xref: /dragonfly/usr.bin/patch/patch.c (revision 8a7bdfea)
1 /*
2  * $OpenBSD: patch.c,v 1.45 2007/04/18 21:52:24 sobrado Exp $
3  * $DragonFly: src/usr.bin/patch/patch.c,v 1.7 2007/09/29 23:11:10 swildner Exp $
4  */
5 
6 /*
7  * patch - a program to apply diffs to original files
8  *
9  * Copyright 1986, Larry Wall
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following condition is met:
13  * 1. Redistributions of source code must retain the above copyright notice,
14  * this condition and the following disclaimer.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
17  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
20  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
23  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * -C option added in 1998, original code by Marc Espie, based on FreeBSD
29  * behaviour
30  */
31 
32 #include <sys/types.h>
33 #include <sys/stat.h>
34 
35 #include <ctype.h>
36 #include <getopt.h>
37 #include <limits.h>
38 #include <stdio.h>
39 #include <string.h>
40 #include <stdlib.h>
41 #include <unistd.h>
42 
43 #include "common.h"
44 #include "util.h"
45 #include "pch.h"
46 #include "inp.h"
47 #include "backupfile.h"
48 #include "pathnames.h"
49 
50 mode_t		filemode = 0644;
51 
52 char		buf[MAXLINELEN];	/* general purpose buffer */
53 size_t		buf_len = sizeof(buf);
54 
55 bool		using_plan_a = true;	/* try to keep everything in memory */
56 bool		out_of_mem = false;	/* ran out of memory in plan a */
57 
58 #define MAXFILEC 2
59 
60 char		*filearg[MAXFILEC];
61 bool		ok_to_create_file = false;
62 char		*outname = NULL;
63 char		*origprae = NULL;
64 char		*TMPOUTNAME;
65 char		*TMPINNAME;
66 char		*TMPREJNAME;
67 char		*TMPPATNAME;
68 bool		toutkeep = false;
69 bool		trejkeep = false;
70 bool		warn_on_invalid_line;
71 bool		last_line_missing_eol;
72 
73 #ifdef DEBUGGING
74 int		debug = 0;
75 #endif
76 
77 bool		force = false;
78 bool		batch = false;
79 bool		verbose = true;
80 bool		reverse = false;
81 bool		noreverse = false;
82 bool		skip_rest_of_patch = false;
83 int		strippath = 957;
84 bool		canonicalize = false;
85 bool		check_only = false;
86 int		diff_type = 0;
87 char		*revision = NULL;	/* prerequisite revision, if any */
88 LINENUM		input_lines = 0;	/* how long is input file in lines */
89 int		posix = 0;		/* strict POSIX mode? */
90 
91 static void	reinitialize_almost_everything(void);
92 static void	get_some_switches(void);
93 static LINENUM	locate_hunk(LINENUM);
94 static void	abort_context_hunk(void);
95 static void	rej_line(int, LINENUM);
96 static void	abort_hunk(void);
97 static void	apply_hunk(LINENUM);
98 static void	init_output(const char *);
99 static void	init_reject(const char *);
100 static void	copy_till(LINENUM, bool);
101 static void	spew_output(void);
102 static void	dump_line(LINENUM, bool);
103 static bool	patch_match(LINENUM, LINENUM, LINENUM);
104 static bool	similar(const char *, const char *, int);
105 static void	usage(void);
106 
107 /* true if -E was specified on command line.  */
108 static bool	remove_empty_files = false;
109 
110 /* true if -R was specified on command line.  */
111 static bool	reverse_flag_specified = false;
112 
113 /* buffer holding the name of the rejected patch file. */
114 static char	rejname[NAME_MAX + 1];
115 
116 /* buffer for stderr */
117 static char	serrbuf[BUFSIZ];
118 
119 /* how many input lines have been irretractibly output */
120 static LINENUM	last_frozen_line = 0;
121 
122 static int	Argc;		/* guess */
123 static char	**Argv;
124 static int	Argc_last;	/* for restarting plan_b */
125 static char	**Argv_last;
126 
127 static FILE	*ofp = NULL;	/* output file pointer */
128 static FILE	*rejfp = NULL;	/* reject file pointer */
129 
130 static int	filec = 0;	/* how many file arguments? */
131 static LINENUM	last_offset = 0;
132 static LINENUM	maxfuzz = 2;
133 
134 /* patch using ifdef, ifndef, etc. */
135 static bool		do_defines = false;
136 /* #ifdef xyzzy */
137 static char		if_defined[128];
138 /* #ifndef xyzzy */
139 static char		not_defined[128];
140 /* #else */
141 static const char	else_defined[] = "#else\n";
142 /* #endif xyzzy */
143 static char		end_defined[128];
144 
145 
146 /* Apply a set of diffs as appropriate. */
147 
148 int
149 main(int argc, char *argv[])
150 {
151 	int	error = 0, hunk, failed, i, fd;
152 	LINENUM	where = 0, newwhere, fuzz, mymaxfuzz;
153 	const	char *tmpdir;
154 	char	*v;
155 
156 	setbuf(stderr, serrbuf);
157 	for (i = 0; i < MAXFILEC; i++)
158 		filearg[i] = NULL;
159 
160 	/* Cons up the names of the temporary files.  */
161 	if ((tmpdir = getenv("TMPDIR")) == NULL || *tmpdir == '\0')
162 		tmpdir = _PATH_TMP;
163 	for (i = strlen(tmpdir) - 1; i > 0 && tmpdir[i] == '/'; i--)
164 		;
165 	i++;
166 	if (asprintf(&TMPOUTNAME, "%.*s/patchoXXXXXXXXXX", i, tmpdir) == -1)
167 		fatal("cannot allocate memory");
168 	if ((fd = mkstemp(TMPOUTNAME)) < 0)
169 		pfatal("can't create %s", TMPOUTNAME);
170 	close(fd);
171 
172 	if (asprintf(&TMPINNAME, "%.*s/patchiXXXXXXXXXX", i, tmpdir) == -1)
173 		fatal("cannot allocate memory");
174 	if ((fd = mkstemp(TMPINNAME)) < 0)
175 		pfatal("can't create %s", TMPINNAME);
176 	close(fd);
177 
178 	if (asprintf(&TMPREJNAME, "%.*s/patchrXXXXXXXXXX", i, tmpdir) == -1)
179 		fatal("cannot allocate memory");
180 	if ((fd = mkstemp(TMPREJNAME)) < 0)
181 		pfatal("can't create %s", TMPREJNAME);
182 	close(fd);
183 
184 	if (asprintf(&TMPPATNAME, "%.*s/patchpXXXXXXXXXX", i, tmpdir) == -1)
185 		fatal("cannot allocate memory");
186 	if ((fd = mkstemp(TMPPATNAME)) < 0)
187 		pfatal("can't create %s", TMPPATNAME);
188 	close(fd);
189 
190 	v = getenv("SIMPLE_BACKUP_SUFFIX");
191 	if (v)
192 		simple_backup_suffix = v;
193 	else
194 		simple_backup_suffix = ORIGEXT;
195 
196 	/* parse switches */
197 	Argc = argc;
198 	Argv = argv;
199 	get_some_switches();
200 
201 	if (backup_type == none) {
202 		if ((v = getenv("PATCH_VERSION_CONTROL")) == NULL)
203 			v = getenv("VERSION_CONTROL");
204 		if (v != NULL || !posix)
205 			backup_type = get_version(v);	/* OK to pass NULL. */
206 	}
207 
208 	/* make sure we clean up /tmp in case of disaster */
209 	set_signals(0);
210 
211 	for (open_patch_file(filearg[1]); there_is_another_patch();
212 	    reinitialize_almost_everything()) {
213 		/* for each patch in patch file */
214 
215 		warn_on_invalid_line = true;
216 
217 		if (outname == NULL)
218 			outname = savestr(filearg[0]);
219 
220 		/* for ed script just up and do it and exit */
221 		if (diff_type == ED_DIFF) {
222 			do_ed_script();
223 			continue;
224 		}
225 		/* initialize the patched file */
226 		if (!skip_rest_of_patch)
227 			init_output(TMPOUTNAME);
228 
229 		/* initialize reject file */
230 		init_reject(TMPREJNAME);
231 
232 		/* find out where all the lines are */
233 		if (!skip_rest_of_patch)
234 			scan_input(filearg[0]);
235 
236 		/* from here on, open no standard i/o files, because malloc */
237 		/* might misfire and we can't catch it easily */
238 
239 		/* apply each hunk of patch */
240 		hunk = 0;
241 		failed = 0;
242 		out_of_mem = false;
243 		while (another_hunk()) {
244 			hunk++;
245 			fuzz = 0;
246 			mymaxfuzz = pch_context();
247 			if (maxfuzz < mymaxfuzz)
248 				mymaxfuzz = maxfuzz;
249 			if (!skip_rest_of_patch) {
250 				do {
251 					where = locate_hunk(fuzz);
252 					if (hunk == 1 && where == 0 && !force) {
253 						/* dwim for reversed patch? */
254 						if (!pch_swap()) {
255 							if (fuzz == 0)
256 								say("Not enough memory to try swapped hunk!  Assuming unswapped.\n");
257 							continue;
258 						}
259 						reverse = !reverse;
260 						/* try again */
261 						where = locate_hunk(fuzz);
262 						if (where == 0) {
263 							/* didn't find it swapped */
264 							if (!pch_swap())
265 								/* put it back to normal */
266 								fatal("lost hunk on alloc error!\n");
267 							reverse = !reverse;
268 						} else if (noreverse) {
269 							if (!pch_swap())
270 								/* put it back to normal */
271 								fatal("lost hunk on alloc error!\n");
272 							reverse = !reverse;
273 							say("Ignoring previously applied (or reversed) patch.\n");
274 							skip_rest_of_patch = true;
275 						} else if (batch) {
276 							if (verbose)
277 								say("%seversed (or previously applied) patch detected!  %s -R.",
278 								    reverse ? "R" : "Unr",
279 								    reverse ? "Assuming" : "Ignoring");
280 						} else {
281 							ask("%seversed (or previously applied) patch detected!  %s -R? [y] ",
282 							    reverse ? "R" : "Unr",
283 							    reverse ? "Assume" : "Ignore");
284 							if (*buf == 'n') {
285 								ask("Apply anyway? [n] ");
286 								if (*buf != 'y')
287 									skip_rest_of_patch = true;
288 								where = 0;
289 								reverse = !reverse;
290 								if (!pch_swap())
291 									/* put it back to normal */
292 									fatal("lost hunk on alloc error!\n");
293 							}
294 						}
295 					}
296 				} while (!skip_rest_of_patch && where == 0 &&
297 				    ++fuzz <= mymaxfuzz);
298 
299 				if (skip_rest_of_patch) {	/* just got decided */
300 					fclose(ofp);
301 					ofp = NULL;
302 				}
303 			}
304 			newwhere = pch_newfirst() + last_offset;
305 			if (skip_rest_of_patch) {
306 				abort_hunk();
307 				failed++;
308 				if (verbose)
309 					say("Hunk #%d ignored at %ld.\n",
310 					    hunk, newwhere);
311 			} else if (where == 0) {
312 				abort_hunk();
313 				failed++;
314 				if (verbose)
315 					say("Hunk #%d failed at %ld.\n",
316 					    hunk, newwhere);
317 			} else {
318 				apply_hunk(where);
319 				if (verbose) {
320 					say("Hunk #%d succeeded at %ld",
321 					    hunk, newwhere);
322 					if (fuzz != 0)
323 						say(" with fuzz %ld", fuzz);
324 					if (last_offset)
325 						say(" (offset %ld line%s)",
326 						    last_offset,
327 						    last_offset == 1L ? "" : "s");
328 					say(".\n");
329 				}
330 			}
331 		}
332 
333 		if (out_of_mem && using_plan_a) {
334 			Argc = Argc_last;
335 			Argv = Argv_last;
336 			say("\n\nRan out of memory using Plan A--trying again...\n\n");
337 			if (ofp)
338 				fclose(ofp);
339 			ofp = NULL;
340 			if (rejfp)
341 				fclose(rejfp);
342 			rejfp = NULL;
343 			continue;
344 		}
345 		if (hunk == 0)
346 			fatal("Internal error: hunk should not be 0\n");
347 
348 		/* finish spewing out the new file */
349 		if (!skip_rest_of_patch)
350 			spew_output();
351 
352 		/* and put the output where desired */
353 		ignore_signals();
354 		if (!skip_rest_of_patch) {
355 			struct stat	statbuf;
356 			char	*realout = outname;
357 
358 			if (!check_only) {
359 				if (move_file(TMPOUTNAME, outname) < 0) {
360 					toutkeep = true;
361 					realout = TMPOUTNAME;
362 					chmod(TMPOUTNAME, filemode);
363 				} else
364 					chmod(outname, filemode);
365 
366 				if (remove_empty_files &&
367 				    stat(realout, &statbuf) == 0 &&
368 				    statbuf.st_size == 0) {
369 					if (verbose)
370 						say("Removing %s (empty after patching).\n",
371 						    realout);
372 					unlink(realout);
373 				}
374 			}
375 		}
376 		fclose(rejfp);
377 		rejfp = NULL;
378 		if (failed) {
379 			error = 1;
380 			if (*rejname == '\0') {
381 				if (strlcpy(rejname, outname,
382 				    sizeof(rejname)) >= sizeof(rejname))
383 					fatal("filename %s is too long\n", outname);
384 				if (strlcat(rejname, REJEXT,
385 				    sizeof(rejname)) >= sizeof(rejname))
386 					fatal("filename %s is too long\n", outname);
387 			}
388 			if (skip_rest_of_patch) {
389 				say("%d out of %d hunks ignored--saving rejects to %s\n",
390 				    failed, hunk, rejname);
391 			} else {
392 				say("%d out of %d hunks failed--saving rejects to %s\n",
393 				    failed, hunk, rejname);
394 			}
395 			if (!check_only && move_file(TMPREJNAME, rejname) < 0)
396 				trejkeep = true;
397 		}
398 		set_signals(1);
399 	}
400 	my_exit(error);
401 	/* NOTREACHED */
402 }
403 
404 /* Prepare to find the next patch to do in the patch file. */
405 
406 static void
407 reinitialize_almost_everything(void)
408 {
409 	re_patch();
410 	re_input();
411 
412 	input_lines = 0;
413 	last_frozen_line = 0;
414 
415 	filec = 0;
416 	if (!out_of_mem) {
417 		free(filearg[0]);
418 		filearg[0] = NULL;
419 	}
420 
421 	free(outname);
422 	outname = NULL;
423 
424 	last_offset = 0;
425 	diff_type = 0;
426 
427 	free(revision);
428 	revision = NULL;
429 
430 	reverse = reverse_flag_specified;
431 	skip_rest_of_patch = false;
432 
433 	get_some_switches();
434 }
435 
436 /* Process switches and filenames. */
437 
438 static void
439 get_some_switches(void)
440 {
441 	const char *options = "b::B:cCd:D:eEfF:i:lnNo:p:r:RstuvV:x:z:";
442 	static struct option longopts[] = {
443 		{"backup",		no_argument,		0,	'b'},
444 		{"batch",		no_argument,		0,	't'},
445 		{"check",		no_argument,		0,	'C'},
446 		{"context",		no_argument,		0,	'c'},
447 		{"debug",		required_argument,	0,	'x'},
448 		{"directory",		required_argument,	0,	'd'},
449 		{"ed",			no_argument,		0,	'e'},
450 		{"force",		no_argument,		0,	'f'},
451 		{"forward",		no_argument,		0,	'N'},
452 		{"fuzz",		required_argument,	0,	'F'},
453 		{"ifdef",		required_argument,	0,	'D'},
454 		{"input",		required_argument,	0,	'i'},
455 		{"ignore-whitespace",	no_argument,		0,	'l'},
456 		{"normal",		no_argument,		0,	'n'},
457 		{"output",		required_argument,	0,	'o'},
458 		{"prefix",		required_argument,	0,	'B'},
459 		{"quiet",		no_argument,		0,	's'},
460 		{"reject-file",		required_argument,	0,	'r'},
461 		{"remove-empty-files",	no_argument,		0,	'E'},
462 		{"reverse",		no_argument,		0,	'R'},
463 		{"silent",		no_argument,		0,	's'},
464 		{"strip",		required_argument,	0,	'p'},
465 		{"suffix",		required_argument,	0,	'z'},
466 		{"unified",		no_argument,		0,	'u'},
467 		{"version",		no_argument,		0,	'v'},
468 		{"version-control",	required_argument,	0,	'V'},
469 		{"posix",		no_argument,		&posix,	1},
470 		{NULL,			0,			0,	0}
471 	};
472 	int ch;
473 
474 	rejname[0] = '\0';
475 	Argc_last = Argc;
476 	Argv_last = Argv;
477 	if (!Argc)
478 		return;
479 	optreset = optind = 1;
480 	while ((ch = getopt_long(Argc, Argv, options, longopts, NULL)) != -1) {
481 		switch (ch) {
482 		case 'b':
483 			if (backup_type == none)
484 				backup_type = numbered_existing;
485 			if (optarg == NULL)
486 				break;
487 			if (verbose)
488 				say("Warning, the ``-b suffix'' option has been"
489 				    " obsoleted by the -z option.\n");
490 			/* FALLTHROUGH */
491 		case 'z':
492 			/* must directly follow 'b' case for backwards compat */
493 			simple_backup_suffix = savestr(optarg);
494 			break;
495 		case 'B':
496 			origprae = savestr(optarg);
497 			break;
498 		case 'c':
499 			diff_type = CONTEXT_DIFF;
500 			break;
501 		case 'C':
502 			check_only = true;
503 			break;
504 		case 'd':
505 			if (chdir(optarg) < 0)
506 				pfatal("can't cd to %s", optarg);
507 			break;
508 		case 'D':
509 			do_defines = true;
510 			if (!isalpha((unsigned char)*optarg) && *optarg != '_')
511 				fatal("argument to -D is not an identifier\n");
512 			snprintf(if_defined, sizeof if_defined,
513 			    "#ifdef %s\n", optarg);
514 			snprintf(not_defined, sizeof not_defined,
515 			    "#ifndef %s\n", optarg);
516 			snprintf(end_defined, sizeof end_defined,
517 			    "#endif /* %s */\n", optarg);
518 			break;
519 		case 'e':
520 			diff_type = ED_DIFF;
521 			break;
522 		case 'E':
523 			remove_empty_files = true;
524 			break;
525 		case 'f':
526 			force = true;
527 			break;
528 		case 'F':
529 			maxfuzz = atoi(optarg);
530 			break;
531 		case 'i':
532 			if (++filec == MAXFILEC)
533 				fatal("too many file arguments\n");
534 			filearg[filec] = savestr(optarg);
535 			break;
536 		case 'l':
537 			canonicalize = true;
538 			break;
539 		case 'n':
540 			diff_type = NORMAL_DIFF;
541 			break;
542 		case 'N':
543 			noreverse = true;
544 			break;
545 		case 'o':
546 			outname = savestr(optarg);
547 			break;
548 		case 'p':
549 			strippath = atoi(optarg);
550 			break;
551 		case 'r':
552 			if (strlcpy(rejname, optarg,
553 			    sizeof(rejname)) >= sizeof(rejname))
554 				fatal("argument for -r is too long\n");
555 			break;
556 		case 'R':
557 			reverse = true;
558 			reverse_flag_specified = true;
559 			break;
560 		case 's':
561 			verbose = false;
562 			break;
563 		case 't':
564 			batch = true;
565 			break;
566 		case 'u':
567 			diff_type = UNI_DIFF;
568 			break;
569 		case 'v':
570 			version();
571 			break;
572 		case 'V':
573 			backup_type = get_version(optarg);
574 			break;
575 #ifdef DEBUGGING
576 		case 'x':
577 			debug = atoi(optarg);
578 			break;
579 #endif
580 		default:
581 			if (ch != '\0')
582 				usage();
583 			break;
584 		}
585 	}
586 	Argc -= optind;
587 	Argv += optind;
588 
589 	if (Argc > 0) {
590 		filearg[0] = savestr(*Argv++);
591 		Argc--;
592 		while (Argc > 0) {
593 			if (++filec == MAXFILEC)
594 				fatal("too many file arguments\n");
595 			filearg[filec] = savestr(*Argv++);
596 			Argc--;
597 		}
598 	}
599 
600 	if (getenv("POSIXLY_CORRECT") != NULL)
601 		posix = 1;
602 }
603 
604 static void
605 usage(void)
606 {
607 	fprintf(stderr,
608 "usage: patch [-bCcEeflNnRstuv] [-B backup-prefix] [-D symbol] [-d directory]\n"
609 "             [-F max-fuzz] [-i patchfile] [-o out-file] [-p strip-count]\n"
610 "             [-r rej-name] [-V t | nil | never] [-x number] [-z backup-ext]\n"
611 "             [--posix] [origfile [patchfile]]\n"
612 "       patch <patchfile\n");
613 	my_exit(EXIT_SUCCESS);
614 }
615 
616 /*
617  * Attempt to find the right place to apply this hunk of patch.
618  */
619 static LINENUM
620 locate_hunk(LINENUM fuzz)
621 {
622 	LINENUM	first_guess = pch_first() + last_offset;
623 	LINENUM	offset;
624 	LINENUM	pat_lines = pch_ptrn_lines();
625 	LINENUM	max_pos_offset = input_lines - first_guess - pat_lines + 1;
626 	LINENUM	max_neg_offset = first_guess - last_frozen_line - 1 + pch_context();
627 
628 	if (pat_lines == 0) {		/* null range matches always */
629 		if (verbose && fuzz == 0 && (diff_type == CONTEXT_DIFF
630 		    || diff_type == NEW_CONTEXT_DIFF
631 		    || diff_type == UNI_DIFF)) {
632 			say("Empty context always matches.\n");
633 		}
634 		if (diff_type == CONTEXT_DIFF
635 		    || diff_type == NEW_CONTEXT_DIFF
636 		    || diff_type == UNI_DIFF) {
637 			if (fuzz == 0)
638 				return (input_lines == 0 ? first_guess : 0);
639 		} else
640 			return (first_guess);
641 	}
642 	if (max_neg_offset >= first_guess)	/* do not try lines < 0 */
643 		max_neg_offset = first_guess - 1;
644 	if (first_guess <= input_lines && patch_match(first_guess, 0, fuzz))
645 		return first_guess;
646 	for (offset = 1; ; offset++) {
647 		bool	check_after = (offset <= max_pos_offset);
648 		bool	check_before = (offset <= max_neg_offset);
649 
650 		if (check_after && patch_match(first_guess, offset, fuzz)) {
651 #ifdef DEBUGGING
652 			if (debug & 1)
653 				say("Offset changing from %ld to %ld\n",
654 				    last_offset, offset);
655 #endif
656 			last_offset = offset;
657 			return first_guess + offset;
658 		} else if (check_before && patch_match(first_guess, -offset, fuzz)) {
659 #ifdef DEBUGGING
660 			if (debug & 1)
661 				say("Offset changing from %ld to %ld\n",
662 				    last_offset, -offset);
663 #endif
664 			last_offset = -offset;
665 			return first_guess - offset;
666 		} else if (!check_before && !check_after)
667 			return 0;
668 	}
669 }
670 
671 /* We did not find the pattern, dump out the hunk so they can handle it. */
672 
673 static void
674 abort_context_hunk(void)
675 {
676 	LINENUM	i;
677 	const LINENUM	pat_end = pch_end();
678 	/*
679 	 * add in last_offset to guess the same as the previous successful
680 	 * hunk
681 	 */
682 	const LINENUM	oldfirst = pch_first() + last_offset;
683 	const LINENUM	newfirst = pch_newfirst() + last_offset;
684 	const LINENUM	oldlast = oldfirst + pch_ptrn_lines() - 1;
685 	const LINENUM	newlast = newfirst + pch_repl_lines() - 1;
686 	const char	*stars = (diff_type >= NEW_CONTEXT_DIFF ? " ****" : "");
687 	const char	*minuses = (diff_type >= NEW_CONTEXT_DIFF ? " ----" : " -----");
688 
689 	fprintf(rejfp, "***************\n");
690 	for (i = 0; i <= pat_end; i++) {
691 		switch (pch_char(i)) {
692 		case '*':
693 			if (oldlast < oldfirst)
694 				fprintf(rejfp, "*** 0%s\n", stars);
695 			else if (oldlast == oldfirst)
696 				fprintf(rejfp, "*** %ld%s\n", oldfirst, stars);
697 			else
698 				fprintf(rejfp, "*** %ld,%ld%s\n", oldfirst,
699 				    oldlast, stars);
700 			break;
701 		case '=':
702 			if (newlast < newfirst)
703 				fprintf(rejfp, "--- 0%s\n", minuses);
704 			else if (newlast == newfirst)
705 				fprintf(rejfp, "--- %ld%s\n", newfirst, minuses);
706 			else
707 				fprintf(rejfp, "--- %ld,%ld%s\n", newfirst,
708 				    newlast, minuses);
709 			break;
710 		case '\n':
711 			fprintf(rejfp, "%s", pfetch(i));
712 			break;
713 		case ' ':
714 		case '-':
715 		case '+':
716 		case '!':
717 			fprintf(rejfp, "%c %s", pch_char(i), pfetch(i));
718 			break;
719 		default:
720 			fatal("fatal internal error in abort_context_hunk\n");
721 		}
722 	}
723 }
724 
725 static void
726 rej_line(int ch, LINENUM i)
727 {
728 	size_t len;
729 	const char *line = pfetch(i);
730 
731 	len = strlen(line);
732 
733 	fprintf(rejfp, "%c%s", ch, line);
734 	if (len == 0 || line[len-1] != '\n')
735 		fprintf(rejfp, "\n\\ No newline at end of file\n");
736 }
737 
738 static void
739 abort_hunk(void)
740 {
741 	LINENUM		i, j, split;
742 	int		ch1, ch2;
743 	const LINENUM	pat_end = pch_end();
744 	const LINENUM	oldfirst = pch_first() + last_offset;
745 	const LINENUM	newfirst = pch_newfirst() + last_offset;
746 
747 	if (diff_type != UNI_DIFF) {
748 		abort_context_hunk();
749 		return;
750 	}
751 	split = -1;
752 	for (i = 0; i <= pat_end; i++) {
753 		if (pch_char(i) == '=') {
754 			split = i;
755 			break;
756 		}
757 	}
758 	if (split == -1) {
759 		fprintf(rejfp, "malformed hunk: no split found\n");
760 		return;
761 	}
762 	i = 0;
763 	j = split + 1;
764 	fprintf(rejfp, "@@ -%ld,%ld +%ld,%ld @@\n",
765 	    pch_ptrn_lines() ? oldfirst : 0,
766 	    pch_ptrn_lines(), newfirst, pch_repl_lines());
767 	while (i < split || j <= pat_end) {
768 		ch1 = i < split ? pch_char(i) : -1;
769 		ch2 = j <= pat_end ? pch_char(j) : -1;
770 		if (ch1 == '-') {
771 			rej_line('-', i);
772 			i++;
773 		} else if (ch1 == ' ' && ch2 == ' ') {
774 			rej_line(' ', i);
775 			i++;
776 			j++;
777 		} else if (ch1 == '!' && ch2 == '!') {
778 			while (i < split && ch1 == '!') {
779 				rej_line('-', i);
780 				i++;
781 				ch1 = i < split ? pch_char(i) : -1;
782 			}
783 			while (j <= pat_end && ch2 == '!') {
784 				rej_line('+', j);
785 				j++;
786 				ch2 = j <= pat_end ? pch_char(j) : -1;
787 			}
788 		} else if (ch1 == '*') {
789 			i++;
790 		} else if (ch2 == '+' || ch2 == ' ') {
791 			rej_line(ch2, j);
792 			j++;
793 		} else {
794 			fprintf(rejfp, "internal error on (%ld %ld %ld)\n",
795 			    i, split, j);
796 			rej_line(ch1, i);
797 			rej_line(ch2, j);
798 			return;
799 		}
800 	}
801 }
802 
803 /* We found where to apply it (we hope), so do it. */
804 
805 static void
806 apply_hunk(LINENUM where)
807 {
808 	LINENUM		old = 1;
809 	const LINENUM	lastline = pch_ptrn_lines();
810 	LINENUM		new = lastline + 1;
811 #define OUTSIDE 0
812 #define IN_IFNDEF 1
813 #define IN_IFDEF 2
814 #define IN_ELSE 3
815 	int		def_state = OUTSIDE;
816 	const LINENUM	pat_end = pch_end();
817 
818 	where--;
819 	while (pch_char(new) == '=' || pch_char(new) == '\n')
820 		new++;
821 
822 	while (old <= lastline) {
823 		if (pch_char(old) == '-') {
824 			copy_till(where + old - 1, false);
825 			if (do_defines) {
826 				if (def_state == OUTSIDE) {
827 					fputs(not_defined, ofp);
828 					def_state = IN_IFNDEF;
829 				} else if (def_state == IN_IFDEF) {
830 					fputs(else_defined, ofp);
831 					def_state = IN_ELSE;
832 				}
833 				fputs(pfetch(old), ofp);
834 			}
835 			last_frozen_line++;
836 			old++;
837 		} else if (new > pat_end) {
838 			break;
839 		} else if (pch_char(new) == '+') {
840 			copy_till(where + old - 1, false);
841 			if (do_defines) {
842 				if (def_state == IN_IFNDEF) {
843 					fputs(else_defined, ofp);
844 					def_state = IN_ELSE;
845 				} else if (def_state == OUTSIDE) {
846 					fputs(if_defined, ofp);
847 					def_state = IN_IFDEF;
848 				}
849 			}
850 			fputs(pfetch(new), ofp);
851 			new++;
852 		} else if (pch_char(new) != pch_char(old)) {
853 			say("Out-of-sync patch, lines %ld,%ld--mangled text or line numbers, maybe?\n",
854 			    pch_hunk_beg() + old,
855 			    pch_hunk_beg() + new);
856 #ifdef DEBUGGING
857 			say("oldchar = '%c', newchar = '%c'\n",
858 			    pch_char(old), pch_char(new));
859 #endif
860 			my_exit(2);
861 		} else if (pch_char(new) == '!') {
862 			copy_till(where + old - 1, false);
863 			if (do_defines) {
864 				fputs(not_defined, ofp);
865 				def_state = IN_IFNDEF;
866 			}
867 			while (pch_char(old) == '!') {
868 				if (do_defines) {
869 					fputs(pfetch(old), ofp);
870 				}
871 				last_frozen_line++;
872 				old++;
873 			}
874 			if (do_defines) {
875 				fputs(else_defined, ofp);
876 				def_state = IN_ELSE;
877 			}
878 			while (pch_char(new) == '!') {
879 				fputs(pfetch(new), ofp);
880 				new++;
881 			}
882 		} else {
883 			if (pch_char(new) != ' ')
884 				fatal("Internal error: expected ' '\n");
885 			old++;
886 			new++;
887 			if (do_defines && def_state != OUTSIDE) {
888 				fputs(end_defined, ofp);
889 				def_state = OUTSIDE;
890 			}
891 		}
892 	}
893 	if (new <= pat_end && pch_char(new) == '+') {
894 		copy_till(where + old - 1, false);
895 		if (do_defines) {
896 			if (def_state == OUTSIDE) {
897 				fputs(if_defined, ofp);
898 				def_state = IN_IFDEF;
899 			} else if (def_state == IN_IFNDEF) {
900 				fputs(else_defined, ofp);
901 				def_state = IN_ELSE;
902 			}
903 		}
904 		while (new <= pat_end && pch_char(new) == '+') {
905 			fputs(pfetch(new), ofp);
906 			new++;
907 		}
908 	}
909 	if (do_defines && def_state != OUTSIDE) {
910 		fputs(end_defined, ofp);
911 	}
912 }
913 
914 /*
915  * Open the new file.
916  */
917 static void
918 init_output(const char *name)
919 {
920 	ofp = fopen(name, "w");
921 	if (ofp == NULL)
922 		pfatal("can't create %s", name);
923 }
924 
925 /*
926  * Open a file to put hunks we can't locate.
927  */
928 static void
929 init_reject(const char *name)
930 {
931 	rejfp = fopen(name, "w");
932 	if (rejfp == NULL)
933 		pfatal("can't create %s", name);
934 }
935 
936 /*
937  * Copy input file to output, up to wherever hunk is to be applied.
938  * If endoffile is true, treat the last line specially since it may
939  * lack a newline.
940  */
941 static void
942 copy_till(LINENUM lastline, bool endoffile)
943 {
944 	if (last_frozen_line > lastline)
945 		fatal("misordered hunks! output would be garbled\n");
946 	while (last_frozen_line < lastline) {
947 		if (++last_frozen_line == lastline && endoffile)
948 			dump_line(last_frozen_line, !last_line_missing_eol);
949 		else
950 			dump_line(last_frozen_line, true);
951 	}
952 }
953 
954 /*
955  * Finish copying the input file to the output file.
956  */
957 static void
958 spew_output(void)
959 {
960 #ifdef DEBUGGING
961 	if (debug & 256)
962 		say("il=%ld lfl=%ld\n", input_lines, last_frozen_line);
963 #endif
964 	if (input_lines)
965 		copy_till(input_lines, true);	/* dump remainder of file */
966 	fclose(ofp);
967 	ofp = NULL;
968 }
969 
970 /*
971  * Copy one line from input to output.
972  */
973 static void
974 dump_line(LINENUM line, bool write_newline)
975 {
976 	char	*s;
977 
978 	s = ifetch(line, 0);
979 	if (s == NULL)
980 		return;
981 	/* Note: string is not NUL terminated. */
982 	for (; *s != '\n'; s++)
983 		putc(*s, ofp);
984 	if (write_newline)
985 		putc('\n', ofp);
986 }
987 
988 /*
989  * Does the patch pattern match at line base+offset?
990  */
991 static bool
992 patch_match(LINENUM base, LINENUM offset, LINENUM fuzz)
993 {
994 	LINENUM		pline = 1 + fuzz;
995 	LINENUM		iline;
996 	LINENUM		pat_lines = pch_ptrn_lines() - fuzz;
997 	const char	*ilineptr;
998 	const char	*plineptr;
999 	short		plinelen;
1000 
1001 	for (iline = base + offset + fuzz; pline <= pat_lines; pline++, iline++) {
1002 		ilineptr = ifetch(iline, offset >= 0);
1003 		if (ilineptr == NULL)
1004 			return false;
1005 		plineptr = pfetch(pline);
1006 		plinelen = pch_line_len(pline);
1007 		if (canonicalize) {
1008 			if (!similar(ilineptr, plineptr, plinelen))
1009 				return false;
1010 		} else if (strnNE(ilineptr, plineptr, plinelen))
1011 			return false;
1012 		if (iline == input_lines) {
1013 			/*
1014 			 * We are looking at the last line of the file.
1015 			 * If the file has no eol, the patch line should
1016 			 * not have one either and vice-versa. Note that
1017 			 * plinelen > 0.
1018 			 */
1019 			if (last_line_missing_eol) {
1020 				if (plineptr[plinelen - 1] == '\n')
1021 					return false;
1022 			} else {
1023 				if (plineptr[plinelen - 1] != '\n')
1024 					return false;
1025 			}
1026 		}
1027 	}
1028 	return true;
1029 }
1030 
1031 /*
1032  * Do two lines match with canonicalized white space?
1033  */
1034 static bool
1035 similar(const char *a, const char *b, int len)
1036 {
1037 	while (len) {
1038 		if (isspace((unsigned char)*b)) {	/* whitespace (or \n) to match? */
1039 			if (!isspace((unsigned char)*a))	/* no corresponding whitespace? */
1040 				return false;
1041 			while (len && isspace((unsigned char)*b) && *b != '\n')
1042 				b++, len--;	/* skip pattern whitespace */
1043 			while (isspace((unsigned char)*a) && *a != '\n')
1044 				a++;	/* skip target whitespace */
1045 			if (*a == '\n' || *b == '\n')
1046 				return (*a == *b);	/* should end in sync */
1047 		} else if (*a++ != *b++)	/* match non-whitespace chars */
1048 			return false;
1049 		else
1050 			len--;	/* probably not necessary */
1051 	}
1052 	return true;		/* actually, this is not reached */
1053 	/* since there is always a \n */
1054 }
1055