
253  Renamed makefile.elf to makefile.lnx.
254
255Version 0.99c [February 7, 1998]
256  More type casting.  Removed erroneous overflow test in pngmem.c.
257  Added png_buffered_memcpy() and png_buffered_memset(), apply them to rowbytes.
258  Added UNIX manual pages libpng.3 (incorporating libpng.txt) and  png.5.
259
260Version 0.99d [February 11, 1998]
261  Renamed "far_to_near()" "png_far_to_near()"
262  Revised libpng.3
263  Version 99c "buffered" operations didn't work as intended.  Replaced them
264    with png_memcpy_check() and png_memset_check().
265  Added many "if (png_ptr == NULL) return" to quell compiler warnings about
266    unused png_ptr, mostly in pngget.c and pngset.c.
267  Check for overlength tRNS chunk present when indexed-color PLTE is read.
268  Cleaned up spelling errors in libpng.3/libpng.txt
269  Corrected a problem with png_get_tRNS() which returned undefined trans array
270
271Version 0.99e [February 28, 1998]
272  Corrected png_get_tRNS() again.
273  Add parentheses for easier reading of pngget.c, fixed "||" should be "&&".
274  Touched up example.c to make more of it compileable, although the entire
275    file still can't be compiled (Willem van Schaik)
276  Fixed a bug in png_do_shift() (Bryan Tsai)
277  Added a space in png.h prototype for png_write_chunk_start()
278  Replaced pngtest.png with one created with zlib 1.1.1
279  Changed pngtest to report PASS even when file size is different (Jean-loup G.)
280  Corrected some logic errors in png_do_invert_alpha() (Chris Patterson)
281
282Version 0.99f [March 5, 1998]
283  Corrected a bug in pngpread() introduced in version 99c (Kevin Bracey)
284  Moved makefiles into a "scripts" directory, and added INSTALL instruction file
285  Added makefile.os2 and pngos2.def (A. Zabolotny) and makefile.s2x (W. Sebok)
286  Added pointers to "note on libpng versions" in makefile.lnx and README
287  Added row callback feature when reading and writing nonprogressive rows
288    and added a test of this feature in pngtest.c
289  Added user transform callbacks, with test of the feature in pngtest.c
290
291Version 0.99g [March 6, 1998, morning]
292  Minor changes to pngtest.c to suppress compiler warnings.
293  Removed "beta" language from documentation.
294
295Version 0.99h [March 6, 1998, evening]
296  Minor changes to previous minor changes to pngtest.c
297  Changed PNG_READ_NOT_FULLY_SUPPORTED to PNG_READ_TRANSFORMS_NOT_SUPPORTED
298    and added PNG_PROGRESSIVE_READ_NOT_SUPPORTED macro
299  Added user transform capability
300
301Version 1.00 [March 7, 1998]
302  Changed several typedefs in pngrutil.c
303  Added makefile.wat (Pawel Mrochen), updated makefile.tc3 (Willem van Schaik)
304  Replaced "while(1)" with "for(;;)"
305  Added PNGARG() to prototypes in pngtest.c and removed some prototypes
306  Updated some of the makefiles (Tom Lane)
307  Changed some typedefs (s_start, etc.) in pngrutil.c
308  Fixed dimensions of "short_months" array in pngwrite.c
309  Replaced ansi2knr.c with the one from jpeg-v6
310
311Version 1.0.0 [March 8, 1998]
312  Changed name from 1.00 to 1.0.0 (Adam Costello)
313  Added smakefile.ppc (with SCOPTIONS.ppc) for Amiga PPC (Andreas Kleinert)
314
315Version 1.0.0a [March 9, 1998]
316  Fixed three bugs in pngrtran.c to make gamma+background handling consistent
317    (Greg Roelofs)
318  Changed format of the PNG_LIBPNG_VER integer to xyyzz instead of xyz
319    for major, minor, and bugfix releases.  This is 10001. (Adam Costello,
320    Tom Lane)
321  Make months range from 1-12 in png_convert_to_rfc1123
322
323Version 1.0.0b [March 13, 1998]
324  Quieted compiler complaints about two empty "for" loops in pngrutil.c
325  Minor changes to makefile.s2x
326  Removed #ifdef/#endif around a png_free() in pngread.c
327
328Version 1.0.1 [March 14, 1998]
329  Changed makefile.s2x to reduce security risk of using a relative pathname
330  Fixed some typos in the documentation (Greg).
331  Fixed a problem with value of "channels" returned by png_read_update_info()
332
333Version 1.0.1a [April 21, 1998]
334  Optimized Paeth calculations by replacing abs() function calls with intrinsics
335  plus other loop optimizations. Improves avg decoding speed by about 20%.
336  Commented out i386istic "align" compiler flags in makefile.lnx.
337  Reduced the default warning level in some makefiles, to make them consistent.
338  Removed references to IJG and JPEG in the ansi2knr.c copyright statement.
339  Fixed a bug in png_do_strip_filler with XXRRGGBB => RRGGBB transformation.
340  Added grayscale and 16-bit capability to png_do_read_filler().
341  Fixed a bug in pngset.c, introduced in version 0.99c, that sets rowbytes
342    too large when writing an image with bit_depth < 8 (Bob Dellaca).
343  Corrected some bugs in the experimental weighted filtering heuristics.
344  Moved a misplaced pngrutil code block that truncates tRNS if it has more
345    than num_palette entries -- test was done before num_palette was defined.
346  Fixed a png_convert_to_rfc1123() bug that converts day 31 to 0 (Steve Eddins).
347  Changed compiler flags in makefile.wat for better optimization
348    (Pawel Mrochen).
349
350Version 1.0.1b [May 2, 1998]
351  Relocated png_do_gray_to_rgb() within png_do_read_transformations() (Greg).
352  Relocated the png_composite macros from pngrtran.c to png.h (Greg).
353  Added makefile.sco (contributed by Mike Hopkirk).
354  Fixed two bugs (missing definitions of "istop") introduced in libpng-1.0.1a.
355  Fixed a bug in pngrtran.c that would set channels=5 under some circumstances.
356  More work on the Paeth-filtering, achieving imperceptible speedup
357    (A Kleinert).
358  More work on loop optimization which may help when compiled with C++
359    compilers.
360  Added warnings when people try to use transforms they've defined out.
361  Collapsed 4 "i" and "c" loops into single "i" loops in pngrtran and pngwtran.
362  Revised paragraph about png_set_expand() in libpng.txt and libpng.3 (Greg)
363
364Version 1.0.1c [May 11, 1998]
365  Fixed a bug in pngrtran.c (introduced in libpng-1.0.1a) where the masks for
366    filler bytes should have been 0xff instead of 0xf.
367  Added max_pixel_depth=32 in pngrutil.c when using FILLER with palette images.
368  Moved PNG_WRITE_WEIGHTED_FILTER_SUPPORTED and PNG_WRITE_FLUSH_SUPPORTED
369    out of the PNG_WRITE_TRANSFORMS_NOT_SUPPORTED block of pngconf.h
370  Added "PNG_NO_WRITE_TRANSFORMS" etc., as alternatives for *_NOT_SUPPORTED,
371    for consistency, in pngconf.h
372  Added individual "ifndef PNG_NO_[CAPABILITY]" in pngconf.h to make it easier
373    to remove unwanted capabilities via the compile line
374  Made some corrections to grammar (which, it's) in documentation (Greg).
375  Corrected example.c, use of row_pointers in png_write_image().
376
377Version 1.0.1d [May 24, 1998]
378  Corrected several statements that used side effects illegally in pngrutil.c
379    and pngtrans.c, that were introduced in version 1.0.1b
380  Revised png_read_rows() to avoid repeated if-testing for NULL (A Kleinert)
381  More corrections to example.c, use of row_pointers in png_write_image()
382    and png_read_rows().
383  Added pngdll.mak and pngdef.pas to scripts directory, contributed by
384    Bob Dellaca, to make a png32bd.dll with Borland C++ 4.5
385  Fixed error in example.c with png_set_text: num_text is 3, not 2 (Guido V.)
386  Changed several loops from count-down to count-up, for consistency.
387
388Version 1.0.1e [June 6, 1998]
389  Revised libpng.txt and libpng.3 description of png_set_read|write_fn(), and
390    added warnings when people try to set png_read_fn and png_write_fn in
391    the same structure.
392  Added a test such that png_do_gamma will be done when num_trans==0
393    for truecolor images that have defined a background.  This corrects an
394    error that was introduced in libpng-0.90 that can cause gamma processing
395    to be skipped.
396  Added tests in png.h to include "trans" and "trans_values" in structures
397    when PNG_READ_BACKGROUND_SUPPORTED or PNG_READ_EXPAND_SUPPORTED is defined.
398  Add png_free(png_ptr->time_buffer) in png_destroy_read_struct()
399  Moved png_convert_to_rfc_1123() from pngwrite.c to png.c
400  Added capability for user-provided malloc_fn() and free_fn() functions,
401    and revised pngtest.c to demonstrate their use, replacing the
402    PNGTEST_DEBUG_MEM feature.
403  Added makefile.w32, for Microsoft C++ 4.0 and later (Tim Wegner).
404
405Version 1.0.2 [June 14, 1998]
406  Fixed two bugs in makefile.bor .
407
408Version 1.0.2a [December 30, 1998]
409  Replaced and extended code that was removed from png_set_filler() in 1.0.1a.
410  Fixed a bug in png_do_filler() that made it fail to write filler bytes in
411    the left-most pixel of each row (Kevin Bracey).
412  Changed "static pngcharp tIME_string" to "static char tIME_string[30]"
413    in pngtest.c (Duncan Simpson).
414  Fixed a bug in pngtest.c that caused pngtest to try to write a tIME chunk
415    even when no tIME chunk was present in the source file.
416  Fixed a problem in pngrutil.c: gray_to_rgb didn't always work with 16-bit.
417  Fixed a problem in png_read_push_finish_row(), which would not skip some
418    passes that it should skip, for images that are less than 3 pixels high.
419  Interchanged the order of calls to png_do_swap() and png_do_shift()
420    in pngwtran.c (John Cromer).
421  Added #ifdef PNG_DEBUG/#endif surrounding use of PNG_DEBUG in png.h .
422  Changed "bad adaptive filter type" from error to warning in pngrutil.c .
423  Fixed a documentation error about default filtering with 8-bit indexed-color.
424  Separated the PNG_NO_STDIO macro into PNG_NO_STDIO and PNG_NO_CONSOLE_IO
425    (L. Peter Deutsch).
426  Added png_set_rgb_to_gray() and png_get_rgb_to_gray_status() functions.
427  Added png_get_copyright() and png_get_header_version() functions.
428  Revised comments on png_set_progressive_read_fn() in libpng.txt and example.c
429  Added information about debugging in libpng.txt and libpng.3 .
430  Changed "ln -sf" to "ln -s -f" in makefile.s2x, makefile.lnx, and
431    makefile.sco.
432  Removed lines after Dynamic Dependencies" in makefile.aco .
433  Revised makefile.dec to make a shared library (Jeremie Petit).
434  Removed trailing blanks from all files.
435
436Version 1.0.2a [January 6, 1999]
437  Removed misplaced #endif and #ifdef PNG_NO_EXTERN near the end of png.h
438  Added "if" tests to silence complaints about unused png_ptr in png.h and png.c
439  Changed "check_if_png" function in example.c to return true (nonzero) if PNG.
440  Changed libpng.txt to demonstrate png_sig_cmp() instead of png_check_sig()
441    which is obsolete.
442
443Version 1.0.3 [January 14, 1999]
444  Added makefile.hux, for Hewlett Packard HPUX 10.20 and 11.00 (Jim Rice)
445  Added a statement of Y2K compliance in png.h, libpng.3, and Y2KINFO.
446
447Version 1.0.3a [August 12, 1999]
448  Added check for PNG_READ_INTERLACE_SUPPORTED in pngread.c; issue a warning
449    if an attempt is made to read an interlaced image when it's not supported.
450  Added check if png_ptr->trans is defined before freeing it in pngread.c
451  Modified the Y2K statement to include versions back to version 0.71
452  Fixed a bug in the check for valid IHDR bit_depth/color_types in pngrutil.c
453  Modified makefile.wat (added -zp8 flag, ".symbolic", changed some comments)
454  Replaced leading blanks with tab characters in makefile.hux
455  Changed "dworkin.wustl.edu" to "ccrc.wustl.edu" in various documents.
456  Changed (float)red and (float)green to (double)red, (double)green
457    in png_set_rgb_to_gray() to avoid "promotion" problems in AIX.
458  Fixed a bug in pngconf.h that omitted <stdio.h> when PNG_DEBUG==0 (K Bracey).
459  Reformatted libpng.3 and libpngpf.3 with proper fonts (script by J. vanZandt).
460  Updated documentation to refer to the PNG-1.2 specification.
461  Removed ansi2knr.c and left pointers to the latest source for ansi2knr.c
462    in makefile.knr, INSTALL, and README (L. Peter Deutsch)
463  Fixed bugs in calculation of the length of rowbytes when adding alpha
464    channels to 16-bit images, in pngrtran.c (Chris Nokleberg)
465  Added function png_set_user_transform_info() to store user_transform_ptr,
466    user_depth, and user_channels into the png_struct, and a function
467    png_get_user_transform_ptr() to retrieve the pointer (Chris Nokleberg)
468  Added function png_set_empty_plte_permitted() to make libpng useable
469    in MNG applications.
470  Corrected the typedef for png_free_ptr in png.h (Jesse Jones).
471  Correct gamma with srgb is 45455 instead of 45000 in pngrutil.c, to be
472    consistent with PNG-1.2, and allow variance of 500 before complaining.
473  Added assembler code contributed by Intel in file pngvcrd.c and modified
474    makefile.w32 to use it (Nirav Chhatrapati, INTEL Corporation,
475    Gilles Vollant)
476  Changed "ln -s -f" to "ln -f -s" in the makefiles to make Solaris happy.
477  Added some aliases for png_set_expand() in pngrtran.c, namely
478    png_set_expand_PLTE(), png_set_expand_depth(), and png_set_expand_tRNS()
479    (Greg Roelofs, in "PNG: The Definitive Guide").
480  Added makefile.beo for BEOS on X86, contributed by Sander Stok.
481
482Version 1.0.3b [August 26, 1999]
483  Replaced 2147483647L several places with PNG_MAX_UINT macro, defined in png.h
484  Changed leading blanks to tabs in all makefiles.
485  Define PNG_USE_PNGVCRD in makefile.w32, to get MMX assembler code.
486  Made alternate versions of  png_set_expand() in pngrtran.c, namely
487    png_set_gray_1_2_4_to_8, png_set_palette_to_rgb, and png_set_tRNS_to_alpha
488    (Greg Roelofs, in "PNG: The Definitive Guide").  Deleted the 1.0.3a aliases.
489  Relocated start of 'extern "C"' block in png.h so it doesn't include pngconf.h
490  Revised calculation of num_blocks in pngmem.c to avoid a potentially
491    negative shift distance, whose results are undefined in the C language.
492  Added a check in pngset.c to prevent writing multiple tIME chunks.
493  Added a check in pngwrite.c to detect invalid small window_bits sizes.
494
495Version 1.0.3d [September 4, 1999]
496  Fixed type casting of igamma in pngrutil.c
497  Added new png_expand functions to scripts/pngdef.pas and pngos2.def
498  Added a demo read_user_transform_fn that examines the row filters in pngtest.c
499
500Version 1.0.4 [September 24, 1999, not distributed publicly]
501  Define PNG_ALWAYS_EXTERN in pngconf.h if __STDC__ is defined
502  Delete #define PNG_INTERNAL and include "png.h" from pngasmrd.h
503  Made several minor corrections to pngtest.c
504  Renamed the makefiles with longer but more user friendly extensions.
505  Copied the PNG copyright and license to a separate LICENSE file.
506  Revised documentation, png.h, and example.c to remove reference to
507    "viewing_gamma" which no longer appears in the PNG specification.
508  Revised pngvcrd.c to use MMX code for interlacing only on the final pass.
509  Updated pngvcrd.c to use the faster C filter algorithms from libpng-1.0.1a
510  Split makefile.win32vc into two versions, makefile.vcawin32 (uses MMX
511    assembler code) and makefile.vcwin32 (doesn't).
512  Added a CPU timing report to pngtest.c (enabled by defining PNGTEST_TIMING)
513  Added a copy of pngnow.png to the distribution.
514
515Version 1.0.4a [September 25, 1999]
516  Increase max_pixel_depth in pngrutil.c if a user transform needs it.
517  Changed several division operations to right-shifts in pngvcrd.c
518
519Version 1.0.4b [September 30, 1999]
520  Added parentheses in line 3732 of pngvcrd.c
521  Added a comment in makefile.linux warning about buggy -O3 in pgcc 2.95.1
522
523Version 1.0.4c [October 1, 1999]
524  Added a "png_check_version" function in png.c and pngtest.c that will generate
525    a helpful compiler error if an old png.h is found in the search path.
526  Changed type of png_user_transform_depth|channels from int to png_byte.
527  Added "Libpng is OSI Certified Open Source Software" statement to png.h
528
529Version 1.0.4d [October 6, 1999]
530  Changed 0.45 to 0.45455 in png_set_sRGB()
531  Removed unused PLTE entries from pngnow.png
532  Re-enabled some parts of pngvcrd.c (png_combine_row) that work properly.
533
534Version 1.0.4e [October 10, 1999]
535  Fixed sign error in pngvcrd.c (Greg Roelofs)
536  Replaced some instances of memcpy with simple assignments in pngvcrd (GR-P)
537
538Version 1.0.4f [October 15, 1999]
539  Surrounded example.c code with #if 0 .. #endif to prevent people from
540    inadvertently trying to compile it.
541  Changed png_get_header_version() from a function to a macro in png.h
542  Added type casting mostly in pngrtran.c and pngwtran.c
543  Removed some pointless "ptr = NULL" in pngmem.c
544  Added a "contrib" directory containing the source code from Greg's book.
545
546Version 1.0.5 [October 15, 1999]
547  Minor editing of the INSTALL and README files.
548
549Version 1.0.5a [October 23, 1999]
550  Added contrib/pngsuite and contrib/pngminus (Willem van Schaik)
551  Fixed a typo in the png_set_sRGB() function call in example.c (Jan Nijtmans)
552  Further optimization and bugfix of pngvcrd.c
553  Revised pngset.c so that it does not allocate or free memory in the user's
554    text_ptr structure.  Instead, it makes its own copy.
555  Created separate write_end_info_struct in pngtest.c for a more severe test.
556  Added code in pngwrite.c to free info_ptr->text[i].key to stop a memory leak.
557
558Version 1.0.5b [November 23, 1999]
559  Moved PNG_FLAG_HAVE_CHUNK_HEADER, PNG_FLAG_BACKGROUND_IS_GRAY and
560    PNG_FLAG_WROTE_tIME from flags to mode.
561  Added png_write_info_before_PLTE() function.
562  Fixed some typecasting in contrib/gregbook/*.c
563  Updated scripts/makevms.com and added makevms.com to contrib/gregbook
564    and contrib/pngminus (Martin Zinser)
565
566Version 1.0.5c [November 26, 1999]
567  Moved png_get_header_version from png.h to png.c, to accommodate ansi2knr.
568  Removed all global arrays (according to PNG_NO_GLOBAL_ARRAYS macro), to
569    accommodate making DLL's: Moved usr_png_ver from global variable to function
570    png_get_header_ver() in png.c.  Moved png_sig to png_sig_bytes in png.c and
571    eliminated use of png_sig in pngwutil.c.  Moved the various png_CHNK arrays
572    into pngtypes.h.  Eliminated use of global png_pass arrays.  Declared the
573    png_CHNK and png_pass arrays to be "const".  Made the global arrays
574    available to applications (although none are used in libpng itself) when
575    PNG_NO_GLOBAL_ARRAYS is not defined or when PNG_GLOBAL_ARRAYS is defined.
576  Removed some extraneous "-I" from contrib/pngminus/makefile.std
577  Changed the PNG_sRGB_INTENT macros in png.h to be consistent with PNG-1.2.
578  Change PNG_SRGB_INTENT to PNG_sRGB_INTENT in libpng.txt and libpng.3
579
580Version 1.0.5d [November 29, 1999]
581  Add type cast (png_const_charp) two places in png.c
582  Eliminated pngtypes.h; use macros instead to declare PNG_CHNK arrays.
583  Renamed "PNG_GLOBAL_ARRAYS" to "PNG_USE_GLOBAL_ARRAYS" and made available
584    to applications a macro "PNG_USE_LOCAL_ARRAYS".
585  comment out (with #ifdef) all the new declarations when
586    PNG_USE_GLOBAL_ARRAYS is defined.
587  Added PNG_EXPORT_VAR macro to accommodate making DLL's.
588
589Version 1.0.5e [November 30, 1999]
590  Added iCCP, iTXt, and sPLT support; added "lang" member to the png_text
591    structure; refactored the inflate/deflate support to make adding new chunks
592    with trailing compressed parts easier in the future, and added new functions
593    png_free_iCCP, png_free_pCAL, png_free_sPLT, png_free_text, png_get_iCCP,
594    png_get_spalettes, png_set_iCCP, png_set_spalettes (Eric S. Raymond).
595    NOTE: Applications that write text chunks MUST define png_text->lang
596    before calling png_set_text(). It must be set to NULL if you want to
597    write tEXt or zTXt chunks.  If you want your application to be able to
598    run with older versions of libpng, use
599
600      #ifdef PNG_iTXt_SUPPORTED
601         png_text[i].lang = NULL;
602      #endif
603
604  Changed png_get_oFFs() and png_set_oFFs() to use signed rather than unsigned
605    offsets (Eric S. Raymond).
606  Combined PNG_READ_cHNK_SUPPORTED and PNG_WRITE_cHNK_SUPPORTED macros into
607    PNG_cHNK_SUPPORTED and combined the three types of PNG_text_SUPPORTED
608    macros, leaving the separate macros also available.
609  Removed comments on #endifs at the end of many short, non-nested #if-blocks.
610
611Version 1.0.5f [December 6, 1999]
612  Changed makefile.solaris to issue a warning about potential problems when
613    the ucb "ld" is in the path ahead of the ccs "ld".
614  Removed "- [date]" from the "synopsis" line in libpng.3 and libpngpf.3.
615  Added sCAL chunk support (Eric S. Raymond).
616
617Version 1.0.5g [December 7, 1999]
618  Fixed "png_free_spallettes" typo in png.h
619  Added code to handle new chunks in pngpread.c
620  Moved PNG_CHNK string macro definitions outside of PNG_NO_EXTERN block
621  Added "translated_key" to png_text structure and png_write_iTXt().
622  Added code in pngwrite.c to work around a newly discovered zlib bug.
623
624Version 1.0.5h [December 10, 1999]
625  NOTE: regarding the note for version 1.0.5e, the following must also
626    be included in your code:
627        png_text[i].translated_key = NULL;
628  Unknown chunk handling is now supported.
629  Option to eliminate all floating point support was added.  Some new
630    fixed-point functions such as png_set_gAMA_fixed() were added.
631  Expanded tabs and removed trailing blanks in source files.
632
633Version 1.0.5i [December 13, 1999]
634  Added some type casts to silence compiler warnings.
635  Renamed "png_free_spalette" to "png_free_spalettes" for consistency.
636  Removed leading blanks from a #define in pngvcrd.c
637  Added some parameters to the new png_set_keep_unknown_chunks() function.
638  Added a test for up->location != 0 in the first instance of writing
639    unknown chunks in pngwrite.c
640  Changed "num" to "i" in png_free_spalettes() and png_free_unknowns() to
641    prevent recursion.
642  Added png_free_hIST() function.
643  Various patches to fix bugs in the sCAL and integer cHRM processing,
644    and to add some convenience macros for use with sCAL.
645
646Version 1.0.5j [December 21, 1999]
647  Changed "unit" parameter of png_write_sCAL from png_byte to int, to work
648    around buggy compilers.
649  Added new type "png_fixed_point" for integers that hold float*100000 values
650  Restored backward compatibility of tEXt/zTXt chunk processing:
651    Restored the first four members of png_text to the same order as v.1.0.5d.
652    Added members "lang_key" and "itxt_length" to png_text struct.  Set
653    text_length=0 when "text" contains iTXt data.  Use the "compression"
654    member to distinguish among tEXt/zTXt/iTXt types.  Added
655    PNG_ITXT_COMPRESSION_NONE (1) and PNG_ITXT_COMPRESSION_zTXt(2) macros.
656    The "Note" above, about backward incompatibility of libpng-1.0.5e, no
657    longer applies.
658  Fixed png_read|write_iTXt() to read|write parameters in the right order,
659    and to write the iTXt chunk after IDAT if it appears in the end_ptr.
660  Added pnggccrd.c, version of pngvcrd.c Intel assembler for gcc (Greg Roelofs)
661  Reversed the order of trying to write floating-point and fixed-point gAMA.
662
663Version 1.0.5k [December 27, 1999]
664  Added many parentheses, e.g., "if (a && b & c)" becomes "if (a && (b & c))"
665  Added png_handle_as_unknown() function (Glenn)
666  Added png_free_chunk_list() function and chunk_list and num_chunk_list members
667    of png_ptr.
668  Eliminated erroneous warnings about multiple sPLT chunks and sPLT-after-PLTE.
669  Fixed a libpng-1.0.5h bug in pngrutil.c that was issuing erroneous warnings
670    about ignoring incorrect gAMA with sRGB (gAMA was in fact not ignored)
671  Added png_free_tRNS(); png_set_tRNS() now malloc's its own trans array (ESR).
672  Define png_get_int_32 when oFFs chunk is supported as well as when pCAL is.
673  Changed type of proflen from png_int_32 to png_uint_32 in png_get_iCCP().
674
675Version 1.0.5l [January 1, 2000]
676  Added functions png_set_read_user_chunk_fn() and png_get_user_chunk_ptr()
677    for setting a callback function to handle unknown chunks and for
678    retrieving the associated user pointer (Glenn).
679
680Version 1.0.5m [January 7, 2000]
681  Added high-level functions png_read_png(), png_write_png(), png_free_pixels().
682
683Version 1.0.5n [January 9, 2000]
684  Added png_free_PLTE() function, and modified png_set_PLTE() to malloc its
685    own memory for info_ptr->palette.  This makes it safe for the calling
686    application to free its copy of the palette any time after it calls
687    png_set_PLTE().
688
689Version 1.0.5o [January 20, 2000]
690  Cosmetic changes only (removed some trailing blanks and TABs)
691
692Version 1.0.5p [January 31, 2000]
693  Renamed pngdll.mak to makefile.bd32
694  Cosmetic changes in pngtest.c
695
696Version 1.0.5q [February 5, 2000]
697  Relocated the makefile.solaris warning about PATH problems.
698  Fixed pngvcrd.c bug by pushing/popping registers in mmxsupport (Bruce Oberg)
699  Revised makefile.gcmmx
700  Added PNG_SETJMP_SUPPORTED, PNG_SETJMP_NOT_SUPPORTED, and PNG_ABORT() macros
701
702Version 1.0.5r [February 7, 2000]
703  Removed superfluous prototype for png_get_itxt from png.h
704  Fixed a bug in pngrtran.c that improperly expanded the background color.
705  Return *num_text=0 from png_get_text() when appropriate, and fix documentation
706    of png_get_text() in libpng.txt/libpng.3.
707
708Version 1.0.5s [February 18, 2000]
709  Added "png_jmp_env()" macro to pngconf.h, to help people migrate to the
710    new error handler that's planned for the next libpng release, and changed
711    example.c, pngtest.c, and contrib programs to use this macro.
712  Revised some of the DLL-export macros in pngconf.h (Greg Roelofs)
713  Fixed a bug in png_read_png() that caused it to fail to expand some images
714    that it should have expanded.
715  Fixed some mistakes in the unused and undocumented INCH_CONVERSIONS functions
716    in pngget.c
717  Changed the allocation of palette, history, and trans arrays back to
718    the version 1.0.5 method (linking instead of copying) which restores
719    backward compatibility with version 1.0.5.  Added some remarks about
720    that in example.c.  Added "free_me" member to info_ptr and png_ptr
721    and added png_free_data() function.
722  Updated makefile.linux and makefile.gccmmx to make directories conditionally.
723  Made cosmetic changes to pngasmrd.h
724  Added png_set_rows() and png_get_rows(), for use with png_read|write_png().
725  Modified png_read_png() to allocate info_ptr->row_pointers only if it
726    hasn't already been allocated.
727
728Version 1.0.5t [March 4, 2000]
729  Changed png_jmp_env() migration aiding macro to png_jmpbuf().
730  Fixed "interlace" typo (should be "interlaced") in contrib/gregbook/read2-x.c
731  Fixed bug with use of PNG_BEFORE_IHDR bit in png_ptr->mode, introduced when
732    PNG_FLAG_HAVE_CHUNK_HEADER was moved into png_ptr->mode in version 1.0.5b
733  Files in contrib/gregbook were revised to use png_jmpbuf() and to select
734    a 24-bit visual if one is available, and to allow abbreviated options.
735  Files in contrib/pngminus were revised to use the png_jmpbuf() macro.
736  Removed spaces in makefile.linux and makefile.gcmmx, introduced in 1.0.5s
737
738Version 1.0.5u [March 5, 2000]
739  Simplified the code that detects old png.h in png.c and pngtest.c
740  Renamed png_spalette (_p, _pp) to png_sPLT_t (_tp, _tpp)
741  Increased precision of rgb_to_gray calculations from 8 to 15 bits and
742    added png_set_rgb_to_gray_fixed() function.
743  Added makefile.bc32 (32-bit Borland C++, C mode)
744
745Version 1.0.5v [March 11, 2000]
746  Added some parentheses to the png_jmpbuf macro definition.
747  Updated references to the zlib home page, which has moved to freesoftware.com.
748  Corrected bugs in documentation regarding png_read_row() and png_write_row().
749  Updated documentation of png_rgb_to_gray calculations in libpng.3/libpng.txt.
750  Renamed makefile.borland,turboc3 back to makefile.bor,tc3 as in version 1.0.3,
751    revised borland makefiles; added makefile.ibmvac3 and makefile.gcc (Cosmin)
752
753Version 1.0.6 [March 20, 2000]
754  Minor revisions of makefile.bor, libpng.txt, and gregbook/rpng2-win.c
755  Added makefile.sggcc (SGI IRIX with gcc)
756
757Version 1.0.6d [April 7, 2000]
758  Changed sprintf() to strcpy() in png_write_sCAL_s() to work without STDIO
759  Added data_length parameter to png_decompress_chunk() function
760  Revised documentation to remove reference to abandoned png_free_chnk functions
761  Fixed an error in png_rgb_to_gray_fixed()
762  Revised example.c, usage of png_destroy_write_struct().
763  Renamed makefile.ibmvac3 to makefile.ibmc, added libpng.icc IBM project file
764  Added a check for info_ptr->free_me&PNG_FREE_TEXT when freeing text in png.c
765  Simplify png_sig_bytes() function to remove use of non-ISO-C strdup().
766
767Version 1.0.6e [April 9, 2000]
768  Added png_data_freer() function.
769  In the code that checks for over-length tRNS chunks, added check of
770    info_ptr->num_trans as well as png_ptr->num_trans (Matthias Benckmann)
771  Minor revisions of libpng.txt/libpng.3.
772  Check for existing data and free it if the free_me flag is set, in png_set_*()
773    and png_handle_*().
774  Only define PNG_WEIGHTED_FILTERS_SUPPORTED when PNG_FLOATING_POINT_SUPPORTED
775    is defined.
776  Changed several instances of PNG_NO_CONSOLE_ID to PNG_NO_STDIO in pngrutil.c
777    and mentioned the purposes of the two macros in libpng.txt/libpng.3.
778
779Version 1.0.6f [April 14, 2000]
780  Revised png_set_iCCP() and png_set_rows() to avoid prematurely freeing data.
781  Add checks in png_set_text() for NULL members of the input text structure.
782  Revised libpng.txt/libpng.3.
783  Removed superfluous prototype for png_set_iTXt from png.h
784  Removed "else" from pngread.c, after png_error(), and changed "0" to "length".
785  Changed several png_errors about malformed ancillary chunks to png_warnings.
786
787Version 1.0.6g [April 24, 2000]
788  Added png_pass-* arrays to pnggccrd.c when PNG_USE_LOCAL_ARRAYS is defined.
789  Relocated paragraph about png_set_background() in libpng.3/libpng.txt
790    and other revisions (Matthias Benckmann)
791  Relocated info_ptr->free_me, png_ptr->free_me, and other info_ptr and
792    png_ptr members to restore binary compatibility with libpng-1.0.5
793    (breaks compatibility with libpng-1.0.6).
794
795Version 1.0.6h [April 24, 2000]
796  Changed shared library so-number pattern from 2.x.y.z to xy.z (this builds
797    libpng.so.10 & libpng.so.10.6h instead of libpng.so.2 & libpng.so.2.1.0.6h)
798    This is a temporary change for test purposes.
799
800Version 1.0.6i [May 2, 2000]
801  Rearranged some members at the end of png_info and png_struct, to put
802    unknown_chunks_num and free_me within the original size of the png_structs
803    and free_me, png_read_user_fn, and png_free_fn within the original png_info,
804    because some old applications allocate the structs directly instead of
805    using png_create_*().
806  Added documentation of user memory functions in libpng.txt/libpng.3
807  Modified png_read_png so that it will use user_allocated row_pointers
808    if present, unless free_me directs that it be freed, and added description
809    of the use of png_set_rows() and png_get_rows() in libpng.txt/libpng.3.
810  Added PNG_LEGACY_SUPPORTED macro, and #ifdef out all new (since version
811    1.00) members of png_struct and png_info, to regain binary compatibility
812    when you define this macro.  Capabilities lost in this event
813    are user transforms (new in version 1.0.0),the user transform pointer
814    (new in version 1.0.2), rgb_to_gray (new in 1.0.5), iCCP, sCAL, sPLT,
815    the high-level interface, and unknown chunks support (all new in 1.0.6).
816    This was necessary because of old applications that allocate the structs
817    directly as authors were instructed to do in libpng-0.88 and earlier,
818    instead of using png_create_*().
819  Added modes PNG_CREATED_READ_STRUCT and PNG_CREATED_WRITE_STRUCT which
820    can be used to detect codes that directly allocate the structs, and
821    code to check these modes in png_read_init() and png_write_init() and
822    generate a libpng error if the modes aren't set and PNG_LEGACY_SUPPORTED
823    was not defined.
824  Added makefile.intel and updated makefile.watcom (Pawel Mrochen)
825
826Version 1.0.6j [May 3, 2000]
827  Overloaded png_read_init() and png_write_init() with macros that convert
828    calls to png_read_init_2() or png_write_init_2() that check the version
829    and structure sizes.
830
831Version 1.0.7beta11 [May 7, 2000]
832  Removed the new PNG_CREATED_READ_STRUCT and PNG_CREATED_WRITE_STRUCT modes
833    which are no longer used.
834  Eliminated the three new members of png_text when PNG_LEGACY_SUPPORTED is
835    defined or when neither PNG_READ_iTXt_SUPPORTED nor PNG_WRITE_iTXt_SUPPORTED
836    is defined.
837  Made PNG_NO_READ|WRITE_iTXt the default setting, to avoid memory
838    overrun when old applications fill the info_ptr->text structure directly.
839  Added PNGAPI macro, and added it to the definitions of all exported functions.
840  Relocated version macro definitions ahead of the includes of zlib.h and
841    pngconf.h in png.h.
842
843Version 1.0.7beta12 [May 12, 2000]
844  Revised pngset.c to avoid a problem with expanding the png_debug macro.
845  Deleted some extraneous defines from pngconf.h
846  Made PNG_NO_CONSOLE_IO the default condition when PNG_BUILD_DLL is defined.
847  Use MSC _RPTn debugging instead of fprintf if _MSC_VER is defined.
848  Added png_access_version_number() function.
849  Check for mask&PNG_FREE_CHNK (for TEXT, SCAL, PCAL) in png_free_data().
850  Expanded libpng.3/libpng.txt information about png_data_freer().
851
852Version 1.0.7beta14 [May 17, 2000] (beta13 was not published)
853  Changed pnggccrd.c and pngvcrd.c to handle bad adaptive filter types as
854    warnings instead of errors, as pngrutil.c does.
855  Set the PNG_INFO_IDAT valid flag in png_set_rows() so png_write_png()
856    will actually write IDATs.
857  Made the default PNG_USE_LOCAL_ARRAYS depend on PNG_DLL instead of WIN32.
858  Make png_free_data() ignore its final parameter except when freeing data
859    that can have multiple instances (text, sPLT, unknowns).
860  Fixed a new bug in png_set_rows().
861  Removed info_ptr->valid tests from png_free_data(), as in version 1.0.5.
862  Added png_set_invalid() function.
863  Fixed incorrect illustrations of png_destroy_write_struct() in example.c.
864
865Version 1.0.7beta15 [May 30, 2000]
866  Revised the deliberately erroneous Linux setjmp code in pngconf.h to produce
867    fewer error messages.
868  Rearranged checks for Z_OK to check the most likely path first in pngpread.c
869    and pngwutil.c.
870  Added checks in pngtest.c for png_create_*() returning NULL, and mentioned
871    in libpng.txt/libpng.3 the need for applications to check this.
872  Changed names of png_default_*() functions in pngtest to pngtest_*().
873  Changed return type of png_get_x|y_offset_*() from png_uint_32 to png_int_32.
874  Fixed some bugs in the unused PNG_INCH_CONVERSIONS functions in pngget.c
875  Set each pointer to NULL after freeing it in png_free_data().
876  Worked around a problem in pngconf.h; AIX's strings.h defines an "index"
877    macro that conflicts with libpng's png_color_16.index. (Dimitri
878    Papadapoulos)
879  Added "msvc" directory with MSVC++ project files (Simon-Pierre Cadieux).
880
881Version 1.0.7beta16 [June 4, 2000]
882  Revised the workaround of AIX string.h "index" bug.
883  Added a check for overlength PLTE chunk in pngrutil.c.
884  Added PNG_NO_POINTER_INDEXING macro to use array-indexing instead of pointer
885    indexing in pngrutil.c and pngwutil.c to accommodate a buggy compiler.
886  Added a warning in png_decompress_chunk() when it runs out of data, e.g.
887    when it tries to read an erroneous PhotoShop iCCP chunk.
888  Added PNG_USE_DLL macro.
889  Revised the copyright/disclaimer/license notice.
890  Added contrib/msvctest directory
891
892Version 1.0.7rc1 [June 9, 2000]
893  Corrected the definition of PNG_TRANSFORM_INVERT_ALPHA  (0x0400 not 0x0200)
894  Added contrib/visupng directory (Willem van Schaik)
895
896Version 1.0.7beta18 [June 23, 2000]
897  Revised PNGAPI definition, and pngvcrd.c to work with __GCC__
898    and do not redefine PNGAPI if it is passed in via a compiler directive.
899  Revised visupng/PngFile.c to remove returns from within the Try block.
900  Removed leading underscores from "_PNG_H" and "_PNG_SAVE_BSD_SOURCE" macros.
901  Updated contrib/visupng/cexcept.h to version 1.0.0.
902  Fixed bugs in pngwrite.c and pngwutil.c that prevented writing iCCP chunks.
903
904Version 1.0.7rc2 [June 28, 2000]
905  Updated license to include disclaimers required by UCITA.
906  Fixed "DJBPP" typo in pnggccrd.c introduced in beta18.
907
908Version 1.0.7 [July 1, 2000]
909  Revised the definition of "trans_values" in libpng.3/libpng.txt
910
911Version 1.0.8beta1 [July 8, 2000]
912  Added png_free(png_ptr, key) two places in pngpread.c to stop memory leaks.
913  Changed PNG_NO_STDIO to PNG_NO_CONSOLE_IO, several places in pngrutil.c and
914    pngwutil.c.
915  Changed PNG_EXPORT_VAR to use PNG_IMPEXP, in pngconf.h.
916  Removed unused "#include <assert.h>" from png.c
917  Added WindowsCE support.
918  Revised pnggccrd.c to work with gcc-2.95.2 and in the Cygwin environment.
919
920Version 1.0.8beta2 [July 10, 2000]
921  Added project files to the wince directory and made further revisions
922    of pngtest.c, pngrio.c, and pngwio.c in support of WindowsCE.
923
924Version 1.0.8beta3 [July 11, 2000]
925  Only set the PNG_FLAG_FREE_TRNS or PNG_FREE_TRNS flag in png_handle_tRNS()
926    for indexed-color input files to avoid potential double-freeing trans array
927    under some unusual conditions; problem was introduced in version 1.0.6f.
928  Further revisions to pngtest.c and files in the wince subdirectory.
929
930Version 1.0.8beta4 [July 14, 2000]
931  Added the files pngbar.png and pngbar.jpg to the distribution.
932  Added makefile.cygwin, and cygwin support in pngconf.h
933  Added PNG_NO_ZALLOC_ZERO macro (makes png_zalloc skip zeroing memory)
934
935Version 1.0.8rc1 [July 16, 2000]
936  Revised png_debug() macros and statements to eliminate compiler warnings.
937
938Version 1.0.8 [July 24, 2000]
939  Added png_flush() in pngwrite.c, after png_write_IEND().
940  Updated makefile.hpux to build a shared library.
941
942Version 1.0.9beta1 [November 10, 2000]
943  Fixed typo in scripts/makefile.hpux
944  Updated makevms.com in scripts and contrib/* and contrib/* (Martin Zinser)
945  Fixed seqence-point bug in contrib/pngminus/png2pnm (Martin Zinser)
946  Changed "cdrom.com" in documentation to "libpng.org"
947  Revised pnggccrd.c to get it all working, and updated makefile.gcmmx (Greg).
948  Changed type of "params" from voidp to png_voidp in png_read|write_png().
949  Make sure PNGAPI and PNG_IMPEXP are defined in pngconf.h.
950  Revised the 3 instances of WRITEFILE in pngtest.c.
951  Relocated "msvc" and "wince" project subdirectories into "dll" subdirectory.
952  Updated png.rc in dll/msvc project
953  Revised makefile.dec to define and use LIBPATH and INCPATH
954  Increased size of global png_libpng_ver[] array from 12 to 18 chars.
955  Made global png_libpng_ver[], png_sig[] and png_pass_*[] arrays const.
956  Removed duplicate png_crc_finish() from png_handle_bKGD() function.
957  Added a warning when application calls png_read_update_info() multiple times.
958  Revised makefile.cygwin
959  Fixed bugs in iCCP support in pngrutil.c and pngwutil.c.
960  Replaced png_set_empty_plte_permitted() with png_permit_mng_features().
961
962Version 1.0.9beta2 [November 19, 2000]
963  Renamed the "dll" subdirectory "projects".
964  Added borland project files to "projects" subdirectory.
965  Set VS_FF_PRERELEASE and VS_FF_PATCHED flags in msvc/png.rc when appropriate.
966  Add error message in png_set_compression_buffer_size() when malloc fails.
967
968Version 1.0.9beta3 [November 23, 2000]
969  Revised PNG_LIBPNG_BUILD_TYPE macro in png.h, used in the msvc project.
970  Removed the png_flush() in pngwrite.c that crashes some applications
971    that don't set png_output_flush_fn.
972  Added makefile.macosx and makefile.aix to scripts directory.
973
974Version 1.0.9beta4 [December 1, 2000]
975  Change png_chunk_warning to png_warning in png_check_keyword().
976  Increased the first part of msg buffer from 16 to 18 in png_chunk_error().
977
978Version 1.0.9beta5 [December 15, 2000]
979  Added support for filter method 64 (for PNG datastreams embedded in MNG).
980
981Version 1.0.9beta6 [December 18, 2000]
982  Revised png_set_filter() to accept filter method 64 when appropriate.
983  Added new PNG_HAVE_PNG_SIGNATURE bit to png_ptr->mode and use it to
984    help prevent applications from using MNG features in PNG datastreams.
985  Added png_permit_mng_features() function.
986  Revised libpng.3/libpng.txt.  Changed "filter type" to "filter method".
987
988Version 1.0.9rc1 [December 23, 2000]
989  Revised test for PNG_HAVE_PNG_SIGNATURE in pngrutil.c
990  Fixed error handling of unknown compression type in png_decompress_chunk().
991  In pngconf.h, define __cdecl when _MSC_VER is defined.
992
993Version 1.0.9beta7 [December 28, 2000]
994  Changed PNG_TEXT_COMPRESSION_zTXt to PNG_COMPRESSION_TYPE_BASE several places.
995  Revised memory management in png_set_hIST and png_handle_hIST in a backward
996    compatible manner.  PLTE and tRNS were revised similarly.
997  Revised the iCCP chunk reader to ignore trailing garbage.
998
999Version 1.0.9beta8 [January 12, 2001]
1000  Moved pngasmrd.h into pngconf.h.
1001  Improved handling of out-of-spec garbage iCCP chunks generated by PhotoShop.
1002
1003Version 1.0.9beta9 [January 15, 2001]
1004  Added png_set_invalid, png_permit_mng_features, and png_mmx_supported to
1005    wince and msvc project module definition files.
1006  Minor revision of makefile.cygwin.
1007  Fixed bug with progressive reading of narrow interlaced images in pngpread.c
1008
1009Version 1.0.9beta10 [January 16, 2001]
1010  Do not typedef png_FILE_p in pngconf.h when PNG_NO_STDIO is defined.
1011  Fixed "png_mmx_supported" typo in project definition files.
1012
1013Version 1.0.9beta11 [January 19, 2001]
1014  Updated makefile.sgi to make shared library.
1015  Removed png_mmx_support() function and disabled PNG_MNG_FEATURES_SUPPORTED
1016    by default, for the benefit of DLL forward compatibility.  These will
1017    be re-enabled in version 1.2.0.
1018
1019Version 1.0.9rc2 [January 22, 2001]
1020  Revised cygwin support.
1021
1022Version 1.0.9 [January 31, 2001]
1023  Added check of cygwin's ALL_STATIC in pngconf.h
1024  Added "-nommx" parameter to contrib/gregbook/rpng2-win and rpng2-x demos.
1025
1026Version 1.0.10beta1 [March 14, 2001]
1027  Revised makefile.dec, makefile.sgi, and makefile.sggcc; added makefile.hpgcc.
1028  Reformatted libpng.3 to eliminate bad line breaks.
1029  Added checks for _mmx_supported in the read_filter_row function of pnggccrd.c
1030  Added prototype for png_mmx_support() near the top of pnggccrd.c
1031  Moved some error checking from png_handle_IHDR to png_set_IHDR.
1032  Added PNG_NO_READ_SUPPORTED and PNG_NO_WRITE_SUPPORTED macros.
1033  Revised png_mmx_support() function in pnggccrd.c
1034  Restored version 1.0.8 PNG_WRITE_EMPTY_PLTE_SUPPORTED behavior in pngwutil.c
1035  Fixed memory leak in contrib/visupng/PngFile.c
1036  Fixed bugs in png_combine_row() in pnggccrd.c and pngvcrd.c (C version)
1037  Added warnings when retrieving or setting gamma=0.
1038  Increased the first part of msg buffer from 16 to 18 in png_chunk_warning().
1039
1040Version 1.0.10rc1 [March 23, 2001]
1041  Changed all instances of memcpy, strcpy, and strlen to png_memcpy, png_strcpy,
1042    and png_strlen.
1043  Revised png_mmx_supported() function in pnggccrd.c to return proper value.
1044  Fixed bug in progressive reading (pngpread.c) with small images (height < 8).
1045
1046Version 1.0.10 [March 30, 2001]
1047  Deleted extraneous space (introduced in 1.0.9) from line 42 of makefile.cygwin
1048  Added beos project files (Chris Herborth)
1049
1050Version 1.0.11beta1 [April 3, 2001]
1051  Added type casts on several png_malloc() calls (Dimitri Papadapoulos).
1052  Removed a no-longer needed AIX work-around from pngconf.h
1053  Changed several "//" single-line comments to C-style in pnggccrd.c
1054
1055Version 1.0.11beta2 [April 11, 2001]
1056  Removed PNGAPI from several functions whose prototypes did not have PNGAPI.
1057  Updated scripts/pngos2.def
1058
1059Version 1.0.11beta3 [April 14, 2001]
1060  Added checking the results of many instances of png_malloc() for NULL
1061
1062Version 1.0.11beta4 [April 20, 2001]
1063  Undid the changes from version 1.0.11beta3.  Added a check for NULL return
1064    from user's malloc_fn().
1065  Removed some useless type casts of the NULL pointer.
1066  Added makefile.netbsd
1067
1068Version 1.0.11 [April 27, 2001]
1069  Revised makefile.netbsd
1070
1071Version 1.0.12beta1 [May 14, 2001]
1072  Test for Windows platform in pngconf.h when including malloc.h (Emmanuel Blot)
1073  Updated makefile.cygwin and handling of Cygwin's ALL_STATIC in pngconf.h
1074  Added some never-to-be-executed code in pnggccrd.c to quiet compiler warnings.
1075  Eliminated the png_error about apps using png_read|write_init().  Instead,
1076    libpng will reallocate the png_struct and info_struct if they are too small.
1077    This retains future binary compatibility for old applications written for
1078    libpng-0.88 and earlier.
1079
1080Version 1.2.0beta1 [May 6, 2001]
1081  Bumped DLLNUM to 2.
1082  Re-enabled PNG_MNG_FEATURES_SUPPORTED and enabled PNG_ASSEMBLER_CODE_SUPPORTED
1083    by default.
1084  Added runtime selection of MMX features.
1085  Added png_set_strip_error_numbers function and related macros.
1086
1087Version 1.2.0beta2 [May 7, 2001]
1088  Finished merging 1.2.0beta1 with version 1.0.11
1089  Added a check for attempts to read or write PLTE in grayscale PNG datastreams.
1090
1091Version 1.2.0beta3 [May 17, 2001]
1092  Enabled user memory function by default.
1093  Modified png_create_struct so it passes user mem_ptr to user memory allocator.
1094  Increased png_mng_features flag from png_byte to png_uint_32.
1095  Bumped shared-library (so-number) and dll-number to 3.
1096
1097Version 1.2.0beta4 [June 23, 2001]
1098  Check for missing profile length field in iCCP chunk and free chunk_data
1099    in case of truncated iCCP chunk.
1100  Bumped shared-library number to 3 in makefile.sgi and makefile.sggcc
1101  Bumped dll-number from 2 to 3 in makefile.cygwin
1102  Revised contrib/gregbook/rpng*-x.c to avoid a memory leak and to exit cleanly
1103    if user attempts to run it on an 8-bit display.
1104  Updated contrib/gregbook
1105  Use png_malloc instead of png_zalloc to allocate palette in pngset.c
1106  Updated makefile.ibmc
1107  Added some typecasts to eliminate gcc 3.0 warnings.  Changed prototypes
1108    of png_write_oFFS width and height from png_uint_32 to png_int_32.
1109  Updated example.c
1110  Revised prototypes for png_debug_malloc and png_debug_free in pngtest.c
1111
1112Version 1.2.0beta5 [August 8, 2001]
1113  Revised contrib/gregbook
1114  Revised makefile.gcmmx
1115  Revised pnggccrd.c to conditionally compile some thread-unsafe code only
1116    when PNG_THREAD_UNSAFE_OK is defined.
1117  Added tests to prevent pngwutil.c from writing a bKGD or tRNS chunk with
1118    value exceeding 2^bit_depth-1
1119  Revised makefile.sgi and makefile.sggcc
1120  Replaced calls to fprintf(stderr,...) with png_warning() in pnggccrd.c
1121  Removed restriction that do_invert_mono only operate on 1-bit opaque files
1122
1123Version 1.2.0 [September 1, 2001]
1124  Changed a png_warning() to png_debug() in pnggccrd.c
1125  Fixed contrib/gregbook/rpng-x.c, rpng2-x.c to avoid crash with XFreeGC().
1126
1127Version 1.2.1beta1 [October 19, 2001]
1128  Revised makefile.std in contrib/pngminus
1129  Include background_1 in png_struct regardless of gamma support.
1130  Revised makefile.netbsd and makefile.macosx, added makefile.darwin.
1131  Revised example.c to provide more details about using row_callback().
1132
1133Version 1.2.1beta2 [October 25, 2001]
1134  Added type cast to each NULL appearing in a function call, except for
1135    WINCE functions.
1136  Added makefile.so9.
1137
1138Version 1.2.1beta3 [October 27, 2001]
1139  Removed type casts from all NULLs.
1140  Simplified png_create_struct_2().
1141
1142Version 1.2.1beta4 [November 7, 2001]
1143  Revised png_create_info_struct() and png_creat_struct_2().
1144  Added error message if png_write_info() was omitted.
1145  Type cast NULLs appearing in function calls when _NO_PROTO or
1146    PNG_TYPECAST_NULL is defined.
1147
1148Version 1.2.1rc1 [November 24, 2001]
1149  Type cast NULLs appearing in function calls except when PNG_NO_TYPECAST_NULL
1150    is defined.
1151  Changed typecast of "size" argument to png_size_t in pngmem.c calls to
1152    the user malloc_fn, to agree with the prototype in png.h
1153  Added a pop/push operation to pnggccrd.c, to preserve Eflag (Maxim Sobolev)
1154  Updated makefile.sgi to recognize LIBPATH and INCPATH.
1155  Updated various makefiles so "make clean" does not remove previous major
1156    version of the shared library.
1157
1158Version 1.2.1rc2 [December 4, 2001]
1159  Always allocate 256-entry internal palette, hist, and trans arrays, to
1160    avoid out-of-bounds memory reference caused by invalid PNG datastreams.
1161  Added a check for prefix_length > data_length in iCCP chunk handler.
1162
1163Version 1.2.1 [December 7, 2001]
1164  None.
1165
1166Version 1.2.2beta1 [February 22, 2002]
1167  Fixed a bug with reading the length of iCCP profiles (Larry Reeves).
1168  Revised makefile.linux, makefile.gcmmx, and makefile.sgi to generate
1169    libpng.a, libpng12.so (not libpng.so.3), and libpng12/png.h
1170  Revised makefile.darwin to remove "-undefined suppress" option.
1171  Added checks for gamma and chromaticity values over 21474.83, which exceed
1172    the limit for PNG unsigned 32-bit integers when encoded.
1173  Revised calls to png_create_read_struct() and png_create_write_struct()
1174    for simpler debugging.
1175  Revised png_zalloc() so zlib handles errors (uses PNG_FLAG_MALLOC_NULL_MEM_OK)
1176
1177Version 1.2.2beta2 [February 23, 2002]
1178  Check chunk_length and idat_size for invalid (over PNG_MAX_UINT) lengths.
1179  Check for invalid image dimensions in png_get_IHDR.
1180  Added missing "fi;" in the install target of the SGI makefiles.
1181  Added install-static to all makefiles that make shared libraries.
1182  Always do gamma compensation when image is partially transparent.
1183
1184Version 1.2.2beta3 [March 7, 2002]
1185  Compute background.gray and background_1.gray even when color_type is RGB
1186    in case image gets reduced to gray later.
1187  Modified shared-library makefiles to install pkgconfig/libpngNN.pc.
1188  Export (with PNGAPI) png_zalloc, png_zfree, and png_handle_as_unknown
1189  Removed unused png_write_destroy_info prototype from png.h
1190  Eliminated incorrect use of width_mmx from pnggccrd.c in pixel_bytes == 8 case
1191  Added install-shared target to all makefiles that make shared libraries.
1192  Stopped a double free of palette, hist, and trans when not using free_me.
1193  Added makefile.32sunu for Sun Ultra 32 and makefile.64sunu for Sun Ultra 64.
1194
1195Version 1.2.2beta4 [March 8, 2002]
1196  Compute background.gray and background_1.gray even when color_type is RGB
1197    in case image gets reduced to gray later (Jason Summers).
1198  Relocated a misplaced /bin/rm in the "install-shared" makefile targets
1199  Added PNG_1_0_X macro which can be used to build a 1.0.x-compatible library.
1200
1201Version 1.2.2beta5 [March 26, 2002]
1202  Added missing PNGAPI to several function definitions.
1203  Check for invalid bit_depth or color_type in png_get_IHDR(), and
1204    check for missing PLTE or IHDR in png_push_read_chunk() (Matthias Clasen).
1205  Revised iTXt support to accept NULL for lang and lang_key.
1206  Compute gamma for color components of background even when color_type is gray.
1207  Changed "()" to "{}" in scripts/libpng.pc.in.
1208  Revised makefiles to put png.h and pngconf.h only in $prefix/include/libpngNN
1209  Revised makefiles to make symlink to libpng.so.NN in addition to libpngNN.so
1210
1211Version 1.2.2beta6 [March 31, 2002]
1212
1213Version 1.0.13beta1 [March 31, 2002]
1214  Prevent png_zalloc() from trying to memset memory that it failed to acquire.
1215  Add typecasts of PNG_MAX_UINT in pngset_cHRM_fixed() (Matt Holgate).
1216  Ensure that the right function (user or default) is used to free the
1217    png_struct after an error in png_create_read_struct_2().
1218
1219Version 1.2.2rc1 [April 7, 2002]
1220
1221Version 1.0.13rc1 [April 7, 2002]
1222  Save the ebx register in pnggccrd.c (Sami Farin)
1223  Add "mem_ptr = png_ptr->mem_ptr" in png_destroy_write_struct() (Paul Gardner).
1224  Updated makefiles to put headers in include/libpng and remove old include/*.h.
1225
1226Version 1.2.2 [April 15, 2002]
1227
1228Version 1.0.13 [April 15, 2002]
1229  Revised description of png_set_filter() in libpng.3/libpng.txt.
1230  Revised makefile.netbsd and added makefile.neNNbsd and makefile.freebsd
1231
1232Version 1.0.13patch01 [April 17, 2002]
1233
1234Version 1.2.2patch01 [April 17, 2002]
1235  Changed ${PNGMAJ}.${PNGVER} bug to ${PNGVER} in makefile.sgi and
1236    makefile.sggcc
1237  Fixed VER -> PNGVER typo in makefile.macosx and added install-static to
1238    install
1239  Added install: target to makefile.32sunu and makefile.64sunu
1240
1241Version 1.0.13patch03 [April 18, 2002]
1242
1243Version 1.2.2patch03 [April 18, 2002]
1244  Revised 15 makefiles to link libpng.a to libpngNN.a and the include libpng
1245  subdirectory to libpngNN subdirectory without the full pathname.
1246  Moved generation of libpng.pc from "install" to "all" in 15 makefiles.
1247
1248Version 1.2.3rc1 [April 28, 2002]
1249  Added install-man target to 15 makefiles (Dimitri Papadopolous-Orfanos).
1250  Added $(DESTDIR) feature to 24 makefiles (Tim Mooney)
1251  Fixed bug with $prefix, should be $(prefix) in makefile.hpux.
1252  Updated cygwin-specific portion of pngconf.h and revised makefile.cygwin
1253  Added a link from libpngNN.pc to libpng.pc in 15 makefiles.
1254  Added links from include/libpngNN/*.h to include/*.h in 24 makefiles.
1255  Revised makefile.darwin to make relative links without full pathname.
1256  Added setjmp() at the end of png_create_*_struct_2() in case user forgets
1257    to put one in their application.
1258  Restored png_zalloc() and png_zfree() prototypes to version 1.2.1 and
1259    removed them from module definition files.
1260
1261Version 1.2.3rc2 [May 1, 2002]
1262  Fixed bug in reporting number of channels in pngget.c and pngset.c,
1263    that was introduced in version 1.2.2beta5.
1264  Exported png_zalloc(), png_zfree(), png_default_read(), png_default_write(),
1265    png_default_flush(), and png_push_fill_buffer() and included them in
1266    module definition files.
1267  Added "libpng.pc" dependency to the "install-shared" target in 15 makefiles.
1268
1269Version 1.2.3rc3 [May 1, 2002]
1270  Revised prototype for png_default_flush()
1271  Remove old libpng.pc and libpngNN.pc before installing new ones.
1272
1273Version 1.2.3rc4 [May 2, 2002]
1274  Typos in *.def files (png_default_read|write -> png_default_read|write_data)
1275  In makefiles, changed rm libpng.NN.pc to rm libpngNN.pc
1276  Added libpng-config and libpngNN-config and modified makefiles to install
1277    them.
1278  Changed $(MANPATH) to $(DESTDIR)$(MANPATH) in makefiles
1279  Added "Win32 DLL VB" configuration to projects/msvc/libpng.dsp
1280
1281Version 1.2.3rc5 [May 11, 2002]
1282  Changed "error" and "message" in prototypes to "error_message" and
1283    "warning_message" to avoid namespace conflict.
1284  Revised 15 makefiles to build libpng-config from libpng-config-*.in
1285  Once more restored png_zalloc and png_zfree to regular nonexported form.
1286  Restored png_default_read|write_data, png_default_flush, png_read_fill_buffer
1287    to nonexported form, but with PNGAPI, and removed them from module def
1288    files.
1289
1290Version 1.2.3rc6 [May 14, 2002]
1291  Removed "PNGAPI" from png_zalloc() and png_zfree() in png.c
1292  Changed "Gz" to "Gd" in projects/msvc/libpng.dsp and zlib.dsp.
1293  Removed leftover libpng-config "sed" script from four makefiles.
1294  Revised libpng-config creating script in 16 makefiles.
1295
1296Version 1.2.3 [May 22, 2002]
1297  Revised libpng-config target in makefile.cygwin.
1298  Removed description of png_set_mem_fn() from documentation.
1299  Revised makefile.freebsd.
1300  Minor cosmetic changes to 15 makefiles, e.g., $(DI) = $(DESTDIR)/$(INCDIR).
1301  Revised projects/msvc/README.txt
1302  Changed -lpng to -lpngNN in LDFLAGS in several makefiles.
1303
1304Version 1.2.4beta1 [May 24, 2002]
1305  Added libpng.pc and libpng-config to "all:" target in 16 makefiles.
1306  Fixed bug in 16 makefiles: $(DESTDIR)/$(LIBPATH) to $(DESTDIR)$(LIBPATH)
1307  Added missing "\" before closing double quote in makefile.gcmmx.
1308  Plugged various memory leaks; added png_malloc_warn() and png_set_text_2()
1309    functions.
1310
1311Version 1.2.4beta2 [June 25, 2002]
1312  Plugged memory leak of png_ptr->current_text (Matt Holgate).
1313  Check for buffer overflow before reading CRC in pngpread.c (Warwick Allison)
1314  Added -soname to the loader flags in makefile.dec, makefile.sgi, and
1315    makefile.sggcc.
1316  Added "test-installed" target to makefile.linux, makefile.gcmmx,
1317    makefile.sgi, and makefile.sggcc.
1318
1319Version 1.2.4beta3 [June 28, 2002]
1320  Plugged memory leak of row_buf in pngtest.c when there is a png_error().
1321  Detect buffer overflow in pngpread.c when IDAT is corrupted with extra data.
1322  Added "test-installed" target to makefile.32sunu, makefile.64sunu,
1323    makefile.beos, makefile.darwin, makefile.dec, makefile.macosx,
1324    makefile.solaris, makefile.hpux, makefile.hpgcc, and makefile.so9.
1325
1326Version 1.2.4rc1 and 1.0.14rc1 [July 2, 2002]
1327  Added "test-installed" target to makefile.cygwin and makefile.sco.
1328  Revised pnggccrd.c to be able to back out version 1.0.x via PNG_1_0_X macro.
1329
1330Version 1.2.4 and 1.0.14 [July 8, 2002]
1331  Changed png_warning() to png_error() when width is too large to process.
1332
1333Version 1.2.4patch01 [July 20, 2002]
1334  Revised makefile.cygwin to use DLL number 12 instead of 13.
1335
1336Version 1.2.5beta1 [August 6, 2002]
1337  Added code to contrib/gregbook/readpng2.c to ignore unused chunks.
1338  Replaced toucan.png in contrib/gregbook (it has been corrupt since 1.0.11)
1339  Removed some stray *.o files from contrib/gregbook.
1340  Changed png_error() to png_warning() about "Too much data" in pngpread.c
1341    and about "Extra compressed data" in pngrutil.c.
1342  Prevent png_ptr->pass from exceeding 7 in png_push_finish_row().
1343  Updated makefile.hpgcc
1344  Updated png.c and pnggccrd.c handling of return from png_mmx_support()
1345
1346Version 1.2.5beta2 [August 15, 2002]
1347  Only issue png_warning() about "Too much data" in pngpread.c when avail_in
1348    is nonzero.
1349  Updated makefiles to install a separate libpng.so.3 with its own rpath.
1350
1351Version 1.2.5rc1 and 1.0.15rc1 [August 24, 2002]
1352  Revised makefiles to not remove previous minor versions of shared libraries.
1353
1354Version 1.2.5rc2 and 1.0.15rc2 [September 16, 2002]
1355  Revised 13 makefiles to remove "-lz" and "-L$(ZLIBLIB)", etc., from shared
1356    library loader directive.
1357  Added missing "$OBJSDLL" line to makefile.gcmmx.
1358  Added missing "; fi" to makefile.32sunu.
1359
1360Version 1.2.5rc3 and 1.0.15rc3 [September 18, 2002]
1361  Revised libpng-config script.
1362
1363Version 1.2.5 and 1.0.15 [October 3, 2002]
1364  Revised makefile.macosx, makefile.darwin, makefile.hpgcc, and makefile.hpux,
1365    and makefile.aix.
1366  Relocated two misplaced PNGAPI lines in pngtest.c
1367
1368Version 1.2.6beta1 [October 22, 2002]
1369  Commented out warning about uninitialized mmx_support in pnggccrd.c.
1370  Changed "IBMCPP__" flag to "__IBMCPP__" in pngconf.h.
1371  Relocated two more misplaced PNGAPI lines in pngtest.c
1372  Fixed memory overrun bug in png_do_read_filler() with 16-bit datastreams,
1373    introduced in version 1.0.2.
1374  Revised makefile.macosx, makefile.dec, makefile.aix, and makefile.32sunu.
1375
1376Version 1.2.6beta2 [November 1, 2002]
1377  Added libpng-config "--ldopts" output.
1378  Added "AR=ar" and "ARFLAGS=rc" and changed "ar rc" to "$(AR) $(ARFLAGS)"
1379    in makefiles.
1380
1381Version 1.2.6beta3 [July 18, 2004]
1382  Reverted makefile changes from version 1.2.6beta2 and some of the changes
1383    from version 1.2.6beta1; these will be postponed until version 1.2.7.
1384    Version 1.2.6 is going to be a simple bugfix release.
1385  Changed the one instance of "ln -sf" to "ln -f -s" in each Sun makefile.
1386  Fixed potential overrun in pngerror.c by using strncpy instead of memcpy.
1387  Added "#!/bin/sh" at the top of configure, for recognition of the
1388    'x' flag under Cygwin (Cosmin).
1389  Optimized vacuous tests that silence compiler warnings, in png.c (Cosmin).
1390  Added support for PNG_USER_CONFIG, in pngconf.h (Cosmin).
1391  Fixed the special memory handler for Borland C under DOS, in pngmem.c
1392    (Cosmin).
1393  Removed some spurious assignments in pngrutil.c (Cosmin).
1394  Replaced 65536 with 65536L, and 0xffff with 0xffffL, to silence warnings
1395    on 16-bit platforms (Cosmin).
1396  Enclosed shift op expressions in parentheses, to silence warnings (Cosmin).
1397  Used proper type png_fixed_point, to avoid problems on 16-bit platforms,
1398    in png_handle_sRGB() (Cosmin).
1399  Added compression_type to png_struct, and optimized the window size
1400    inside the deflate stream (Cosmin).
1401  Fixed definition of isnonalpha(), in pngerror.c and pngrutil.c (Cosmin).
1402  Fixed handling of unknown chunks that come after IDAT (Cosmin).
1403  Allowed png_error() and png_warning() to work even if png_ptr == NULL
1404    (Cosmin).
1405  Replaced row_info->rowbytes with row_bytes in png_write_find_filter()
1406    (Cosmin).
1407  Fixed definition of PNG_LIBPNG_VER_DLLNUM (Simon-Pierre).
1408  Used PNG_LIBPNG_VER and PNG_LIBPNG_VER_STRING instead of the hardcoded
1409    values in png.c (Simon-Pierre, Cosmin).
1410  Initialized png_libpng_ver[] with PNG_LIBPNG_VER_STRING (Simon-Pierre).
1411  Replaced PNG_LIBPNG_VER_MAJOR with PNG_LIBPNG_VER_DLLNUM in png.rc
1412    (Simon-Pierre).
1413  Moved the definition of PNG_HEADER_VERSION_STRING near the definitions
1414    of the other PNG_LIBPNG_VER_... symbols in png.h (Cosmin).
1415  Relocated #ifndef PNGAPI guards in pngconf.h (Simon-Pierre, Cosmin).
1416  Updated scripts/makefile.vc(a)win32 (Cosmin).
1417  Updated the MSVC project (Simon-Pierre, Cosmin).
1418  Updated the Borland C++ Builder project (Cosmin).
1419  Avoided access to asm_flags in pngvcrd.c, if PNG_1_0_X is defined (Cosmin).
1420  Commented out warning about uninitialized mmx_support in pngvcrd.c (Cosmin).
1421  Removed scripts/makefile.bd32 and scripts/pngdef.pas (Cosmin).
1422  Added extra guard around inclusion of Turbo C memory headers, in pngconf.h
1423    (Cosmin).
1424  Renamed projects/msvc/ to projects/visualc6/, and projects/borland/ to
1425    projects/cbuilder5/ (Cosmin).
1426  Moved projects/visualc6/png32ms.def to scripts/pngw32.def,
1427    and projects/visualc6/png.rc to scripts/pngw32.rc (Cosmin).
1428  Added projects/visualc6/pngtest.dsp; removed contrib/msvctest/ (Cosmin).
1429  Changed line endings to DOS style in cbuilder5 and visualc6 files, even
1430    in the tar.* distributions (Cosmin).
1431  Updated contrib/visupng/VisualPng.dsp (Cosmin).
1432  Updated contrib/visupng/cexcept.h to version 2.0.0 (Cosmin).
1433  Added a separate distribution with "configure" and supporting files (Junichi).
1434
1435Version 1.2.6beta4 [July 28, 2004]
1436  Added user ability to change png_size_t via a PNG_SIZE_T macro.
1437  Added png_sizeof() and png_convert_size() functions.
1438  Added PNG_SIZE_MAX (maximum value of a png_size_t variable.
1439  Added check in png_malloc_default() for (size_t)size != (png_uint_32)size
1440    which would indicate an overflow.
1441  Changed sPLT failure action from png_error to png_warning and abandon chunk.
1442  Changed sCAL and iCCP failures from png_error to png_warning and abandon.
1443  Added png_get_uint_31(png_ptr, buf) function.
1444  Added PNG_UINT_32_MAX macro.
1445  Renamed PNG_MAX_UINT to PNG_UINT_31_MAX.
1446  Made png_zalloc() issue a png_warning and return NULL on potential
1447    overflow.
1448  Turn on PNG_NO_ZALLOC_ZERO by default in version 1.2.x
1449  Revised "clobber list" in pnggccrd.c so it will compile under gcc-3.4.
1450  Revised Borland portion of png_malloc() to return NULL or issue
1451    png_error() according to setting of PNG_FLAG_MALLOC_NULL_MEM_OK.
1452  Added PNG_NO_SEQUENTIAL_READ_SUPPORTED macro to conditionally remove
1453    sequential read support.
1454  Added some "#if PNG_WRITE_SUPPORTED" blocks.
1455  Added #ifdef to remove some redundancy in png_malloc_default().
1456  Use png_malloc instead of png_zalloc to allocate the palette.
1457
1458Version 1.0.16rc1 and 1.2.6rc1 [August 4, 2004]
1459  Fixed buffer overflow vulnerability (CVE-2004-0597) in png_handle_tRNS().
1460  Fixed NULL dereference vulnerability (CVE-2004-0598) in png_handle_iCCP().
1461  Fixed integer overflow vulnerability (CVE-2004-0599) in png_read_png().
1462  Fixed some harmless bugs in png_handle_sBIT, etc, that would cause
1463    duplicate chunk types to go undetected.
1464  Fixed some timestamps in the -config version
1465  Rearranged order of processing of color types in png_handle_tRNS().
1466  Added ROWBYTES macro to calculate rowbytes without integer overflow.
1467  Updated makefile.darwin and removed makefile.macosx from scripts directory.
1468  Imposed default one million column, one-million row limits on the image
1469    dimensions, and added png_set_user_limits() function to override them.
1470  Revised use of PNG_SET_USER_LIMITS_SUPPORTED macro.
1471  Fixed wrong cast of returns from png_get_user_width|height_max().
1472  Changed some "keep the compiler happy" from empty statements to returns,
1473  Revised libpng.txt to remove 1.2.x stuff from the 1.0.x distribution
1474
1475Version 1.0.16rc2 and 1.2.6rc2 [August 7, 2004]
1476  Revised makefile.darwin and makefile.solaris.  Removed makefile.macosx.
1477  Revised pngtest's png_debug_malloc() to use png_malloc() instead of
1478    png_malloc_default() which is not supposed to be exported.
1479  Fixed off-by-one error in one of the conversions to PNG_ROWBYTES() in
1480    pngpread.c.  Bug was introduced in 1.2.6rc1.
1481  Fixed bug in RGB to RGBX transformation introduced in 1.2.6rc1.
1482  Fixed old bug in RGB to Gray transformation.
1483  Fixed problem with 64-bit compilers by casting arguments to abs()
1484    to png_int_32.
1485  Changed "ln -sf" to "ln -f -s" in three makefiles (solaris, sco, so9).
1486  Changed "HANDLE_CHUNK_*" to "PNG_HANDLE_CHUNK_*" (Cosmin)
1487  Added "-@/bin/rm -f $(DL)/$(LIBNAME).so.$(PNGMAJ)" to 15 *NIX makefiles.
1488  Added code to update the row_info->colortype in png_do_read_filler() (MSB).
1489
1490Version 1.0.16rc3 and 1.2.6rc3 [August 9, 2004]
1491  Eliminated use of "abs()" in testing cHRM and gAMA values, to avoid
1492    trouble with some 64-bit compilers.  Created PNG_OUT_OF_RANGE() macro.
1493  Revised documentation of png_set_keep_unknown_chunks().
1494  Check handle_as_unknown status in pngpread.c, as in pngread.c previously.
1495  Moved  "PNG_HANDLE_CHUNK_*" macros out of PNG_INTERNAL section of png.h
1496  Added "rim" definitions for CONST4 and CONST6 in pnggccrd.c
1497
1498Version 1.0.16rc4 and 1.2.6rc4 [August 10, 2004]
1499  Fixed mistake in pngtest.c introduced in 1.2.6rc2 (declaration of
1500    "pinfo" was out of place).
1501
1502Version 1.0.16rc5 and 1.2.6rc5 [August 10, 2004]
1503  Moved  "PNG_HANDLE_CHUNK_*" macros out of PNG_ASSEMBLER_CODE_SUPPORTED
1504    section of png.h where they were inadvertently placed in version rc3.
1505
1506Version 1.2.6 and 1.0.16 [August 15, 2004]
1507  Revised pngtest so memory allocation testing is only done when PNG_DEBUG==1.
1508
1509Version 1.2.7beta1 [August 26, 2004]
1510  Removed unused pngasmrd.h file.
1511  Removed references to uu.net for archived files.  Added references to
1512    PNG Spec (second edition) and the PNG ISO/IEC Standard.
1513  Added "test-dd" target in 15 makefiles, to run pngtest in DESTDIR.
1514  Fixed bug with "optimized window size" in the IDAT datastream, that
1515    causes libpng to write PNG files with incorrect zlib header bytes.
1516
1517Version 1.2.7beta2 [August 28, 2004]
1518  Fixed bug with sCAL chunk and big-endian machines (David Munro).
1519  Undid new code added in 1.2.6rc2 to update the color_type in
1520    png_set_filler().
1521  Added png_set_add_alpha() that updates color type.
1522
1523Version 1.0.17rc1 and 1.2.7rc1 [September 4, 2004]
1524  Revised png_set_strip_filler() to not remove alpha if color_type has alpha.
1525
1526Version 1.2.7 and 1.0.17 [September 12, 2004]
1527  Added makefile.hp64
1528  Changed projects/msvc/png32ms.def to scripts/png32ms.def in makefile.cygwin
1529
1530Version 1.2.8beta1 [November 1, 2004]
1531  Fixed bug in png_text_compress() that would fail to complete a large block.
1532  Fixed bug, introduced in libpng-1.2.7, that overruns a buffer during
1533    strip alpha operation in png_do_strip_filler().
1534  Added PNG_1_2_X definition in pngconf.h
1535  Use #ifdef to comment out png_info_init in png.c and png_read_init in
1536    pngread.c (as of 1.3.0)
1537
1538Version 1.2.8beta2 [November 2, 2004]
1539  Reduce color_type to a nonalpha type after strip alpha operation in
1540    png_do_strip_filler().
1541
1542Version 1.2.8beta3 [November 3, 2004]
1543  Revised definitions of PNG_MAX_UINT_32, PNG_MAX_SIZE, and PNG_MAXSUM
1544
1545Version 1.2.8beta4 [November 12, 2004]
1546  Fixed (again) definition of PNG_LIBPNG_VER_DLLNUM in png.h (Cosmin).
1547  Added PNG_LIBPNG_BUILD_PRIVATE in png.h (Cosmin).
1548  Set png_ptr->zstream.data_type to Z_BINARY, to avoid unnecessary detection
1549    of data type in deflate (Cosmin).
1550  Deprecated but continue to support SPECIALBUILD and PRIVATEBUILD in favor of
1551    PNG_LIBPNG_BUILD_SPECIAL_STRING and PNG_LIBPNG_BUILD_PRIVATE_STRING.
1552
1553Version 1.2.8beta5 [November 20, 2004]
1554  Use png_ptr->flags instead of png_ptr->transformations to pass
1555    PNG_STRIP_ALPHA info to png_do_strip_filler(), to preserve ABI
1556    compatibility.
1557  Revised handling of SPECIALBUILD, PRIVATEBUILD,
1558    PNG_LIBPNG_BUILD_SPECIAL_STRING and PNG_LIBPNG_BUILD_PRIVATE_STRING.
1559
1560Version 1.2.8rc1 [November 24, 2004]
1561  Moved handling of BUILD macros from pngconf.h to png.h
1562  Added definition of PNG_LIBPNG_BASE_TYPE in png.h, inadvertently
1563    omitted from beta5.
1564  Revised scripts/pngw32.rc
1565  Despammed mailing addresses by masking "@" with "at".
1566  Inadvertently installed a supposedly faster test version of pngrutil.c
1567
1568Version 1.2.8rc2 [November 26, 2004]
1569  Added two missing "\" in png.h
1570  Change tests in pngread.c and pngpread.c to
1571    if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
1572       png_do_read_transformations(png_ptr);
1573
1574Version 1.2.8rc3 [November 28, 2004]
1575  Reverted pngrutil.c to version libpng-1.2.8beta5.
1576  Added scripts/makefile.elf with supporting code in pngconf.h for symbol
1577    versioning (John Bowler).
1578
1579Version 1.2.8rc4 [November 29, 2004]
1580  Added projects/visualc7 (Simon-pierre).
1581
1582Version 1.2.8rc5 [November 29, 2004]
1583  Fixed new typo in scripts/pngw32.rc
1584
1585Version 1.2.8 [December 3, 2004]
1586  Removed projects/visualc7, added projects/visualc71.
1587
1588Version 1.2.9beta1 [February 21, 2006]
1589  Initialized some structure members in pngwutil.c to avoid gcc-4.0.0 complaints
1590  Revised man page and libpng.txt to make it clear that one should not call
1591    png_read_end or png_write_end after png_read_png or png_write_png.
1592  Updated references to png-mng-implement mailing list.
1593  Fixed an incorrect typecast in pngrutil.c
1594  Added PNG_NO_READ_SUPPORTED conditional for making a write-only library.
1595  Added PNG_NO_WRITE_INTERLACING_SUPPORTED conditional.
1596  Optimized alpha-inversion loops in pngwtran.c
1597  Moved test for nonzero gamma outside of png_build_gamma_table() in pngrtran.c
1598  Make sure num_trans is <= 256 before copying data in png_set_tRNS().
1599  Make sure num_palette is <= 256 before copying data in png_set_PLTE().
1600  Interchanged order of write_swap_alpha and write_invert_alpha transforms.
1601  Added parentheses in the definition of PNG_LIBPNG_BUILD_TYPE (Cosmin).
1602  Optimized zlib window flag (CINFO) in contrib/pngsuite/*.png (Cosmin).
1603  Updated scripts/makefile.bc32 for Borland C++ 5.6 (Cosmin).
1604  Exported png_get_uint_32, png_save_uint_32, png_get_uint_16, png_save_uint_16,
1605    png_get_int_32, png_save_int_32, png_get_uint_31 (Cosmin).
1606  Added type cast (png_byte) in png_write_sCAL() (Cosmin).
1607  Fixed scripts/makefile.cygwin (Christian Biesinger, Cosmin).
1608  Default iTXt support was inadvertently enabled.
1609
1610Version 1.2.9beta2 [February 21, 2006]
1611  Check for png_rgb_to_gray and png_gray_to_rgb read transformations before
1612    checking for png_read_dither in pngrtran.c
1613  Revised checking of chromaticity limits to accommodate extended RGB
1614    colorspace (John Denker).
1615  Changed line endings in some of the project files to CRLF, even in the
1616    "Unix" tar distributions (Cosmin).
1617  Made png_get_int_32 and png_save_int_32 always available (Cosmin).
1618  Updated scripts/pngos2.def, scripts/pngw32.def and projects/wince/png32ce.def
1619    with the newly exported functions.
1620  Eliminated distributions without the "configure" script.
1621  Updated INSTALL instructions.
1622
1623Version 1.2.9beta3 [February 24, 2006]
1624  Fixed CRCRLF line endings in contrib/visupng/VisualPng.dsp
1625  Made libpng.pc respect EXEC_PREFIX (D. P. Kreil, J. Bowler)
1626  Removed reference to pngasmrd.h from Makefile.am
1627  Renamed CHANGES to ChangeLog.
1628  Renamed LICENSE to COPYING.
1629  Renamed ANNOUNCE to NEWS.
1630  Created AUTHORS file.
1631
1632Version 1.2.9beta4 [March 3, 2006]
1633  Changed definition of PKGCONFIG from $prefix/lib to $libdir in configure.ac
1634  Reverted to filenames LICENSE and ANNOUNCE; removed AUTHORS and COPYING.
1635  Removed newline from the end of some error and warning messages.
1636  Removed test for sqrt() from configure.ac and configure.
1637  Made swap tables in pngtrans.c PNG_CONST (Carlo Bramix).
1638  Disabled default iTXt support that was inadvertently enabled in
1639    libpng-1.2.9beta1.
1640  Added "OS2" to list of systems that don't need underscores, in pnggccrd.c
1641  Removed libpng version and date from *.c files.
1642
1643Version 1.2.9beta5 [March 4, 2006]
1644  Removed trailing blanks from source files.
1645  Put version and date of latest change in each source file, and changed
1646    copyright year accordingly.
1647  More cleanup of configure.ac, Makefile.am, and associated scripts.
1648  Restored scripts/makefile.elf which was inadvertently deleted.
1649
1650Version 1.2.9beta6 [March 6, 2006]
1651  Fixed typo (RELEASE) in configuration files.
1652
1653Version 1.2.9beta7 [March 7, 2006]
1654  Removed libpng.vers and libpng.sym from libpng12_la_SOURCES in Makefile.am
1655  Fixed inconsistent #ifdef's around png_sig_bytes() and png_set_sCAL_s()
1656    in png.h.
1657  Updated makefile.elf as suggested by debian.
1658  Made cosmetic changes to some makefiles, adding LN_SF and other macros.
1659  Made some makefiles accept "exec_prefix".
1660
1661Version 1.2.9beta8 [March 9, 2006]
1662  Fixed some "#if defined (..." which should be "#if defined(..."
1663    Bug introduced in libpng-1.2.8.
1664  Fixed inconsistency in definition of png_default_read_data()
1665  Restored blank that was lost from makefile.sggcc "clean" target in beta7.
1666  Revised calculation of "current" and "major" for irix in ltmain.sh
1667  Changed "mkdir" to "MKDIR_P" in some makefiles.
1668  Separated PNG_EXPAND and PNG_EXPAND_tRNS.
1669  Added png_set_expand_gray_1_2_4_to_8() and deprecated
1670    png_set_gray_1_2_4_to_8() which also expands tRNS to alpha.
1671
1672Version 1.2.9beta9 [March 10, 2006]
1673  Include "config.h" in pngconf.h when available.
1674  Added some checks for NULL png_ptr or NULL info_ptr (timeless)
1675
1676Version 1.2.9beta10 [March 20, 2006]
1677  Removed extra CR from contrib/visualpng/VisualPng.dsw (Cosmin)
1678  Made pnggccrd.c PIC-compliant (Christian Aichinger).
1679  Added makefile.mingw (Wolfgang Glas).
1680  Revised pngconf.h MMX checking.
1681
1682Version 1.2.9beta11 [March 22, 2006]
1683  Fixed out-of-order declaration in pngwrite.c that was introduced in beta9
1684  Simplified some makefiles by using LIBSO, LIBSOMAJ, and LIBSOVER macros.
1685
1686Version 1.2.9rc1 [March 31, 2006]
1687  Defined PNG_USER_PRIVATEBUILD when including "pngusr.h" (Cosmin).
1688  Removed nonsensical assertion check from pngtest.c (Cosmin).
1689
1690Version 1.2.9 [April 14, 2006]
1691  Revised makefile.beos and added "none" selector in ltmain.sh
1692
1693Version 1.2.10beta1 [April 15, 2006]
1694  Renamed "config.h" to "png_conf.h" and revised Makefile.am to add
1695    -DPNG_BUILDING_LIBPNG to compile directive, and modified pngconf.h
1696    to include png_conf.h only when PNG_BUILDING_LIBPNG is defined.
1697
1698Version 1.2.10beta2 [April 15, 2006]
1699  Manually updated Makefile.in and configure.  Changed png_conf.h.in
1700    back to config.h.
1701
1702Version 1.2.10beta3 [April 15, 2006]
1703  Change png_conf.h back to config.h in pngconf.h.
1704
1705Version 1.2.10beta4 [April 16, 2006]
1706  Change PNG_BUILDING_LIBPNG to PNG_CONFIGURE_LIBPNG in config/Makefile*.
1707
1708Version 1.2.10beta5 [April 16, 2006]
1709  Added a configure check for compiling assembler code in pnggccrd.c
1710
1711Version 1.2.10beta6 [April 17, 2006]
1712  Revised the configure check for pnggccrd.c
1713  Moved -DPNG_CONFIGURE_LIBPNG into @LIBPNG_DEFINES@
1714  Added @LIBPNG_DEFINES@ to arguments when building libpng.sym
1715
1716Version 1.2.10beta7 [April 18, 2006]
1717  Change "exec_prefix=$prefix" to "exec_prefix=$(prefix)" in makefiles.
1718
1719Version 1.2.10rc1 [April 19, 2006]
1720  Ensure pngconf.h doesn't define both PNG_USE_PNGGCCRD and PNG_USE_PNGVCRD
1721  Fixed "LN_FS" typo in makefile.sco and makefile.solaris.
1722
1723Version 1.2.10rc2 [April 20, 2006]
1724  Added a backslash between -DPNG_CONFIGURE_LIBPNG and -DPNG_NO_ASSEMBLER_CODE
1725   in configure.ac and configure
1726  Made the configure warning about versioned symbols less arrogant.
1727
1728Version 1.2.10rc3 [April 21, 2006]
1729  Added a note in libpng.txt that png_set_sig_bytes(8) can be used when
1730    writing an embedded PNG without the 8-byte signature.
1731  Revised makefiles and configure to avoid making links to libpng.so.*
1732
1733Version 1.2.10 [April 23, 2006]
1734  Reverted configure to "rc2" state.
1735
1736Version 1.2.11beta1 [May 31, 2006]
1737  scripts/libpng.pc.in contained "configure" style version info and would
1738    not work with makefiles.
1739  The shared-library makefiles were linking to libpng.so.0 instead of
1740    libpng.so.3 compatibility as the library.
1741
1742Version 1.2.11beta2 [June 2, 2006]
1743  Increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid
1744    buffer overflow.
1745  Fixed bug in example.c (png_set_palette_rgb -> png_set_palette_to_rgb)
1746
1747Version 1.2.11beta3 [June 5, 2006]
1748  Prepended "#! /bin/sh" to ltmail.sh and contrib/pngminus/*.sh (Cosmin).
1749  Removed the accidental leftover Makefile.in~ (Cosmin).
1750  Avoided potential buffer overflow and optimized buffer in
1751    png_write_sCAL(), png_write_sCAL_s() (Cosmin).
1752  Removed the include directories and libraries from CFLAGS and LDFLAGS
1753    in scripts/makefile.gcc (Nelson A. de Oliveira, Cosmin).
1754
1755Version 1.2.11beta4 [June 6, 2006]
1756  Allow zero-length IDAT chunks after the entire zlib datastream, but not
1757    after another intervening chunk type.
1758
1759Version 1.0.19rc1, 1.2.11rc1 [June 13, 2006]
1760  Deleted extraneous square brackets from [config.h] in configure.ac
1761
1762Version 1.0.19rc2, 1.2.11rc2 [June 14, 2006]
1763  Added prototypes for PNG_INCH_CONVERSIONS functions to png.h
1764  Revised INSTALL and autogen.sh
1765  Fixed typo in several makefiles (-W1 should be -Wl)
1766  Added typedef for png_int_32 and png_uint_32 on 64-bit systems.
1767
1768Version 1.0.19rc3, 1.2.11rc3 [June 15, 2006]
1769  Removed the new typedefs for 64-bit systems (delay until version 1.4.0)
1770  Added one zero element to png_gamma_shift[] array in pngrtran.c to avoid
1771    reading out of bounds.
1772
1773Version 1.0.19rc4, 1.2.11rc4 [June 15, 2006]
1774  Really removed the new typedefs for 64-bit systems.
1775
1776Version 1.0.19rc5, 1.2.11rc5 [June 22, 2006]
1777  Removed png_sig_bytes entry from scripts/pngw32.def
1778
1779Version 1.0.19, 1.2.11 [June 26, 2006]
1780  None.
1781
1782Version 1.0.20, 1.2.12 [June 27, 2006]
1783  Really increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid
1784    buffer overflow.
1785
1786Version 1.2.13beta1 [October 2, 2006]
1787  Removed AC_FUNC_MALLOC from configure.ac
1788  Work around Intel-Mac compiler bug by setting PNG_NO_MMX_CODE in pngconf.h
1789  Change "logical" to "bitwise" throughout documentation.
1790  Detect and fix attempt to write wrong iCCP profile length (CVE-2006-7244)
1791
1792Version 1.0.21, 1.2.13 [November 14, 2006]
1793  Fix potential buffer overflow in sPLT chunk handler.
1794  Fix Makefile.am to not try to link to noexistent files.
1795  Check all exported functions for NULL png_ptr.
1796
1797Version 1.2.14beta1 [November 17, 2006]
1798  Relocated three misplaced tests for NULL png_ptr.
1799  Built Makefile.in with automake-1.9.6 instead of 1.9.2.
1800  Build configure with autoconf-2.60 instead of 2.59
1801
1802Version 1.2.14beta2 [November 17, 2006]
1803  Added some typecasts in png_zalloc().
1804
1805Version 1.2.14rc1 [November 20, 2006]
1806  Changed "strtod" to "png_strtod" in pngrutil.c
1807
1808Version 1.0.22, 1.2.14    [November 27, 2006]
1809  Added missing "$(srcdir)" in Makefile.am and Makefile.in
1810
1811Version 1.2.15beta1 [December 3, 2006]
1812  Generated configure with autoconf-2.61 instead of 2.60
1813  Revised configure.ac to update libpng.pc and libpng-config.
1814
1815Version 1.2.15beta2 [December 3, 2006]
1816  Always export MMX asm functions, just stubs if not building pnggccrd.c
1817
1818Version 1.2.15beta3 [December 4, 2006]
1819  Add "png_bytep" typecast to profile while calculating length in pngwutil.c
1820
1821Version 1.2.15beta4 [December 7, 2006]
1822  Added scripts/CMakeLists.txt
1823  Changed PNG_NO_ASSEMBLER_CODE to PNG_NO_MMX_CODE in scripts, like 1.4.0beta
1824
1825Version 1.2.15beta5 [December 7, 2006]
1826  Changed some instances of PNG_ASSEMBLER_* to PNG_MMX_* in pnggccrd.c
1827  Revised scripts/CMakeLists.txt
1828
1829Version 1.2.15beta6 [December 13, 2006]
1830  Revised scripts/CMakeLists.txt and configure.ac
1831
1832Version 1.2.15rc1 [December 18, 2006]
1833  Revised scripts/CMakeLists.txt
1834
1835Version 1.2.15rc2 [December 21, 2006]
1836  Added conditional #undef jmpbuf in pngtest.c to undo #define in AIX headers.
1837  Added scripts/makefile.nommx
1838
1839Version 1.2.15rc3 [December 25, 2006]
1840  Fixed shared library numbering error that was introduced in 1.2.15beta6.
1841
1842Version 1.2.15rc4 [December 27, 2006]
1843  Fixed handling of rgb_to_gray when png_ptr->color.gray isn't set.
1844
1845Version 1.2.15rc5 [December 31, 2006]
1846  Revised handling of rgb_to_gray.
1847
1848Version 1.2.15 [January 5, 2007]
1849  Added some (unsigned long) typecasts in pngtest.c to avoid printing errors.
1850
1851Version 1.2.16beta1 [January 6, 2007]
1852  Fix bugs in makefile.nommx
1853
1854Version 1.2.16beta2 [January 16, 2007]
1855  Revised scripts/CMakeLists.txt
1856
1857Version 1.2.16 [January 31, 2007]
1858  No changes.
1859
1860Version 1.2.17beta1 [March 6, 2007]
1861  Revised scripts/CMakeLists.txt to install both shared and static libraries.
1862  Deleted a redundant line from pngset.c.
1863
1864Version 1.2.17beta2 [April 26, 2007]
1865  Relocated misplaced test for png_ptr == NULL in pngpread.c
1866  Change "==" to "&" for testing PNG_RGB_TO_GRAY_ERR & PNG_RGB_TO_GRAY_WARN
1867    flags.
1868  Changed remaining instances of PNG_ASSEMBLER_* to PNG_MMX_*
1869  Added pngerror() when write_IHDR fails in deflateInit2().
1870  Added "const" to some array declarations.
1871  Mention examples of libpng usage in the libpng*.txt and libpng.3 documents.
1872
1873Version 1.2.17rc1 [May 4, 2007]
1874  No changes.
1875
1876Version 1.2.17rc2 [May 8, 2007]
1877  Moved several PNG_HAVE_* macros out of PNG_INTERNAL because applications
1878    calling set_unknown_chunk_location() need them.
1879  Changed transformation flag from PNG_EXPAND_tRNS to PNG_EXPAND in
1880    png_set_expand_gray_1_2_4_to_8().
1881  Added png_ptr->unknown_chunk to hold working unknown chunk data, so it
1882    can be free'ed in case of error.  Revised unknown chunk handling in
1883    pngrutil.c and pngpread.c to use this structure.
1884
1885Version 1.2.17rc3 [May 8, 2007]
1886  Revised symbol-handling in configure script.
1887
1888Version 1.2.17rc4 [May 10, 2007]
1889  Revised unknown chunk handling to avoid storing unknown critical chunks.
1890
1891Version 1.0.25 [May 15, 2007]
1892Version 1.2.17 [May 15, 2007]
1893  Added "png_ptr->num_trans=0" before error return in png_handle_tRNS,
1894    to eliminate a vulnerability (CVE-2007-2445, CERT VU#684664)
1895
1896Version 1.0.26 [May 15, 2007]
1897Version 1.2.18 [May 15, 2007]
1898  Reverted the libpng-1.2.17rc3 change to symbol-handling in configure script
1899
1900Version 1.2.19beta1 [May 18, 2007]
1901  Changed "const static" to "static PNG_CONST" everywhere, mostly undoing
1902    change of libpng-1.2.17beta2.  Changed other "const" to "PNG_CONST"
1903  Changed some handling of unused parameters, to avoid compiler warnings.
1904    "if (unused == NULL) return;" becomes "unused = unused".
1905
1906Version 1.2.19beta2 [May 18, 2007]
1907  Only use the valid bits of tRNS value in png_do_expand() (Brian Cartier)
1908
1909Version 1.2.19beta3 [May 19, 2007]
1910  Add some "png_byte" typecasts in png_check_keyword() and write new_key
1911  instead of key in zTXt chunk (Kevin Ryde).
1912
1913Version 1.2.19beta4 [May 21, 2007]
1914  Add png_snprintf() function and use it in place of sprint() for improved
1915    defense against buffer overflows.
1916
1917Version 1.2.19beta5 [May 21, 2007]
1918  Fixed png_handle_tRNS() to only use the valid bits of tRNS value.
1919  Changed handling of more unused parameters, to avoid compiler warnings.
1920  Removed some PNG_CONST in pngwutil.c to avoid compiler warnings.
1921
1922Version 1.2.19beta6 [May 22, 2007]
1923  Added some #ifdef PNG_MMX_CODE_SUPPORTED where needed in pngvcrd.c
1924  Added a special "_MSC_VER" case that defines png_snprintf to _snprintf
1925
1926Version 1.2.19beta7 [May 22, 2007]
1927  Squelched png_squelch_warnings() in pnggccrd.c and added
1928    an #ifdef PNG_MMX_CODE_SUPPORTED block around the declarations that caused
1929    the warnings that png_squelch_warnings was squelching.
1930
1931Version 1.2.19beta8 [May 22, 2007]
1932  Removed __MMX__ from test in pngconf.h.
1933
1934Version 1.2.19beta9 [May 23, 2007]
1935  Made png_squelch_warnings() available via PNG_SQUELCH_WARNINGS macro.
1936  Revised png_squelch_warnings() so it might work.
1937  Updated makefile.sgcc and makefile.solaris; added makefile.solaris-x86.
1938
1939Version 1.2.19beta10 [May 24, 2007]
1940  Resquelched png_squelch_warnings(), use "__attribute__((used))" instead.
1941
1942Version 1.4.0beta1 [April 20, 2006]
1943  Enabled iTXt support (changes png_struct, thus requires so-number change).
1944  Cleaned up PNG_ASSEMBLER_CODE_SUPPORTED vs PNG_MMX_CODE_SUPPORTED
1945  Eliminated PNG_1_0_X and PNG_1_2_X macros.
1946  Removed deprecated functions png_read_init, png_write_init, png_info_init,
1947    png_permit_empty_plte, png_set_gray_1_2_4_to_8, png_check_sig, and
1948    removed the deprecated macro PNG_MAX_UINT.
1949  Moved "PNG_INTERNAL" parts of png.h and pngconf.h into pngintrn.h
1950  Removed many WIN32_WCE #ifdefs (Cosmin).
1951  Reduced dependency on C-runtime library when on Windows (Simon-Pierre)
1952  Replaced sprintf() with png_sprintf() (Simon-Pierre)
1953
1954Version 1.4.0beta2 [April 20, 2006]
1955  Revised makefiles and configure to avoid making links to libpng.so.*
1956  Moved some leftover MMX-related defines from pngconf.h to pngintrn.h
1957  Updated scripts/pngos2.def, pngw32.def, and projects/wince/png32ce.def
1958
1959Version 1.4.0beta3 [May 10, 2006]
1960  Updated scripts/pngw32.def to comment out MMX functions.
1961  Added PNG_NO_GET_INT_32 and PNG_NO_SAVE_INT_32 macros.
1962  Scripts/libpng.pc.in contained "configure" style version info and would
1963    not work with makefiles.
1964  Revised pngconf.h and added pngconf.h.in, so makefiles and configure can
1965    pass defines to libpng and applications.
1966
1967Version 1.4.0beta4 [May 11, 2006]
1968  Revised configure.ac, Makefile.am, and many of the makefiles to write
1969    their defines in pngconf.h.
1970
1971Version 1.4.0beta5 [May 15, 2006]
1972  Added a missing semicolon in Makefile.am and Makefile.in
1973  Deleted extraneous square brackets from configure.ac
1974
1975Version 1.4.0beta6 [June 2, 2006]
1976  Increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid
1977    buffer overflow.
1978  Changed sonum from 0 to 1.
1979  Removed unused prototype for png_check_sig() from png.h
1980
1981Version 1.4.0beta7 [June 16, 2006]
1982  Exported png_write_sig (Cosmin).
1983  Optimized buffer in png_handle_cHRM() (Cosmin).
1984  Set pHYs = 2835 x 2835 pixels per meter, and added
1985    sCAL = 0.352778e-3 x 0.352778e-3 meters, in pngtest.png (Cosmin).
1986  Added png_set_benign_errors(), png_benign_error(), png_chunk_benign_error().
1987  Added typedef for png_int_32 and png_uint_32 on 64-bit systems.
1988  Added "(unsigned long)" typecast on png_uint_32 variables in printf lists.
1989
1990Version 1.4.0beta8 [June 22, 2006]
1991  Added demonstration of user chunk support in pngtest.c, to support the
1992    public sTER chunk and a private vpAg chunk.
1993
1994Version 1.4.0beta9 [July 3, 2006]
1995  Removed ordinals from scripts/pngw32.def and removed png_info_int and
1996    png_set_gray_1_2_4_to_8 entries.
1997  Inline call of png_get_uint_32() in png_get_uint_31().
1998  Use png_get_uint_31() to get vpAg width and height in pngtest.c
1999  Removed WINCE and Netware projects.
2000  Removed standalone Y2KINFO file.
2001
2002Version 1.4.0beta10 [July 12, 2006]
2003  Eliminated automatic copy of pngconf.h to pngconf.h.in from configure and
2004    some makefiles, because it was not working reliably.  Instead, distribute
2005    pngconf.h.in along with pngconf.h and cause configure and some of the
2006    makefiles to update pngconf.h from pngconf.h.in.
2007  Added pngconf.h to DEPENDENCIES in Makefile.am
2008
2009Version 1.4.0beta11 [August 19, 2006]
2010  Removed AC_FUNC_MALLOC from configure.ac.
2011  Added a warning when writing iCCP profile with mismatched profile length.
2012  Patched pnggccrd.c to assemble on x86_64 platforms.
2013  Moved chunk header reading into a separate function png_read_chunk_header()
2014    in pngrutil.c.  The chunk header (len+sig) is now serialized in a single
2015    operation (Cosmin).
2016  Implemented support for I/O states. Added png_ptr member io_state, and
2017    functions png_get_io_chunk_name() and png_get_io_state() in pngget.c
2018    (Cosmin).
2019  Added png_get_io_chunk_name and png_get_io_state to scripts/*.def (Cosmin).
2020  Renamed scripts/pngw32.* to scripts/pngwin.* (Cosmin).
2021  Removed the include directories and libraries from CFLAGS and LDFLAGS
2022    in scripts/makefile.gcc (Cosmin).
2023  Used png_save_uint_32() to set vpAg width and height in pngtest.c (Cosmin).
2024  Cast to proper type when getting/setting vpAg units in pngtest.c (Cosmin).
2025  Added pngintrn.h to the Visual C++ projects (Cosmin).
2026  Removed scripts/list (Cosmin).
2027  Updated copyright year in scripts/pngwin.def (Cosmin).
2028  Removed PNG_TYPECAST_NULL and used standard NULL consistently (Cosmin).
2029  Disallowed the user to redefine png_size_t, and enforced a consistent use
2030    of png_size_t across libpng (Cosmin).
2031  Changed the type of png_ptr->rowbytes, PNG_ROWBYTES() and friends
2032    to png_size_t (Cosmin).
2033  Removed png_convert_size() and replaced png_sizeof with sizeof (Cosmin).
2034  Removed some unnecessary type casts (Cosmin).
2035  Changed prototype of png_get_compression_buffer_size() and
2036    png_set_compression_buffer_size() to work with png_size_t instead of
2037    png_uint_32 (Cosmin).
2038  Removed png_memcpy_check() and png_memset_check() (Cosmin).
2039  Fixed a typo (png_byte --> png_bytep) in libpng.3 and libpng.txt (Cosmin).
2040  Clarified that png_zalloc() does not clear the allocated memory,
2041    and png_zalloc() and png_zfree() cannot be PNGAPI (Cosmin).
2042  Renamed png_mem_size_t to png_alloc_size_t, fixed its definition in
2043    pngconf.h, and used it in all memory allocation functions (Cosmin).
2044  Renamed pngintrn.h to pngpriv.h, added a comment at the top of the file
2045    mentioning that the symbols declared in that file are private, and
2046    updated the scripts and the Visual C++ projects accordingly (Cosmin).
2047  Removed circular references between pngconf.h and pngconf.h.in in
2048    scripts/makefile.vc*win32 (Cosmin).
2049  Removing trailing '.' from the warning and error messages (Cosmin).
2050  Added pngdefs.h that is built by makefile or configure, instead of
2051    pngconf.h.in (Glenn).
2052  Detect and fix attempt to write wrong iCCP profile length.
2053
2054Version 1.4.0beta12 [October 19, 2006]
2055  Changed "logical" to "bitwise" in the documentation.
2056  Work around Intel-Mac compiler bug by setting PNG_NO_MMX_CODE in pngconf.h
2057  Add a typecast to stifle compiler warning in pngrutil.c
2058
2059Version 1.4.0beta13 [November 10, 2006]
2060  Fix potential buffer overflow in sPLT chunk handler.
2061  Fix Makefile.am to not try to link to noexistent files.
2062
2063Version 1.4.0beta14 [November 15, 2006]
2064  Check all exported functions for NULL png_ptr.
2065
2066Version 1.4.0beta15 [November 17, 2006]
2067  Relocated two misplaced tests for NULL png_ptr.
2068  Built Makefile.in with automake-1.9.6 instead of 1.9.2.
2069  Build configure with autoconf-2.60 instead of 2.59
2070  Add "install: all" in Makefile.am so "configure; make install" will work.
2071
2072Version 1.4.0beta16 [November 17, 2006]
2073  Added a typecast in png_zalloc().
2074
2075Version 1.4.0beta17 [December 4, 2006]
2076  Changed "new_key[79] = '\0';" to "(*new_key)[79] = '\0';" in pngwutil.c
2077  Add "png_bytep" typecast to profile while calculating length in pngwutil.c
2078
2079Version 1.4.0beta18 [December 7, 2006]
2080  Added scripts/CMakeLists.txt
2081
2082Version 1.4.0beta19 [May 16, 2007]
2083  Revised scripts/CMakeLists.txt
2084  Rebuilt configure and Makefile.in with newer tools.
2085  Added conditional #undef jmpbuf in pngtest.c to undo #define in AIX headers.
2086  Added scripts/makefile.nommx
2087
2088Version 1.4.0beta20 [July 9, 2008]
2089  Moved several PNG_HAVE_* macros from pngpriv.h to png.h because applications
2090    calling set_unknown_chunk_location() need them.
2091  Moved several macro definitions from pngpriv.h to pngconf.h
2092  Merge with changes to the 1.2.X branch, as of 1.2.30beta04.
2093  Deleted all use of the MMX assembler code and Intel-licensed optimizations.
2094  Revised makefile.mingw
2095
2096Version 1.4.0beta21 [July 21, 2008]
2097  Moved local array "chunkdata" from pngrutil.c to the png_struct, so
2098    it will be freed by png_read_destroy() in case of a read error (Kurt
2099    Christensen).
2100
2101Version 1.4.0beta22 [July 21, 2008]
2102  Change "purpose" and "buffer" to png_ptr->chunkdata to avoid memory leaking.
2103
2104Version 1.4.0beta23 [July 22, 2008]
2105  Change "chunkdata = NULL" to "png_ptr->chunkdata = NULL" several places in
2106    png_decompress_chunk().
2107
2108Version 1.4.0beta24 [July 25, 2008]
2109  Change all remaining "chunkdata" to "png_ptr->chunkdata" in
2110    png_decompress_chunk(), and remove "chunkdata" from parameter list.
2111  Put a call to png_check_chunk_name() in png_read_chunk_header().
2112  Revised png_check_chunk_name() to reject a name with a lowercase 3rd byte.
2113  Removed two calls to png_check_chunk_name() occurring later in the process.
2114  Define PNG_NO_ERROR_NUMBERS by default in pngconf.h
2115
2116Version 1.4.0beta25 [July 30, 2008]
2117  Added a call to png_check_chunk_name() in pngpread.c
2118  Reverted png_check_chunk_name() to accept a name with a lowercase 3rd byte.
2119  Added png_push_have_buffer() function to pngpread.c
2120  Eliminated PNG_BIG_ENDIAN_SUPPORTED and associated png_get_* macros.
2121  Made inline expansion of png_get_*() optional with PNG_USE_READ_MACROS.
2122  Eliminated all PNG_USELESS_TESTS and PNG_CORRECT_PALETTE_SUPPORTED code.
2123  Synced contrib directory and configure files with libpng-1.2.30beta06.
2124  Eliminated no-longer-used pngdefs.h (but it's still built in the makefiles)
2125  Relocated a misplaced "#endif /* PNG_NO_WRITE_FILTER */" in pngwutil.c
2126
2127Version 1.4.0beta26 [August 4, 2008]
2128  Removed png_push_have_buffer() function in pngpread.c.  It increased the
2129    compiled library size slightly.
2130  Changed "-Wall" to "-W -Wall" in the CFLAGS in all makefiles (Cosmin Truta)
2131  Declared png_ptr "volatile" in pngread.c and pngwrite.c to avoid warnings.
2132  Updated contrib/visupng/cexcept.h to version 2.0.1
2133  Added PNG_LITERAL_CHARACTER macros for #, [, and ].
2134
2135Version 1.4.0beta27 [August 5, 2008]
2136  Revised usage of PNG_LITERAL_SHARP in pngerror.c.
2137  Moved newline character from individual png_debug messages into the
2138    png_debug macros.
2139  Allow user to #define their own png_debug, png_debug1, and png_debug2.
2140
2141Version 1.4.0beta28 [August 5, 2008]
2142  Revised usage of PNG_LITERAL_SHARP in pngerror.c.
2143  Added PNG_STRING_NEWLINE macro
2144
2145Version 1.4.0beta29 [August 9, 2008]
2146  Revised usage of PNG_STRING_NEWLINE to work on non-ISO compilers.
2147  Added PNG_STRING_COPYRIGHT macro.
2148  Added non-ISO versions of png_debug macros.
2149
2150Version 1.4.0beta30 [August 14, 2008]
2151  Added premultiplied alpha feature (Volker Wiendl).
2152
2153Version 1.4.0beta31 [August 18, 2008]
2154  Moved png_set_premultiply_alpha from pngtrans.c to pngrtran.c
2155  Removed extra crc check at the end of png_handle_cHRM().  Bug introduced
2156    in libpng-1.4.0beta20.
2157
2158Version 1.4.0beta32 [August 19, 2008]
2159  Added PNG_WRITE_FLUSH_SUPPORTED block around new png_flush() call.
2160  Revised PNG_NO_STDIO version of png_write_flush()
2161
2162Version 1.4.0beta33 [August 20, 2008]
2163  Added png_get|set_chunk_cache_max() to limit the total number of sPLT,
2164    text, and unknown chunks that can be stored.
2165
2166Version 1.4.0beta34 [September 6, 2008]
2167  Shortened tIME_string to 29 bytes in pngtest.c
2168  Fixed off-by-one error introduced in png_push_read_zTXt() function in
2169    libpng-1.2.30beta04/pngpread.c (Harald van Dijk)
2170
2171Version 1.4.0beta35 [October 6, 2008]
2172  Changed "trans_values" to "trans_color".
2173  Changed so-number from 0 to 14.  Some OS do not like 0.
2174  Revised makefile.darwin to fix shared library numbering.
2175  Change png_set_gray_1_2_4_to_8() to png_set_expand_gray_1_2_4_to_8()
2176    in example.c (debian bug report)
2177
2178Version 1.4.0beta36 [October 25, 2008]
2179  Sync with tEXt vulnerability fix in libpng-1.2.33rc02.
2180
2181Version 1.4.0beta37 [November 13, 2008]
2182  Added png_check_cHRM in png.c and moved checking from pngget.c, pngrutil.c,
2183    and pngwrite.c
2184
2185Version 1.4.0beta38 [November 22, 2008]
2186  Added check for zero-area RGB cHRM triangle in png_check_cHRM() and
2187    png_check_cHRM_fixed().
2188
2189Version 1.4.0beta39 [November 23, 2008]
2190  Revised png_warning() to write its message on standard output by default
2191    when warning_fn is NULL.
2192
2193Version 1.4.0beta40 [November 24, 2008]
2194  Eliminated png_check_cHRM().  Instead, always use png_check_cHRM_fixed().
2195  In png_check_cHRM_fixed(), ensure white_y is > 0, and removed redundant
2196    check for all-zero coordinates that is detected by the triangle check.
2197
2198Version 1.4.0beta41 [November 26, 2008]
2199  Fixed string vs pointer-to-string error in png_check_keyword().
2200  Rearranged test expressions in png_check_cHRM_fixed() to avoid internal
2201    overflows.
2202  Added PNG_NO_CHECK_cHRM conditional.
2203
2204Version 1.4.0beta42, 43 [December 1, 2008]
2205  Merge png_debug with version 1.2.34beta04.
2206
2207Version 1.4.0beta44 [December 6, 2008]
2208  Removed redundant check for key==NULL before calling png_check_keyword()
2209    to ensure that new_key gets initialized and removed extra warning
2210    (Merge with version 1.2.34beta05 -- Arvan Pritchard).
2211
2212Version 1.4.0beta45 [December 9, 2008]
2213  In png_write_png(), respect the placement of the filler bytes in an earlier
2214    call to png_set_filler() (Jim Barry).
2215
2216Version 1.4.0beta46 [December 10, 2008]
2217  Undid previous change and added PNG_TRANSFORM_STRIP_FILLER_BEFORE and
2218    PNG_TRANSFORM_STRIP_FILLER_AFTER conditionals and deprecated
2219    PNG_TRANSFORM_STRIP_FILLER (Jim Barry).
2220
2221Version 1.4.0beta47 [December 15, 2008]
2222  Support for dithering was disabled by default, because it has never
2223    been well tested and doesn't work very well.  The code has not
2224    been removed, however, and can be enabled by building libpng with
2225    PNG_READ_DITHER_SUPPORTED defined.
2226
2227Version 1.4.0beta48 [February 14, 2009]
2228  Added new exported function png_calloc().
2229  Combined several instances of png_malloc(); png_memset() into png_calloc().
2230  Removed prototype for png_freeptr() that was added in libpng-1.4.0beta24
2231    but was never defined.
2232
2233Version 1.4.0beta49 [February 28, 2009]
2234  Added png_fileno() macro to pngconf.h, used in pngwio.c
2235  Corrected order of #ifdef's in png_debug definition in png.h
2236  Fixed bug introduced in libpng-1.4.0beta48 with the memset arguments
2237    for pcal_params.
2238  Fixed order of #ifdef directives in the png_debug defines in png.h
2239    (bug introduced in libpng-1.2.34/1.4.0beta29).
2240  Revised comments in png_set_read_fn() and png_set_write_fn().
2241
2242Version 1.4.0beta50 [March 18, 2009]
2243  Use png_calloc() instead of png_malloc() to allocate big_row_buf when
2244    reading an interlaced file, to avoid a possible UMR.
2245  Undid revision of PNG_NO_STDIO version of png_write_flush().  Users
2246    having trouble with fflush() can build with PNG_NO_WRITE_FLUSH defined
2247    or supply their own flush_fn() replacement.
2248  Revised libpng*.txt and png.h documentation about use of png_write_flush()
2249    and png_set_write_fn().
2250  Removed fflush() from pngtest.c.
2251  Added "#define PNG_NO_WRITE_FLUSH" to contrib/pngminim/encoder/pngusr.h
2252
2253Version 1.4.0beta51 [March 21, 2009]
2254  Removed new png_fileno() macro from pngconf.h .
2255
2256Version 1.4.0beta52 [March 27, 2009]
2257  Relocated png_do_chop() ahead of building gamma tables in pngrtran.c
2258    This avoids building 16-bit gamma tables unnecessarily.
2259  Removed fflush() from pngtest.c.
2260  Added "#define PNG_NO_WRITE_FLUSH" to contrib/pngminim/encoder/pngusr.h
2261  Added a section on differences between 1.0.x and 1.2.x to libpng.3/libpng.txt
2262
2263Version 1.4.0beta53 [April 1, 2009]
2264  Removed some remaining MMX macros from pngpriv.h
2265  Fixed potential memory leak of "new_name" in png_write_iCCP() (Ralph Giles)
2266
2267Version 1.4.0beta54 [April 13, 2009]
2268  Added "ifndef PNG_SKIP_SETJMP_CHECK" block in pngconf.h to allow
2269    application code writers to bypass the check for multiple inclusion
2270    of setjmp.h when they know that it is safe to ignore the situation.
2271  Eliminated internal use of setjmp() in pngread.c and pngwrite.c
2272  Reordered ancillary chunks in pngtest.png to be the same as what
2273    pngtest now produces, and made some cosmetic changes to pngtest output.
2274  Eliminated deprecated png_read_init_3() and png_write_init_3() functions.
2275
2276Version 1.4.0beta55 [April 15, 2009]
2277  Simplified error handling in pngread.c and pngwrite.c by putting
2278    the new png_read_cleanup() and png_write_cleanup() functions inline.
2279
2280Version 1.4.0beta56 [April 25, 2009]
2281  Renamed "user_chunk_data" to "my_user_chunk_data" in pngtest.c to suppress
2282    "shadowed declaration" warning from gcc-4.3.3.
2283  Renamed "gamma" to "png_gamma" in pngset.c to avoid "shadowed declaration"
2284    warning about a global "gamma" variable in math.h on some platforms.
2285
2286Version 1.4.0beta57 [May 2, 2009]
2287  Removed prototype for png_freeptr() that was added in libpng-1.4.0beta24
2288    but was never defined (again).
2289  Rebuilt configure scripts with autoconf-2.63 instead of 2.62
2290  Removed pngprefs.h and MMX from makefiles
2291
2292Version 1.4.0beta58 [May 14, 2009]
2293  Changed pngw32.def to pngwin.def in makefile.mingw (typo was introduced
2294    in beta57).
2295  Clarified usage of sig_bit versus sig_bit_p in example.c (Vincent Torri)
2296
2297Version 1.4.0beta59 [May 15, 2009]
2298  Reformated sources in libpng style (3-space intentation, comment format)
2299  Fixed typo in libpng docs (PNG_FILTER_AVE should be PNG_FILTER_AVG)
2300  Added sections about the git repository and our coding style to the
2301    documentation
2302  Relocated misplaced #endif in pngwrite.c, sCAL chunk handler.
2303
2304Version 1.4.0beta60 [May 19, 2009]
2305  Conditionally compile png_read_finish_row() which is not used by
2306    progressive readers.
2307  Added contrib/pngminim/preader to demonstrate building minimal progressive
2308    decoder, based on contrib/gregbook with embedded libpng and zlib.
2309
2310Version 1.4.0beta61 [May 20, 2009]
2311  In contrib/pngminim/*, renamed "makefile.std" to "makefile", since there
2312    is only one makefile in those directories, and revised the README files
2313    accordingly.
2314  More reformatting of comments, mostly to capitalize sentences.
2315
2316Version 1.4.0beta62 [June 2, 2009]
2317  Added "#define PNG_NO_WRITE_SWAP" to contrib/pngminim/encoder/pngusr.h
2318    and "define PNG_NO_READ_SWAP" to decoder/pngusr.h and preader/pngusr.h
2319  Reformatted several remaining "else statement" into two lines.
2320  Added a section to the libpng documentation about using png_get_io_ptr()
2321    in configure scripts to detect the presence of libpng.
2322
2323Version 1.4.0beta63 [June 15, 2009]
2324  Revised libpng*.txt and libpng.3 to mention calling png_set_IHDR()
2325    multiple times and to specify the sample order in the tRNS chunk,
2326    because the ISO PNG specification has a typo in the tRNS table.
2327  Changed several PNG_UNKNOWN_CHUNK_SUPPORTED to
2328    PNG_HANDLE_AS_UNKNOWN_SUPPORTED, to make the png_set_keep mechanism
2329    available for ignoring known chunks even when not saving unknown chunks.
2330  Adopted preference for consistent use of "#ifdef" and "#ifndef" versus
2331    "#if defined()" and "if !defined()" where possible.
2332
2333Version 1.4.0beta64 [June 24, 2009]
2334  Eliminated PNG_LEGACY_SUPPORTED code.
2335  Moved the various unknown chunk macro definitions outside of the
2336    PNG_READ|WRITE_ANCILLARY_CHUNK_SUPPORTED blocks.
2337
2338Version 1.4.0beta65 [June 26, 2009]
2339  Added a reference to the libpng license in each file.
2340
2341Version 1.4.0beta66 [June 27, 2009]
2342  Refer to the libpng license instead of the libpng license in each file.
2343
2344Version 1.4.0beta67 [July 6, 2009]
2345  Relocated INVERT_ALPHA within png_read_png() and png_write_png().
2346  Added high-level API transform PNG_TRANSFORM_GRAY_TO_RGB.
2347  Added an "xcode" project to the projects directory (Alam Arias).
2348
2349Version 1.4.0beta68 [July 19, 2009]
2350  Avoid some tests in filter selection in pngwutil.c
2351
2352Version 1.4.0beta69 [July 25, 2009]
2353  Simplified the new filter-selection test.  This runs faster in the
2354    common "PNG_ALL_FILTERS" and PNG_FILTER_NONE cases.
2355  Removed extraneous declaration from the new call to png_read_gray_to_rgb()
2356    (bug introduced in libpng-1.4.0beta67).
2357  Fixed up xcode project (Alam Arias)
2358  Added a prototype for png_64bit_product() in png.c
2359
2360Version 1.4.0beta70 [July 27, 2009]
2361  Avoid a possible NULL dereference in debug build, in png_set_text_2().
2362    (bug introduced in libpng-0.95, discovered by Evan Rouault)
2363
2364Version 1.4.0beta71 [July 29, 2009]
2365  Rebuilt configure scripts with autoconf-2.64.
2366
2367Version 1.4.0beta72 [August 1, 2009]
2368  Replaced *.tar.lzma with *.tar.xz in distribution.  Get the xz codec
2369    from <http://tukaani.org/xz>.
2370
2371Version 1.4.0beta73 [August 1, 2009]
2372  Reject attempt to write iCCP chunk with negative embedded profile length
2373    (JD Chen) (CVE-2009-5063).
2374
2375Version 1.4.0beta74 [August 8, 2009]
2376  Changed png_ptr and info_ptr member "trans" to "trans_alpha".
2377
2378Version 1.4.0beta75 [August 21, 2009]
2379  Removed an extra png_debug() recently added to png_write_find_filter().
2380  Fixed incorrect #ifdef in pngset.c regarding unknown chunk support.
2381
2382Version 1.4.0beta76 [August 22, 2009]
2383  Moved an incorrectly located test in png_read_row() in pngread.c
2384
2385Version 1.4.0beta77 [August 27, 2009]
2386  Removed lpXYZ.tar.bz2 (with CRLF), KNOWNBUG, libpng-x.y.z-KNOWNBUG.txt,
2387    and the "noconfig" files from the distribution.
2388  Moved CMakeLists.txt from scripts into the main libpng directory.
2389  Various bugfixes and improvements to CMakeLists.txt (Philip Lowman)
2390
2391Version 1.4.0beta78 [August 31, 2009]
2392  Converted all PNG_NO_* tests to PNG_*_SUPPORTED everywhere except pngconf.h
2393  Eliminated PNG_NO_FREE_ME and PNG_FREE_ME_SUPPORTED macros.
2394  Use png_malloc plus a loop instead of png_calloc() to initialize
2395    row_pointers in png_read_png().
2396
2397Version 1.4.0beta79 [September 1, 2009]
2398  Eliminated PNG_GLOBAL_ARRAYS and PNG_LOCAL_ARRAYS; always use local arrays.
2399  Eliminated PNG_CALLOC_SUPPORTED macro and always provide png_calloc().
2400
2401Version 1.4.0beta80 [September 17, 2009]
2402  Removed scripts/libpng.icc
2403  Changed typecast of filler from png_byte to png_uint_16 in png_set_filler().
2404    (Dennis Gustafsson)
2405  Fixed typo introduced in beta78 in pngtest.c ("#if def " should be "#ifdef ")
2406
2407Version 1.4.0beta81 [September 23, 2009]
2408  Eliminated unused PNG_FLAG_FREE_* defines from pngpriv.h
2409  Expanded TAB characters in pngrtran.c
2410  Removed PNG_CONST from all "PNG_CONST PNG_CHNK" declarations to avoid
2411    compiler complaints about doubly declaring things "const".
2412  Changed all "#if [!]defined(X)" to "if[n]def X" where possible.
2413  Eliminated unused png_ptr->row_buf_size
2414
2415Version 1.4.0beta82 [September 25, 2009]
2416  Moved redundant IHDR checking into new png_check_IHDR() in png.c
2417    and report all errors found in the IHDR data.
2418  Eliminated useless call to png_check_cHRM() from pngset.c
2419
2420Version 1.4.0beta83 [September 25, 2009]
2421  Revised png_check_IHDR() to eliminate bogus complaint about filter_type.
2422
2423Version 1.4.0beta84 [September 30, 2009]
2424  Fixed some inconsistent indentation in pngconf.h
2425  Revised png_check_IHDR() to add a test for width variable less than 32-bit.
2426
2427Version 1.4.0beta85 [October 1, 2009]
2428  Revised png_check_IHDR() again, to check info_ptr members instead of
2429    the contents of the returned parameters.
2430
2431Version 1.4.0beta86 [October 9, 2009]
2432  Updated the "xcode" project (Alam Arias).
2433  Eliminated a shadowed declaration of "pp" in png_handle_sPLT().
2434
2435Version 1.4.0rc01 [October 19, 2009]
2436  Trivial cosmetic changes.
2437
2438Version 1.4.0beta87 [October 30, 2009]
2439  Moved version 1.4.0 back into beta.
2440
2441Version 1.4.0beta88 [October 30, 2009]
2442  Revised libpng*.txt section about differences between 1.2.x and 1.4.0
2443    because most of the new features have now been ported back to 1.2.41
2444
2445Version 1.4.0beta89 [November 1, 2009]
2446  More bugfixes and improvements to CMakeLists.txt (Philip Lowman)
2447  Removed a harmless extra png_set_invert_alpha() from pngwrite.c
2448  Apply png_user_chunk_cache_max within png_decompress_chunk().
2449  Merged libpng-1.2.41.txt with libpng-1.4.0.txt where appropriate.
2450
2451Version 1.4.0beta90 [November 2, 2009]
2452  Removed all remaining WIN32_WCE #ifdefs except those involving the
2453    time.h "tm" structure
2454
2455Version 1.4.0beta91 [November 3, 2009]
2456  Updated scripts/pngw32.def and projects/wince/png32ce.def
2457  Copied projects/wince/png32ce.def to the scripts directory.
2458  Added scripts/makefile.wce
2459  Patched ltmain.sh for wince support.
2460  Added PNG_CONVERT_tIME_SUPPORTED macro.
2461
2462Version 1.4.0beta92 [November 4, 2009]
2463  Make inclusion of time.h in pngconf.h depend on PNG_CONVERT_tIME_SUPPORTED
2464  Make #define PNG_CONVERT_tIME_SUPPORTED depend on PNG_WRITE_tIME_SUPPORTED
2465  Revised libpng*.txt to describe differences from 1.2.40 to 1.4.0 (instead
2466    of differences from 1.2.41 to 1.4.0)
2467
2468Version 1.4.0beta93 [November 7, 2009]
2469  Added PNG_DEPSTRUCT, PNG_DEPRECATED, PNG_USE_RESULT, PNG_NORETURN, and
2470    PNG_ALLOCATED macros to detect deprecated direct access to the
2471    png_struct or info_struct members and other deprecated usage in
2472    applications (John Bowler).
2473  Updated scripts/makefile* to add "-DPNG_CONFIGURE_LIBPNG" to CFLAGS,
2474    to prevent warnings about direct access to png structs by libpng
2475    functions while building libpng.  They need to be tested, especially
2476    those using compilers other than gcc.
2477  Updated projects/visualc6 and visualc71 with "/d PNG_CONFIGURE_LIBPNG".
2478    They should work but still need to be updated to remove
2479    references to pnggccrd.c or pngvcrd.c and ASM building.
2480  Added README.txt to the beos, cbuilder5, netware, and xcode projects warning
2481    that they need to be updated, to remove references to pnggccrd.c and
2482    pngvcrd.c and to depend on pngpriv.h
2483  Removed three direct references to read_info_ptr members in pngtest.c
2484    that were detected by the new PNG_DEPSTRUCT macro.
2485  Moved the png_debug macro definitions and the png_read_destroy(),
2486    png_write_destroy() and png_far_to_near() prototypes from png.h
2487    to pngpriv.h (John Bowler)
2488  Moved the synopsis lines for png_read_destroy(), png_write_destroy()
2489    png_debug(), png_debug1(), and png_debug2() from libpng.3 to libpngpf.3.
2490
2491Version 1.4.0beta94 [November 9, 2009]
2492  Removed the obsolete, unused pnggccrd.c and pngvcrd.c files.
2493  Updated CMakeLists.txt to add "-DPNG_CONFIGURE_LIBPNG" to the definitions.
2494  Removed dependency of pngtest.o on pngpriv.h in the makefiles.
2495  Only #define PNG_DEPSTRUCT, etc. in pngconf.h if not already defined.
2496
2497Version 1.4.0beta95 [November 10, 2009]
2498  Changed png_check_sig() to !png_sig_cmp() in contrib programs.
2499  Added -DPNG_CONFIGURE_LIBPNG to contrib/pngminm/*/makefile
2500  Changed png_check_sig() to !png_sig_cmp() in contrib programs.
2501  Corrected the png_get_IHDR() call in contrib/gregbook/readpng2.c
2502  Changed pngminim/*/gather.sh to stop trying to remove pnggccrd.c and pngvcrd.c
2503  Added dependency on pngpriv.h in contrib/pngminim/*/makefile
2504
2505Version 1.4.0beta96 [November 12, 2009]
2506  Renamed scripts/makefile.wce to scripts/makefile.cegcc
2507  Revised Makefile.am to use libpng.sys while building libpng.so
2508    so that only PNG_EXPORT functions are exported.
2509  Removed the deprecated png_check_sig() function/macro.
2510  Removed recently removed function names from scripts/*.def
2511  Revised pngtest.png to put chunks in the same order written by pngtest
2512    (evidently the same change made in libpng-1.0beta54 was lost).
2513  Added PNG_PRIVATE macro definition in pngconf.h for possible future use.
2514
2515Version 1.4.0beta97 [November 13, 2009]
2516  Restored pngtest.png to the libpng-1.4.0beta7 version.
2517  Removed projects/beos and netware.txt; no one seems to be supporting them.
2518  Revised Makefile.in
2519
2520Version 1.4.0beta98 [November 13, 2009]
2521  Added the "xcode" project to zip distributions,
2522  Fixed a typo in scripts/pngwin.def introduced in beta97.
2523
2524Version 1.4.0beta99 [November 14, 2009]
2525  Moved libpng-config.in and libpng.pc-configure.in out of the scripts
2526    directory, to libpng-config.in and libpng-pc.in, respectively, and
2527    modified Makefile.am and configure.ac accordingly.  Now "configure"
2528    needs nothing from the "scripts" directory.
2529  Avoid redefining PNG_CONST in pngconf.h
2530
2531Version 1.4.0beta100 [November 14, 2009]
2532  Removed ASM builds from projects/visualc6 and projects/visualc71
2533  Removed scripts/makefile.nommx and makefile.vcawin32
2534  Revised CMakeLists.txt to account for new location of libpng-config.in
2535    and libpng-pc.in
2536  Updated INSTALL to reflect removal and relocation of files.
2537
2538Version 1.4.0beta101 [November 14, 2009]
2539  Restored the binary files (*.jpg, *.png, some project files) that were
2540    accidentally deleted from the zip and 7z distributions when the xcode
2541    project was added.
2542
2543Version 1.4.0beta102 [November 18, 2009]
2544  Added libpng-config.in and libpng-pc.in to the zip and 7z distributions.
2545  Fixed a typo in projects/visualc6/pngtest.dsp, introduced in beta100.
2546  Moved descriptions of makefiles and other scripts out of INSTALL into
2547    scripts/README.txt
2548  Updated the copyright year in scripts/pngwin.rc from 2006 to 2009.
2549
2550Version 1.4.0beta103 [November 21, 2009]
2551  Removed obsolete comments about ASM from projects/visualc71/README_zlib.txt
2552  Align row_buf on 16-byte boundary in memory.
2553  Restored the PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED guard around the call
2554    to png_flush() after png_write_IEND().  See 1.4.0beta32, 1.4.0beta50
2555    changes above and 1.2.30, 1.2.30rc01 and rc03 in 1.2.41 CHANGES.  Someone
2556    needs this feature.
2557  Make the 'png_jmpbuf' macro expand to a call that records the correct
2558    longjmp function as well as returning a pointer to the setjmp
2559    jmp_buf buffer, and marked direct access to jmpbuf 'deprecated'.
2560    (John Bowler)
2561
2562Version 1.4.0beta104 [November 22, 2009]
2563  Removed png_longjmp_ptr from scripts/*.def and libpng.3
2564  Rebuilt configure scripts with autoconf-2.65
2565
2566Version 1.4.0beta105 [November 25, 2009]
2567  Use fast integer PNG_DIVIDE_BY_255() or PNG_DIVIDE_BY_65535()
2568    to accomplish alpha premultiplication when
2569    PNG_READ_COMPOSITE_NODIV_SUPPORTED is defined.
2570  Changed "/255" to "/255.0" in background calculations to make it clear
2571    that the 255 is used as a double.
2572
2573Version 1.4.0beta106 [November 27, 2009]
2574  Removed premultiplied alpha feature.
2575
2576Version 1.4.0beta107 [December 4, 2009]
2577  Updated README
2578  Added "#define PNG_NO_PEDANTIC_WARNINGS" in the libpng source files.
2579  Removed "-DPNG_CONFIGURE_LIBPNG" from the makefiles and projects.
2580  Revised scripts/makefile.netbsd, makefile.openbsd, and makefile.sco
2581    to put png.h and pngconf.h in $prefix/include, like the other scripts,
2582    instead of in $prefix/include/libpng.  Also revised makefile.sco
2583    to put them in $prefix/include/libpng15 instead of in
2584    $prefix/include/libpng/libpng15.
2585
2586Version 1.4.0beta108 [December 11, 2009]
2587  Removed leftover "-DPNG_CONFIGURE_LIBPNG" from contrib/pngminim/*/makefile
2588  Relocated png_do_chop() to its original position in pngrtran.c; the
2589    change in version 1.2.41beta08 caused transparency to be handled wrong
2590    in some 16-bit datastreams (Yusaku Sugai).
2591
2592Version 1.4.0beta109 [December 13, 2009]
2593  Added "bit_depth" parameter to the private png_build_gamma_table() function.
2594  Pass bit_depth=8 to png_build_gamma_table() when bit_depth is 16 but the
2595    PNG_16_TO_8 transform has been set, to avoid unnecessary build of 16-bit
2596    tables.
2597
2598Version 1.4.0rc02 [December 20, 2009]
2599  Declared png_cleanup_needed "volatile" in pngread.c and pngwrite.c
2600
2601Version 1.4.0rc03 [December 22, 2009]
2602  Renamed libpng-pc.in back to libpng.pc.in and revised CMakeLists.txt
2603    (revising the change in 1.4.0beta99)
2604
2605Version 1.4.0rc04 [December 25, 2009]
2606  Swapped PNG_UNKNOWN_CHUNKS_SUPPORTED and PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2607    in pngset.c to be consistent with other changes in version 1.2.38.
2608
2609Version 1.4.0rc05 [December 25, 2009]
2610  Changed "libpng-pc.in" to "libpng.pc.in" in configure.ac, configure, and
2611    Makefile.in to be consistent with changes in libpng-1.4.0rc03
2612
2613Version 1.4.0rc06 [December 29, 2009]
2614  Reverted the gamma_table changes from libpng-1.4.0beta109.
2615  Fixed some indentation errors.
2616
2617Version 1.4.0rc07 [January 1, 2010]
2618  Revised libpng*.txt and libpng.3 about 1.2.x->1.4.x differences.
2619  Use png_calloc() instead of png_malloc(); png_memset() in pngrutil.c
2620  Update copyright year to 2010.
2621
2622Version 1.4.0rc08 [January 2, 2010]
2623  Avoid deprecated references to png_ptr-io_ptr and png_ptr->error_ptr
2624    in pngtest.c
2625
2626Version 1.4.0 [January 3, 2010]
2627  No changes.
2628
2629Version 1.4.1beta01 [January 8, 2010]
2630  Updated CMakeLists.txt for consistent indentation and to avoid an
2631    unclosed if-statement warning (Philip Lowman).
2632  Revised Makefile.am and Makefile.in to remove references to Y2KINFO,
2633    KNOWNBUG, and libpng.la (Robert Schwebel).
2634  Revised the makefiles to install the same files and symbolic
2635    links as configure, except for libpng.la and libpng14.la.
2636  Make png_set|get_compression_buffer_size() available even when
2637    PNG_WRITE_SUPPORTED is not enabled.
2638  Revised Makefile.am and Makefile.in to simplify their maintenance.
2639  Revised scripts/makefile.linux to install a link to libpng14.so.14.1
2640
2641Version 1.4.1beta02 [January 9, 2010]
2642  Revised the rest of the makefiles to install a link to libpng14.so.14.1
2643
2644Version 1.4.1beta03 [January 10, 2010]
2645  Removed png_set_premultiply_alpha() from scripts/*.def
2646
2647Version 1.4.1rc01 [January 16, 2010]
2648  No changes.
2649
2650Version 1.4.1beta04 [January 23, 2010]
2651  Revised png_decompress_chunk() to improve speed and memory usage when
2652    decoding large chunks.
2653  Added png_set|get_chunk_malloc_max() functions.
2654
2655Version 1.4.1beta05 [January 26, 2010]
2656  Relocated "int k" declaration in pngtest.c to minimize its scope.
2657
2658Version 1.4.1beta06 [January 28, 2010]
2659  Revised png_decompress_chunk() to use a two-pass method suggested by
2660    John Bowler.
2661
2662Version 1.4.1beta07 [February 6, 2010]
2663  Folded some long lines in the source files.
2664  Added defineable PNG_USER_CHUNK_CACHE_MAX, PNG_USER_CHUNK_MALLOC_MAX,
2665    and a PNG_USER_LIMITS_SUPPORTED flag.
2666  Eliminated use of png_ptr->irowbytes and reused the slot in png_ptr as
2667    png_ptr->png_user_chunk_malloc_max.
2668  Revised png_push_save_buffer() to do fewer but larger png_malloc() calls.
2669
2670Version 1.4.1beta08 [February 6, 2010]
2671  Minor cleanup and updating of dates and copyright year.
2672
2673Version 1.5.0beta01 [February 7, 2010]
2674  Moved declaration of png_struct into private pngstruct.h and png_info
2675    into pnginfo.h
2676
2677Version 1.4.1beta09 and 1.5.0beta02 [February 7, 2010]
2678  Reverted to original png_push_save_buffer() code.
2679
2680Version 1.4.1beta10 and 1.5.0beta03 [February 8, 2010]
2681  Return allocated "old_buffer" in png_push_save_buffer() before
2682    calling png_error(), to avoid a potential memory leak.
2683  Updated configure script to use SO number 15.
2684
2685Version 1.5.0beta04 [February 9, 2010]
2686  Removed malformed "incomplete struct declaration" of png_info from png.h
2687
2688Version 1.5.0beta05 [February 12, 2010]
2689  Removed PNG_DEPSTRUCT markup in pngstruct.h and pnginfo.h, and undid the
2690    linewrapping that it entailed.
2691  Revised comments in pngstruct.h and pnginfo.h and added pointers to
2692    the libpng license.
2693  Changed PNG_INTERNAL to PNG_EXPOSE_INTERNAL_STRUCTURES
2694  Removed the cbuilder5 project, which has not been updated to 1.4.0.
2695
2696Version 1.4.1beta12 and 1.5.0beta06 [February 14, 2010]
2697  Fixed type declaration of png_get_chunk_malloc_max() in pngget.c (Daisuke
2698    Nishikawa)
2699
2700Version 1.5.0beta07 [omitted]
2701
2702Version 1.5.0beta08 [February 19, 2010]
2703  Changed #ifdef PNG_NO_STDIO_SUPPORTED to #ifdef PNG_NO_CONSOLE_IO_SUPPORTED
2704    wherever png_snprintf() is used to construct error and warning messages.
2705  Noted in scripts/makefile.mingw that it expects to be run under MSYS.
2706  Removed obsolete unused MMX-querying support from contrib/gregbook
2707  Added exported png_longjmp() function.
2708  Removed the AIX redefinition of jmpbuf in png.h
2709  Added -D_ALLSOURCE in configure.ac, makefile.aix, and CMakeLists.txt
2710    when building on AIX.
2711
2712Version 1.5.0beta09 [February 19, 2010]
2713  Removed -D_ALLSOURCE from configure.ac, makefile.aix, and CMakeLists.txt.
2714  Changed the name of png_ptr->jmpbuf to png_ptr->png_jmpbuf in pngstruct.h
2715
2716Version 1.5.0beta10 [February 25, 2010]
2717  Removed unused gzio.c from contrib/pngminim gather and makefile scripts
2718  Removed replacement error handlers from contrib/gregbook.  Because of
2719    the new png_longjmp() function they are no longer needed.
2720
2721Version 1.5.0beta11 [March 6, 2010]
2722  Removed checking for already-included setjmp.h from pngconf.h
2723  Fixed inconsistent indentations and made numerous cosmetic changes.
2724  Revised the "SEE ALSO" style of libpng.3, libpngpf.3, and png.5
2725
2726Version 1.5.0beta12 [March 9, 2010]
2727  Moved "#include png.h" inside pngpriv.h and removed "#include png.h" from
2728    the source files, along with "#define PNG_EXPOSE_INTERNAL_STRUCTURES"
2729    and "#define PNG_NO_PEDANTIC_WARNINGS" (John Bowler).
2730  Created new pngdebug.h and moved debug definitions there.
2731
2732Version 1.5.0beta13 [March 10, 2010]
2733  Protect pngstruct.h, pnginfo.h, and pngdebug.h from being included twice.
2734  Revise the "#ifdef" blocks in png_inflate() so it will compile when neither
2735    PNG_USER_CHUNK_MALLOC_MAX nor PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
2736    is defined.
2737  Removed unused png_measure_compressed_chunk() from pngpriv.h and libpngpf.3
2738  Moved the 'config.h' support from pngconf.h to pngpriv.h
2739  Removed PNGAPI from the png_longjmp_ptr typedef.
2740  Eliminated dependence of pngtest.c on the private pngdebug.h file.
2741  Make all png_debug macros into *unterminated* statements or
2742    expressions (i.e. a trailing ';' must always be added) and correct
2743    the format statements in various png_debug messages.
2744
2745Version 1.5.0beta14 [March 14, 2010]
2746  Removed direct access to png_ptr->io_ptr from the Windows code in pngtest.c
2747  Revised Makefile.am to account for recent additions and replacements.
2748  Corrected CE and OS/2 DEF files (scripts/png*def) for symbols removed and
2749    added ordinal numbers to the Windows DEF file and corrected the duplicated
2750    ordinal numbers on CE symbols that are commented out.
2751  Added back in export symbols that can be present in the Windows build but
2752    are disabled by default.
2753  PNG_EXPORT changed to include an 'ordinal' field for DEF file generation.
2754    PNG_CALLBACK added to make callback definitions uniform.  PNGAPI split
2755    into PNGCAPI (base C form), PNGAPI (exports) and PNGCBAPI (callbacks),
2756    and appropriate changes made to all files.  Cygwin builds re-hinged to
2757    allow procedure call standard changes and to remove the need for the DEF
2758    file (fixes build on Cygwin).
2759  Enabled 'attribute' warnings that are relevant to library APIs and callbacks.
2760  Changed rules for generation of the various symbol files and added a new
2761    rule for a DEF file (which is also added to the distribution).
2762  Updated the symbol file generation to stop it adding spurious spaces
2763    to EOL (coming from preprocessor macro expansion).  Added a facility
2764    to join tokens in the output and rewrite *.dfn to use this.
2765  Eliminated scripts/*.def in favor of libpng.def; updated projects/visualc71
2766    and removed scripts/makefile.cygwin.
2767  Made PNG_BUILD_DLL safe: it can be set whenever a DLL is being built.
2768  Removed the include of sys/types.h - apparently unnecessary now on the
2769    platforms on which it happened (all but Mac OS and RISC OS).
2770  Moved the Mac OS test into pngpriv.h (the only place it is used.)
2771
2772Version 1.5.0beta15 [March 17, 2010]
2773  Added symbols.chk target to Makefile.am to validate the symbols in png.h
2774    against the new DEF file scripts/symbols.def.
2775  Changed the default DEF file back to pngwin.def.
2776  Removed makefile.mingw.
2777  Eliminated PNG_NO_EXTERN and PNG_ALL_EXTERN
2778
2779Version 1.5.0beta16 [April 1, 2010]
2780  Make png_text_struct independent of PNG_iTXt_SUPPORTED, so that
2781    fields are initialized in all configurations.  The READ/WRITE
2782    macros (PNG_(READ|WRITE)_iTXt_SUPPORTED) still function as
2783    before to disable code to actually read or write iTXt chunks
2784    and iTXt_SUPPORTED can be used to detect presence of either
2785    read or write support (but it is probably better to check for
2786    the one actually required - read or write.)
2787  Combined multiple png_warning() calls for a single error.
2788  Restored the macro definition of png_check_sig().
2789
2790Version 1.5.0beta17 [April 17, 2010]
2791  Added some "(long)" typecasts to printf calls in png_handle_cHRM().
2792  Documented the fact that png_set_dither() was disabled since libpng-1.4.0.
2793  Reenabled png_set_dither() but renamed it to png_set_quantize() to reflect
2794    more accurately what it actually does.  At the same time, renamed
2795    the PNG_DITHER_[RED,GREEN_BLUE]_BITS macros to
2796    PNG_QUANTIZE_[RED,GREEN,BLUE]_BITS.
2797  Added some "(long)" typecasts to printf calls in png_handle_cHRM().
2798  Freeze build-time only configuration in the build.
2799    In all prior versions of libpng most configuration options
2800    controlled by compiler #defines had to be repeated by the
2801    application code that used libpng.  This patch changes this
2802    so that compilation options that can only be changed at build
2803    time are frozen in the build.  Options that are compiler
2804    dependent (and those that are system dependent) are evaluated
2805    each time - pngconf.h holds these.  Options that can be changed
2806    per-file in the application are in png.h.  Frozen options are
2807    in the new installed header file pnglibconf.h (John Bowler)
2808  Removed the xcode project because it has not been updated to work
2809    with libpng-1.5.0.
2810  Removed the ability to include optional pngusr.h
2811
2812Version 1.5.0beta18 [April 17, 2010]
2813  Restored the ability to include optional pngusr.h
2814  Moved replacements for png_error() and png_warning() from the
2815    contrib/pngminim project to pngerror.c, for use when warnings or
2816    errors are disabled via PNG_NO_WARN or PNG_NO_ERROR_TEXT, to avoid
2817    storing unneeded error/warning text.
2818  Updated contrib/pngminim project to work with the new pnglibconf.h
2819  Added some PNG_NO_* defines to contrib/pngminim/*/pngusr.h to save space.
2820
2821Version 1.5.0beta19 [April 24, 2010]
2822  Added PNG_{READ,WRITE}_INT_FUNCTIONS_SUPPORTED.  This allows the functions
2823    to read and write ints to be disabled independently of PNG_USE_READ_MACROS,
2824    which allows libpng to be built with the functions even though the default
2825    is to use the macros - this allows applications to choose at app build
2826    time whether or not to use macros (previously impossible because the
2827    functions weren't in the default build.)
2828  Changed Windows calling convention back to __cdecl for API functions.
2829    For Windows/x86 platforms only:
2830      __stdcall is no longer needed for Visual Basic, so libpng-1.5.0 uses
2831      __cdecl throughout (both API functions and callbacks) on Windows/x86
2832      platforms.
2833  Replaced visualc6 and visualc71 projects with new vstudio project
2834  Relaxed the overly-restrictive permissions of some files.
2835
2836Version 1.5.0beta20 [April 24, 2010]
2837  Relaxed more overly-restrictive permissions of some files.
2838
2839Version 1.5.0beta21 [April 27, 2010]
2840  Removed some unwanted binary bytes and changed CRLF to NEWLINE in the new
2841    vstudio project files, and some trivial editing of some files in the
2842    scripts directory.
2843  Set PNG_NO_READ_BGR, PNG_NO_IO_STATE, and PNG_NO_TIME_RFC1123 in
2844    contrib/pngminim/decoder/pngusr.h to make a smaller decoder application.
2845
2846Version 1.5.0beta22 [April 28, 2010]
2847  Fixed dependencies of GET_INT_32 - it does not require READ_INT_FUNCTIONS
2848    because it has a macro equivalent.
2849  Improved the options.awk script; added an "everything off" option.
2850  Revised contrib/pngminim to use the "everything off" option in pngusr.dfa.
2851
2852Version 1.5.0beta23 [April 29, 2010]
2853  Corrected PNG_REMOVED macro to take five arguments.
2854    The macro was documented with two arguments (name,ordinal), however
2855    the symbol checking .dfn files assumed five arguments.  The five
2856    argument form seems more useful so it is changed to that.
2857  Corrected PNG_UNKNOWN_CHUNKS_SUPPORTED to PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2858    in gregbook/readpng2.c
2859  Corrected protection of png_get_user_transform_ptr. The API declaration in
2860    png.h is removed if both READ and WRITE USER_TRANSFORM are turned off
2861    but was left defined in pngtrans.c
2862  Added logunsupported=1 to cause pnglibconf.h to document disabled options.
2863    This makes the installed pnglibconf.h more readable but causes no
2864    other change.  The intention is that users of libpng will find it
2865    easier to understand if an API they need is missing.
2866  Include png_reset_zstream() in png.c only when PNG_READ_SUPPORTED is defined.
2867  Removed dummy_inflate.c from contrib/pngminim/encoder
2868  Removed contrib/pngminim/*/gather.sh; gathering is now done in the makefile.
2869
2870Version 1.5.0beta24 [May 7, 2010]
2871  Use bitwise "&" instead of arithmetic mod in pngrutil.c calculation of the
2872    offset of the png_ptr->rowbuf pointer into png_ptr->big_row_buf.
2873  Added more blank lines for readability.
2874
2875Version 1.5.0beta25 [June 18, 2010]
2876  In pngpread.c: png_push_have_row() add check for new_row > height
2877  Removed the now-redundant check for out-of-bounds new_row from example.c
2878
2879Version 1.5.0beta26 [June 18, 2010]
2880  In pngpread.c: png_push_process_row() add check for too many rows.
2881
2882Version 1.5.0beta27 [June 18, 2010]
2883  Removed the check added in beta25 as it is now redundant.
2884
2885Version 1.5.0beta28 [June 20, 2010]
2886  Rewrote png_process_IDAT_data to consistently treat extra data as warnings
2887    and handle end conditions more cleanly.
2888  Removed the new (beta26) check in png_push_process_row().
2889
2890Version 1.5.0beta29 [June 21, 2010]
2891  Revised scripts/options.awk to work on Sunos (but still doesn't work)
2892  Added comment to options.awk and contrib/pngminim/*/makefile to try nawk.
2893
2894Version 1.5.0beta30 [June 22, 2010]
2895  Stop memory leak when reading a malformed sCAL chunk.
2896
2897Version 1.5.0beta31 [June 26, 2010]
2898  Revised pngpread.c patch of beta28 to avoid an endless loop.
2899  Removed some trailing blanks.
2900
2901Version 1.5.0beta32 [June 26, 2010]
2902  Removed leftover scripts/options.patch and scripts/options.rej
2903
2904Version 1.5.0beta33 [July 6, 3010]
2905  Made FIXED and FLOATING options consistent in the APIs they enable and
2906    disable.  Corrected scripts/options.awk to handle both command line
2907    options and options specified in the .dfa files.
2908  Changed char *msg to PNG_CONST char *msg in pngrutil.c
2909  Make png_set_sRGB_gAMA_and_cHRM set values using either the fixed or
2910    floating point APIs, but not both.
2911  Reversed patch to remove error handler when the jmp_buf is stored in the
2912    main program structure, not the png_struct.
2913    The error handler is needed because the default handler in libpng will
2914    always use the jmp_buf in the library control structure; this is never
2915    set.  The gregbook code is a useful example because, even though it
2916    uses setjmp/longjmp, it shows how error handling can be implemented
2917    using control mechanisms not directly supported by libpng.  The
2918    technique will work correctly with mechanisms such as Microsoft
2919    Structure Exceptions or C++ exceptions (compiler willing - note that gcc
2920    does not by default support interworking of C and C++ error handling.)
2921  Reverted changes to call png_longjmp in contrib/gregbook where it is not
2922    appropriate.  If mainprog->jmpbuf is used by setjmp, then png_longjmp
2923    cannot be used.
2924  Changed "extern PNG_EXPORT" to "PNG_EXPORT" in png.h (Jan Nijtmans)
2925  Changed "extern" to "PNG_EXTERN" in pngpriv.h (except for the 'extern "C" {')
2926
2927Version 1.5.0beta34 [July 12, 2010]
2928  Put #ifndef PNG_EXTERN, #endif around the define PNG_EXTERN in pngpriv.h
2929
2930Version 1.5.0beta35 [July 24, 2010]
2931  Removed some newly-added TAB characters.
2932  Added -DNO_PNG_SNPRINTF to CFLAGS in scripts/makefile.dj2
2933  Moved the definition of png_snprintf() outside of the enclosing
2934    #ifdef blocks in pngconf.h
2935
2936Version 1.5.0beta36 [July 29, 2010]
2937  Patches by John Bowler:
2938  Fixed point APIs are now supported throughout (no missing APIs).
2939  Internal fixed point arithmetic support exists for all internal floating
2940    point operations.
2941  sCAL validates the floating point strings it is passed.
2942  Safe, albeit rudimentary, Watcom support is provided by PNG_API_RULE==2
2943  Two new APIs exist to get the number of passes without turning on the
2944    PNG_INTERLACE transform and to get the number of rows in the current
2945    pass.
2946  A new test program, pngvalid.c, validates the gamma code.
2947  Errors in the 16-bit gamma correction (overflows) have been corrected.
2948  cHRM chunk testing is done consistently (previously the floating point
2949    API bypassed it, because the test really didn't work on FP, now the test
2950    is performed on the actual values to be stored in the PNG file so it
2951    works in the FP case too.)
2952  Most floating point APIs now simply call the fixed point APIs after
2953    converting the values to the fixed point form used in the PNG file.
2954  The standard headers no longer include zlib.h, which is currently only
2955    required for pngstruct.h and can therefore be internal.
2956  Revised png_get_int_32 to undo the PNG two's complement representation of
2957    negative numbers.
2958
2959Version 1.5.0beta37 [July 30, 2010]
2960  Added a typecast in png_get_int_32() in png.h and pngrutil.h to avoid
2961    a compiler warning.
2962  Replaced oFFs 0,0 with oFFs -10,20 in pngtest.png
2963
2964Version 1.5.0beta38 [July 31, 2010]
2965  Implemented remaining "_fixed" functions.
2966  Corrected a number of recently introduced warnings mostly resulting from
2967    safe but uncast assignments to shorter integers.  Also added a zlib
2968    VStudio release library project because the latest zlib Official Windows
2969    build does not include such a thing.
2970  Revised png_get_int_16() to be similar to png_get_int_32().
2971  Restored projects/visualc71.
2972
2973Version 1.5.0beta39 [August 2, 2010]
2974  VisualC/GCC warning fixes, VisualC build fixes
2975  The changes include support for function attributes in VC in addition to
2976    those already present in GCC - necessary because without these some
2977    warnings are unavoidable.  Fixes include signed/unsigned fixes in
2978    pngvalid and checks with gcc -Wall -Wextra -Wunused.
2979  VC requires function attributes on function definitions as well as
2980    declarations, PNG_FUNCTION has been added to enable this and the
2981    relevant function definitions changed.
2982
2983Version 1.5.0beta40 [August 6, 2010]
2984  Correct use of _WINDOWS_ in pngconf.h
2985  Removed png_mem_ #defines; they are no longer used.
2986  Added the sRGB chunk to pngtest.png
2987
2988Version 1.5.0beta41 [August 11, 2010]
2989  Added the cHRM chunk to pngtest.png
2990  Don't try to use version-script with cygwin/mingw.
2991  Revised contrib/gregbook to work under cygwin/mingw.
2992
2993Version 1.5.0beta42 [August 18, 2010]
2994  Add .dll.a to the list of extensions to be symlinked by Makefile.am (Yaakov)
2995  Made all API functions that have const arguments and constant string
2996    literal pointers declare them (John Bowler).
2997
2998Version 1.5.0beta43 [August 20, 2010]
2999  Removed spurious tabs, shorten long lines (no source change)
3000    Also added scripts/chkfmt to validate the format of all the files that can
3001    reasonably be validated (it is suggested to run "make distclean" before
3002    checking, because some machine generated files have long lines.)
3003  Reformatted the CHANGES file to be more consistent throughout.
3004  Made changes to address various issues identified by GCC, mostly
3005    signed/unsigned and shortening problems on assignment but also a few
3006    difficult to optimize (for GCC) loops.
3007  Fixed non-GCC fixed point builds.  In png.c a declaration was misplaced
3008    in an earlier update.  Fixed to declare the auto variables at the head.
3009  Use cexcept.h in pngvalid.c.
3010
3011Version 1.5.0beta44 [August 24, 2010]
3012  Updated CMakeLists.txt to use CMAKE_INSTALL_LIBDIR variable; useful for
3013    installing libpng in /usr/lib64 (Funda Wang).
3014  Revised CMakeLists.txt to put the man pages in share/man/man* not man/man*
3015  Revised CMakeLists.txt to make symlinks instead of copies when installing.
3016  Changed PNG_LIB_NAME from pngNN to libpngNN in CMakeLists.txt (Philip Lowman)
3017  Implemented memory checks within pngvalid
3018  Reformatted/rearranged pngvalid.c to assist use of progressive reader.
3019  Check interlaced images in pngvalid
3020  Clarified pngusr.h comments in pnglibconf.dfa
3021  Simplified the pngvalid error-handling code now that cexcept.h is in place.
3022  Implemented progressive reader in pngvalid.c for standard tests
3023  Implemented progressive read in pngvalid.c gamma tests
3024  Turn on progressive reader in pngvalid.c by default and tidy code.
3025
3026Version 1.5.0beta45 [August 26, 2010]
3027  Added an explicit make step to projects/vstudio for pnglibconf.h
3028    Also corrected zlib.vcxproj into which Visual Studio had introduced
3029    what it calls an "authoring error".  The change to make pnglibconf.h
3030    simply copies the file; in the future it may actually generate the
3031    file from scripts/pnglibconf.dfa as the other build systems do.
3032  Changed pngvalid to work when floating point APIs are disabled
3033  Renamed the prebuilt scripts/pnglibconf.h to scripts/pnglibconf.h.prebuilt
3034  Supply default values for PNG_USER_PRIVATEBUILD and PNG_USER_DLLFNAME_POSTFIX
3035    in pngpriv.h in case the user neglected to define them in their pngusr.h
3036
3037Version 1.5.0beta46 [August 28, 2010]
3038  Added new private header files to libpng_sources in CMakeLists.txt
3039  Added PNG_READ_16BIT, PNG_WRITE_16BIT, and PNG_16BIT options.
3040  Added reference to scripts/pnglibconf.h.prebuilt in the visualc71 project.
3041
3042Version 1.5.0beta47 [September 11, 2010]
3043  Fixed a number of problems with 64-bit compilation reported by Visual
3044    Studio 2010 (John Bowler).
3045
3046Version 1.5.0beta48 [October 4, 2010]
3047  Updated CMakeLists.txt (Philip Lowman).
3048  Revised autogen.sh to recognize and use $AUTOCONF, $AUTOMAKE, $AUTOHEADER,
3049    $AUTOPOINT, $ACLOCAL and $LIBTOOLIZE
3050  Fixed problem with symbols creation in Makefile.am which was assuming that
3051    all versions of ccp write to standard output by default (Martin Banky). The
3052    bug was introduced in libpng-1.2.9beta5.
3053  Removed unused mkinstalldirs.
3054
3055Version 1.5.0beta49 [October 8, 2010]
3056  Undid Makefile.am revision of 1.5.0beta48.
3057
3058Version 1.5.0beta50 [October 14, 2010]
3059  Revised Makefile.in to account for mkinstalldirs being removed.
3060  Added some "(unsigned long)" typecasts in printf statements in pngvalid.c.
3061  Suppressed a compiler warning in png_handle_sPLT().
3062  Check for out-of-range text compression mode in png_set_text().
3063
3064Version 1.5.0beta51 [October 15, 2010]
3065  Changed embedded dates to "(PENDING RELEASE) in beta releases (and future
3066    rc releases) to minimize the difference between releases.
3067
3068Version 1.5.0beta52 [October 16, 2010]
3069  Restored some of the embedded dates (in png.h, png.c, documentation, etc.)
3070
3071Version 1.5.0beta53 [October 18, 2010]
3072  Updated INSTALL to mention using "make maintainer-clean" and to remove
3073    obsolete statement about a custom ltmain.sh
3074  Disabled "color-tests" by default in Makefile.am so it will work with
3075    automake versions earlier than 1.11.1
3076  Use document name "libpng-manual.txt" instead of "libpng-<version>.txt"
3077    to simplify version differences.
3078  Removed obsolete remarks about setjmp handling from INSTALL.
3079  Revised and renamed the typedef in png.h and png.c that was designed
3080    to catch library and header mismatch.
3081
3082Version 1.5.0beta54 [November 10, 2010]
3083  Require 48 bytes, not 64 bytes, for big_row_buf in overflow checks.
3084  Used a consistent structure for the pngget.c functions.
3085
3086Version 1.5.0beta55 [November 21, 2010]
3087  Revised png_get_uint_32, png_get_int_32, png_get_uint_16 (Cosmin)
3088  Moved reading of file signature into png_read_sig (Cosmin)
3089  Fixed atomicity of chunk header serialization (Cosmin)
3090  Added test for io_state in pngtest.c (Cosmin)
3091  Added "#!/bin/sh" at the top of contrib/pngminim/*/gather.sh scripts.
3092  Changes to remove gcc warnings (John Bowler)
3093    Certain optional gcc warning flags resulted in warnings in libpng code.
3094    With these changes only -Wconversion and -Wcast-qual cannot be turned on.
3095    Changes are trivial rearrangements of code.  -Wconversion is not possible
3096    for pngrutil.c (because of the widespread use of += et al on variables
3097    smaller than (int) or (unsigned int)) and -Wcast-qual is not possible
3098    with pngwio.c and pngwutil.c because the 'write' callback and zlib
3099    compression both fail to declare their input buffers with 'const'.
3100
3101Version 1.5.0beta56 [December 7, 2010]
3102  Added the private PNG_UNUSED() macro definition in pngpriv.h.
3103  Added some commentary about PNG_EXPORT in png.h and pngconf.h
3104  Revised PNG_EXPORT() macro and added PNG_EXPORTA() macro, with the
3105    objective of simplifying and improving the cosmetic appearance of png.h.
3106  Fixed some incorrect "=" macro names in pnglibconf.dfa
3107  Included documentation of changes in 1.5.0 from 1.4.x in libpng-manual.txt
3108
3109Version 1.5.0beta57 [December 9, 2010]
3110  Documented the pngvalid gamma error summary with additional comments and
3111    print statements.
3112  Improved missing symbol handling in checksym.awk; symbols missing in both
3113    the old and new files can now be optionally ignored, treated as errors
3114    or warnings.
3115  Removed references to pngvcrd.c and pnggccrd.c from the vstudio project.
3116  Updated "libpng14" to "libpng15" in the visualc71 project.
3117  Enabled the strip16 tests in pngvalid.`
3118  Don't display test results (except PASS/FAIL) when running "make test".
3119    Instead put them in pngtest-log.txt
3120  Added "--with-zprefix=<string>" to configure.ac
3121  Updated the prebuilt configuration files to autoconf version 2.68
3122
3123Version 1.5.0beta58 [December 19, 2010]
3124  Fixed interlace image handling and add test cases (John Bowler)
3125  Fixed the clean rule in Makefile.am to remove pngtest-log.txt
3126  Made minor changes to work around warnings in gcc 3.4
3127
3128Version 1.5.0rc01 [December 27, 2010]
3129  No changes.
3130
3131Version 1.5.0rc02 [December 27, 2010]
3132  Eliminated references to the scripts/*.def files in project/visualc71.
3133
3134Version 1.5.0rc03 [December 28, 2010]
3135  Eliminated scripts/*.def and revised Makefile.am accordingly
3136
3137Version 1.5.0rc04 [December 29, 2010]
3138  Fixed bug in background transformation handling in pngrtran.c (it was
3139    looking for the flag in png_ptr->transformations instead of in
3140    png_ptr->flags) (David Raymond).
3141
3142Version 1.5.0rc05 [December 31, 2010]
3143  Fixed typo in a comment in CMakeLists.txt (libpng14 => libpng15) (Cosmin)
3144
3145Version 1.5.0rc06 [January 4, 2011]
3146  Changed the new configure option "zprefix=string" to "zlib-prefix=string"
3147
3148Version 1.5.0rc07 [January 4, 2011]
3149  Updated copyright year.
3150
3151Version 1.5.0 [January 6, 2011]
3152  No changes.
3153
3154version 1.5.1beta01 [January 8, 2011]
3155  Added description of png_set_crc_action() to the manual.
3156  Added a note in the manual that the type of the iCCP profile was changed
3157    from png_charpp to png_bytepp in png_get_iCCP().  This change happened
3158    in version 1.5.0beta36 but is not noted in the CHANGES.  Similarly,
3159    it was changed from png_charpp to png_const_bytepp in png_set_iCCP().
3160  Ensure that png_rgb_to_gray ignores palette mapped images, if libpng
3161    internally happens to call it with one, and fixed a failure to handle
3162    palette mapped images correctly.  This fixes CVE-2690.
3163
3164Version 1.5.1beta02 [January 14, 2011]
3165  Fixed a bug in handling of interlaced images (bero at arklinux.org).
3166  Updated CMakeLists.txt (Clifford Yapp)
3167
3168Version 1.5.1beta03 [January 14, 2011]
3169  Fixed typecasting of some png_debug() statements (Cosmin)
3170
3171Version 1.5.1beta04 [January 16, 2011]
3172  Updated documentation of png_set|get_tRNS() (Thomas Klausner).
3173  Mentioned in the documentation that applications must #include "zlib.h"
3174    if they need access to anything in zlib.h, and that a number of
3175    macros such as png_memset() are no longer accessible by applications.
3176  Corrected pngvalid gamma test "sample" function to access all of the color
3177    samples of each pixel, instead of sampling the red channel three times.
3178  Prefixed variable names index, div, exp, gamma with "png_" to avoid "shadow"
3179    warnings, and (mistakenly) changed png_exp() to exp().
3180
3181Version 1.5.1beta05 [January 16, 2011]
3182  Changed variable names png_index, png_div, png_exp, and png_gamma to
3183    char_index, divisor, exp_b10, and gamma_val, respectively, and
3184    changed exp() back to png_exp().
3185
3186Version 1.5.1beta06 [January 20, 2011]
3187  Prevent png_push_crc_skip() from hanging while reading an unknown chunk
3188    or an over-large compressed zTXt chunk with the progressive reader.
3189  Eliminated more GCC "shadow" warnings.
3190  Revised png_fixed() in png.c to avoid compiler warning about reaching the
3191    end without returning anything.
3192
3193Version 1.5.1beta07 [January 22, 2011]
3194  In the manual, describe the png_get_IHDR() arguments in the correct order.
3195  Added const_png_structp and const_png_infop types, and used them in
3196    prototypes for most png_get_*() functions.
3197
3198Version 1.5.1beta08 [January 23, 2011]
3199  Added png_get_io_chunk_type() and deprecated png_get_io_chunk_name()
3200  Added synopses for the IO_STATE functions and other missing synopses
3201    to the manual. Removed the synopses from libpngpf.3 because they
3202    were out of date and no longer useful.  Better information can be
3203    obtained by reading the prototypes and comments in pngpriv.h
3204  Attempted to fix cpp on Solaris with S. Studio 12 cc, fix build
3205    Added a make macro DFNCPP that is a CPP that will accept the tokens in
3206    a .dfn file and adds configure stuff to test for such a CPP.  ./configure
3207    should fail if one is not available.
3208  Corrected const_png_ in png.h to png_const_ to avoid polluting the namespace.
3209  Added png_get_current_row_number and png_get_current_pass_number for the
3210    benefit of the user transform callback.
3211  Added png_process_data_pause and png_process_data_skip for the benefit of
3212    progressive readers that need to stop data processing or want to optimize
3213    skipping of unread data (e.g., if the reader marks a chunk to be skipped.)
3214
3215Version 1.5.1beta09 [January 24, 2011]
3216  Enhanced pngvalid, corrected an error in gray_to_rgb, corrected doc error.
3217    pngvalid contains tests of transforms, which tests are currently disabled
3218    because they are incompletely tested.  gray_to_rgb was failing to expand
3219    the bit depth for smaller bit depth images; this seems to be a long
3220    standing error and resulted, apparently, in invalid output
3221    (CVE-2011-0408, CERT VU#643140).  The documentation did not accurately
3222    describe what libpng really does when converting RGB to gray.
3223
3224Version 1.5.1beta10 [January 27, 2010]
3225  Fixed incorrect examples of callback prototypes in the manual, that were
3226    introduced in libpng-1.0.0.
3227  In addition the order of the png_get_uint macros with respect to the
3228    relevant function definitions has been reversed.  This helps the
3229    preprocessing of the symbol files be more robust.  Furthermore, the
3230    symbol file preprocessing now uses -DPNG_NO_USE_READ_MACROS even when
3231    the library may actually be built with PNG_USE_READ_MACROS; this stops
3232    the read macros interfering with the symbol file format.
3233  Made the manual, synopses, and function prototypes use the function
3234    argument names file_gamma, int_file_gamma, and srgb_intent consistently.
3235
3236Version 1.5.1beta11 [January 28, 2011]
3237  Changed PNG_UNUSED from "param=param;" to "{if(param){}}".
3238  Corrected local variable type in new API png_process_data_skip()
3239    The type was self-evidently incorrect but only causes problems on 64-bit
3240    architectures.
3241  Added transform tests to pngvalid and simplified the arguments.
3242
3243Version 1.5.1rc01 [January 29, 2011]
3244  No changes.
3245
3246Version 1.5.1rc02 [January 31, 2011]
3247  Added a request in the manual that applications do not use "png_" or
3248    "PNG_" to begin any of their own symbols.
3249  Changed PNG_UNUSED to "(void)param;" and updated the commentary in pngpriv.h
3250
3251Version 1.5.1 [February 3, 2011]
3252  No changes.
3253
3254Version 1.5.2beta01 [February 13, 2011]
3255  More -Wshadow fixes for older gcc compilers.  Older gcc versions apparently
3256    check formal parameters names in function declarations (as well as
3257    definitions) to see if they match a name in the global namespace.
3258  Revised PNG_EXPORTA macro to not use an empty parameter, to accommodate the
3259    old VisualC++ preprocessor.
3260  Turned on interlace handling in png_read_png().
3261  Fixed gcc pedantic warnings.
3262  Handle longjmp in Cygwin.
3263  Fixed png_get_current_row_number() in the interlaced case.
3264  Cleaned up ALPHA flags and transformations.
3265  Implemented expansion to 16 bits.
3266
3267Version 1.5.2beta02 [February 19, 2011]
3268  Fixed mistake in the descriptions of user read_transform and write_transform
3269    function prototypes in the manual.  The row_info struct is png_row_infop.
3270  Reverted png_get_current_row_number() to previous (1.5.2beta01) behavior.
3271  Corrected png_get_current_row_number documentation
3272  Fixed the read/write row callback documentation.
3273    This documents the current behavior, where the callback is called after
3274    every row with information pertaining to the next row.
3275
3276Version 1.5.2beta03 [March 3, 2011]
3277  Fixed scripts/makefile.vcwin32
3278  Updated contrib/pngsuite/README to add the word "modify".
3279  Define PNG_ALLOCATED to blank when _MSC_VER<1300.
3280
3281Version 1.5.2rc01 [March 19, 2011]
3282  Define remaining attributes to blank when MSC_VER<1300.
3283  ifdef out mask arrays in pngread.c when interlacing is not supported.
3284
3285Version 1.5.2rc02 [March 22, 2011]
3286  Added a hint to try CPP=/bin/cpp if "cpp -E" fails in scripts/pnglibconf.mak
3287    and in contrib/pngminim/*/makefile, eg., on SunOS 5.10, and removed "strip"
3288    from the makefiles.
3289  Fixed a bug (present since libpng-1.0.7) that makes png_handle_sPLT() fail
3290    to compile when PNG_NO_POINTER_INDEXING is defined (Chubanov Kirill)
3291
3292Version 1.5.2rc03 [March 24, 2011]
3293  Don't include standard header files in png.h while building the symbol table,
3294    to avoid cpp failure on SunOS (introduced PNG_BUILDING_SYMBOL_TABLE macro).
3295
3296Version 1.5.2 [March 31, 2011]
3297  No changes.
3298
3299Version 1.5.3beta01 [April 1, 2011]
3300  Re-initialize the zlib compressor before compressing non-IDAT chunks.
3301  Added API functions (png_set_text_compression_level() and four others) to
3302    set parameters for zlib compression of non-IDAT chunks.
3303
3304Version 1.5.3beta02 [April 3, 2011]
3305  Updated scripts/symbols.def with new API functions.
3306  Only compile the new zlib re-initializing code when text or iCCP is
3307    supported, using PNG_WRITE_COMPRESSED_TEXT_SUPPORTED macro.
3308  Improved the optimization of the zlib CMF byte (see libpng-1.2.6beta03).
3309  Optimize the zlib CMF byte in non-IDAT compressed chunks
3310
3311Version 1.5.3beta03 [April 16, 2011]
3312  Fixed gcc -ansi -pedantic compile. A strict ANSI system does not have
3313    snprintf, and the "__STRICT_ANSI__" detects that condition more reliably
3314    than __STDC__ (John Bowler).
3315  Removed the PNG_PTR_NORETURN attribute because it too dangerous. It tells
3316    the compiler that a user supplied callback (the error handler) does not
3317    return, yet there is no guarantee in practice that the application code
3318    will correctly implement the error handler because the compiler only
3319    issues a warning if there is a mistake (John Bowler).
3320  Removed the no-longer-used PNG_DEPSTRUCT macro.
3321  Updated the zlib version to 1.2.5 in the VStudio project.
3322  Fixed 64-bit builds where png_uint_32 is smaller than png_size_t in
3323    pngwutil.c (John Bowler).
3324  Fixed bug with stripping the filler or alpha channel when writing, that
3325    was introduced in libpng-1.5.2beta01 (bug report by Andrew Church).
3326
3327Version 1.5.3beta04 [April 27, 2011]
3328  Updated pngtest.png with the new zlib CMF optimization.
3329  Cleaned up conditional compilation code and of background/gamma handling
3330    Internal changes only except a new option to avoid compiling the
3331    png_build_grayscale_palette API (which is not used at all internally.)
3332    The main change is to move the transform tests (READ_TRANSFORMS,
3333    WRITE_TRANSFORMS) up one level to the caller of the APIs.  This avoids
3334    calls to spurious functions if all transforms are disabled and slightly
3335    simplifies those functions.  Pngvalid modified to handle this.
3336    A minor change is to stop the strip_16 and expand_16 interfaces from
3337    disabling each other; this allows the future alpha premultiplication
3338    code to use 16-bit intermediate values while still producing 8-bit output.
3339    png_do_background and png_do_gamma have been simplified to take a single
3340    pointer to the png_struct rather than pointers to every item required
3341    from the png_struct. This makes no practical difference to the internal
3342    code.
3343  A serious bug in the pngvalid internal routine 'standard_display_init' has
3344    been fixed - this failed to initialize the red channel and accidentally
3345    initialized the alpha channel twice.
3346  Changed png_struct jmp_buf member name from png_jmpbuf to tmp_jmpbuf to
3347    avoid a possible clash with the png_jmpbuf macro on some platforms.
3348
3349Version 1.5.3beta05 [May 6, 2011]
3350  Added the "_POSIX_SOURCE" feature test macro to ensure libpng sees the
3351    correct API. _POSIX_SOURCE is defined in pngpriv.h, pngtest.c and
3352    pngvalid.c to ensure that POSIX conformant systems disable non-POSIX APIs.
3353  Removed png_snprintf and added formatted warning messages.  This change adds
3354    internal APIs to allow png_warning messages to have parameters without
3355    requiring the host OS to implement snprintf.  As a side effect the
3356    dependency of the tIME-supporting RFC1132 code on stdio is removed and
3357    PNG_NO_WARNINGS does actually work now.
3358  Pass "" instead of '\0' to png_default_error() in png_err().  This mistake
3359    was introduced in libpng-1.2.20beta01.  This fixes CVE-2011-2691.
3360  Added PNG_WRITE_OPTIMIZE_CMF_SUPPORTED macro to make the zlib "CMF" byte
3361    optimization configurable.
3362  IDAT compression failed if preceded by a compressed text chunk (bug
3363    introduced in libpng-1.5.3beta01-02).  This was because the attempt to
3364    reset the zlib stream in png_write_IDAT happened after the first IDAT
3365    chunk had been deflated - much too late.  In this change internal
3366    functions were added to claim/release the z_stream and, hopefully, make
3367    the code more robust.  Also deflateEnd checking is added - previously
3368    libpng would ignore an error at the end of the stream.
3369
3370Version 1.5.3beta06 [May 8, 2011]
3371  Removed the -D_ALL_SOURCE from definitions for AIX in CMakeLists.txt
3372  Implemented premultiplied alpha support: png_set_alpha_mode API
3373
3374Version 1.5.3beta07 [May 11, 2011]
3375  Added expand_16 support to the high level interface.
3376  Added named value and 'flag' gamma support to png_set_gamma.  Made a minor
3377    change from the previous (unreleased) ABI/API to hide the exact value used
3378    for Macs - it's not a good idea to embed this in the ABI!
3379  Moved macro definitions for PNG_HAVE_IHDR, PNG_HAVE_PLTE, and PNG_AFTER_IDAT
3380    from pngpriv.h to png.h because they must be visible to applications
3381    that call png_set_unknown_chunks().
3382  Check for up->location !PNG_AFTER_IDAT when writing unknown chunks
3383    before IDAT.
3384
3385Version 1.5.3beta08 [May 16, 2011]
3386  Improved "pngvalid --speed" to exclude more of pngvalid from the time.
3387  Documented png_set_alpha_mode(), other changes in libpng.3/libpng-manual.txt
3388  The cHRM chunk now sets the defaults for png_set_rgb_to_gray() (when negative
3389    parameters are supplied by the caller), while in the absence of cHRM
3390    sRGB/Rec 709 values are still used.  This introduced a divide-by-zero
3391    bug in png_handle_cHRM().
3392  The bKGD chunk no longer overwrites the background value set by
3393    png_set_background(), allowing the latter to be used before the file
3394    header is read. It never performed any useful function to override
3395    the default anyway.
3396  Added memory overwrite and palette image checks to pngvalid.c
3397    Previously palette image code was poorly checked. Since the transformation
3398    code has a special palette path in most cases this was a severe weakness.
3399  Minor cleanup and some extra checking in pngrutil.c and pngrtran.c. When
3400    expanding an indexed image, always expand to RGBA if transparency is
3401    present.
3402
3403Version 1.5.3beta09 [May 17, 2011]
3404  Reversed earlier 1.5.3 change of transformation order; move png_expand_16
3405    back where it was.  The change doesn't work because it requires 16-bit
3406    gamma tables when the code only generates 8-bit ones.  This fails
3407    silently; the libpng code just doesn't do any gamma correction.  Moving
3408    the tests back leaves the old, inaccurate, 8-bit gamma calculations, but
3409    these are clearly better than none!
3410
3411Version 1.5.3beta10 [May 20, 2011]
3412
3413  png_set_background() and png_expand_16() did not work together correctly.
3414    This problem is present in 1.5.2; if png_set_background is called with
3415    need_expand false and the matching 16 bit color libpng erroneously just
3416    treats it as an 8-bit color because of where png_do_expand_16 is in the
3417    transform list.  This simple fix reduces the supplied colour to 8-bits,
3418    so it gets smashed, but this is better than the current behavior.
3419  Added tests for expand16, more fixes for palette image tests to pngvalid.
3420    Corrects the code for palette image tests and disables attempts to
3421    validate palette colors.
3422
3423Version 1.5.3rc01 [June 3, 2011]
3424  No changes.
3425
3426Version 1.5.3rc02 [June 8, 2011]
3427  Fixed uninitialized memory read in png_format_buffer() (Bug report by
3428    Frank Busse, CVE-2011-2501, related to CVE-2004-0421).
3429
3430Version 1.5.3beta11 [June 11, 2011]
3431  Fixed png_handle_sCAL which is broken in 1.5. This fixes CVE 2011-2692.
3432  Added sCAL to pngtest.png
3433  Revised documentation about png_set_user_limits() to say that it also affects
3434    png writing.
3435  Revised handling of png_set_user_limits() so that it can increase the
3436    limit beyond the PNG_USER_WIDTH|HEIGHT_MAX; previously it could only
3437    reduce it.
3438  Make the 16-to-8 scaling accurate. Dividing by 256 with no rounding is
3439    wrong (high by one) 25% of the time. Dividing by 257 with rounding is
3440    wrong in 128 out of 65536 cases. Getting the right answer all the time
3441    without division is easy.
3442  Added "_SUPPORTED" to the PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION macro.
3443  Added projects/owatcom, an IDE project for OpenWatcom to replace
3444    scripts/makefile.watcom.  This project works with OpenWatcom 1.9. The
3445    IDE autogenerates appropriate makefiles (libpng.mk) for batch processing.
3446    The project is configurable, unlike the Visual Studio project, so long
3447    as the developer has an awk.
3448  Changed png_set_gAMA to limit the gamma value range so that the inverse
3449    of the stored value cannot overflow the fixed point representation,
3450    and changed other things OpenWatcom warns about.
3451  Revised pngvalid.c to test PNG_ALPHA_MODE_SUPPORTED correctly. This allows
3452    pngvalid to build when ALPHA_MODE is not supported, which is required if
3453    it is to build on libpng 1.4.
3454  Removed string/memory macros that are no longer used and are not
3455    necessarily fully supportable, particularly png_strncpy and png_snprintf.
3456  Added log option to pngvalid.c and attempted to improve gamma messages.
3457
3458Version 1.5.3 [omitted]
3459  People found the presence of a beta release following an rc release
3460    to be confusing; therefore we bump the version to libpng-1.5.4beta01
3461    and there will be no libpng-1.5.3 release.
3462
3463Version 1.5.4beta01 [June 14, 2011]
3464  Made it possible to undefine PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
3465    to get the same (inaccurate) output as libpng-1.5.2 and earlier.
3466  Moved definitions of PNG_HAVE_IHDR, PNG_AFTER_IDAT, and PNG_HAVE_PLTE
3467    outside of an unknown-chunk block in png.h because they are also
3468    needed for other uses.
3469
3470Version 1.5.4beta02 [June 14, 2011]
3471  Fixed and clarified LEGACY 16-to-8 scaling code.
3472  Added png_set_chop_16() API, to match inaccurate results from previous
3473    libpng versions.
3474  Removed the ACCURATE and LEGACY options (they are no longer useable)
3475  Use the old scaling method for background if png_set_chop_16() was
3476    called.
3477  Made png_set_chop_16() API removeable by disabling PNG_CHOP_16_TO_8_SUPPORTED
3478
3479Version 1.5.4beta03 [June 15, 2011]
3480  Fixed a problem in png_do_expand_palette() exposed by optimization in
3481    1.5.3beta06
3482  Also removed a spurious and confusing "trans" member ("trans") from png_info.
3483  The palette expand optimization prevented expansion to an intermediate RGBA
3484    form if tRNS was present but alpha was marked to be stripped; this exposed
3485    a check for tRNS in png_do_expand_palette() which is inconsistent with the
3486    code elsewhere in libpng.
3487  Correction to the expand_16 code; removed extra instance of
3488    png_set_scale_16_to_8 from pngpriv.h
3489
3490Version 1.5.4beta04 [June 16, 2011]
3491  Added a missing "#ifdef PNG_READ_BACKGROUND_SUPPORTED/#endif" in pngrtran.c
3492  Added PNG_TRANSFORM_CHOP_16 to the high-level read transforms.
3493  Made PNG_READ_16_TO_8_ACCURATE_SCALE configurable again.  If this is
3494    not enabled, png_set_strip_16() and png_do_scale_16_to_8() aren't built.
3495  Revised contrib/visupng, gregbook, and pngminim to demonstrate chop_16_to_8
3496
3497Version 1.5.4beta05 [June 16, 2011]
3498  Renamed png_set_strip_16() to png_set_scale_16() and renamed
3499    png_set_chop_16() to png_set_strip(16) in an attempt to minimize the
3500    behavior changes between libpng14 and libpng15.
3501
3502Version 1.5.4beta06 [June 18, 2011]
3503  Fixed new bug that was causing both strip_16 and scale_16 to be applied.
3504
3505Version 1.5.4beta07 [June 19, 2011]
3506  Fixed pngvalid, simplified macros, added checking for 0 in sCAL.
3507    The ACCURATE scale macro is no longer defined in 1.5 - call the
3508    png_scale_16_to_8 API.  Made sure that PNG_READ_16_TO_8 is still defined
3509    if the png_strip_16_to_8 API is present.  png_check_fp_number now
3510    maintains some state so that positive, negative and zero values are
3511    identified.  sCAL uses these to be strictly spec conformant.
3512
3513Version 1.5.4beta08 [June 23, 2011]
3514  Fixed pngvalid if ACCURATE_SCALE is defined.
3515  Updated scripts/pnglibconf.h.prebuilt.
3516
3517Version 1.5.4rc01 [June 30, 2011]
3518  Define PNG_ALLOCATED to "restrict" only if MSC_VER >= 1400.
3519
3520Version 1.5.4 [July 7, 2011]
3521  No changes.
3522
3523Version 1.5.5beta01 [July 13, 2011]
3524  Fixed some typos and made other minor changes in the manual.
3525  Updated contrib/pngminus/makefile.std (Samuli Souminen)
3526
3527Version 1.5.5beta02 [July 14, 2011]
3528  Revised Makefile.am and Makefile.in to look in the right directory for
3529    pnglibconf.h.prebuilt
3530
3531Version 1.5.5beta03 [July 27, 2011]
3532  Enabled compilation with g++ compiler.  This compiler does not recognize
3533    the file extension, so it always compiles with C++ rules.  Made minor
3534    changes to pngrutil.c to cast results where C++ expects it but C does not.
3535  Minor editing of libpng.3 and libpng-manual.txt.
3536
3537Version 1.5.5beta04 [July 29, 2011]
3538  Revised CMakeLists.txt (Clifford Yapp)
3539  Updated commentary about the png_rgb_to_gray() default coefficients
3540    in the manual and in pngrtran.c
3541
3542Version 1.5.5beta05 [August 17, 2011]
3543  Prevent unexpected API exports from non-libpng DLLs on Windows.  The "_DLL"
3544    is removed from the test of whether a DLL is being built (this erroneously
3545    caused the libpng APIs to be marked as DLL exports in static builds under
3546    Microsoft Visual Studio).  Almost all of the libpng building configuration
3547    is moved from pngconf.h to pngpriv.h, but PNG_DLL_EXPORT remains in
3548    pngconf.h, though, so that it is colocated with the import definition (it
3549    is no longer used anywhere in the installed headers).  The VStudio project
3550    definitions have been cleaned up: "_USRDLL" has been removed from the
3551    static library builds (this was incorrect), and PNG_USE_DLL has been added
3552    to pngvalid to test the functionality (pngtest does not supply it,
3553    deliberately).  The spurious "_EXPORTS" has been removed from the
3554    libpng build (all these errors were a result of copy/paste between project
3555    configurations.)
3556  Added new types and internal functions for CIE RGB end point handling to
3557    pngpriv.h (functions yet to be implemented).
3558
3559Version 1.5.5beta06 [August 26, 2011]
3560  Ensure the CMAKE_LIBRARY_OUTPUT_DIRECTORY is set in CMakeLists.txt
3561    (Clifford Yap)
3562  Fixes to rgb_to_gray and cHRM XYZ APIs (John Bowler):
3563    The rgb_to_gray code had errors when combined with gamma correction.
3564    Some pixels were treated as true grey when they weren't and such pixels
3565    and true grey ones were not gamma corrected (the original value of the
3566    red component was used instead).  APIs to get and set cHRM using color
3567    space end points have been added and the rgb_to_gray code that defaults
3568    based on cHRM, and the divide-by-zero bug in png_handle_cHRM (CERT
3569    VU#477046, CVE-2011-3328, introduced in 1.5.4) have been corrected.
3570  A considerable number of tests has been added to pngvalid for the
3571    rgb_to_gray transform.
3572  Arithmetic errors in rgb_to_gray whereby the calculated gray value was
3573    truncated to the bit depth rather than rounded have been fixed except in
3574    the 8-bit non-gamma-corrected case (where consistency seems more important
3575    than correctness.)  The code still has considerable inaccuracies in the
3576    8-bit case because 8-bit linear arithmetic is used.
3577
3578Version 1.5.5beta07 [September 7, 2011]
3579  Added "$(ARCH)" option to makefile.darwin
3580  Added SunOS support to configure.ac and Makefile.am
3581  Changed png_chunk_benign_error() to png_warning() in png.c, in
3582    png_XYZ_from_xy_checked().
3583
3584Version 1.5.5beta08 [September 10, 2011]
3585  Fixed 64-bit compilation errors (gcc). The errors fixed relate
3586    to conditions where types that are 32 bits in the GCC 32-bit
3587    world (uLong and png_size_t) become 64 bits in the 64-bit
3588    world.  This produces potential truncation errors which the
3589    compiler correctly flags.
3590  Relocated new HAVE_SOLARIS_LD definition in configure.ac
3591  Constant changes for 64-bit compatibility (removal of L suffixes). The
3592    16-bit cases still use "L" as we don't have a 16-bit test system.
3593
3594Version 1.5.5rc01 [September 15, 2011]
3595  Removed "L" suffixes in pngpriv.h
3596
3597Version 1.5.5 [September 22, 2011]
3598  No changes.
3599
3600Version 1.5.6beta01 [September 22, 2011]
3601  Fixed some 64-bit type conversion warnings in pngrtran.c
3602  Moved row_info from png_struct to a local variable.
3603  The various interlace mask arrays have been made into arrays of
3604    bytes and made PNG_CONST and static (previously some arrays were
3605    marked PNG_CONST and some weren't).
3606  Additional checks have been added to the transform code to validate the
3607    pixel depths after the transforms on both read and write.
3608  Removed some redundant code from pngwrite.c, in png_destroy_write_struct().
3609  Changed chunk reading/writing code to use png_uint_32 instead of png_byte[4].
3610    This removes the need to allocate temporary strings for chunk names on
3611    the stack in the read/write code.  Unknown chunk handling still uses the
3612    string form because this is exposed in the API.
3613
3614Version 1.5.6beta02 [September 26, 2011]
3615  Added a note in the manual the png_read_update_info() must be called only
3616    once with a particular info_ptr.
3617  Fixed a typo in the definition of the new PNG_STRING_FROM_CHUNK(s,c) macro.
3618
3619Version 1.5.6beta03 [September 28, 2011]
3620  Revised test-pngtest.sh to report FAIL when pngtest fails.
3621  Added "--strict" option to pngtest, to report FAIL when the failure is
3622    only because the resulting valid files are different.
3623  Revised CMakeLists.txt to work with mingw and removed some material from
3624    CMakeLists.txt that is no longer useful in libpng-1.5.
3625
3626Version 1.5.6beta04 [October 5, 2011]
3627  Fixed typo in Makefile.in and Makefile.am ("-M Wl" should be "-M -Wl")."
3628
3629Version 1.5.6beta05 [October 12, 2011]
3630  Speed up png_combine_row() for interlaced images. This reduces the generality
3631    of the code, allowing it to be optimized for Adam7 interlace.  The masks
3632    passed to png_combine_row() are now generated internally, avoiding
3633    some code duplication and localizing the interlace handling somewhat.
3634  Align png_struct::row_buf - previously it was always unaligned, caused by
3635    a bug in the code that attempted to align it; the code needs to subtract
3636    one from the pointer to take account of the filter byte prepended to
3637    each row.
3638  Optimized png_combine_row() when rows are aligned. This gains a small
3639    percentage for 16-bit and 32-bit pixels in the typical case where the
3640    output row buffers are appropriately aligned. The optimization was not
3641    previously possible because the png_struct buffer was always misaligned.
3642  Fixed bug in png_write_chunk_header() debug print, introduced in 1.5.6beta01.
3643
3644Version 1.5.6beta06 [October 17, 2011]
3645  Removed two redundant tests for uninitialized row.
3646  Fixed a relatively harmless memory overwrite in compressed text writing
3647    with a 1 byte zlib buffer.
3648  Add ability to call png_read_update_info multiple times to pngvalid.c.
3649  Fixes for multiple calls to png_read_update_info. These fixes attend to
3650    most of the errors revealed in pngvalid, however doing the gamma work
3651    twice results in inaccuracies that can't be easily fixed.  There is now
3652    a warning in the code if this is going to happen.
3653  Turned on multiple png_read_update_info in pngvalid transform tests.
3654  Prevent libpng from overwriting unused bits at the end of the image when
3655    it is not byte aligned, while reading. Prior to libpng-1.5.6 libpng would
3656    overwrite the partial byte at the end of each row if the row width was not
3657    an exact multiple of 8 bits and the image is not interlaced.
3658
3659Version 1.5.6beta07 [October 21, 2011]
3660  Made png_ptr->prev_row an aligned pointer into png_ptr->big_prev_row
3661    (Mans Rullgard).
3662
3663Version 1.5.6rc01 [October 26, 2011]
3664  Changed misleading "Missing PLTE before cHRM" warning to "Out of place cHRM"
3665
3666Version 1.5.6rc02 [October 27, 2011]
3667  Added LSR() macro to defend against buggy compilers that evaluate non-taken
3668    code branches and complain about out-of-range shifts.
3669
3670Version 1.5.6rc03 [October 28, 2011]
3671  Renamed the LSR() macro to PNG_LSR() and added PNG_LSL() macro.
3672  Fixed compiler warnings with Intel and MSYS compilers. The logical shift
3673    fix for Microsoft Visual C is required by other compilers, so this
3674    enables that fix for all compilers when using compile-time constants.
3675    Under MSYS 'byte' is a name declared in a system header file, so we
3676    changed the name of a local variable to avoid the warnings that result.
3677  Added #define PNG_ALIGN_TYPE PNG_ALIGN_NONE to contrib/pngminim/*/pngusr.h
3678
3679Version 1.5.6 [November 3, 2011]
3680  No changes.
3681
3682Version 1.5.7beta01 [November 4, 2011]
3683  Added support for ARM processor, when decoding all PNG up-filtered rows
3684    and any other-filtered rows with 3 or 4 bytes per pixel (Mans Rullgard).
3685  Fixed bug in pngvalid on early allocation failure; fixed type cast in
3686    pngmem.c; pngvalid would attempt to call png_error() if the allocation
3687    of a png_struct or png_info failed. This would probably have led to a
3688    crash.  The pngmem.c implementation of png_malloc() included a cast
3689    to png_size_t which would fail on large allocations on 16-bit systems.
3690  Fix for the preprocessor of the Intel C compiler. The preprocessor
3691    splits adjacent @ signs with a space; this changes the concatenation
3692    token from @-@-@ to PNG_JOIN; that should work with all compiler
3693    preprocessors.
3694  Paeth filter speed improvements from work by Siarhei Siamashka. This
3695    changes the 'Paeth' reconstruction function to improve the GCC code
3696    generation on x86. The changes are only part of the suggested ones;
3697    just the changes that definitely improve speed and remain simple.
3698    The changes also slightly increase the clarity of the code.
3699
3700Version 1.5.7beta02 [November 11, 2011]
3701  Check compression_type parameter in png_get_iCCP and remove spurious
3702    casts. The compression_type parameter is always assigned to, so must
3703    be non-NULL. The cast of the profile length potentially truncated the
3704    value unnecessarily on a 16-bit int system, so the cast of the (byte)
3705    compression type to (int) is specified by ANSI-C anyway.
3706  Fixed FP division by zero in pngvalid.c; the 'test_pixel' code left
3707    the sBIT fields in the test pixel as 0, which resulted in a floating
3708    point division by zero which was irrelevant but causes systems where
3709    FP exceptions cause a crash. Added code to pngvalid to turn on FP
3710    exceptions if the appropriate glibc support is there to ensure this is
3711    tested in the future.
3712  Updated scripts/pnglibconf.mak and scripts/makefile.std to handle the
3713    new PNG_JOIN macro.
3714  Added versioning to pnglibconf.h comments.
3715  Simplified read/write API initial version; basic read/write tested on
3716    a variety of images, limited documentation (in the header file.)
3717  Installed more accurate linear to sRGB conversion tables. The slightly
3718    modified tables reduce the number of 16-bit values that
3719    convert to an off-by-one 8-bit value.  The "makesRGB.c" code that was used
3720    to generate the tables is now in a contrib/sRGBtables sub-directory.
3721
3722Version 1.5.7beta03 [November 17, 2011]
3723  Removed PNG_CONST from the sRGB table declarations in pngpriv.h and png.c
3724  Added run-time detection of NEON support.
3725  Added contrib/libtests; includes simplified API test and timing test and
3726    a color conversion utility for rapid checking of failed 'pngstest' results.
3727  Multiple transform bug fixes plus a work-round for double gamma correction.
3728    libpng does not support more than one transform that requires linear data
3729    at once - if this is tried typically the results is double gamma
3730    correction. Since the simplified APIs can need rgb to gray combined with
3731    a compose operation it is necessary to do one of these outside the main
3732    libpng transform code. This check-in also contains fixes to various bugs
3733    in the simplified APIs themselves and to some bugs in compose and rgb to
3734    gray (on palette) itself.
3735  Fixes for C++ compilation using g++ When libpng source is compiled
3736    using g++. The compiler imposes C++ rules on the C source; thus it
3737    is desirable to make the source work with either C or C++ rules
3738    without throwing away useful error information.  This change adds
3739    png_voidcast to allow C semantic (void*) cases or the corresponding
3740    C++ static_cast operation, as appropriate.
3741  Added --noexecstack to assembler file compilation. GCC does not set
3742    this on assembler compilation, even though it does on C compilation.
3743    This creates security issues if assembler code is enabled; the
3744    work-around is to set it by default in the flags for $(CCAS)
3745  Work around compilers that don't support declaration of const data. Some
3746    compilers fault 'extern const' data declarations (because the data is
3747    not initialized); this turns on const-ness only for compilers where
3748    this is known to work.
3749
3750Version 1.5.7beta04 [November 17, 2011]
3751  Since the gcc driver does not recognize the --noexecstack flag, we must
3752    use the -Wa prefix to have it passed through to the assembler.
3753    Also removed a duplicate setting of this flag.
3754  Added files that were omitted from the libpng-1.5.7beta03 zip distribution.
3755
3756Version 1.5.7beta05 [November 25, 2011]
3757  Removed "zTXt" from warning in generic chunk decompression function.
3758  Validate time settings passed to png_set_tIME() and png_convert_to_rfc1123()
3759    (Frank Busse). Note: This prevented CVE-2015-7981 from affecting
3760    libpng-1.5.7 and later.
3761  Added MINGW support to CMakeLists.txt
3762  Reject invalid compression flag or method when reading the iTXt chunk.
3763  Backed out 'simplified' API changes. The API seems too complex and there
3764    is a lack of consensus or enthusiasm for the proposals.  The API also
3765    reveals significant bugs inside libpng (double gamma correction and the
3766    known bug of being unable to retrieve a corrected palette). It seems
3767    better to wait until the bugs, at least, are corrected.
3768  Moved pngvalid.c into contrib/libtests
3769  Rebuilt Makefile.in, configure, etc., with autoconf-2.68
3770
3771Version 1.5.7rc01 [December 1, 2011]
3772  Replaced an "#if" with "#ifdef" in pngrtran.c
3773  Revised #if PNG_DO_BC block in png.c (use #ifdef and add #else)
3774
3775Version 1.5.7rc02 [December 5, 2011]
3776  Revised project files and contrib/pngvalid/pngvalid.c to account for
3777    the relocation of pngvalid into contrib/libtests.
3778  Revised pngconf.h to use " __declspec(restrict)" only when MSC_VER >= 1400,
3779    as in libpng-1.5.4.
3780  Put CRLF line endings in the owatcom project files.
3781
3782Version 1.5.7rc03 [December 7, 2011]
3783  Updated CMakeLists.txt to account for the relocation of pngvalid.c
3784
3785Version 1.5.7 [December 15, 2011]
3786  Minor fixes to pngvalid.c for gcc 4.6.2 compatibility to remove warnings
3787    reported by earlier versions.
3788  Fixed minor memset/sizeof errors in pngvalid.c.
3789
3790Version 1.6.0beta01 [December 15, 2011]
3791  Removed machine-generated configure files from the GIT repository (they will
3792    continue to appear in the tarball distributions and in the libpng15 and
3793    earlier GIT branches).
3794  Restored the new 'simplified' API, which was started in libpng-1.5.7beta02
3795    but later deleted from libpng-1.5.7beta05.
3796  Added example programs for the new 'simplified' API.
3797  Added ANSI-C (C90) headers and require them, and take advantage of the
3798    change. Also fixed some of the projects/* and contrib/* files that needed
3799    updates for libpng16 and the move of pngvalid.c.
3800    With this change the required ANSI-C header files are assumed to exist: the
3801    implementation must provide float.h, limits.h, stdarg.h and stddef.h and
3802    libpng relies on limits.h and stddef.h existing and behaving as defined
3803    (the other two required headers aren't used).  Non-ANSI systems that don't
3804    have stddef.h or limits.h will have to provide an appropriate fake
3805    containing the relevant types and #defines.
3806  Dropped support for 16-bit platforms. The use of FAR/far has been eliminated
3807    and the definition of png_alloc_size_t is now controlled by a flag so
3808    that 'small size_t' systems can select it if necessary.  Libpng 1.6 may
3809    not currently work on such systems -- it seems likely that it will
3810    ask 'malloc' for more than 65535 bytes with any image that has a
3811    sufficiently large row size (rather than simply failing to read such
3812    images).
3813  New tools directory containing tools used to generate libpng code.
3814  Fixed race conditions in parallel make builds. With higher degrees of
3815    parallelism during 'make' the use of the same temporary file names such
3816    as 'dfn*' can result in a race where a temporary file from one arm of the
3817    build is deleted or overwritten in another arm.  This changes the
3818    temporary files for suffix rules to always use $* and ensures that the
3819    non-suffix rules use unique file names.
3820
3821Version 1.6.0beta02 [December 21, 2011]
3822  Correct configure builds where build and source directories are separate.
3823    The include path of 'config.h' was erroneously made relative in pngvalid.c
3824    in libpng 1.5.7.
3825
3826Version 1.6.0beta03 [December 22, 2011]
3827  Start-up code size improvements, error handler flexibility. These changes
3828    alter how the tricky allocation of the initial png_struct and png_info
3829    structures are handled. png_info is now handled in pretty much the same
3830    way as everything else, except that the allocations handle NULL return
3831    silently.  png_struct is changed in a similar way on allocation and on
3832    deallocation a 'safety' error handler is put in place (which should never
3833    be required).  The error handler itself is changed to permit mismatches
3834    in the application and libpng error buffer size; however, this means a
3835    silent change to the API to return the jmp_buf if the size doesn't match
3836    the size from the libpng compilation; libpng now allocates the memory and
3837    this may fail.  Overall these changes result in slight code size
3838    reductions; however, this is a reduction in code that is always executed
3839    so is particularly valuable.  Overall on a 64-bit system the libpng DLL
3840    decreases in code size by 1733 bytes.  pngerror.o increases in size by
3841    about 465 bytes because of the new functionality.
3842  Added png_convert_to_rfc1123_buffer() and deprecated png_convert_to_rfc1123()
3843    to avoid including a spurious buffer in the png_struct.
3844
3845Version 1.6.0beta04 [December 30, 2011]
3846  Regenerated configure scripts with automake-1.11.2
3847  Eliminated png_info_destroy(). It is now used only in png.c and only calls
3848    one other internal function and memset().
3849  Enabled png_get_sCAL_fixed() if floating point APIs are enabled. Previously
3850    it was disabled whenever internal fixed point arithmetic was selected,
3851    which meant it didn't exist even on systems where FP was available but not
3852    preferred.
3853  Added pngvalid.c compile time checks for const APIs.
3854  Implemented 'restrict' for png_info and png_struct. Because of the way
3855    libpng works both png_info and png_struct are always accessed via a
3856    single pointer.  This means adding C99 'restrict' to the pointer gives
3857    the compiler some opportunity to optimize the code.  This change allows
3858    that.
3859  Moved AC_MSG_CHECKING([if libraries can be versioned]) later to the proper
3860    location in configure.ac (Gilles Espinasse).
3861  Changed png_memcpy to C assignment where appropriate. Changed all those
3862    uses of png_memcpy that were doing a simple assignment to assignments
3863    (all those cases where the thing being copied is a non-array C L-value).
3864  Added some error checking to png_set_*() routines.
3865  Removed the reference to the non-exported function png_memcpy() from
3866    example.c.
3867  Fixed the Visual C 64-bit build - it requires jmp_buf to be aligned, but
3868    it had become misaligned.
3869  Revised contrib/pngminus/pnm2png.c to avoid warnings when png_uint_32
3870    and unsigned long are of different sizes.
3871
3872Version 1.6.0beta05 [January 15, 2012]
3873  Updated manual with description of the simplified API (copied from png.h)
3874  Fix bug in pngerror.c: some long warnings were being improperly truncated
3875    (CVE-2011-3464, bug introduced in libpng-1.5.3beta05).
3876
3877Version 1.6.0beta06 [January 24, 2012]
3878  Added palette support to the simplified APIs. This commit
3879    changes some of the macro definitions in png.h, app code
3880    may need corresponding changes.
3881  Increased the formatted warning buffer to 192 bytes.
3882  Added color-map support to simplified API. This is an initial version for
3883    review; the documentation has not yet been updated.
3884  Fixed Min/GW uninstall to remove libpng.dll.a
3885
3886Version 1.6.0beta07 [January 28, 2012]
3887  Eliminated Intel icc/icl compiler warnings. The Intel (GCC derived)
3888    compiler issues slightly different warnings from those issued by the
3889    current vesions of GCC. This eliminates those warnings by
3890    adding/removing casts and small code rewrites.
3891  Updated configure.ac from autoupdate: added --enable-werror option.
3892    Also some layout regularization and removal of introduced tab characters
3893    (replaced with 3-character indentation).  Obsolete macros identified by
3894    autoupdate have been removed; the replacements are all in 2.59 so
3895    the pre-req hasn't been changed.  --enable-werror checks for support
3896    for -Werror (or the given argument) in the compiler.  This mimics the
3897    gcc configure option by allowing -Werror to be turned on safely; without
3898    the option the tests written in configure itself fail compilation because
3899    they cause compiler warnings.
3900  Rewrote autogen.sh to run autoreconf instead of running tools one-by-one.
3901  Conditionalize the install rules for MINGW and CYGWIN in CMakeLists.txt and
3902    set CMAKE_LIBRARY_OUTPUT_DIRECTORY to "lib" on all platforms (C. Yapp).
3903  Freeze libtool files in the 'scripts' directory. This version of autogen.sh
3904    attempts to dissuade people from running it when it is not, or should not,
3905    be necessary.  In fact, autogen.sh does not work when run in a libpng
3906    directory extracted from a tar distribution anymore. You must run it in
3907    a GIT clone instead.
3908  Added two images to contrib/pngsuite (1-bit and 2-bit transparent grayscale),
3909    and renamed three whose names were inconsistent with those in
3910    pngsuite/README.txt.
3911
3912Version 1.6.0beta08 [February 1, 2012]
3913  Fixed Image::colormap misalignment in pngstest.c
3914  Check libtool/libtoolize version number (2.4.2) in configure.ac
3915  Divide test-pngstest.sh into separate pngstest runs for basic and
3916    transparent images.
3917  Moved automake options to AM_INIT_AUTOMAKE in configure.ac
3918  Added color-tests, silent-rules (Not yet implemented in Makefile.am) and
3919    version checking to configure.ac
3920  Improved pngstest speed by not doing redundant tests and add const to
3921    the background parameter of png_image_finish_read. The --background
3922    option is now done automagically only when required, so that commandline
3923    option no longer exists.
3924  Cleaned up pngpriv.h to consistently declare all functions and data.
3925    Also eliminated PNG_CONST_DATA, which is apparently not needed but we
3926    can't be sure until it is gone.
3927  Added symbol prefixing that allows all the libpng external symbols
3928    to be prefixed (suggested by Reuben Hawkins).
3929  Updated "ftbb*.png" list in the owatcom and vstudio projects.
3930  Fixed 'prefix' builds on clean systems. The generation of pngprefix.h
3931    should not require itself.
3932  Updated INSTALL to explain that autogen.sh must be run in a GIT clone,
3933    not in a libpng directory extracted from a tar distribution.
3934
3935Version 1.6.0beta09 [February 1, 2012]
3936  Reverted the prebuilt configure files to libpng-1.6.0beta05 condition.
3937
3938Version 1.6.0beta10 [February 3, 2012]
3939  Added Z_SOLO for zlib-1.2.6+ and correct pngstest tests
3940  Updated list of test images in CMakeLists.txt
3941  Updated the prebuilt configure files to current condition.
3942  Revised INSTALL information about autogen.sh; it works in tar distributions.
3943
3944Version 1.6.0beta11 [February 16, 2012]
3945  Fix character count in pngstest command in projects/owatcom/pngstest.tgt
3946  Revised test-pngstest.sh to report PASS/FAIL for each image.
3947  Updated documentation about the simplified API.
3948  Corrected estimate of error in libpng png_set_rgb_to_gray API.  The API is
3949    extremely inaccurate for sRGB conversions because it uses an 8-bit
3950    intermediate linear value and it does not use the sRGB transform, so it
3951    suffers from the known instability in gamma transforms for values close
3952    to 0 (see Poynton).  The net result is that the calculation has a maximum
3953    error of 14.99/255; 0.5/255^(1/2.2).  pngstest now uses 15 for the
3954    permitted 8-bit error. This may still not be enough because of arithmetic
3955    error.
3956  Removed some unused arrays (with #ifdef) from png_read_push_finish_row().
3957  Fixed a memory overwrite bug in simplified read of RGB PNG with
3958    non-linear gamma Also bugs in the error checking in pngread.c and changed
3959    quite a lot of the checks in pngstest.c to be correct; either correctly
3960    written or not over-optimistic.  The pngstest changes are insufficient to
3961    allow all possible RGB transforms to be passed; pngstest cmppixel needs
3962    to be rewritten to make it clearer which errors it allows and then changed
3963    to permit known inaccuracies.
3964  Removed tests for no-longer-used *_EMPTY_PLTE_SUPPORTED from pngstruct.h
3965  Fixed fixed/float API export conditionals. 1) If FIXED_POINT or
3966    FLOATING_POINT options were switched off, png.h ended up with lone ';'
3967    characters.  This is not valid ANSI-C outside a function.  The ';'
3968    characters have been moved inside the definition of PNG_FP_EXPORT and
3969    PNG_FIXED_EXPORT. 2) If either option was switched off, the declaration
3970    of the corresponding functions were completely omitted, even though some
3971    of them are still used internally.  The result is still valid, but
3972    produces warnings from gcc with some warning options (including -Wall). The
3973    fix is to cause png.h to declare the functions with PNG_INTERNAL_FUNCTION
3974    when png.h is included from pngpriv.h.
3975  Check for invalid palette index while reading paletted PNG.  When one is
3976    found, issue a warning and increase png_ptr->num_palette accordingly.
3977    Apps are responsible for checking to see if that happened.
3978
3979Version 1.6.0beta12 [February 18, 2012]
3980  Do not increase num_palette on invalid_index.
3981  Relocated check for invalid palette index to pngrtran.c, after unpacking
3982    the sub-8-bit pixels.
3983  Fixed CVE-2011-3026 buffer overrun bug.  This bug was introduced when
3984    iCCP chunk support was added at libpng-1.0.6. Deal more correctly with the
3985    test on iCCP chunk length. Also removed spurious casts that may hide
3986    problems on 16-bit systems.
3987
3988Version 1.6.0beta13 [February 24, 2012]
3989  Eliminated redundant png_push_read_tEXt|zTXt|iTXt|unknown code from
3990    pngpread.c and use the sequential png_handle_tEXt, etc., in pngrutil.c;
3991    now that png_ptr->buffer is inaccessible to applications, the special
3992    handling is no longer useful.
3993  Added PNG_SAFE_LIMITS feature to pnglibconf.dfa, pngpriv.h, and new
3994    pngusr.dfa to reset the user limits to safe ones if PNG_SAFE_LIMITS is
3995    defined.  To enable, use "CPPFLAGS=-DPNG_SAFE_LIMITS_SUPPORTED=1" on the
3996    configure command or put #define PNG_SAFE_LIMITS_SUPPORTED in
3997    pnglibconf.h.prebuilt and pnglibconf.h.
3998
3999Version 1.6.0beta14 [February 27, 2012]
4000  Added information about the new limits in the manual.
4001  Updated Makefile.in
4002
4003Version 1.6.0beta15 [March 2, 2012]
4004  Removed unused "current_text" members of png_struct and the png_free()
4005    of png_ptr->current_text from pngread.c
4006  Rewrote pngstest.c for substantial speed improvement.
4007  Fixed transparent pixel and 16-bit rgb tests in pngstest and removed a
4008    spurious check in pngwrite.c
4009  Added PNG_IMAGE_FLAG_FAST for the benefit of applications that store
4010    intermediate files, or intermediate in-memory data, while processing
4011    image data with the simplified API.  The option makes the files larger
4012    but faster to write and read.  pngstest now uses this by default; this
4013    can be disabled with the --slow option.
4014  Improved pngstest fine tuning of error numbers, new test file generator.
4015    The generator generates images that test the full range of sample values,
4016    allow the error numbers in pngstest to be tuned and checked.  makepng
4017    also allows generation of images with extra chunks, although this is
4018    still work-in-progress.
4019  Added check for invalid palette index while reading.
4020  Fixed some bugs in ICC profile writing. The code should now accept
4021    all potentially valid ICC profiles and reject obviously invalid ones.
4022    It now uses png_error() to do so rather than casually writing a PNG
4023    without the necessary color data.
4024  Removed whitespace from the end of lines in all source files and scripts.
4025
4026Version 1.6.0beta16 [March 6, 2012]
4027  Relocated palette-index checking function from pngrutil.c to pngtrans.c
4028  Added palette-index checking while writing.
4029  Changed png_inflate() and calling routines to avoid overflow problems.
4030    This is an intermediate check-in that solves the immediate problems and
4031    introduces one performance improvement (avoiding a copy via png_ptr->zbuf.)
4032    Further changes will be made to make ICC profile handling more secure.
4033  Fixed build warnings (MSVC, GCC, GCC v3). Cygwin GCC with default options
4034    declares 'index' as a global, causing a warning if it is used as a local
4035    variable.  GCC 64-bit warns about assigning a (size_t) (unsigned 64-bit)
4036    to an (int) (signed 32-bit).  MSVC, however, warns about using the
4037    unary '-' operator on an unsigned value (even though it is well defined
4038    by ANSI-C to be ~x+1).  The padding calculation was changed to use a
4039    different method.  Removed the tests on png_ptr->pass.
4040  Added contrib/libtests/tarith.c to test internal arithmetic functions from
4041    png.c. This is a libpng maintainer program used to validate changes to the
4042    internal arithmetic functions.
4043  Made read 'inflate' handling like write 'deflate' handling. The read
4044    code now claims and releases png_ptr->zstream, like the write code.
4045    The bug whereby the progressive reader failed to release the zstream
4046    is now fixed, all initialization is delayed, and the code checks for
4047    changed parameters on deflate rather than always calling
4048    deflatedEnd/deflateInit.
4049  Validate the zTXt strings in pngvalid.
4050  Added code to validate the windowBits value passed to deflateInit2().
4051    If the call to deflateInit2() is wrong a png_warning will be issued
4052    (in fact this is harmless, but the PNG data produced may be sub-optimal).
4053
4054Version 1.6.0beta17 [March 10, 2012]
4055  Fixed PNG_LIBPNG_BUILD_BASE_TYPE definition.
4056  Reject all iCCP chunks after the first, even if the first one is invalid.
4057  Deflate/inflate was reworked to move common zlib calls into single
4058    functions [rw]util.c.  A new shared keyword check routine was also added
4059    and the 'zbuf' is no longer allocated on progressive read.  It is now
4060    possible to call png_inflate() incrementally.  A warning is no longer
4061    issued if the language tag or translated keyword in the iTXt chunk
4062    has zero length.
4063  If benign errors are disabled use maximum window on ancillary inflate.
4064    This works round a bug introduced in 1.5.4 where compressed ancillary
4065    chunks could end up with a too-small windowBits value in the deflate
4066    header.
4067
4068Version 1.6.0beta18 [March 16, 2012]
4069  Issue a png_benign_error() instead of png_warning() about bad palette index.
4070  In pngtest, treat benign errors as errors if "-strict" is present.
4071  Fixed an off-by-one error in the palette index checking function.
4072  Fixed a compiler warning under Cygwin (Windows-7, 32-bit system)
4073  Revised example.c to put text strings in a temporary character array
4074    instead of directly assigning string constants to png_textp members.
4075    This avoids compiler warnings when -Wwrite-strings is enabled.
4076  Added output flushing to aid debugging under Visual Studio. Unfortunately
4077    this is necessary because the VS2010 output window otherwise simply loses
4078    the error messages on error (they weren't flushed to the window before
4079    the process exited, apparently!)
4080  Added configuration support for benign errors and changed the read
4081    default. Also changed some warnings in the iCCP and sRGB handling
4082    from to benign errors. Configuration now makes read benign
4083    errors warnings and write benign errors to errors by default (thus
4084    changing the behavior on read).  The simplified API always forces
4085    read benign errors to warnings (regardless of the system default, unless
4086    this is disabled in which case the simplified API can't be built.)
4087
4088Version 1.6.0beta19 [March 18, 2012]
4089  Work around for duplicate row start calls; added warning messages.
4090    This turns on PNG_FLAG_DETECT_UNINITIALIZED to detect app code that
4091    fails to call one of the 'start' routines (not enabled in libpng-1.5
4092    because it is technically an API change, since it did normally work
4093    before.)  It also makes duplicate calls to png_read_start_row (an
4094    internal function called at the start of the image read) benign, as
4095    they were before changes to use png_inflate_claim. Somehow webkit is
4096    causing this to happen; this is probably a mis-feature in the zlib
4097    changes so this commit is only a work-round.
4098  Removed erroneous setting of DETECT_UNINITIALIZED and added more
4099    checks. The code now does a png_error if an attempt is made to do the
4100    row initialization twice; this is an application error and it has
4101    serious consequences because the transform data in png_struct is
4102    changed by each call.
4103  Added application error reporting and added chunk names to read
4104    benign errors; also added --strict to pngstest - not enabled
4105    yet because a warning is produced.
4106  Avoid the double gamma correction warning in the simplified API.
4107    This allows the --strict option to pass in the pngstest checks
4108
4109Version 1.6.0beta20 [March 29, 2012]
4110  Changed chunk handler warnings into benign errors, incrementally load iCCP
4111  Added checksum-icc.c to contrib/tools
4112  Prevent PNG_EXPAND+PNG_SHIFT doing the shift twice.
4113  Recognize known sRGB ICC profiles while reading; prefer writing the
4114    iCCP profile over writing the sRGB chunk, controlled by the
4115    PNG_sRGB_PROFILE_CHECKS option.
4116  Revised png_set_text_2() to avoid potential memory corruption (fixes
4117    CVE-2011-3048, also known as CVE-2012-3425).
4118
4119Version 1.6.0beta21 [April 27, 2012]
4120  Revised scripts/makefile.darwin: use system zlib; remove quotes around
4121    architecture list; add missing ppc architecture; add architecture options
4122    to shared library link; don't try to create a shared lib based on missing
4123    RELEASE variable.
4124  Enable png_set_check_for_invalid_index() for both read and write.
4125  Removed #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED in pngpriv.h around
4126    declaration of png_handle_unknown().
4127  Added -lssp_nonshared in a comment in scripts/makefile.freebsd
4128    and changed deprecated NOOBJ and NOPROFILE to NO_OBJ and NO_PROFILE.
4129
4130Version 1.6.0beta22 [May 23, 2012]
4131  Removed need for -Wno-cast-align with clang.  clang correctly warns on
4132    alignment increasing pointer casts when -Wcast-align is passed. This
4133    fixes the cases that clang warns about either by eliminating the
4134    casts from png_bytep to png_uint_16p (pngread.c), or, for pngrutil.c
4135    where the cast is previously verified or pngstest.c where it is OK, by
4136    introducing new png_aligncast macros to do the cast in a way that clang
4137    accepts.
4138
4139Version 1.6.0beta23 [June 6, 2012]
4140  Revised CMakeLists.txt to not attempt to make a symlink under mingw.
4141  Made fixes for new optimization warnings from gcc 4.7.0. The compiler
4142    performs an optimization which is safe; however it then warns about it.
4143    Changing the type of 'palette_number' in pngvalid.c removes the warning.
4144  Do not depend upon a GCC feature macro being available for use in generating
4145    the linker mapfile symbol prefix.
4146  Improved performance of new do_check_palette_indexes() function (only
4147    update the value when it actually increases, move test for whether
4148    the check is wanted out of the function.
4149
4150Version 1.6.0beta24 [June 7, 2012]
4151  Don't check palette indexes if num_palette is 0 (as it can be in MNG files).
4152
4153Version 1.6.0beta25 [June 16, 2012]
4154  Revised png_set_keep_unknown_chunks() so num_chunks < 0 means ignore all
4155    unknown chunks and all known chunks except for IHDR, PLTE, tRNS, IDAT,
4156    and IEND.  Previously it only meant ignore all unknown chunks, the
4157    same as num_chunks == 0. Revised png_image_skip_unused_chunks() to
4158    provide a list of chunks to be processed instead of a list of chunks to
4159    ignore.  Revised contrib/gregbook/readpng2.c accordingly.
4160
4161Version 1.6.0beta26 [July 10, 2012]
4162  Removed scripts/makefile.cegcc from the *.zip and *.7z distributions; it
4163    depends on configure, which is not included in those archives.
4164  Moved scripts/chkfmt to contrib/tools.
4165  Changed "a+w" to "u+w" in Makefile.in to fix CVE-2012-3386.
4166
4167Version 1.6.0beta27 [August 11, 2012]
4168  Do not compile PNG_DEPRECATED, PNG_ALLOC and PNG_PRIVATE when __GNUC__ < 3.
4169  Do not use __restrict when GNUC is <= 3.1
4170  Removed references to png_zalloc() and png_zfree() from the manual.
4171  Fixed configurations where floating point is completely disabled.  Because
4172    of the changes to support symbol prefixing PNG_INTERNAL_FUNCTION declares
4173    floating point APIs during libpng builds even if they are completely
4174    disabled. This requires the png floating point types (png_double*) to be
4175    declared even though the functions are never actually defined.  This
4176    change provides a dummy definition so that the declarations work, yet any
4177    implementation will fail to compile because of an incomplete type.
4178  Re-eliminated the use of strcpy() in pngtest.c.  An unnecessary use of
4179    strcpy() was accidentally re-introduced in libpng16; this change replaces
4180    it with strncpy().
4181  Eliminated use of png_sizeof(); use sizeof() instead.
4182  Use a consistent style for (sizeof type) and (sizeof (array))
4183  Cleanup of png_set_filler().  This function does very different things on
4184    read and write.  In libpng 1.6 the two cases can be distinguished and
4185    considerable code cleanup, and extra error checking, is possible.  This
4186    makes calls on the write side that have no effect be ignored with a
4187    png_app_error(), which can be disabled in the app using
4188    png_set_benign_errors(), and removes the spurious use of usr_channels
4189    on the read side.
4190  Insist on autotools 1.12.1 for git builds because there are security issues
4191    with 1.12 and insisting on anything less would allow 1.12 to be used.
4192  Removed info_ptr->signature[8] from WRITE-only builds.
4193  Add some conditions for compiling png_fixed().  This is a small function
4194    but it requires "-lm" on some platforms.
4195  Cause pngtest --strict to fail on any warning from libpng (not just errors)
4196    and cause it not to fail at the comparison step if libpng lacks support
4197    for writing chunks that it reads from the input (currently only implemented
4198    for compressed text chunks).
4199  Make all three "make check" test programs work without READ or WRITE support.
4200    Now "make check" will succeed even if libpng is compiled with -DPNG_NO_READ
4201    or -DPNG_NO_WRITE.  The tests performed are reduced, but the basic reading
4202    and writing of a PNG file is always tested by one or more of the tests.
4203  Consistently use strlen(), memset(), memcpy(), and memcmp() instead of the
4204    png_strlen(), png_memset(), png_memcpy(), and png_memcmp() macros.
4205  Removed the png_sizeof(), png_strlen(), png_memset(), png_memcpy(), and
4206    png_memcmp() macros.
4207  Work around gcc 3.x and Microsoft Visual Studio 2010 complaints. Both object
4208    to the split initialization of num_chunks.
4209
4210Version 1.6.0beta28 [August 29, 2012]
4211  Unknown handling fixes and clean up. This adds more correct option
4212    control of the unknown handling, corrects the pre-existing bug where
4213    the per-chunk 'keep' setting is ignored and makes it possible to skip
4214    IDAT chunks in the sequential reader (broken in earlier 1.6 versions).
4215    There is a new test program, test-unknown.c, which is a work in progress
4216    (not currently part of the test suite).  Comments in the header files now
4217    explain how the unknown handling works.
4218  Allow fine grain control of unknown chunk APIs. This change allows
4219    png_set_keep_unknown_chunks() to be turned off if not required and causes
4220    both read and write to behave appropriately (on read this is only possible
4221    if the user callback is used to handle unknown chunks).  The change
4222    also removes the support for storing unknown chunks in the info_struct
4223    if the only unknown handling enabled is via the callback, allowing libpng
4224    to be configured with callback reading and none of the unnecessary code.
4225  Corrected fix for unknown handling in pngtest. This reinstates the
4226    libpng handling of unknown chunks other than vpAg and sTER (including
4227    unsafe-to-copy chunks which were dropped before) and eliminates the
4228    repositioning of vpAg and sTER in pngtest.png by changing pngtest.png
4229    (so the chunks are where libpng would put them).
4230  Added "tunknown" test and corrected a logic error in png_handle_unknown()
4231    when SAVE support is absent.  Moved the shell test scripts for
4232    contrib/libtests from the libpng top directory to contrib/libtests.
4233    png_handle_unknown() must always read or skip the chunk, if
4234    SAVE_UNKNOWN_CHUNKS is turned off *and* the application does not set
4235    a user callback an unknown chunk will not be read, leading to a read
4236    error, which was revealed by the "tunknown" test.
4237  Cleaned up and corrected ICC profile handling.
4238    contrib/libtests/makepng: corrected 'rgb' and 'gray' cases.  profile_error
4239    messages could be truncated; made a correct buffer size calculation and
4240    adjusted pngerror.c appropriately. png_icc_check_* checking improved;
4241    changed the functions to receive the correct color type of the PNG on read
4242    or write and check that it matches the color space of the profile (despite
4243    what the comments said before, there is danger in assuming the app will
4244    cope correctly with an RGB profile on a grayscale image and, since it
4245    violates the PNG spec, allowing it is certain to produce inconsistent
4246    app behavior and might even cause app crashes.) Check that profiles
4247    contain the tags needed to process the PNG (tags all required by the ICC
4248    spec). Removed unused PNG_STATIC from pngpriv.h.
4249
4250Version 1.6.0beta29 [September 4, 2012]
4251  Fixed the simplified API example programs to add the *colormap parameter
4252    to several of he API and improved the error message if the version field
4253    is not set.
4254  Added contrib/examples/* to the *.zip and *.7z distributions.
4255  Updated simplified API synopses and description of the png_image structure
4256    in the manual.
4257  Made makepng and pngtest produce identical PNGs, add "--relaxed" option
4258    to pngtest. The "--relaxed" option turns off the benign errors that are
4259    enabled by default in pre-RC builds. makepng can now write ICC profiles
4260    where the length has not been extended to a multiple of 4, and pngtest
4261    now intercepts all libpng errors, allowing the previously-introduced
4262    "--strict test" on no warnings to actually work.
4263  Improved ICC profile handling including cHRM chunk generation and fixed
4264    Cygwin+MSVC build errors. The ICC profile handling now includes more
4265    checking.  Several errors that caused rejection of the profile are now
4266    handled with a warning in such a way that the invalid profiles will be
4267    read by default in release (but not pre-RC) builds but will not be
4268    written by default.  The easy part of handling the cHRM chunk is written,
4269    where the ICC profile contains the required data.  The more difficult
4270    part plus guessing a gAMA value requires code to pass selected RGB values
4271    through the profile.
4272
4273Version 1.6.0beta30 [October 24, 2012]
4274  Changed ICC profile matrix/vector types to not depend on array type rules.
4275    By the ANSI-C standard the new types should be identical to the previous
4276    versions, and all known versions of gcc tested with the previous versions
4277    except for GCC-4.2.1 work with this version.  The change makes the ANSI-C
4278    rule that const applied to an array of elements applies instead to the
4279    elements in the array moot by explicitly applying const to the base
4280    elements of the png_icc_matrix and png_icc_vector types. The accidental
4281    (harmless) 'const' previously applied to the parameters of two of the
4282    functions have also been removed.
4283  Added a work around for GCC 4.2 optimization bug.
4284  Marked the broken (bad white point) original HP sRGB profiles correctly and
4285    correct comments.
4286  Added -DZ_SOLO to contrib/pngminim/*/makefile to work with zlib-1.2.7
4287  Use /MDd for vstudio debug builds. Also added pngunkown to the vstudio
4288    builds, fixed build errors and corrected a minor exit code error in
4289    pngvalid if the 'touch' file name is invalid.
4290  Add updated WARNING file to projects/vstudio from libpng 1.5/vstudio
4291  Fixed build when using #define PNG_NO_READ_GAMMA in png_do_compose() in
4292    pngrtran.c (Domani Hannes).
4293
4294Version 1.6.0beta31 [November 1, 2012]
4295  Undid the erroneous change to vstudio/pngvalid build in libpng-1.6.0beta30.
4296  Made pngvalid so that it will build outside the libpng source tree.
4297  Made builds -DPNG_NO_READ_GAMMA compile (the unit tests still fail).
4298  Made PNG_NO_READ_GAMMA switch off interfaces that depend on READ_GAMMA.
4299    Prior to 1.6.0 switching off READ_GAMMA did unpredictable things to the
4300    interfaces that use it (specifically, png_do_background in 1.4 would
4301    simply display composite for grayscale images but do composition
4302    with the incorrect arithmetic for color ones). In 1.6 the semantic
4303    of -DPNG_NO_READ_GAMMA is changed to simply disable any interface that
4304    depends on it; this obliges people who set it to consider whether they
4305    really want it off if they happen to use any of the interfaces in
4306    question (typically most users who disable it won't).
4307  Fixed GUIDs in projects/vstudio. Some were duplicated or missing,
4308    resulting in VS2010 having to update the files.
4309  Removed non-working ICC profile support code that was mostly added to
4310    libpng-1.6.0beta29 and beta30. There was too much code for too little
4311    gain; implementing full ICC color correction may be desirable but is left
4312    up to applications.
4313
4314Version 1.6.0beta32 [November 25, 2012]
4315  Fixed an intermittent SEGV in pngstest due to an uninitialized array element.
4316  Added the ability for contrib/libtests/makepng.c to make a PNG with just one
4317    color. This is useful for debugging pngstest color inaccuracy reports.
4318  Fixed error checking in the simplified write API (Olaf van der Spek)
4319  Made png_user_version_check() ok to use with libpng version 1.10.x and later.
4320
4321Version 1.6.0beta33 [December 15, 2012]
4322  Fixed typo in png.c (PNG_SET_CHUNK_MALLOC_MAX should be PNG_CHUNK_MALLOC_MAX)
4323    that causes the MALLOC_MAX limit not to work (John Bowler)
4324  Change png_warning() to png_app_error() in pngwrite.c and comment the
4325    fall-through condition.
4326  Change png_warning() to png_app_warning() in png_write_tRNS().
4327  Rearranged the ARM-NEON optimizations: Isolated the machine specific code
4328    to the hardware subdirectory and added comments to pngrutil.c so that
4329    implementors of other optimizations know what to do.
4330  Fixed cases of unquoted DESTDIR in Makefile.am
4331  Rebuilt Makefile.in, etc., with autoconf-2.69 and automake-1.12.5.
4332
4333Version 1.6.0beta34 [December 19, 2012]
4334  Cleaned up whitespace in the synopsis portion of the manpage "libpng.3"
4335  Disassembled the version number in scripts/options.awk (necessary for
4336    building on SunOs).
4337
4338Version 1.6.0beta35 [December 23, 2012]
4339  Made default Zlib compression settings be configurable. This adds #defines to
4340    pnglibconf.h to control the defaults.
4341  Fixed Windows build issues, enabled ARM compilation. Various warnings issued
4342    by earlier versions of GCC fixed for Cygwin and Min/GW (which both use old
4343    GCCs.) ARM support is enabled by default in zlib.props (unsupported by
4344    Microsoft) and ARM compilation is made possible by deleting the check for
4345    x86. The test programs cannot be run because they are not signed.
4346
4347Version 1.6.0beta36 [January 2, 2013]
4348  Discontinued distributing libpng-1.x.x.tar.bz2.
4349  Discontinued distributing libpng-1.7.0-1.6.0-diff.txt and similar.
4350  Rebuilt configure with autoconf-2.69 (inadvertently not done in beta33)
4351  Fixed 'make distcheck' on SUN OS - libpng.so was not being removed
4352
4353Version 1.6.0beta37 [January 10, 2013]
4354  Fixed conceivable but difficult to repro overflow. Also added two test
4355    programs to generate and test a PNG which should have the problem.
4356
4357Version 1.6.0beta39 [January 19, 2013]
4358  Again corrected attempt at overflow detection in png_set_unknown_chunks()
4359  (CVE-2013-7353).  Added overflow detection in png_set_sPLT() and
4360  png_set_text_2() (CVE-2013-7354).
4361
4362Version 1.6.0beta40 [January 20, 2013]
4363  Use consistent handling of overflows in text, sPLT and unknown png_set_* APIs
4364
4365Version 1.6.0rc01 [January 26, 2013]
4366  No changes.
4367
4368Version 1.6.0rc02 [February 4, 2013]
4369  Added png_get_palette_max() function.
4370
4371Version 1.6.0rc03 [February 5, 2013]
4372  Fixed the png_get_palette_max API.
4373
4374Version 1.6.0rc04 [February 7, 2013]
4375  Turn serial tests back on (recently turned off by autotools upgrade).
4376
4377Version 1.6.0rc05 [February 8, 2013]
4378  Update manual about png_get_palette_max().
4379
4380Version 1.6.0rc06 [February 9, 2013]
4381  Fixed missing dependency in --prefix builds The intermediate
4382    internal 'prefix.h' file can only be generated correctly after
4383    pnglibconf.h, however the dependency was not in Makefile.am.  The
4384    symptoms are unpredictable depending on the order make chooses to
4385    build pngprefix.h and pnglibconf.h, often the error goes unnoticed
4386    because there is a system pnglibconf.h to use instead.
4387
4388Version 1.6.0rc07 [February 10, 2013]
4389  Enclosed the new png_get_palette_max in #ifdef PNG_GET_PALETTE_MAX_SUPPORTED
4390    block, and revised pnglibconf.h and pnglibconf.h.prebuilt accordingly.
4391
4392Version 1.6.0rc08 [February 10, 2013]
4393  Fix typo in png.h #ifdef
4394
4395Version 1.6.0 [February 14, 2013]
4396  No changes.
4397
4398Version 1.6.1beta01 [February 16, 2013]
4399  Made symbol prefixing work with the ARM neon optimizations. Also allow
4400    pngpriv.h to be included for preprocessor definitions only, so it can
4401    be used in non-C/C++ files. Back ported from libpng 1.7.
4402  Made sRGB check numbers consistent.
4403  Ported libpng 1.5 options.awk/dfn file handling to 1.6, fixed one bug.
4404  Removed cc -E workround, corrected png_get_palette_max API Tested on
4405    SUN OS cc 5.9, which demonstrates the tokenization problem previously
4406    avoided by using /lib/cpp.  Since all .dfn output is now protected in
4407    double quotes unless it is to be macro substituted the fix should
4408    work everywhere.
4409  Enabled parallel tests - back ported from libpng-1.7.
4410  scripts/pnglibconf.dfa formatting improvements back ported from libpng17.
4411  Fixed a race condition in the creation of the build 'scripts' directory
4412    while building with a parallel make.
4413  Use approved/supported Android method to check for NEON, use Linux/POSIX
4414    1003.1 API to check /proc/self/auxv avoiding buffer allocation and other
4415    library calls (ported from libpng15).
4416
4417Version 1.6.1beta02 [February 19, 2013]
4418  Use parentheses more consistently in "#if defined(MACRO)" tests.
4419  Folded long lines.
4420  Reenabled code to allow zero length PLTE chunks for MNG.
4421
4422Version 1.6.1beta03 [February 22, 2013]
4423  Fixed ALIGNED_MEMORY support.
4424  Added a new configure option:
4425    --enable-arm-neon=always will stop the run-time checks. New checks
4426    within arm/arm_init.c will cause the code not to be compiled unless
4427    __ARM_NEON__ is set. This should make it fail safe (if someone asks
4428    for it on then the build will fail if it can't be done.)
4429  Updated the INSTALL document.
4430
4431Version 1.6.1beta04 [February 27, 2013]
4432  Revised INSTALL to recommend using CPPFLAGS instead of INCLUDES.
4433  Revised scripts/makefile.freebsd to respect ZLIBLIB and ZLIBINC.
4434  Revised scripts/dfn.awk to work with the buggy MSYS awk that has trouble
4435    with CRLF line endings.
4436
4437Version 1.6.1beta05 [March 1, 2013]
4438  Avoid a possible memory leak in contrib/gregbook/readpng.c
4439
4440Version 1.6.1beta06 [March 4, 2013]
4441  Better documentation of unknown handling API interactions.
4442  Corrected Android builds and corrected libpng.vers with symbol
4443    prefixing.  It also makes those tests compile and link on Android.
4444  Added an API png_set_option() to set optimization options externally,
4445    providing an alternative and general solution for the non-portable
4446    run-time tests used by the ARM Neon code, using the PNG_ARM_NEON option.
4447  The order of settings vs options in pnglibconf.h is reversed to allow
4448    settings to depend on options and options can now set (or override) the
4449    defaults for settings.
4450
4451Version 1.6.1beta07 [March 7, 2013]
4452  Corrected simplified API default gamma for color-mapped output, added
4453    a flag to change default. In 1.6.0 when the simplified API was used
4454    to produce color-mapped output from an input image with no gamma
4455    information the gamma assumed for the input could be different from
4456    that assumed for non-color-mapped output.  In particular 16-bit depth
4457    input files were assumed to be sRGB encoded, whereas in the 'direct'
4458    case they were assumed to have linear data.  This was an error.  The
4459    fix makes the simplified API treat all input files the same way and
4460    adds a new flag to the png_image::flags member to allow the
4461    application/user to specify that 16-bit files contain sRGB data
4462    rather than the default linear.
4463  Fixed bugs in the pngpixel and makepng test programs.
4464
4465Version 1.6.1beta08 [March 7, 2013]
4466  Fixed CMakelists.txt to allow building a single variant of the library
4467    (Claudio Bley):
4468  Introduced a PNG_LIB_TARGETS variable that lists all activated library
4469    targets.  It is an error if this variable ends up empty, ie. you have
4470    to build at least one library variant.
4471  Made the *_COPY targets only depend on library targets actually being build.
4472  Use PNG_LIB_TARGETS to unify a code path.
4473  Changed the CREATE_SYMLINK macro to expect the full path to a file as the
4474    first argument. When symlinking the filename component of that path is
4475    determined and used as the link target.
4476  Use copy_if_different in the CREATE_SYMLINK macro.
4477
4478Version 1.6.1beta09 [March 13, 2013]
4479  Eliminated two warnings from the Intel C compiler. The warnings are
4480    technically valid, although a reasonable treatment of division would
4481    show it to be incorrect.
4482
4483Version 1.6.1rc01 [March 21, 2013]
4484  No changes.
4485
4486Version 1.6.1 [March 28, 2013]
4487  No changes.
4488
4489Version 1.6.2beta01 [April 14, 2013]
4490  Updated documentation of 1.5.x to 1.6.x changes in iCCP chunk handling.
4491  Fixed incorrect warning of excess deflate data. End condition - the
4492    warning would be produced if the end of the deflate stream wasn't read
4493    in the last row.  The warning is harmless.
4494  Corrected the test on user transform changes on read. It was in the
4495    png_set of the transform function, but that doesn't matter unless the
4496    transform function changes the rowbuf size, and that is only valid if
4497    transform_info is called.
4498  Corrected a misplaced closing bracket in contrib/libtests/pngvalid.c
4499    (Flavio Medeiros).
4500  Corrected length written to uncompressed iTXt chunks (Samuli Suominen).
4501    Bug was introduced in libpng-1.6.0.
4502
4503Version 1.6.2rc01 [April 18, 2013]
4504  Added contrib/tools/fixitxt.c, to repair the erroneous iTXt chunk length
4505    written by libpng-1.6.0 and 1.6.1.
4506  Disallow storing sRGB information when the sRGB is not supported.
4507
4508Version 1.6.2rc02 [April 18, 2013]
4509  Merge pngtest.c with libpng-1.7.0
4510
4511Version 1.6.2rc03 [April 22, 2013]
4512  Trivial spelling cleanup.
4513
4514Version 1.6.2rc04 and 1.6.2rc05 [omitted]
4515
4516Version 1.6.2rc06 [April 24, 2013]
4517  Reverted to version 1.6.2rc03.  Recent changes to arm/neon support
4518    have been ported to libpng-1.7.0beta09 and will reappear in version
4519    1.6.3beta01.
4520
4521Version 1.6.2 [April 25, 2013]
4522  No changes.
4523
4524Version 1.6.3beta01 [April 25, 2013]
4525  Revised stack marking in arm/filter_neon.S and configure.ac.
4526  Ensure that NEON filter stuff is completely disabled when switched 'off'.
4527    Previously the ARM NEON specific files were still built if the option
4528    was switched 'off' as opposed to being explicitly disabled.
4529
4530Version 1.6.3beta02 [April 26, 2013]
4531  Test for 'arm*' not just 'arm' in the host_cpu configure variable.
4532  Rebuilt the configure scripts.
4533
4534Version 1.6.3beta03 [April 30, 2013]
4535  Expanded manual paragraph about writing private chunks, particularly
4536    the need to call png_set_keep_unknown_chunks() when writing them.
4537  Avoid dereferencing NULL pointer possibly returned from
4538    png_create_write_struct() (Andrew Church).
4539
4540Version 1.6.3beta05 [May 9, 2013]
4541  Calculate our own zlib windowBits when decoding rather than trusting the
4542    CMF bytes in the PNG datastream.
4543  Added an option to force maximum window size for inflating, which was
4544    the behavior of libpng15 and earlier, via a new PNG_MAXIMUM_INFLATE_WINDOW
4545    option for png_set_options().
4546  Added png-fix-itxt and png-fix-too-far-back to the built programs and
4547    removed warnings from the source code and timepng that are revealed as
4548    a result.
4549  Detect wrong libpng versions linked to png-fix-too-far-back, which currently
4550    only works with libpng versions that can be made to reliably fail when
4551    the deflate data contains an out-of-window reference.  This means only
4552    1.6 and later.
4553  Fixed gnu issues: g++ needs a static_cast, gcc 4.4.7 has a broken warning
4554    message which it is easier to work round than ignore.
4555  Updated contrib/pngminus/pnm2png.c (Paul Stewart):
4556    Check for EOF
4557    Ignore "#" delimited comments in input file to pnm2png.c.
4558    Fixed whitespace handling
4559    Added a call to png_set_packing()
4560    Initialize dimension values so if sscanf fails at least we have known
4561      invalid values.
4562  Attempt to detect configuration issues with png-fix-too-far-back, which
4563    requires both the correct libpng and the correct zlib to function
4564    correctly.
4565  Check ZLIB_VERNUM for mismatches, enclose #error in quotes
4566  Added information in the documentation about problems with and fixes for
4567    the bad CRC and bad iTXt chunk situations.
4568
4569Version 1.6.3beta06 [May 12, 2013]
4570  Allow contrib/pngminus/pnm2png.c to compile without WRITE_INVERT and
4571    WRITE_PACK supported (writes error message that it can't read P1 or
4572    P4 PBM files).
4573  Improved png-fix-too-far-back usage message, added --suffix option.
4574  Revised contrib/pngminim/*/makefile to generate pnglibconf.h with the
4575    right zlib header files.
4576  Separated CPPFLAGS and CFLAGS in contrib/pngminim/*/makefile
4577
4578Version 1.6.3beta07 [June 8, 2013]
4579  Removed a redundant test in png_set_IHDR().
4580  Added set(CMAKE_CONFIGURATION_TYPES ...) to CMakeLists.txt (Andrew Hundt)
4581  Deleted set(CMAKE_BUILD_TYPE) block from CMakeLists.txt
4582  Enclose the prototypes for the simplified write API in
4583    #ifdef PNG_STDIO_SUPPORTED/#endif
4584  Make ARM NEON support work at compile time (not just configure time).
4585    This moves the test on __ARM_NEON__ into pngconf.h to avoid issues when
4586    using a compiler that compiles for multiple architectures at one time.
4587  Removed PNG_FILTER_OPTIMIZATIONS and PNG_ARM_NEON_SUPPORTED from
4588    pnglibconf.h, allowing more of the decisions to be made internally
4589    (pngpriv.h) during the compile.  Without this, symbol prefixing is broken
4590    under certain circumstances on ARM platforms.  Now only the API parts of
4591    the optimizations ('check' vs 'api') are exposed in the public header files
4592    except that the new setting PNG_ARM_NEON_OPT documents how libpng makes the
4593    decision about whether or not to use the optimizations.
4594  Protect symbol prefixing against CC/CPPFLAGS/CFLAGS usage.
4595    Previous iOS/Xcode fixes for the ARM NEON optimizations moved the test
4596    on __ARM_NEON__ from configure time to compile time.  This breaks symbol
4597    prefixing because the definition of the special png_init_filter_functions
4598    call was hidden at configure time if the relevant compiler arguments are
4599    passed in CFLAGS as opposed to CC.  This change attempts to avoid all
4600    the confusion that would result by declaring the init function even when
4601    it is not used, so that it will always get prefixed.
4602
4603Version 1.6.3beta08 [June 18, 2013]
4604  Revised libpng.3 so that "doclifter" can process it.
4605
4606Version 1.6.3beta09 [June 27, 2013]
4607  Revised example.c to illustrate use of PNG_DEFAULT_sRGB and PNG_GAMMA_MAC_18
4608    as parameters for png_set_gamma().  These have been available since
4609    libpng-1.5.4.
4610  Renamed contrib/tools/png-fix-too-far-back.c to pngfix.c and revised it
4611    to check all compressed chunks known to libpng.
4612
4613Version 1.6.3beta10 [July 5, 2013]
4614  Updated documentation to show default behavior of benign errors correctly.
4615  Only compile ARM code when PNG_READ_SUPPORTED is defined.
4616  Fixed undefined behavior in contrib/tools/pngfix.c and added new strip
4617    option. pngfix relied on undefined behavior and even a simple change from
4618    gcc to g++ caused it to fail.  The new strip option 'unsafe' has been
4619    implemented and is the default if --max is given.  Option names have
4620    been clarified, with --strip=transform now stripping the bKGD chunk,
4621    which was stripped previously with --strip=unused.
4622  Added all documented chunk types to pngpriv.h
4623  Unified pngfix.c source with libpng17.
4624
4625Version 1.6.3rc01 [July 11, 2013]
4626  No changes.
4627
4628Version 1.6.3 [July 18, 2013]
4629  Revised manual about changes in iTXt chunk handling made in libpng-1.6.0.
4630  Added "/* SAFE */" comments in pngrutil.c and pngrtran.c where warnings
4631    may be erroneously issued by code-checking applications.
4632
4633Version 1.6.4beta01 [August 21, 2013]
4634  Added information about png_set_options() to the manual.
4635  Delay calling png_init_filter_functions() until a row with nonzero filter
4636    is found.
4637
4638Version 1.6.4beta02 [August 30, 2013]
4639  Fixed inconsistent conditional compilation of png_chunk_unknown_handling()
4640    prototype, definition, and usage.  Made it depend on
4641    PNG_HANDLE_AS_UNKNOWN_SUPPORTED everywhere.
4642
4643Version 1.6.4rc01 [September 5, 2013]
4644  No changes.
4645
4646Version 1.6.4 [September 12, 2013]
4647  No changes.
4648
4649Version 1.6.5 [September 14, 2013]
4650  Removed two stray lines of code from arm/arm_init.c.
4651
4652Version 1.6.6 [September 16, 2013]
4653  Removed two stray lines of code from arm/arm_init.c, again.
4654
4655Version 1.6.7beta01 [September 30, 2013]
4656  Revised unknown chunk code to correct several bugs in the NO_SAVE_/NO_WRITE
4657    combination
4658  Allow HANDLE_AS_UNKNOWN to work when other options are configured off. Also
4659    fixed the pngminim makefiles to work when $(MAKEFLAGS) contains stuff
4660    which terminates the make options (as by default in recent versions of
4661    Gentoo).
4662  Avoid up-cast warnings in pngvalid.c. On ARM the alignment requirements of
4663    png_modifier are greater than that of png_store and as a consequence
4664    compilation of pngvalid.c results in a warning about increased alignment
4665    requirements because of the bare cast to (png_modifier*). The code is safe,
4666    because the pointer is known to point to a stack allocated png_modifier,
4667    but this change avoids the warning.
4668  Fixed default behavior of ARM_NEON_API. If the ARM NEON API option was
4669    compiled without the CHECK option it defaulted to on, not off.
4670  Check user callback behavior in pngunknown.c. Previous versions compiled
4671    if SAVE_UNKNOWN was not available but did nothing since the callback
4672    was never implemented.
4673  Merged pngunknown.c with 1.7 version and back ported 1.7 improvements/fixes
4674
4675Version 1.6.7beta02 [October 12, 2013]
4676  Made changes for compatibility with automake 1.14:
4677    1) Added the 'compile' program to the list of programs that must be cleaned
4678       in autogen.sh
4679    2) Added 'subdir-objects' which causes .c files in sub-directories to be
4680       compiled such that the corresponding .o files are also in the
4681       sub-directory.  This is because automake 1.14 warns that the
4682       current behavior of compiling to the top level directory may be removed
4683       in the future.
4684    3) Updated dependencies on pnglibconf.h to match the new .o locations and
4685       added all the files in contrib/libtests and contrib/tools that depend
4686       on pnglibconf.h
4687    4) Added 'BUILD_SOURCES = pnglibconf.h'; this is the automake recommended
4688       way of handling the dependencies of sources that are machine generated;
4689       unfortunately it only works if the user does 'make all' or 'make check',
4690       so the dependencies (3) are still required.
4691  Cleaned up (char*) casts of zlib messages. The latest version of the Intel C
4692    compiler complains about casting a string literal as (char*), so copied the
4693    treatment of z_const from the library code into pngfix.c
4694  Simplified error message code in pngunknown. The simplification has the
4695    useful side effect of avoiding a bogus warning generated by the latest
4696    version of the Intel C compiler (it objects to
4697    condition ? string-literal : string-literal).
4698  Make autogen.sh work with automake 1.13 as well as 1.14. Do this by always
4699    removing the 1.14 'compile' script but never checking for it.
4700
4701Version 1.6.7beta03 [October 19, 2013]
4702  Added ARMv8 support (James Yu <james.yu at linaro.org>).  Added file
4703    arm/filter_neon_intrinsics.c; enable with -mfpu=neon.
4704  Revised pngvalid to generate size images with as many filters as it can
4705    manage, limited by the number of rows.
4706  Cleaned up ARM NEON compilation handling. The tests are now in pngpriv.h
4707    and detect the broken GCC compilers.
4708
4709Version 1.6.7beta04 [October 26, 2013]
4710  Allow clang derived from older GCC versions to use ARM intrinsics. This
4711    causes all clang builds that use -mfpu=neon to use the intrinsics code,
4712    not the assembler code.  This has only been tested on iOS 7. It may be
4713    necessary to exclude some earlier clang versions but this seems unlikely.
4714  Changed NEON implementation selection mechanism. This allows assembler
4715    or intrinsics to be turned on at compile time during the build by defining
4716    PNG_ARM_NEON_IMPLEMENTATION to the correct value (2 or 1).  This macro
4717    is undefined by default and the build type is selected in pngpriv.h.
4718
4719Version 1.6.7rc01 [November 2, 2013]
4720  No changes.
4721
4722Version 1.6.7rc02 [November 7, 2013]
4723  Fixed #include in filter_neon_intrinsics.c and ctype macros. The ctype char
4724    checking macros take an unsigned char argument, not a signed char.
4725
4726Version 1.6.7 [November 14, 2013]
4727  No changes.
4728
4729Version 1.6.8beta01 [November 24, 2013]
4730  Moved prototype for png_handle_unknown() in pngpriv.h outside of
4731    the #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED/#endif block.
4732  Added "-Wall" to CFLAGS in contrib/pngminim/*/makefile
4733  Conditionally compile some unused functions reported by -Wall in
4734    pngminim.
4735  Fixed 'minimal' builds. Various obviously useful minimal configurations
4736    don't build because of missing contrib/libtests test programs and
4737    overly complex dependencies in scripts/pnglibconf.dfa. This change
4738    adds contrib/conftest/*.dfa files that can be used in automatic build
4739    scripts to ensure that these configurations continue to build.
4740  Enabled WRITE_INVERT and WRITE_PACK in contrib/pngminim/encoder.
4741  Fixed pngvalid 'fail' function declaration on the Intel C Compiler.
4742    This reverts to the previous 'static' implementation and works round
4743    the 'unused static function' warning by using PNG_UNUSED().
4744
4745Version 1.6.8beta02 [November 30, 2013]
4746  Removed or marked PNG_UNUSED some harmless "dead assignments" reported
4747    by clang scan-build.
4748  Changed tabs to 3 spaces in png_debug macros and changed '"%s"m'
4749    to '"%s" m' to improve portability among compilers.
4750  Changed png_free_default() to free() in pngtest.c
4751
4752Version 1.6.8rc01 [December 12, 2013]
4753  Tidied up pngfix inits and fixed pngtest no-write builds.
4754
4755Version 1.6.8rc02 [December 14, 2013]
4756  Handle zero-length PLTE chunk or NULL palette with png_error()
4757    instead of png_chunk_report(), which by default issues a warning
4758    rather than an error, leading to later reading from a NULL pointer
4759    (png_ptr->palette) in png_do_expand_palette(). This is CVE-2013-6954
4760    and VU#650142.  Libpng-1.6.1 through 1.6.7 are vulnerable.
4761    Libpng-1.6.0 and earlier do not have this bug.
4762
4763Version 1.6.8 [December 19, 2013]
4764  No changes.
4765
4766Version 1.6.9beta01 [December 26, 2013]
4767  Bookkeeping: Moved functions around (no changes). Moved transform
4768    function definitions before the place where they are called so that
4769    they can be made static. Move the intrapixel functions and the
4770    grayscale palette builder out of the png?tran.c files. The latter
4771    isn't a transform function and is no longer used internally, and the
4772    former MNG specific functions are better placed in pngread/pngwrite.c
4773  Made transform implementation functions static. This makes the internal
4774    functions called by png_do_{read|write}_transformations static. On an
4775    x86-64 DLL build (Gentoo Linux) this reduces the size of the text
4776    segment of the DLL by 1208 bytes, about 0.6%. It also simplifies
4777    maintenance by removing the declarations from pngpriv.h and allowing
4778    easier changes to the internal interfaces.
4779  Rebuilt configure scripts with automake-1.14.1 and autoconf-2.69
4780    in the tar distributions.
4781
4782Version 1.6.9beta02 [January 1, 2014]
4783  Added checks for libpng 1.5 to pngvalid.c.  This supports the use of
4784    this version of pngvalid in libpng 1.5
4785  Merged with pngvalid.c from libpng-1.7 changes to create a single
4786    pngvalid.c
4787  Removed #error macro from contrib/tools/pngfix.c (Thomas Klausner).
4788  Merged pngrio.c, pngtrans.c, pngwio.c, and pngerror.c with libpng-1.7.0
4789  Merged libpng-1.7.0 changes to make no-interlace configurations work
4790    with test programs.
4791  Revised pngvalid.c to support libpng 1.5, which does not support the
4792    PNG_MAXIMUM_INFLATE_WINDOW option, so #define it out when appropriate in
4793    pngvalid.c
4794  Allow unversioned links created on install to be disabled in configure.
4795    In configure builds 'make install' changes/adds links like png.h
4796    and libpng.a to point to the newly installed, versioned, files (e.g.
4797    libpng17/png.h and libpng17.a). Three new configure options and some
4798    rearrangement of Makefile.am allow creation of these links to be disabled.
4799
4800Version 1.6.9beta03 [January 10, 2014]
4801  Removed potentially misleading warning from png_check_IHDR().
4802
4803Version 1.6.9beta04 [January 20, 2014]
4804  Updated scripts/makefile.* to use CPPFLAGS (Cosmin).
4805  Added clang attribute support (Cosmin).
4806
4807Version 1.6.9rc01 [January 28, 2014]
4808  No changes.
4809
4810Version 1.6.9rc02 [January 30, 2014]
4811  Quiet an uninitialized memory warning from VC2013 in png_get_png().
4812
4813Version 1.6.9 [February 6, 2014]
4814
4815Version 1.6.10beta01 [February 9, 2014]
4816  Backported changes from libpng-1.7.0beta30 and beta31:
4817  Fixed a large number of instances where PNGCBAPI was omitted from
4818    function definitions.
4819  Added pngimage test program for png_read_png() and png_write_png()
4820    with two new test scripts.
4821  Removed dependence on !PNG_READ_EXPAND_SUPPORTED for calling
4822    png_set_packing() in png_read_png().
4823  Fixed combination of ~alpha with shift. On read invert alpha, processing
4824    occurred after shift processing, which causes the final values to be
4825    outside the range that should be produced by the shift. Reversing the
4826    order on read makes the two transforms work together correctly and mirrors
4827    the order used on write.
4828  Do not read invalid sBIT chunks. Previously libpng only checked sBIT
4829    values on write, so a malicious PNG writer could therefore cause
4830    the read code to return an invalid sBIT chunk, which might lead to
4831    application errors or crashes.  Such chunks are now skipped (with
4832    chunk_benign_error).
4833  Make png_read_png() and png_write_png() prototypes in png.h depend
4834    upon PNG_READ_SUPPORTED and PNG_WRITE_SUPPORTED.
4835  Support builds with unsupported PNG_TRANSFORM_* values.  All of the
4836    PNG_TRANSFORM_* values are always defined in png.h and, because they
4837    are used for both read and write in some cases, it is not reliable
4838    to #if out ones that are totally unsupported. This change adds error
4839    detection in png_read_image() and png_write_image() to do a
4840    png_app_error() if the app requests something that cannot be done
4841    and it adds corresponding code to pngimage.c to handle such options
4842    by not attempting to test them.
4843
4844Version 1.6.10beta02 [February 23, 2014]
4845  Moved redefines of png_error(), png_warning(), png_chunk_error(),
4846    and png_chunk_warning() from pngpriv.h to png.h to make them visible
4847    to libpng-calling applications.
4848  Moved OS dependent code from arm/arm_init.c, to allow the included
4849    implementation of the ARM NEON discovery function to be set at
4850    build-time and provide sample implementations from the current code in the
4851    contrib/arm-neon subdirectory. The __linux__ code has also been changed to
4852    compile and link on Android by using /proc/cpuinfo, and the old linux code
4853    is in contrib/arm-neon/linux-auxv.c.  The new code avoids POSIX and Linux
4854    dependencies apart from opening /proc/cpuinfo and is C90 compliant.
4855  Check for info_ptr == NULL early in png_read_end() so we don't need to
4856    run all the png_handle_*() and depend on them to return if info_ptr == NULL.
4857    This improves the performance of png_read_end(png_ptr, NULL) and makes
4858    it more robust against future programming errors.
4859  Check for __has_extension before using it in pngconf.h, to
4860    support older Clang versions (Jeremy Sequoia).
4861  Treat CRC error handling with png_set_crc_action(), instead of with
4862    png_set_benign_errors(), which has been the case since libpng-1.6.0beta18.
4863  Use a user warning handler in contrib/gregbook/readpng2.c instead of default,
4864    so warnings will be put on stderr even if libpng has CONSOLE_IO disabled.
4865  Added png_ptr->process_mode = PNG_READ_IDAT_MODE in png_push_read_chunk
4866    after recognizing the IDAT chunk, which avoids an infinite loop while
4867    reading a datastream whose first IDAT chunk is of zero-length.
4868    This fixes CERT VU#684412 and CVE-2014-0333.
4869  Don't recognize known sRGB profiles as sRGB if they have been hacked,
4870    but don't reject them and don't issue a copyright violation warning.
4871
4872Version 1.6.10beta03 [February 25, 2014]
4873  Moved some documentation from png.h to libpng.3 and libpng-manual.txt
4874  Minor editing of contrib/arm-neon/README and contrib/examples/*.c
4875
4876Version 1.6.10rc01 [February 27, 2014]
4877  Fixed typos in the manual and in scripts/pnglibconf.dfa (CFLAGS -> CPPFLAGS
4878    and PNG_USR_CONFIG -> PNG_USER_CONFIG).
4879
4880Version 1.6.10rc02 [February 28, 2014]
4881  Removed unreachable return statement after png_chunk_error()
4882    in pngrutil.c
4883
4884Version 1.6.10rc03 [March 4, 2014]
4885  Un-deprecated png_data_freer().
4886
4887Version 1.6.10 [March 6, 2014]
4888  No changes.
4889
4890Version 1.6.11beta01 [March 17, 2014]
4891  Use "if (value != 0)" instead of "if (value)" consistently.
4892  Changed ZlibSrcDir from 1.2.5 to 1.2.8 in projects/vstudio.
4893  Moved configuration information from the manual to the INSTALL file.
4894
4895Version 1.6.11beta02 [April 6, 2014]
4896  Removed #if/#else/#endif from inside two pow() calls in pngvalid.c because
4897    they were handled improperly by Portland Group's PGI-14.1 - PGI-14.3
4898    when using its "__builtin_pow()" function.
4899  Silence 'unused parameter' build warnings (Cosmin Truta).
4900  $(CP) is now used alongside $(RM_F).  Also, use 'copy' instead of 'cp'
4901    where applicable, and applied other minor makefile changes (Cosmin).
4902  Don't warn about invalid dimensions exceeding user limits (Cosmin).
4903  Allow an easy replacement of the default pre-built configuration
4904    header with a custom header, via the make PNGLIBCONF_H_PREBUILT
4905    macro (Cosmin).
4906
4907Version 1.6.11beta03 [April 6, 2014]
4908  Fixed a typo in pngrutil.c, introduced in libpng-1.5.6, that interferes
4909    with "blocky" expansion of sub-8-bit interlaced PNG files (Eric Huss).
4910  Optionally use  __builtin_bswap16() in png_do_swap().
4911
4912Version 1.6.11beta04 [April 19, 2014]
4913  Made progressive reading of interlaced images consistent with the
4914    behavior of the sequential reader and consistent with the manual, by
4915    moving some code out of the PNG_READ_INTERLACING_SUPPORTED blocks. The
4916    row_callback now receives the proper pass number and unexpanded rows, when
4917    png_combine_row() isn't built or used, and png_set_interlace_handling()
4918    is not called.
4919  Allow PNG_sRGB_PROFILE_CHECKING = (-1) to mean no sRGB profile checking.
4920
4921Version 1.6.11beta05 [April 26, 2014]
4922  Do not reject ICC V2 profiles that lack padding (Kai-Uwe Behrmann).
4923  Relocated closing bracket of the sRGB profile test loop to avoid getting
4924    "Not recognizing known sRGB profile that has been edited" warning for
4925    ICC V2 profiles that lack the MD5 signature in the profile header.
4926
4927Version 1.6.11beta06 [May 19, 2014]
4928  Added PNG_SKIP_sRGB_CHECK_PROFILE choice for png_set_option().
4929
4930Version 1.6.11rc01 [May 27, 2014]
4931  No changes.
4932
4933Version 1.6.11rc02 [June 3, 2014]
4934  Test ZLIB_VERNUM instead of PNG_ZLIB_VERNUM in contrib/tools/pngfix.c
4935
4936Version 1.6.11 [June 5, 2014]
4937  No changes.
4938
4939Version 1.6.12rc01 [June 6, 2014]
4940  Relocated new code from 1.6.11beta06 in png.c to a point after the
4941    declarations (Max Stepin).
4942
4943Version 1.6.12rc02 [June 7, 2014]
4944  Changed file permissions of contrib/tools/intgamma.sh,
4945    test-driver, and compile from 0644 to 0755 (Cosmin).
4946
4947Version 1.6.12rc03 [June 8, 2014]
4948  Ensure "__has_attribute()" macro exists before trying to use it with
4949    old clang compilers (MacPorts Ticket #43939).
4950
4951Version 1.6.12 [June 12, 2014]
4952  No changes.
4953
4954Version 1.6.13beta01 [July 4, 2014]
4955  Quieted -Wsign-compare and -Wclobber compiler warnings in
4956    contrib/pngminus/*.c
4957  Added "(void) png_ptr;" where needed in contrib/gregbook to quiet
4958    compiler complaints about unused pointers.
4959  Split a long output string in contrib/gregbook/rpng2-x.c.
4960  Added "PNG_SET_OPTION" requirement for sRGB chunk support to pnglibconf.dfa,
4961    Needed for write-only support (John Bowler).
4962  Changed "if defined(__ARM_NEON__)" to
4963    "if (defined(__ARM_NEON__) || defined(__ARM_NEON))" (James Wu).
4964  Fixed clang no-warning builds: png_digit was defined but never used.
4965
4966Version 1.6.13beta02 [July 21, 2014]
4967  Fixed an incorrect separator ("/" should be "\") in scripts/makefile.vcwin32
4968    (bug report from Wolfgang S. Kechel).  Bug was introduced in libpng-1.6.11.
4969    Also fixed makefile.bc32, makefile.bor, makefile.msc, makefile.intel, and
4970    makefile.tc3 similarly.
4971
4972Version 1.6.13beta03 [August 3, 2014]
4973  Removed scripts/makefile.elf. It has not worked since libpng-1.5.0beta14
4974    due to elimination of the PNG_FUNCTION_EXPORT and PNG_DATA_EXPORT
4975    definitions from pngconf.h.
4976  Ensure that CMakeLists.txt makes the target "lib" directory before making
4977    symbolic link into it (SourceForge bug report #226 by Rolf Timmermans).
4978
4979Version 1.6.13beta04 [August 8, 2014]
4980  Added opinion that the ECCN (Export Control Classification Number) for
4981    libpng is EAR99 to the README file.
4982  Eliminated use of "$<" in makefile explicit rules, when copying
4983    $PNGLIBCONF_H_PREBUILT.  This does not work on some versions of make;
4984    bug introduced in libpng version 1.6.11.
4985
4986Version 1.6.13rc01 [August 14, 2014]
4987  Made "ccopts" agree with "CFLAGS" in scripts/makefile.hp* and makefile.*sunu
4988
4989Version 1.6.13 [August 21, 2014]
4990  No changes.
4991
4992Version 1.6.14beta01 [September 14, 2014]
4993  Guard usage of png_ptr->options with #ifdef PNG_SET_OPTION_SUPPORTED.
4994  Do not build contrib/tools/pngfix.c when PNG_SETJMP_NOT_SUPPORTED,
4995    to allow "make" to complete without setjmp support (bug report by
4996    Claudio Fontana)
4997  Add "#include <setjmp.h>" to contrib/tools/pngfix.c (John Bowler)
4998
4999Version 1.6.14beta02 [September 18, 2014]
5000  Use nanosleep() instead of usleep() in contrib/gregbook/rpng2-x.c
5001    because usleep() is deprecated.
5002  Define usleep() in contrib/gregbook/rpng2-x.c if not already defined
5003    in unistd.h and nanosleep() is not available; fixes error introduced
5004    in libpng-1.6.13.
5005  Disable floating point exception handling in pngvalid.c when
5006    PNG_FLOATING_ARITHMETIC is not supported (bug report by "zootus
5007    at users.sourceforge.net").
5008
5009Version 1.6.14beta03 [September 19, 2014]
5010  Define FE_DIVBYZERO, FE_INVALID, and FE_OVERFLOW in pngvalid.c if not
5011    already defined.  Revert floating point exception handling in pngvalid.c
5012    to version 1.6.14beta01 behavior.
5013
5014Version 1.6.14beta04 [September 27, 2014]
5015  Fixed incorrect handling of the iTXt compression flag in pngrutil.c
5016    (bug report by Shunsaku Hirata).  Bug was introduced in libpng-1.6.0.
5017
5018Version 1.6.14beta05 [October 1, 2014]
5019  Added "option READ_iCCP enables READ_COMPRESSED_TEXT" to pnglibconf.dfa
5020
5021Version 1.6.14beta06 [October 5, 2014]
5022  Removed unused "text_len" parameter from private function png_write_zTXt().
5023  Conditionally compile some code in png_deflate_claim(), when
5024    PNG_WARNINGS_SUPPORTED and PNG_ERROR_TEXT_SUPPORTED are disabled.
5025  Replaced repeated code in pngpread.c with PNG_PUSH_SAVE_BUFFER_IF_FULL.
5026  Added "chunk iTXt enables TEXT" and "chunk zTXt enables TEXT"
5027    to pnglibconf.dfa.
5028  Removed "option READ_COMPRESSED_TEXT enables READ_TEXT" from pnglibconf.dfa,
5029    to make it possible to configure a libpng that supports iCCP but not TEXT.
5030
5031Version 1.6.14beta07 [October 7, 2014]
5032  Removed "option WRITE_COMPRESSED_TEXT enables WRITE_TEXT" from pnglibconf.dfa
5033  Only mark text chunks as written after successfully writing them.
5034
5035Version 1.6.14rc01 [October 15, 2014]
5036  Fixed some typos in comments.
5037
5038Version 1.6.14rc02 [October 17, 2014]
5039  Changed png_convert_to_rfc_1123() to png_convert_to_rfc_1123_buffer()
5040    in the manual, to reflect the change made in libpng-1.6.0.
5041  Updated README file to explain that direct access to the png_struct
5042    and info_struct members has not been permitted since libpng-1.5.0.
5043
5044Version 1.6.14 [October 23, 2014]
5045  No changes.
5046
5047Version 1.6.15beta01 [October 29, 2014]
5048  Changed "if (!x)" to "if (x == 0)" and "if (x)" to "if (x != 0)"
5049  Simplified png_free_data().
5050  Added missing "ptr = NULL" after some instances of png_free().
5051
5052Version 1.6.15beta02 [November 1, 2014]
5053  Changed remaining "if (!x)" to "if (x == 0)" and "if (x)" to "if (x != 0)"
5054
5055Version 1.6.15beta03 [November 3, 2014]
5056  Added PNG_USE_ARM_NEON configuration flag (Marcin Juszkiewicz).
5057
5058Version 1.6.15beta04 [November 4, 2014]
5059  Removed new PNG_USE_ARM_NEON configuration flag and made a one-line
5060    revision to configure.ac to support ARM on aarch64 instead (John Bowler).
5061
5062Version 1.6.15beta05 [November 5, 2014]
5063  Use png_get_libpng_ver(NULL) instead of PNG_LIBPNG_VER_STRING in
5064    example.c, pngtest.c, and applications in the contrib directory.
5065  Fixed an out-of-range read in png_user_version_check() (Bug report from
5066    Qixue Xiao, CVE-2015-8540).
5067  Simplified and future-proofed png_user_version_check().
5068  Fixed GCC unsigned int->float warnings. Various versions of GCC
5069    seem to generate warnings when an unsigned value is implicitly
5070    converted to double. This is probably a GCC bug but this change
5071    avoids the issue by explicitly converting to (int) where safe.
5072  Free all allocated memory in pngimage. The file buffer cache was left
5073    allocated at the end of the program, harmless but it causes memory
5074    leak reports from clang.
5075  Fixed array size calculations to avoid warnings. At various points
5076    in the code the number of elements in an array is calculated using
5077    sizeof.  This generates a compile time constant of type (size_t) which
5078    is then typically assigned to an (unsigned int) or (int). Some versions
5079    of GCC on 64-bit systems warn about the apparent narrowing, even though
5080    the same compiler does apparently generate the correct, in-range,
5081    numeric constant.  This adds appropriate, safe, casts to make the
5082    warnings go away.
5083
5084Version 1.6.15beta06 [November 6, 2014]
5085  Reverted use png_get_libpng_ver(NULL) instead of PNG_LIBPNG_VER_STRING
5086    in the manual, example.c, pngtest.c, and applications in the contrib
5087    directory.  It was incorrect advice.
5088
5089Version 1.6.15beta07 [November 7, 2014]
5090  Removed #ifdef PNG_16BIT_SUPPORTED/#endif around png_product2(); it is
5091    needed by png_reciprocal2().
5092  Added #ifdef PNG_16BIT_SUPPORTED/#endif around png_log16bit() and
5093    png_do_swap().
5094  Changed all "#endif /* PNG_FEATURE_SUPPORTED */" to "#endif /* FEATURE */"
5095
5096Version 1.6.15beta08 [November 8, 2014]
5097  More housecleaning in *.h
5098
5099Version 1.6.15rc01 [November 13, 2014]
5100
5101Version 1.6.15rc02 [November 14, 2014]
5102  The macros passed in the command line to Borland make were ignored if
5103    similarly-named macros were already defined in makefiles. This behavior
5104    is different from POSIX make and other make programs.  Surround the
5105    macro definitions with ifndef guards (Cosmin).
5106
5107Version 1.6.15rc03 [November 16, 2014]
5108  Added "-D_CRT_SECURE_NO_WARNINGS" to CFLAGS in scripts/makefile.vcwin32.
5109  Removed the obsolete $ARCH variable from scripts/makefile.darwin.
5110
5111Version 1.6.15 [November 20, 2014]
5112  No changes.
5113
5114Version 1.6.16beta01 [December 14, 2014]
5115  Added ".align 2" to arm/filter_neon.S to support old GAS assemblers that
5116    don't do alignment correctly.
5117  Revised Makefile.am and scripts/symbols.dfn to work with MinGW/MSYS
5118    (Bob Friesenhahn).
5119
5120Version 1.6.16beta02 [December 15, 2014]
5121  Revised Makefile.am and scripts/*.dfn again to work with MinGW/MSYS;
5122    renamed scripts/*.dfn to scripts/*.c (John Bowler).
5123
5124Version 1.6.16beta03 [December 21, 2014]
5125  Quiet a "comparison always true" warning in pngstest.c (John Bowler).
5126
5127Version 1.6.16rc01 [December 21, 2014]
5128  Restored a test on width that was removed from png.c at libpng-1.6.9
5129    (Bug report by Alex Eubanks, CVE-2015-0973).
5130
5131Version 1.6.16rc02 [December 21, 2014]
5132  Undid the update to pngrutil.c in 1.6.16rc01.
5133
5134Version 1.6.16rc03 [December 21, 2014]
5135  Fixed an overflow in png_combine_row() with very wide interlaced images
5136    (Bug report and fix by John Bowler, CVE-2014-9495).
5137
5138Version 1.6.16 [December 22, 2014]
5139  No changes.
5140
5141Version 1.6.17beta01 [January 29, 2015]
5142  Removed duplicate PNG_SAFE_LIMITS_SUPPORTED handling from pngconf.h
5143  Corrected the width limit calculation in png_check_IHDR().
5144  Removed user limits from pngfix. Also pass NULL pointers to
5145    png_read_row to skip the unnecessary row de-interlace stuff.
5146  Added testing of png_set_packing() to pngvalid.c
5147  Regenerated configure scripts in the *.tar distributions with libtool-2.4.4
5148  Implement previously untested cases of libpng transforms in pngvalid.c
5149  Fixed byte order in png_do_read_filler() with 16-bit input. Previously
5150    the high and low bytes of the filler, from png_set_filler() or from
5151    png_set_add_alpha(), were read in the wrong order.
5152  Made the check for out-of-range values in png_set_tRNS() detect
5153    values that are exactly 2^bit_depth, and work on 16-bit platforms.
5154  Merged some parts of libpng-1.6.17beta01 and libpng-1.7.0beta47.
5155  Added #ifndef __COVERITY__ where needed in png.c, pngrutil.c and
5156    pngset.c to avoid warnings about dead code.
5157  Added "& 0xff" to many instances of expressions that are typecast
5158    to (png_byte), to avoid Coverity warnings.
5159
5160Version 1.6.17beta02 [February 7, 2015]
5161  Work around one more Coverity-scan dead-code warning.
5162  Do not build png_product2() when it is unused.
5163
5164Version 1.6.17beta03 [February 17, 2015]
5165  Display user limits in the output from pngtest.
5166  Eliminated the PNG_SAFE_LIMITS macro and restored the 1-million-column
5167    and 1-million-row default limits in pnglibconf.dfa, that can be reset
5168    by the user at build time or run time.  This provides a more robust
5169    defense against DOS and as-yet undiscovered overflows.
5170
5171Version 1.6.17beta04 [February 21, 2015]
5172  Added PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED macro, on by default.
5173  Allow user to call png_get_IHDR() with NULL arguments (Reuben Hawkins).
5174  Rebuilt configure scripts with automake-1.15 and libtool-2.4.6
5175
5176Version 1.6.17beta05 [February 25, 2015]
5177  Restored compiling of png_reciprocal2 with PNG_NO_16BIT.
5178
5179Version 1.6.17beta06 [February 27, 2015]
5180  Moved png_set_filter() prototype into a PNG_WRITE_SUPPORTED block
5181    of png.h.
5182  Avoid runtime checks when converting integer to png_byte with
5183    Visual Studio (Sergey Kosarevsky)
5184
5185Version 1.6.17rc01 [March 4, 2015]
5186  No changes.
5187
5188Version 1.6.17rc02 [March 9, 2015]
5189  Removed some comments that the configure script did not handle
5190    properly from scripts/pnglibconf.dfa and pnglibconf.h.prebuilt.
5191  Free the unknown_chunks structure even when it contains no data.
5192
5193Version 1.6.17rc03 [March 12, 2015]
5194  Updated CMakeLists.txt to add OSX framework, change YES/NO to ON/OFF
5195    for consistency, and remove some useless tests (Alexey Petruchik).
5196
5197Version 1.6.17rc04 [March 16, 2015]
5198  Remove pnglibconf.h, pnglibconf.c, and pnglibconf.out instead of
5199    pnglibconf.* in "make clean" (Cosmin).
5200  Fix bug in calculation of maxbits, in png_write_sBIT, introduced
5201    in libpng-1.6.17beta01 (John Bowler).
5202
5203Version 1.6.17rc05 [March 21, 2015]
5204  Define PNG_FILTER_* and PNG_FILTER_VALUE_* in png.h even when WRITE
5205    is not supported (John Bowler).  This fixes an error introduced in
5206    libpng-1.6.17beta06.
5207  Reverted "& 0xff" additions of version 1.6.17beta01. Libpng passes
5208    the Coverity scan without them.
5209
5210Version 1.6.17rc06 [March 23, 2015]
5211  Remove pnglibconf.dfn and pnglibconf.pre with "make clean".
5212  Reformatted some "&0xff" instances to "& 0xff".
5213  Fixed simplified 8-bit-linear to sRGB alpha. The calculated alpha
5214    value was wrong.  It's not clear if this affected the final stored
5215    value; in the obvious code path the upper and lower 8-bits of the
5216    alpha value were identical and the alpha was truncated to 8-bits
5217    rather than dividing by 257 (John Bowler).
5218
5219Version 1.6.17 [March 26, 2015]
5220  No changes.
5221
5222Version 1.6.18beta01 [April 1, 2015]
5223  Removed PNG_SET_CHUNK_[CACHE|MALLOC]_LIMIT_SUPPORTED macros.  They
5224    have been combined with PNG_SET_USER_LIMITS_SUPPORTED (resolves
5225    bug report by Andrew Church).
5226  Fixed rgb_to_gray checks and added tRNS checks to pngvalid.c.  This
5227    fixes some arithmetic errors that caused some tests to fail on
5228    some 32-bit platforms (Bug reports by Peter Breitenlohner [i686]
5229    and Petr Gajdos [i586]).
5230
5231Version 1.6.18beta02 [April 26, 2015]
5232  Suppressed some warnings from the Borland C++ 5.5.1/5.82 compiler
5233    (Bug report by Viktor Szakats).
5234
5235Version 1.6.18beta03 [May 6, 2015]
5236  Replaced "unexpected" with an integer (0xabadca11) in pngset.c
5237    where a long was expected, to avoid a compiler warning when PNG_DEBUG > 1.
5238  Added contrib/examples/simpleover.c, to demonstrate how to handle
5239    alpha compositing of multiple images, using the "simplified API"
5240    and an example PNG generation tool, contrib/examples/genpng.c
5241    (John Bowler).
5242
5243Version 1.6.18beta04 [May 20, 2015]
5244  PNG_RELEASE_BUILD replaces tests where the code depended on the build base
5245    type and can be defined on the command line, allowing testing in beta
5246    builds (John Bowler).
5247  Avoid Coverity issue 80858 (REVERSE NULL) in pngtest.c PNG_DEBUG builds.
5248  Avoid a harmless potential integer overflow in png_XYZ_from_xy() (Bug
5249    report from Christopher Ferris).
5250
5251Version 1.6.18beta05 [May 31, 2015]
5252  Backport filter selection code from libpng-1.7.0beta51, to combine
5253    sub_row, up_row, avg_row, and paeth_row into try_row and tst_row.
5254  Changed png_voidcast(), etc., to voidcast(), etc., in contrib/tools/pngfix.c
5255    to avoid confusion with the libpng private macros.
5256  Fixed old cut&paste bug in the weighted filter selection code in
5257    pngwutil.c, introduced in libpng-0.95, March 1997.
5258
5259Version 1.6.18beta06 [June 1, 2015]
5260  Removed WRITE_WEIGHTED_FILTERED code, to save a few kbytes of the
5261    compiled library size. It never worked properly and as far as we can
5262    tell, no one uses it. The png_set_filter_heuristics() and
5263    png_set_filter_heuristics_fixed() APIs are retained but deprecated
5264    and do nothing.
5265
5266Version 1.6.18beta07 [June 6, 2015]
5267  Removed non-working progressive reader 'skip' function. This
5268    function has apparently never been used. It was implemented
5269    to support back-door modification of png_struct in libpng-1.4.x
5270    but (because it does nothing and cannot do anything) was apparently
5271    never tested (John Bowler).
5272  Fixed cexcept.h in which GCC 5 now reports that one of the auto
5273    variables in the Try macro needs to be volatile to prevent value
5274    being lost over the setjmp (John Bowler).
5275  Fixed NO_WRITE_FILTER and -Wconversion build breaks (John Bowler).
5276  Fix g++ build breaks (John Bowler).
5277  Quieted some Coverity issues in pngfix.c, png-fix-itxt.c, pngvalid.c,
5278    pngstest.c, and pngimage.c. Most seem harmless, but png-fix-itxt
5279    would only work with iTXt chunks with length 255 or less.
5280  Added #ifdef's to contrib/examples programs so people don't try
5281    to compile them without the minimum required support enabled
5282    (suggested by Flavio Medeiros).
5283
5284Version 1.6.18beta08 [June 30, 2015]
5285  Eliminated the final two Coverity defects (insecure temporary file
5286    handling in contrib/libtests/pngstest.c; possible overflow of
5287    unsigned char in contrib/tools/png-fix-itxt.c). To use the "secure"
5288    file handling, define PNG_USE_MKSTEMP, otherwise "tmpfile()" will
5289    be used.
5290  Removed some unused WEIGHTED_FILTER macros from png.h and pngstruct.h
5291
5292Version 1.6.18beta09 [July 5, 2015]
5293  Removed some useless typecasts from contrib/tools/png-fix-itxt.c
5294  Fixed a new signed-unsigned comparison in pngrtran.c (Max Stepin).
5295  Replaced arbitrary use of 'extern' with #define PNG_LINKAGE_*.  To
5296    preserve API compatibility, the new defines all default to "extern"
5297    (requested by Jan Nijtmans).
5298
5299Version 1.6.18rc01 [July 9, 2015]
5300  Belatedly added Mans Rullgard and James Yu to the list of Contributing
5301    Authors.
5302
5303Version 1.6.18rc02 [July 12, 2015]
5304  Restored unused FILTER_HEURISTIC macros removed at libpng-1.6.18beta08
5305    to png.h to avoid compatibility warnings.
5306
5307Version 1.6.18rc03 [July 15, 2015]
5308  Minor changes to the man page
5309
5310Version 1.6.18 [July 23, 2015]
5311  No changes.
5312
5313Version 1.6.19beta01 [July 30, 2015]
5314  Updated obsolete information about the simplified API macros in the
5315    manual pages (Bug report by Arc Riley).
5316  Avoid potentially dereferencing NULL info_ptr in png_info_init_3().
5317  Rearranged png.h to put the major sections in the same order as
5318    in libpng17.
5319  Eliminated unused PNG_COST_SHIFT, PNG_WEIGHT_SHIFT, PNG_COST_FACTOR, and
5320    PNG_WEIGHT_FACTOR macros.
5321  Suppressed some warnings from the Borland C++ 5.5.1/5.82 compiler
5322    (Bug report by Viktor Szakats).  Several warnings remain and are
5323    unavoidable, where we test for overflow.
5324  Fixed potential leak of png_pixels in contrib/pngminus/pnm2png.c
5325  Fixed uninitialized variable in contrib/gregbook/rpng2-x.c
5326
5327Version 1.6.19beta02 [August 19, 2015]
5328  Moved config.h.in~ from the "libpng_autotools_files" list to the
5329    "libpng_autotools_extra" list in autogen.sh because it was causing a
5330    false positive for missing files (bug report by Robert C. Seacord).
5331  Removed unreachable "break" statements in png.c, pngread.c, and pngrtran.c
5332    to suppress clang warnings (Bug report by Viktor Szakats).
5333  Fixed some bad links in the man page.
5334  Changed "n bit" to "n-bit" in comments.
5335  Added signed/unsigned 16-bit safety net. This removes the dubious
5336    0x8000 flag definitions on 16-bit systems. They aren't supported
5337    yet the defs *probably* work, however it seems much safer to do this
5338    and be advised if anyone, contrary to advice, is building libpng 1.6
5339    on a 16-bit system. It also adds back various switch default clauses
5340    for GCC; GCC errors out if they are not present (with an appropriately
5341    high level of warnings).
5342  Safely convert num_bytes to a png_byte in png_set_sig_bytes() (Robert
5343    Seacord).
5344  Fixed the recently reported 1's complement security issue by replacing
5345    the value that is illegal in the PNG spec, in both signed and unsigned
5346    values, with 0. Illegal unsigned values (anything greater than or equal
5347    to  0x80000000) can still pass through, but since these are not illegal
5348    in ANSI-C (unlike 0x80000000 in the signed case) the checking that
5349    occurs later can catch them (John Bowler).
5350
5351Version 1.6.19beta03 [September 26, 2015]
5352  Fixed png_save_int_32 when int is not 2's complement (John Bowler).
5353  Updated libpng16 with all the recent test changes from libpng17,
5354    including changes to pngvalid.c to ensure that the original,
5355    distributed, version of contrib/visupng/cexcept.h can be used
5356    (John Bowler).
5357  pngvalid contains the correction to the use of SAVE/STORE_
5358    UNKNOWN_CHUNKS; a bug revealed by changes in libpng 1.7. More
5359    tests contain the --strict option to detect warnings and the
5360    pngvalid-standard test has been corrected so that it does not
5361    turn on progressive-read. There is a separate test which does
5362    that. (John Bowler)
5363  Also made some signed/unsigned fixes.
5364  Make pngstest error limits version specific. Splitting the machine
5365    generated error structs out to a file allows the values to be updated
5366    without changing pngstest.c itself. Since libpng 1.6 and 1.7 have
5367    slightly different error limits this simplifies maintenance. The
5368    makepngs.sh script has also been updated to more accurately reflect
5369    current problems in libpng 1.7 (John Bowler).
5370  Incorporated new test PNG files into make check.  tests/pngstest-*
5371    are changed so that the new test files are divided into 8 groups by
5372    gamma and alpha channel.  These tests have considerably better code
5373    and pixel-value coverage than contrib/pngsuite; however,coverage is
5374    still incomplete (John Bowler).
5375  Removed the '--strict' in 1.6 because of the double-gamma-correction
5376    warning, updated pngstest-errors.h for the errors detected with the
5377    new contrib/testspngs PNG test files (John Bowler).
5378
5379Version 1.6.19beta04 [October 15, 2015]
5380  Worked around rgb-to-gray issues in libpng 1.6.  The previous
5381    attempts to ignore the errors in the code aren't quite enough to
5382    deal with the 'channel selection' encoding added to libpng 1.7; abort.
5383    pngvalid.c is changed to drop this encoding in prior versions.
5384  Fixed 'pow' macros in pngvalid.c. It is legal for 'pow' to be a
5385    macro, therefore the argument list cannot contain preprocessing
5386    directives.  Make sure pow is a function where this happens. This is
5387    a minimal safe fix, the issue only arises in non-performance-critical
5388    code (bug report by Curtis Leach, fix by John Bowler).
5389  Added sPLT support to pngtest.c
5390
5391Version 1.6.19rc01 [October 23, 2015]
5392  No changes.
5393
5394Version 1.6.19rc02 [October 31, 2015]
5395  Prevent setting or writing over-length PLTE chunk (Cosmin Truta).
5396  Silently truncate over-length PLTE chunk while reading.
5397  Libpng incorrectly calculated the output rowbytes when the application
5398    decreased either the number of channels or the bit depth (or both) in
5399    a user transform.  This was safe; libpng overallocated buffer space
5400   (potentially by quite a lot; up to 4 times the amount required) but,
5401   from 1.5.4 on, resulted in a png_error (John Bowler).
5402
5403Version 1.6.19rc03 [November 3, 2015]
5404  Fixed some inconsequential cut-and-paste typos in png_set_cHRM_XYZ_fixed().
5405  Clarified COPYRIGHT information to state explicitly that versions
5406    are derived from previous versions.
5407  Removed much of the long list of previous versions from png.h and
5408    libpng.3.
5409
5410Version 1.6.19rc04 [November 5, 2015]
5411  Fixed new bug with CRC error after reading an over-length palette
5412    (bug report by Cosmin Truta) (CVE-2015-8126).
5413
5414Version 1.6.19 [November 12, 2015]
5415  Cleaned up coding style in png_handle_PLTE().
5416
5417Version 1.6.20beta01 [November 20, 2015]
5418  Avoid potential pointer overflow/underflow in png_handle_sPLT() and
5419    png_handle_pCAL() (Bug report by John Regehr).
5420
5421Version 1.6.20beta02 [November 23, 2015]
5422  Fixed incorrect implementation of png_set_PLTE() that uses png_ptr
5423    not info_ptr, that left png_set_PLTE() open to the CVE-2015-8126
5424    vulnerability.  Fixes CVE-2015-8472.
5425
5426Version 1.6.20beta03 [November 24, 2015]
5427  Backported tests from libpng-1.7.0beta69.
5428
5429Version 1.6.20rc01 [November 26, 2015]
5430  Fixed an error in handling of bad zlib CMINFO field in pngfix, found by
5431    American Fuzzy Lop, reported by Brian Carpenter.  inflate() doesn't
5432    immediately fault a bad CMINFO field; instead a 'too far back' error
5433    happens later (at least some times).  pngfix failed to limit CMINFO to
5434    the allowed values but then assumed that window_bits was in range,
5435    triggering an assert. The bug is mostly harmless; the PNG file cannot
5436    be fixed.
5437
5438Version 1.6.20rc02 [November 29, 2015]
5439  In libpng 1.6 zlib initialization was changed to use the window size
5440    in the zlib stream, not a fixed value. This causes some invalid images,
5441    where CINFO is too large, to display 'correctly' if the rest of the
5442    data is valid.  This provides a workaround for zlib versions where the
5443    error arises (ones that support the API change to use the window size
5444    in the stream).
5445
5446Version 1.6.20 [December 3, 2015]
5447  No changes.
5448
5449Version 1.6.21beta01 [December 11, 2015]
5450  Fixed syntax "$(command)" in tests/pngstest that some shells other than
5451    bash could not parse (Bug report by Nelson Beebe). Use `command` instead.
5452
5453Version 1.6.21beta02 [December 14, 2015]
5454  Moved png_check_keyword() from pngwutil.c to pngset.c
5455  Removed LE/BE dependencies in pngvalid, to 'fix' the current problem
5456    in the BigEndian tests by not testing it, making the BE code the same
5457    as the LE version.
5458  Fixes to pngvalid for various reduced build configurations (eliminate unused
5459    statics) and a fix for the case in rgb_to_gray when the digitize option
5460    reduces graylo to 0, producing a large error.
5461
5462Version 1.6.21beta03 [December 18, 2015]
5463  Widened the 'limit' check on the internally calculated error limits in
5464    the 'DIGITIZE' case (the code used prior to 1.7 for rgb_to_gray error
5465    checks) and changed the check to only operate in non-release builds
5466    (base build type not RC or RELEASE.)
5467  Fixed undefined behavior in pngvalid.c, undefined because
5468    (png_byte) << shift is undefined if it changes the signed bit
5469    (because png_byte is promoted to int). The libpng exported functions
5470    png_get_uint_32 and png_get_uint_16 handle this. (Bug reported by
5471    David Drysdale as a result of reports from UBSAN in clang 3.8).
5472  This changes pngvalid to use BE random numbers; this used to produce
5473    errors but these should not be fixed as a result of the previous changes.
5474
5475Version 1.6.21rc01 [January 4, 2016]
5476  In projects/vstudio, combined readme.txt and WARNING into README.txt
5477
5478Version 1.6.21rc02 [January 7, 2016]
5479  Relocated assert() in contrib/tools/pngfix.c, bug found by American
5480    Fuzzy Lop, reported by Brian Carpenter.
5481  Marked 'limit' UNUSED in transform_range_check().  This only affects
5482    release builds.
5483
5484Version 1.6.21 [January 15, 2016]
5485  Worked around a false-positive Coverity issue in pngvalid.c.
5486
5487Version 1.6.22beta01 [January 23, 2016]
5488  Changed PNG_USE_MKSTEMP to __COVERITY__ to select alternate
5489    "tmpfile()" implementation in contrib/libtests/pngstest.c
5490  Fixed NO_STDIO build of pngunknown.c to skip calling png_init_io()
5491    if there is no stdio.h support.
5492  Added a png_image_write_to_memory() API and a number of assist macros
5493    to allow an application that uses the simplified API write to bypass
5494    stdio and write directly to memory.
5495  Added some warnings (png.h) and some check code to detect *possible*
5496    overflow in the ROW_STRIDE and simplified image SIZE macros.  This
5497    disallows image width/height/format that *might* overflow.  This is
5498    a quiet API change that limits in-memory image size (uncompressed) to
5499    less than 4GByte and image row size (stride) to less than 2GByte.
5500  Revised workaround for false-positive Coverity issue in pngvalid.c.
5501
5502Version 1.6.22beta02 [February 8, 2016]
5503  Only use exit(77) in configure builds.
5504  Corrected error in PNG_IMAGE_PNG_SIZE_MAX. This new macro underreported
5505    the palette size because it failed to take into account that the memory
5506    palette has to be expanded to full RGB when it is written to PNG.
5507  Updated CMakeLists.txt, added supporting scripts/gen*.cmake.in
5508    and test.cmake.in (Roger Leigh).
5509  Relaxed limit checks on gamma values in pngrtran.c. As suggested in
5510    the comments gamma values outside the range currently permitted
5511    by png_set_alpha_mode are useful for HDR data encoding.  These values
5512    are already permitted by png_set_gamma so it is reasonable caution to
5513    extend the png_set_alpha_mode range as HDR imaging systems are starting
5514    to emerge.
5515
5516Version 1.6.22beta03 [March 9, 2016]
5517  Added a common-law trademark notice and export control information
5518    to the LICENSE file, png.h, and the man page.
5519  Restored "& 0xff" in png_save_uint_16() and png_save_uint_32() that
5520    were accidentally removed from libpng-1.6.17.
5521  Changed PNG_INFO_cHNK and PNG_FREE_cHNK from 0xnnnn to 0xnnnnU in png.h
5522    (Robert C. Seacord).
5523  Removed dubious "#if INT_MAX" test from png.h that was added to
5524    libpng-1.6.19beta02 (John Bowler).
5525  Add ${INCLUDES} in scripts/genout.cmake.in (Bug report by Nixon Kwok).
5526  Updated LICENSE to say files in the contrib directory are not
5527    necessarily under the libpng license, and that some makefiles have
5528    other copyright owners.
5529  Added INTEL-SSE2 support (Mike Klein and Matt Sarett, Google, Inc.).
5530  Made contrib/libtests/timepng more robust.  The code no longer gives
5531    up/fails on invalid PNG data, it just skips it (with error messages).
5532    The code no longer fails on PNG files with data beyond IEND.  Options
5533    exist to use png_read_png (reading the whole image, not by row) and, in
5534    that case, to apply any of the supported transforms.  This makes for
5535    more realistic testing; the decoded data actually gets used in a
5536    meaningful fashion (John Bowler).
5537  Fixed some misleading indentation (Krishnaraj Bhat).
5538
5539Version 1.6.22beta04 [April 5, 2016]
5540  Force GCC compilation to C89 if needed (Dagobert Michelsen).
5541  SSE filter speed improvements for bpp=3:
5542    memcpy-free implementations of load3() / store3().
5543    call load3() only when needed at the end of a scanline.
5544
5545Version 1.6.22beta05 [April 27, 2016]
5546  Added PNG_FAST_FILTERS macro (defined as
5547    PNG_FILTER_NONE|PNG_FILTER_SUB|PNG_FILTER_UP).
5548  Various fixes for contrib/libtests/timepng.c
5549  Moved INTEL-SSE code from pngpriv.h into contrib/intel/intel_sse.patch.
5550  Fixed typo (missing underscore) in #define PNG_READ_16_TO_8_SUPPORTED
5551    (Bug report by Y.Ohashik).
5552
5553Version 1.6.22beta06 [May 5, 2016]
5554  Rebased contrib/intel_sse.patch.
5555  Quieted two Coverity issues in contrib/libtests/timepng.c.
5556  Fixed issues with scripts/genout.cmake.in (David Capello, Nixon Kwok):
5557    Added support to use multiple directories in ZLIBINCDIR variable,
5558    Fixed CMAKE_C_FLAGS with multiple values when genout is compiled on MSVC,
5559    Fixed pnglibconf.c compilation on OS X including the sysroot path.
5560
5561Version 1.6.22rc01 [May 14, 2016]
5562  No changes.
5563
5564Version 1.6.22rc02 [May 16, 2016]
5565  Removed contrib/timepng from default build; it does not build on platforms
5566    that don't supply clock_gettime().
5567
5568Version 1.6.22rc03 [May 17, 2016]
5569  Restored contrib/timepng to default build but check for the presence
5570    of clock_gettime() in configure.ac and Makefile.am.
5571
5572Version 1.6.22 [May 26, 2016]
5573  No changes.
5574
5575Version 1.6.23beta01 [May 29, 2016]
5576  Stop a potential memory leak in png_set_tRNS() (Bug report by Ted Ying).
5577  Fixed the progressive reader to handle empty first IDAT chunk properly
5578    (patch by Timothy Nikkel).  This bug was introduced in libpng-1.6.0 and
5579    only affected the libpng16 branch.
5580  Added tests in pngvalid.c to check zero-length IDAT chunks in various
5581    positions.  Fixed the sequential reader to handle these more robustly
5582    (John Bowler).
5583
5584Version 1.6.23rc01 [June 2, 2016]
5585  Corrected progressive read input buffer in pngvalid.c. The previous version
5586    the code invariably passed just one byte at a time to libpng.  The intent
5587    was to pass a random number of bytes in the range 0..511.
5588  Moved sse2 prototype from pngpriv.h to contrib/intel/intel_sse.patch.
5589  Added missing ")" in pngerror.c (Matt Sarrett).
5590
5591Version 1.6.23rc02 [June 4, 2016]
5592  Fixed undefined behavior in png_push_save_buffer(). Do not call
5593    memcpy() with a null source, even if count is zero (Leon Scroggins III).
5594
5595Version 1.6.23 [June 9, 2016]
5596  Fixed bad link to RFC2083 in png.5 (Nikola Forro).
5597
5598Version 1.6.24beta01 [June 11, 2016]
5599  Avoid potential overflow of the PNG_IMAGE_SIZE macro.  This macro
5600    is not used within libpng, but is used in some of the examples.
5601
5602Version 1.6.24beta02 [June 23, 2016]
5603  Correct filter heuristic overflow handling. This was broken when the
5604    write filter code was moved out-of-line; if there is a single filter and
5605    the heuristic sum overflows the calculation of the filtered line is not
5606    completed.  In versions prior to 1.6 the code was duplicated in-line
5607    and the check not performed, so the filter operation completed; however,
5608    in the multi-filter case where the sum is performed the 'none' filter would
5609    be selected if all the sums overflowed, even if it wasn't in the filter
5610    list.  The fix to the first problem is simply to provide PNG_SIZE_MAX as
5611    the current lmins sum value; this means the sum can never exceed it and
5612    overflows silently.  A reasonable compiler that does choose to inline
5613    the code will simply eliminate the sum check.
5614  The fix to the second problem is to use high precision arithmetic (this is
5615    implemented in 1.7), however a simple safe fix here is to chose the lowest
5616    numbered filter in the list from png_set_filter (this only works if the
5617    first problem is also fixed) (John Bowler).
5618  Use a more efficient absolute value calculation on SSE2 (Matthieu Darbois).
5619  Fixed the case where PNG_IMAGE_BUFFER_SIZE can overflow in the application
5620    as a result of the application using an increased 'row_stride'; previously
5621    png_image_finish_read only checked for overflow on the base calculation of
5622    components.  (I.e. it checked for overflow of a 32-bit number on the total
5623    number of pixel components in the output format, not the possibly padded row
5624    length and not the number of bytes, which for linear formats is twice the
5625    number of components.)
5626  MSVC does not like '-(unsigned)', so replaced it with 0U-(unsigned)
5627  MSVC does not like (uInt) = -(unsigned) (i.e. as an initializer), unless
5628    the conversion is explicitly invoked by a cast.
5629  Put the SKIP definition in the correct place. It needs to come after the
5630    png.h include (see all the other .c files in contrib/libtests) because it
5631    depends on PNG_LIBPNG_VER.
5632  Removed the three compile warning options from the individual project
5633    files into the zlib.props globals.  It increases the warning level from 4
5634    to All and adds a list of the warnings that need to be turned off.  This is
5635    semi-documentary; the intent is to tell libpng users which warnings have
5636    been examined and judged non-fixable at present.  The warning about
5637    structure padding is fixable, but it would be a significant change (moving
5638    structure members around).
5639
5640Version 1.6.24beta03 [July 4, 2016]
5641  Optimized absolute value calculation in filter selection, similar to
5642    code in the PAETH decoder in pngrutil.c. Build with PNG_USE_ABS to
5643    use this.
5644  Added pngcp to the build together with a pngcp.dfa configuration test.
5645  Added high resolution timing to pngcp.
5646  Added "Common linking failures" section to INSTALL.
5647  Relocated misplaced #endif in png.c sRGB profile checking.
5648  Fixed two Coverity issues in pngcp.c.
5649
5650Version 1.6.24beta04 [July 8, 2016]
5651  Avoid filter-selection heuristic sum calculations in cases where only one
5652    filter is a candidate for selection. This trades off code size (added
5653    private png_setup_*_row_only() functions) for speed.
5654
5655Version 1.6.24beta05 [July 13, 2016]
5656  Fixed some indentation to comply with our coding style.
5657  Added contrib/tools/reindent.
5658
5659Version 1.6.24beta06 [July 18, 2016]
5660  Fixed more indentation to comply with our coding style.
5661  Eliminated unnecessary tests of boolean png_isaligned() vs 0.
5662
5663Version 1.6.24rc01 [July 25, 2016]
5664  No changes.
5665
5666Version 1.6.24rc02 [August 1, 2016]
5667  Conditionally compile SSE2 headers in contrib/intel/intel_sse.patch
5668  Conditionally compile png_decompress_chunk().
5669
5670Version 1.6.24rc03 [August 2, 2016]
5671  Conditionally compile ARM_NEON headers in pngpriv.h
5672  Updated contrib/intel/intel_sse.patch
5673
5674Version 1.6.24[August 4, 2016]
5675  No changes.
5676
5677Version 1.6.25beta01 [August 12, 2016]
5678  Reject oversized iCCP profile immediately.
5679  Cleaned up PNG_DEBUG compile of pngtest.c.
5680  Conditionally compile png_inflate().
5681
5682Version 1.6.25beta02 [August 18, 2016]
5683  Don't install pngcp; it conflicts with pngcp in the pngtools package.
5684  Minor editing of INSTALL, (whitespace, added copyright line)
5685
5686Version 1.6.25rc01 [August 24, 2016]
5687  No changes.
5688
5689Version 1.6.25rc02 [August 29, 2016]
5690  Added MIPS support (Mandar Sahastrabuddhe <Mandar.Sahastrabuddhe@imgtec.com>).
5691  Only the UP filter is currently implemented.
5692
5693Version 1.6.25rc03 [August 29, 2016]
5694  Rebased contrib/intel/intel_sse.patch after the MIPS implementation.
5695
5696Version 1.6.25rc04 [August 30, 2016]
5697  Added MIPS support for SUB, AVG, and PAETH filters (Mandar Sahastrabuddhe).
5698
5699Version 1.6.25rc05 [August 30, 2016]
5700  Rebased contrib/intel/intel_sse.patch after the MIPS implementation update..
5701
5702Version 1.6.25 [September 1, 2016]
5703  No changes.
5704
5705Version 1.6.26beta01 [September 26, 2016]
5706  Fixed handling zero length IDAT in pngfix (bug report by Agostino Sarubbo,
5707    bugfix by John Bowler).
5708  Do not issue a png_error() on read in png_set_pCAL() because png_handle_pCAL
5709    has allocated memory that libpng needs to free.
5710  Conditionally compile png_set_benign_errors() in pngread.c and pngtest.c
5711  Issue a png_benign_error instead of a png_error on ADLER32 mismatch
5712    while decoding compressed data chunks.
5713  Changed PNG_ZLIB_VERNUM to ZLIB_VERNUM in pngpriv.h, pngstruct.h, and
5714    pngrutil.c.
5715  If CRC handling of critical chunks has been set to PNG_CRC_QUIET_USE,
5716    ignore the ADLER32 checksum in the IDAT chunk as well as the chunk CRCs.
5717  Issue png_benign_error() on ADLER32 checksum mismatch instead of png_error().
5718  Add tests/badcrc.png and tests/badadler.png to tests/pngtest.
5719  Merged pngtest.c with libpng-1.7.0beta84/pngtest.c
5720
5721Version 1.6.26beta02 [October 1, 2016]
5722  Updated the documentation about CRC and ADLER32 handling.
5723  Quieted 117 warnings from clang-3.8 in pngtrans.c, pngread.c,
5724     pngwrite.c, pngunknown.c, and pngvalid.c.
5725  Quieted 58 (out of 144) -Wconversion compiler warnings by changing
5726    flag definitions in pngpriv.h from 0xnnnn to 0xnnnnU and trivial changes
5727    in png.c, pngread.c, and pngwutil.c.
5728
5729Version 1.6.26beta03 [October 2, 2016]
5730  Removed contrib/libtests/*.orig and *.rej that slipped into the tarballs.
5731  Quieted the 86 remaining -Wconversion compiler warnings by
5732    revising the png_isaligned() macro and trivial changes in png.c,
5733    pngerror.c, pngget.c, pngmem.c, pngset.c, pngrtran.c, pngrutil.c,
5734    pngwtran.c, pngwrite.c, and pngwutil.c.
5735
5736Version 1.6.26beta04 [October 3, 2016]
5737  Quieted (bogus?) clang warnings about "absolute value has no effect"
5738    when PNG_USE_ABS is defined.
5739  Fixed offsets in contrib/intel/intel_sse.patch
5740
5741Version 1.6.26beta05 [October 6, 2016]
5742  Changed integer constant 4294967294 to unsigned 4294967294U in pngconf.h
5743    to avoid a signed/unsigned compare in the preprocessor.
5744
5745Version 1.6.26beta06 [October 7, 2016]
5746  Use zlib-1.2.8.1 inflateValidate() instead of inflateReset2() to
5747    optionally avoid ADLER32 evaluation.
5748
5749Version 1.6.26rc01 [October 12, 2016]
5750  No changes.
5751
5752Version 1.6.26 [October 20, 2016]
5753  Cosmetic change, "ptr != 0" to "ptr != NULL" in png.c and pngrutil.c
5754  Despammed email addresses (replaced "@" with " at ").
5755
5756Version 1.6.27beta01 [November 2, 2016]
5757  Restrict the new ADLER32-skipping to IDAT chunks.  It broke iCCP chunk
5758    handling: an erroneous iCCP chunk would throw a png_error and reject the
5759    entire PNG image instead of rejecting just the iCCP chunk with a warning,
5760    if built with zlib-1.2.8.1.
5761
5762Version 1.6.27rc01 [December 27, 2016]
5763  Control ADLER32 checking with new PNG_IGNORE_ADLER32 option. Fixes
5764    an endless loop when handling erroneous ADLER32 checksums; bug
5765    introduced in libpng-1.6.26.
5766  Removed the use of a macro containing the pre-processor 'defined'
5767    operator.  It is unclear whether this is valid; a macro that
5768    "generates" 'defined' is not permitted, but the use of the word
5769    "generates" within the C90 standard seems to imply more than simple
5770    substitution of an expression itself containing a well-formed defined
5771    operation.
5772  Added ARM support to CMakeLists.txt (Andreas Franek).
5773
5774Version 1.6.27 [December 29, 2016]
5775  Fixed a potential null pointer dereference in png_set_text_2() (bug report
5776    and patch by Patrick Keshishian, CVE-2016-10087).
5777
5778Version 1.6.28rc01 [January 3, 2017]
5779  Fixed arm/aarch64 detection in CMakeLists.txt (Gianfranco Costamagna).
5780  Added option to Cmake build allowing a custom location of zlib to be
5781    specified in a scenario where libpng is being built as a subproject
5782    alongside zlib by another project (Sam Serrels).
5783  Changed png_ptr->options from a png_byte to png_uint_32, to accommodate
5784    up to 16 options.
5785
5786Version 1.6.28rc02 [January 4, 2017]
5787  Added "include(GNUInstallDirs)" to CMakeLists.txt (Gianfranco Costamagna).
5788  Moved SSE2 optimization code into the main libpng source directory.
5789    Configure libpng with "configure --enable-intel-sse" or compile
5790    libpng with "-DPNG_INTEL_SSE" in CPPFLAGS to enable it.
5791
5792Version 1.6.28rc03 [January 4, 2017]
5793  Backed out the SSE optimization and last CMakeLists.txt to allow time for QA.
5794
5795Version 1.6.28 [January 5, 2017]
5796  No changes.
5797
5798Version 1.6.29beta01 [January 12, 2017]
5799  Readded "include(GNUInstallDirs)" to CMakeLists.txt (Gianfranco Costamagna).
5800  Moved SSE2 optimization code into the main libpng source directory.
5801    Configure libpng with "configure --enable-intel-sse" or compile
5802    libpng with "-DPNG_INTEL_SSE" in CPPFLAGS to enable it.
5803  Simplified conditional compilation in pngvalid.c, for AIX (Michael Felt).
5804
5805Version 1.6.29beta02 [February 22, 2017]
5806  Avoid conditional directives that break statements in pngrutil.c (Romero
5807    Malaquias)
5808  The contrib/examples/pngtopng.c recovery code was in the wrong "if"
5809    branches; the comments were correct.
5810  Added code for PowerPC VSX optimisation (Vadim Barkov).
5811
5812Version 1.6.29beta03 [March 1, 2017]
5813  Avoid potential overflow of shift operations in png_do_expand() (Aaron Boxer).
5814  Change test ZLIB_VERNUM >= 0x1281 to ZLIB_VERNUM >= 0x1290 in pngrutil.c
5815    because Solaris 11 distributes zlib-1.2.8.f that is older than 1.2.8.1,
5816    as suggested in zlib FAQ, item 24.
5817  Suppress clang warnings about implicit sign changes in png.c
5818
5819Version 1.6.29 [March 16, 2017]
5820  No changes.
5821
5822Version 1.6.30beta01 [April 1, 2017]
5823  Added missing "$(CPPFLAGS)" to the compile line for c.pic.o in
5824    makefile.linux and makefile.solaris-x86 (Cosmin).
5825  Revised documentation of png_get_error_ptr() in the libpng manual.
5826  Silence clang -Wcomma and const drop warnings (Viktor Szakats).
5827  Update Sourceforge URLs in documentation (https instead of http).
5828
5829Version 1.6.30beta02 [April 22, 2017]
5830  Document need to check for integer overflow when allocating a pixel
5831    buffer for multiple rows in contrib/gregbook, contrib/pngminus,
5832    example.c, and in the manual (suggested by Jaeseung Choi). This
5833    is similar to the bug reported against pngquant in CVE-2016-5735.
5834  Removed reference to the obsolete PNG_SAFE_LIMITS macro in the documentation.
5835
5836Version 1.6.30beta03 [May 22, 2017]
5837  Check for integer overflow in contrib/visupng and contrib/tools/genpng.
5838  Do not double evaluate CMAKE_SYSTEM_PROCESSOR in CMakeLists.txt.
5839  Test CMAKE_HOST_WIN32 instead of WIN32 in CMakeLists.txt.
5840  Fix some URL in documentation.
5841
5842Version 1.6.30beta04 [June 7, 2017]
5843  Avoid writing an empty IDAT when the last IDAT exactly fills the
5844    compression buffer (bug report by Brian Baird). This bug was
5845    introduced in libpng-1.6.0.
5846
5847Version 1.6.30rc01 [June 14, 2017]
5848  No changes.
5849
5850Version 1.6.30rc02 [June 25, 2017]
5851  Update copyright year in pnglibconf.h, make ltmain.sh executable.
5852  Add a reference to the libpng.download site in README.
5853
5854Version 1.6.30 [June 28, 2017]
5855  No changes.
5856
5857Version 1.6.31beta01 [July 5, 2017]
5858  Guard the definition of _POSIX_SOURCE in pngpriv.h (AIX already defines it;
5859    bug report by Michael Felt).
5860  Revised pngpriv.h to work around failure to compile arm/filter_neon.S
5861    ("typedef" directive is unrecognized by the assembler). The problem
5862    was introduced in libpng-1.6.30beta01.
5863  Added "Requires: zlib" to libpng.pc.in (Pieter Neerincx).
5864  Added special case for FreeBSD in arm/filter_neon.S (Maya Rashish).
5865
5866Version 1.6.31beta02 [July 8, 2017]
5867  Added instructions for disabling hardware optimizations in INSTALL.
5868  Added "--enable-hardware-optimizations" configuration flag to enable
5869    or disable all hardware optimizations with one flag.
5870
5871Version 1.6.31beta03 [July 9, 2017]
5872  Updated CMakeLists.txt to add INTEL_SSE and MIPS_MSA platforms.
5873  Changed "int" to "png_size_t" in intel/filter_sse2.c to prevent
5874    possible integer overflow (Bug report by John Bowler).
5875  Quieted "declaration after statement" warnings in intel/filter_sse2.c.
5876  Added scripts/makefile-linux-opt, which has hardware optimizations enabled.
5877
5878Version 1.6.31beta04 [July 11, 2017]
5879  Removed one of the GCC-7.1.0 'strict-overflow' warnings that result when
5880    integers appear on both sides of a compare.  Worked around the others by
5881    forcing the strict-overflow setting in the relevant functions to a level
5882    where they are not reported (John Bowler).
5883  Changed "FALL THROUGH" comments to "FALLTHROUGH" because GCC doesn't like
5884    the space.
5885  Worked around some C-style casts from (void*) because g++ 5.4.0 objects
5886    to them.
5887  Increased the buffer size for 'sprint' to pass the gcc 7.1.0 'sprint
5888    overflow' check that is on by default with -Wall -Wextra.
5889
5890Version 1.6.31beta05 [July 13, 2017]
5891  Added eXIf chunk support.
5892
5893Version 1.6.31beta06 [July 17, 2017]
5894  Added a minimal eXIf chunk (with Orientation and FocalLengthIn35mmFilm
5895    tags) to pngtest.png.
5896
5897Version 1.6.31beta07 [July 18, 2017]
5898  Revised the eXIf chunk in pngtest.png to fix "Bad IFD1 Directory" warning.
5899
5900Version 1.6.31rc01 [July 19, 2017]
5901  No changes.
5902
5903Version 1.6.31rc02 [July 25, 2017]
5904  Fixed typo in example.c (png_free_image should be png_image_free) (Bug
5905    report by John Smith)
5906
5907Version 1.6.31 [July 27, 2017]
5908  No changes.
5909
5910Version 1.6.32beta01 [July 31, 2017]
5911  Avoid possible NULL dereference in png_handle_eXIf when benign_errors
5912    are allowed. Avoid leaking the input buffer "eXIf_buf".
5913  Eliminated png_ptr->num_exif member from pngstruct.h and added num_exif
5914    to arguments for png_get_eXIf() and png_set_eXIf().
5915  Added calls to png_handle_eXIf(() in pngread.c and png_write_eXIf() in
5916    pngwrite.c, and made various other fixes to png_write_eXIf().
5917  Changed name of png_get_eXIF and png_set_eXIf() to png_get_eXIf_1() and
5918    png_set_eXIf_1(), respectively, to avoid breaking API compatibility
5919    with libpng-1.6.31.
5920
5921Version 1.6.32beta02 [August 1, 2017]
5922  Updated contrib/libtests/pngunknown.c with eXIf chunk.
5923
5924Version 1.6.32beta03 [August 2, 2017]
5925  Initialized btoa[] in pngstest.c
5926  Stop memory leak when returning from png_handle_eXIf() with an error
5927    (Bug report from the OSS-fuzz project).
5928
5929Version 1.6.32beta04 [August 2, 2017]
5930  Replaced local eXIf_buf with info_ptr-eXIf_buf in png_handle_eXIf().
5931  Update libpng.3 and libpng-manual.txt about eXIf functions.
5932
5933Version 1.6.32beta05 [August 2, 2017]
5934  Restored png_get_eXIf() and png_set_eXIf() to maintain API compatibility.
5935
5936Version 1.6.32beta06 [August 2, 2017]
5937  Removed png_get_eXIf_1() and png_set_eXIf_1().
5938
5939Version 1.6.32beta07 [August 3, 2017]
5940  Check length of all chunks except IDAT against user limit to fix an
5941    OSS-fuzz issue (Fixes CVE-2017-12652).
5942
5943Version 1.6.32beta08 [August 3, 2017]
5944  Check length of IDAT against maximum possible IDAT size, accounting
5945    for height, rowbytes, interlacing and zlib/deflate overhead.
5946  Restored png_get_eXIf_1() and png_set_eXIf_1(), because strlen(eXIf_buf)
5947    does not work (the eXIf chunk data can contain zeroes).
5948
5949Version 1.6.32beta09 [August 3, 2017]
5950  Require cmake-2.8.8 in CMakeLists.txt. Revised symlink creation,
5951    no longer using deprecated cmake LOCATION feature (Clifford Yapp).
5952  Fixed five-byte error in the calculation of IDAT maximum possible size.
5953
5954Version 1.6.32beta10 [August 5, 2017]
5955  Moved chunk-length check into a png_check_chunk_length() private
5956    function (Suggested by Max Stepin).
5957  Moved bad pngs from tests to contrib/libtests/crashers
5958  Moved testing of bad pngs into a separate tests/pngtest-badpngs script
5959  Added the --xfail (expected FAIL) option to pngtest.c. It writes XFAIL
5960    in the output but PASS for the libpng test.
5961  Require cmake-3.0.2 in CMakeLists.txt (Clifford Yapp).
5962  Fix "const" declaration info_ptr argument to png_get_eXIf_1() and the
5963    num_exif argument to png_get_eXIf_1() (Github Issue 171).
5964
5965Version 1.6.32beta11 [August 7, 2017]
5966  Added "eXIf" to "chunks_to_ignore[]" in png_set_keep_unknown_chunks().
5967  Added huge_IDAT.png and empty_ancillary_chunks.png to testpngs/crashers.
5968  Make pngtest --strict, --relax, --xfail options imply -m (multiple).
5969  Removed unused chunk_name parameter from png_check_chunk_length().
5970  Relocated setting free_me for eXIf data, to stop an OSS-fuzz leak.
5971  Initialize profile_header[] in png_handle_iCCP() to fix OSS-fuzz issue.
5972  Initialize png_ptr->row_buf[0] to 255 in png_read_row() to fix OSS-fuzz UMR.
5973  Attempt to fix a UMR in png_set_text_2() to fix OSS-fuzz issue.
5974  Increase minimum zlib stream from 9 to 14 in png_handle_iCCP(), to account
5975    for the minimum 'deflate' stream, and relocate the test to a point
5976    after the keyword has been read.
5977  Check that the eXIf chunk has at least 2 bytes and begins with "II" or "MM".
5978
5979Version 1.6.32rc01 [August 18, 2017]
5980  Added a set of "huge_xxxx_chunk.png" files to contrib/testpngs/crashers,
5981    one for each known chunk type, with length = 2GB-1.
5982  Check for 0 return from png_get_rowbytes() and added some (size_t) typecasts
5983    in contrib/pngminus/*.c to stop some Coverity issues (162705, 162706,
5984    and 162707).
5985  Renamed chunks in contrib/testpngs/crashers to avoid having files whose
5986    names differ only in case; this causes problems with some platforms
5987    (github issue #172).
5988
5989Version 1.6.32rc02 [August 22, 2017]
5990  Added contrib/oss-fuzz directory which contains files used by the oss-fuzz
5991    project (https://github.com/google/oss-fuzz/tree/master/projects/libpng).
5992
5993Version 1.6.32 [August 24, 2017]
5994  No changes.
5995
5996Version 1.6.33beta01 [August 28, 2017]
5997  Added PNGMINUS_UNUSED macro to contrib/pngminus/p*.c and added missing
5998    parenthesis in contrib/pngminus/pnm2png.c (bug report by Christian Hesse).
5999  Fixed off-by-one error in png_do_check_palette_indexes() (Bug report
6000    by Mick P., Source Forge Issue #269).
6001
6002Version 1.6.33beta02 [September 3, 2017]
6003  Initialize png_handler.row_ptr in contrib/oss-fuzz/libpng_read_fuzzer.cc
6004    to fix shortlived oss-fuzz issue 3234.
6005  Compute a larger limit on IDAT because some applications write a deflate
6006    buffer for each row (Bug report by Andrew Church).
6007  Use current date (DATE) instead of release-date (RDATE) in last
6008    changed date of contrib/oss-fuzz files.
6009  Enabled ARM support in CMakeLists.txt (Bernd Kuhls).
6010
6011Version 1.6.33beta03 [September 14, 2017]
6012  Fixed incorrect typecast of some arguments to png_malloc() and
6013    png_calloc() that were png_uint_32 instead of png_alloc_size_t
6014    (Bug report by "irwir" in Github libpng issue #175).
6015  Use pnglibconf.h.prebuilt when building for ANDROID with cmake (Github
6016    issue 162, by rcdailey).
6017
6018Version 1.6.33rc01 [September 20, 2017]
6019  Initialize memory allocated by png_inflate to zero, using memset, to
6020    stop an oss-fuzz "use of uninitialized value" detection in png_set_text_2()
6021    due to truncated iTXt or zTXt chunk.
6022  Initialize memory allocated by png_read_buffer to zero, using memset, to
6023    stop an oss-fuzz "use of uninitialized value" detection in
6024    png_icc_check_tag_table() due to truncated iCCP chunk.
6025  Removed a redundant test (suggested by "irwir" in Github issue #180).
6026
6027Version 1.6.33rc02 [September 23, 2017]
6028  Added an interlaced version of each file in contrib/pngsuite.
6029  Relocate new memset() call in pngrutil.c.
6030  Removed more redundant tests (suggested by "irwir" in Github issue #180).
6031  Add support for loading images with associated alpha in the Simplified
6032    API (Samuel Williams).
6033
6034Version 1.6.33 [September 28, 2017]
6035  Revert contrib/oss-fuzz/libpng_read_fuzzer.cc to libpng-1.6.32 state.
6036  Initialize png_handler.row_ptr in contrib/oss-fuzz/libpng_read_fuzzer.cc
6037  Add end_info structure and png_read_end() to the libpng fuzzer.
6038
6039Version 1.6.34 [September 29, 2017]
6040  Removed contrib/pngsuite/i*.png; some of them caused test failures.
6041
6042Version 1.6.35beta01 [March 6, 2018]
6043  Restored 21 of the contrib/pngsuite/i*.png, which do not cause test
6044    failures. Placed the remainder in contrib/pngsuite/interlaced/i*.png.
6045  Added calls to png_set_*() transforms commonly used by browsers to
6046    the fuzzer.
6047  Removed some unnecessary brackets in pngrtran.c
6048  Fixed miscellaneous typos (Patch by github user "luzpaz").
6049  Change "ASM C" to "C ASM" in CMakeLists.txt
6050  Fixed incorrect handling of bKGD chunk in sub-8-bit files (Cosmin)
6051  Added hardware optimization directories to zip and 7z distributions.
6052  Fixed incorrect bitmask for options.
6053  Fixed many spelling typos.
6054
6055Version 1.6.35beta02 [March 28, 2018]
6056  Make png_get_iCCP consistent with man page (allow compression-type argument
6057  to be NULL, bug report by Lenard Szolnoki).
6058
6059Version 1.6.35 [July 15, 2018]
6060  Replaced the remaining uses of png_size_t with size_t (Cosmin)
6061  Fixed the calculation of row_factor in png_check_chunk_length
6062    (reported by Thuan Pham in SourceForge issue #278)
6063  Added missing parentheses to a macro definition
6064    (suggested by "irwir" in GitHub issue #216)
6065
6066Version 1.6.36 [December 1, 2018]
6067  Optimized png_do_expand_palette for ARM processors.
6068  Improved performance by around 10-22% on a recent ARM Chromebook.
6069    (Contributed by Richard Townsend, ARM Holdings)
6070  Fixed manipulation of machine-specific optimization options.
6071    (Contributed by Vicki Pfau)
6072  Used memcpy instead of manual pointer arithmetic on Intel SSE2.
6073    (Contributed by Samuel Williams)
6074  Fixed build errors with MSVC on ARM64.
6075    (Contributed by Zhijie Liang)
6076  Fixed detection of libm in CMakeLists.
6077    (Contributed by Cameron Cawley)
6078  Fixed incorrect creation of pkg-config file in CMakeLists.
6079    (Contributed by Kyle Bentley)
6080  Fixed the CMake build on Windows MSYS by avoiding symlinks.
6081  Fixed a build warning on OpenBSD.
6082    (Contributed by Theo Buehler)
6083  Fixed various typos in comments.
6084    (Contributed by "luz.paz")
6085  Raised the minimum required CMake version from 3.0.2 to 3.1.
6086  Removed yet more of the vestigial support for pre-ANSI C compilers.
6087  Removed ancient makefiles for ancient systems that have been broken
6088    across all previous libpng-1.6.x versions.
6089  Removed the Y2K compliance statement and the export control
6090    information.
6091  Applied various code style and documentation fixes.
6092
6093Version 1.6.37 [April 14, 2019]
6094  Fixed a use-after-free vulnerability (CVE-2019-7317) in png_image_free.
6095  Fixed a memory leak in the ARM NEON implementation of png_do_expand_palette.
6096  Fixed a memory leak in pngtest.c.
6097  Fixed two vulnerabilities (CVE-2018-14048, CVE-2018-14550) in
6098    contrib/pngminus; refactor.
6099  Changed the license of contrib/pngminus to MIT; refresh makefile and docs.
6100    (Contributed by Willem van Schaik)
6101  Fixed a typo in the libpng license v2.
6102    (Contributed by Miguel Ojeda)
6103  Added makefiles for AddressSanitizer-enabled builds.
6104  Cleaned up various makefiles.
6105
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