xref: /openbsd/usr.bin/patch/patch.c (revision 19b2d0aa)
1 /*	$OpenBSD: patch.c,v 1.58 2015/10/07 06:29:26 deraadt Exp $	*/
2 
3 /*
4  * patch - a program to apply diffs to original files
5  *
6  * Copyright 1986, Larry Wall
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following condition is met:
10  * 1. Redistributions of source code must retain the above copyright notice,
11  * this condition and the following disclaimer.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
15  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
16  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
17  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
19  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
20  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  *
25  * -C option added in 1998, original code by Marc Espie, based on FreeBSD
26  * behaviour
27  */
28 
29 #include <sys/types.h>
30 #include <sys/stat.h>
31 #include <unistd.h>
32 
33 #include <ctype.h>
34 #include <getopt.h>
35 #include <limits.h>
36 #include <stdio.h>
37 #include <string.h>
38 #include <stdlib.h>
39 
40 #include "common.h"
41 #include "util.h"
42 #include "pch.h"
43 #include "inp.h"
44 #include "backupfile.h"
45 #include "pathnames.h"
46 
47 mode_t		filemode = 0644;
48 
49 char		buf[MAXLINELEN];	/* general purpose buffer */
50 
51 bool		using_plan_a = true;	/* try to keep everything in memory */
52 bool		out_of_mem = false;	/* ran out of memory in plan a */
53 
54 #define MAXFILEC 2
55 
56 char		*filearg[MAXFILEC];
57 bool		ok_to_create_file = false;
58 char		*outname = NULL;
59 char		*origprae = NULL;
60 char		*TMPOUTNAME;
61 char		*TMPINNAME;
62 char		*TMPREJNAME;
63 char		*TMPPATNAME;
64 bool		toutkeep = false;
65 bool		trejkeep = false;
66 bool		warn_on_invalid_line;
67 bool		last_line_missing_eol;
68 
69 #ifdef DEBUGGING
70 int		debug = 0;
71 #endif
72 
73 bool		force = false;
74 bool		batch = false;
75 bool		verbose = true;
76 bool		reverse = false;
77 bool		noreverse = false;
78 bool		skip_rest_of_patch = false;
79 int		strippath = 957;
80 bool		canonicalize = false;
81 bool		check_only = false;
82 int		diff_type = 0;
83 char		*revision = NULL;	/* prerequisite revision, if any */
84 LINENUM		input_lines = 0;	/* how long is input file in lines */
85 int		posix = 0;		/* strict POSIX mode? */
86 
87 static void	reinitialize_almost_everything(void);
88 static void	get_some_switches(void);
89 static LINENUM	locate_hunk(LINENUM);
90 static void	abort_context_hunk(void);
91 static void	rej_line(int, LINENUM);
92 static void	abort_hunk(void);
93 static void	apply_hunk(LINENUM);
94 static void	init_output(const char *);
95 static void	init_reject(const char *);
96 static void	copy_till(LINENUM, bool);
97 static void	spew_output(void);
98 static void	dump_line(LINENUM, bool);
99 static bool	patch_match(LINENUM, LINENUM, LINENUM);
100 static bool	similar(const char *, const char *, int);
101 static __dead void usage(void);
102 
103 /* true if -E was specified on command line.  */
104 static bool	remove_empty_files = false;
105 
106 /* true if -R was specified on command line.  */
107 static bool	reverse_flag_specified = false;
108 
109 /* buffer holding the name of the rejected patch file. */
110 static char	rejname[NAME_MAX + 1];
111 
112 /* how many input lines have been irretractibly output */
113 static LINENUM	last_frozen_line = 0;
114 
115 static int	Argc;		/* guess */
116 static char	**Argv;
117 static int	Argc_last;	/* for restarting plan_b */
118 static char	**Argv_last;
119 
120 static FILE	*ofp = NULL;	/* output file pointer */
121 static FILE	*rejfp = NULL;	/* reject file pointer */
122 
123 static int	filec = 0;	/* how many file arguments? */
124 static LINENUM	last_offset = 0;
125 static LINENUM	maxfuzz = 2;
126 
127 /* patch using ifdef, ifndef, etc. */
128 static bool		do_defines = false;
129 /* #ifdef xyzzy */
130 static char		if_defined[128];
131 /* #ifndef xyzzy */
132 static char		not_defined[128];
133 /* #else */
134 static const char	else_defined[] = "#else\n";
135 /* #endif xyzzy */
136 static char		end_defined[128];
137 
138 
139 /* Apply a set of diffs as appropriate. */
140 
141 int
142 main(int argc, char *argv[])
143 {
144 	int	error = 0, hunk, failed, i, fd;
145 	bool	patch_seen;
146 	LINENUM	where = 0, newwhere, fuzz, mymaxfuzz;
147 	const	char *tmpdir;
148 	char	*v;
149 
150 	if (tame("stdio rpath wpath cpath tmppath fattr proc exec", NULL) == -1)
151 		perror("tame");
152 
153 	setvbuf(stdout, NULL, _IOLBF, 0);
154 	setvbuf(stderr, NULL, _IOLBF, 0);
155 	for (i = 0; i < MAXFILEC; i++)
156 		filearg[i] = NULL;
157 
158 	/* Cons up the names of the temporary files.  */
159 	if ((tmpdir = getenv("TMPDIR")) == NULL || *tmpdir == '\0')
160 		tmpdir = _PATH_TMP;
161 	for (i = strlen(tmpdir) - 1; i > 0 && tmpdir[i] == '/'; i--)
162 		;
163 	i++;
164 	if (asprintf(&TMPOUTNAME, "%.*s/patchoXXXXXXXXXX", i, tmpdir) == -1)
165 		fatal("cannot allocate memory");
166 	if ((fd = mkstemp(TMPOUTNAME)) < 0)
167 		pfatal("can't create %s", TMPOUTNAME);
168 	close(fd);
169 
170 	if (asprintf(&TMPINNAME, "%.*s/patchiXXXXXXXXXX", i, tmpdir) == -1)
171 		fatal("cannot allocate memory");
172 	if ((fd = mkstemp(TMPINNAME)) < 0)
173 		pfatal("can't create %s", TMPINNAME);
174 	close(fd);
175 
176 	if (asprintf(&TMPREJNAME, "%.*s/patchrXXXXXXXXXX", i, tmpdir) == -1)
177 		fatal("cannot allocate memory");
178 	if ((fd = mkstemp(TMPREJNAME)) < 0)
179 		pfatal("can't create %s", TMPREJNAME);
180 	close(fd);
181 
182 	if (asprintf(&TMPPATNAME, "%.*s/patchpXXXXXXXXXX", i, tmpdir) == -1)
183 		fatal("cannot allocate memory");
184 	if ((fd = mkstemp(TMPPATNAME)) < 0)
185 		pfatal("can't create %s", TMPPATNAME);
186 	close(fd);
187 
188 	v = getenv("SIMPLE_BACKUP_SUFFIX");
189 	if (v)
190 		simple_backup_suffix = v;
191 	else
192 		simple_backup_suffix = ORIGEXT;
193 
194 	/* parse switches */
195 	Argc = argc;
196 	Argv = argv;
197 	get_some_switches();
198 
199 	if (backup_type == none) {
200 		if ((v = getenv("PATCH_VERSION_CONTROL")) == NULL)
201 			v = getenv("VERSION_CONTROL");
202 		if (v != NULL || !posix)
203 			backup_type = get_version(v);	/* OK to pass NULL. */
204 	}
205 
206 	/* make sure we clean up /tmp in case of disaster */
207 	set_signals(0);
208 
209 	patch_seen = false;
210 	for (open_patch_file(filearg[1]); there_is_another_patch();
211 	    reinitialize_almost_everything()) {
212 		/* for each patch in patch file */
213 
214 		patch_seen = true;
215 
216 		warn_on_invalid_line = true;
217 
218 		if (outname == NULL)
219 			outname = xstrdup(filearg[0]);
220 
221 		/* for ed script just up and do it and exit */
222 		if (diff_type == ED_DIFF) {
223 			do_ed_script();
224 			continue;
225 		}
226 		/* initialize the patched file */
227 		if (!skip_rest_of_patch)
228 			init_output(TMPOUTNAME);
229 
230 		/* initialize reject file */
231 		init_reject(TMPREJNAME);
232 
233 		/* find out where all the lines are */
234 		if (!skip_rest_of_patch)
235 			scan_input(filearg[0]);
236 
237 		/* from here on, open no standard i/o files, because malloc */
238 		/* might misfire and we can't catch it easily */
239 
240 		/* apply each hunk of patch */
241 		hunk = 0;
242 		failed = 0;
243 		out_of_mem = false;
244 		while (another_hunk()) {
245 			hunk++;
246 			fuzz = 0;
247 			mymaxfuzz = pch_context();
248 			if (maxfuzz < mymaxfuzz)
249 				mymaxfuzz = maxfuzz;
250 			if (!skip_rest_of_patch) {
251 				do {
252 					where = locate_hunk(fuzz);
253 					if (hunk == 1 && where == 0 && !force) {
254 						/* dwim for reversed patch? */
255 						if (!pch_swap()) {
256 							if (fuzz == 0)
257 								say("Not enough memory to try swapped hunk!  Assuming unswapped.\n");
258 							continue;
259 						}
260 						reverse = !reverse;
261 						/* try again */
262 						where = locate_hunk(fuzz);
263 						if (where == 0) {
264 							/* didn't find it swapped */
265 							if (!pch_swap())
266 								/* put it back to normal */
267 								fatal("lost hunk on alloc error!\n");
268 							reverse = !reverse;
269 						} else if (noreverse) {
270 							if (!pch_swap())
271 								/* put it back to normal */
272 								fatal("lost hunk on alloc error!\n");
273 							reverse = !reverse;
274 							say("Ignoring previously applied (or reversed) patch.\n");
275 							skip_rest_of_patch = true;
276 						} else if (batch) {
277 							if (verbose)
278 								say("%seversed (or previously applied) patch detected!  %s -R.",
279 								    reverse ? "R" : "Unr",
280 								    reverse ? "Assuming" : "Ignoring");
281 						} else {
282 							ask("%seversed (or previously applied) patch detected!  %s -R? [y] ",
283 							    reverse ? "R" : "Unr",
284 							    reverse ? "Assume" : "Ignore");
285 							if (*buf == 'n') {
286 								ask("Apply anyway? [n] ");
287 								if (*buf != 'y')
288 									skip_rest_of_patch = true;
289 								where = 0;
290 								reverse = !reverse;
291 								if (!pch_swap())
292 									/* put it back to normal */
293 									fatal("lost hunk on alloc error!\n");
294 							}
295 						}
296 					}
297 				} while (!skip_rest_of_patch && where == 0 &&
298 				    ++fuzz <= mymaxfuzz);
299 
300 				if (skip_rest_of_patch) {	/* just got decided */
301 					fclose(ofp);
302 					ofp = NULL;
303 				}
304 			}
305 			newwhere = pch_newfirst() + last_offset;
306 			if (skip_rest_of_patch) {
307 				abort_hunk();
308 				failed++;
309 				if (verbose)
310 					say("Hunk #%d ignored at %ld.\n",
311 					    hunk, newwhere);
312 			} else if (where == 0) {
313 				abort_hunk();
314 				failed++;
315 				if (verbose)
316 					say("Hunk #%d failed at %ld.\n",
317 					    hunk, newwhere);
318 			} else {
319 				apply_hunk(where);
320 				if (verbose) {
321 					say("Hunk #%d succeeded at %ld",
322 					    hunk, newwhere);
323 					if (fuzz != 0)
324 						say(" with fuzz %ld", fuzz);
325 					if (last_offset)
326 						say(" (offset %ld line%s)",
327 						    last_offset,
328 						    last_offset == 1L ? "" : "s");
329 					say(".\n");
330 				}
331 			}
332 		}
333 
334 		if (out_of_mem && using_plan_a) {
335 			Argc = Argc_last;
336 			Argv = Argv_last;
337 			say("\n\nRan out of memory using Plan A--trying again...\n\n");
338 			if (ofp)
339 				fclose(ofp);
340 			ofp = NULL;
341 			if (rejfp)
342 				fclose(rejfp);
343 			rejfp = NULL;
344 			continue;
345 		}
346 		if (hunk == 0)
347 			fatal("Internal error: hunk should not be 0\n");
348 
349 		/* finish spewing out the new file */
350 		if (!skip_rest_of_patch)
351 			spew_output();
352 
353 		/* and put the output where desired */
354 		ignore_signals();
355 		if (!skip_rest_of_patch) {
356 			struct stat	statbuf;
357 			char	*realout = outname;
358 
359 			if (!check_only) {
360 				if (move_file(TMPOUTNAME, outname) < 0) {
361 					toutkeep = true;
362 					realout = TMPOUTNAME;
363 					chmod(TMPOUTNAME, filemode);
364 				} else
365 					chmod(outname, filemode);
366 
367 				if (remove_empty_files &&
368 				    stat(realout, &statbuf) == 0 &&
369 				    statbuf.st_size == 0) {
370 					if (verbose)
371 						say("Removing %s (empty after patching).\n",
372 						    realout);
373 					unlink(realout);
374 				}
375 			}
376 		}
377 		fclose(rejfp);
378 		rejfp = NULL;
379 		if (failed) {
380 			error = 1;
381 			if (*rejname == '\0') {
382 				if (strlcpy(rejname, outname,
383 				    sizeof(rejname)) >= sizeof(rejname))
384 					fatal("filename %s is too long\n", outname);
385 				if (strlcat(rejname, REJEXT,
386 				    sizeof(rejname)) >= sizeof(rejname))
387 					fatal("filename %s is too long\n", outname);
388 			}
389 			if (!check_only)
390 				say("%d out of %d hunks %s--saving rejects to %s\n",
391 				    failed, hunk, skip_rest_of_patch ? "ignored" : "failed", rejname);
392 			else
393 				say("%d out of %d hunks %s\n",
394 				    failed, hunk, skip_rest_of_patch ? "ignored" : "failed");
395 			if (!check_only && move_file(TMPREJNAME, rejname) < 0)
396 				trejkeep = true;
397 		}
398 		set_signals(1);
399 	}
400 
401 	if (!patch_seen)
402 		error = 2;
403 
404 	my_exit(error);
405 	/* NOTREACHED */
406 }
407 
408 /* Prepare to find the next patch to do in the patch file. */
409 
410 static void
411 reinitialize_almost_everything(void)
412 {
413 	re_patch();
414 	re_input();
415 
416 	input_lines = 0;
417 	last_frozen_line = 0;
418 
419 	filec = 0;
420 	if (!out_of_mem) {
421 		free(filearg[0]);
422 		filearg[0] = NULL;
423 	}
424 
425 	free(outname);
426 	outname = NULL;
427 
428 	last_offset = 0;
429 	diff_type = 0;
430 
431 	free(revision);
432 	revision = NULL;
433 
434 	reverse = reverse_flag_specified;
435 	skip_rest_of_patch = false;
436 
437 	get_some_switches();
438 }
439 
440 /* Process switches and filenames. */
441 
442 static void
443 get_some_switches(void)
444 {
445 	const char *options = "b::B:cCd:D:eEfF:i:lnNo:p:r:RstuvV:x:z:";
446 	static struct option longopts[] = {
447 		{"backup",		no_argument,		0,	'b'},
448 		{"batch",		no_argument,		0,	't'},
449 		{"check",		no_argument,		0,	'C'},
450 		{"context",		no_argument,		0,	'c'},
451 		{"debug",		required_argument,	0,	'x'},
452 		{"directory",		required_argument,	0,	'd'},
453 		{"ed",			no_argument,		0,	'e'},
454 		{"force",		no_argument,		0,	'f'},
455 		{"forward",		no_argument,		0,	'N'},
456 		{"fuzz",		required_argument,	0,	'F'},
457 		{"ifdef",		required_argument,	0,	'D'},
458 		{"input",		required_argument,	0,	'i'},
459 		{"ignore-whitespace",	no_argument,		0,	'l'},
460 		{"normal",		no_argument,		0,	'n'},
461 		{"output",		required_argument,	0,	'o'},
462 		{"prefix",		required_argument,	0,	'B'},
463 		{"quiet",		no_argument,		0,	's'},
464 		{"reject-file",		required_argument,	0,	'r'},
465 		{"remove-empty-files",	no_argument,		0,	'E'},
466 		{"reverse",		no_argument,		0,	'R'},
467 		{"silent",		no_argument,		0,	's'},
468 		{"strip",		required_argument,	0,	'p'},
469 		{"suffix",		required_argument,	0,	'z'},
470 		{"unified",		no_argument,		0,	'u'},
471 		{"version",		no_argument,		0,	'v'},
472 		{"version-control",	required_argument,	0,	'V'},
473 		{"posix",		no_argument,		&posix,	1},
474 		{NULL,			0,			0,	0}
475 	};
476 	int ch;
477 
478 	rejname[0] = '\0';
479 	Argc_last = Argc;
480 	Argv_last = Argv;
481 	if (!Argc)
482 		return;
483 	optreset = optind = 1;
484 	while ((ch = getopt_long(Argc, Argv, options, longopts, NULL)) != -1) {
485 		switch (ch) {
486 		case 'b':
487 			if (backup_type == none)
488 				backup_type = numbered_existing;
489 			if (optarg == NULL)
490 				break;
491 			if (verbose)
492 				say("Warning, the ``-b suffix'' option has been"
493 				    " obsoleted by the -z option.\n");
494 			/* FALLTHROUGH */
495 		case 'z':
496 			/* must directly follow 'b' case for backwards compat */
497 			simple_backup_suffix = xstrdup(optarg);
498 			break;
499 		case 'B':
500 			origprae = xstrdup(optarg);
501 			break;
502 		case 'c':
503 			diff_type = CONTEXT_DIFF;
504 			break;
505 		case 'C':
506 			check_only = true;
507 			break;
508 		case 'd':
509 			if (chdir(optarg) < 0)
510 				pfatal("can't cd to %s", optarg);
511 			break;
512 		case 'D':
513 			do_defines = true;
514 			if (!isalpha((unsigned char)*optarg) && *optarg != '_')
515 				fatal("argument to -D is not an identifier\n");
516 			snprintf(if_defined, sizeof if_defined,
517 			    "#ifdef %s\n", optarg);
518 			snprintf(not_defined, sizeof not_defined,
519 			    "#ifndef %s\n", optarg);
520 			snprintf(end_defined, sizeof end_defined,
521 			    "#endif /* %s */\n", optarg);
522 			break;
523 		case 'e':
524 			diff_type = ED_DIFF;
525 			break;
526 		case 'E':
527 			remove_empty_files = true;
528 			break;
529 		case 'f':
530 			force = true;
531 			break;
532 		case 'F':
533 			maxfuzz = atoi(optarg);
534 			break;
535 		case 'i':
536 			if (++filec == MAXFILEC)
537 				fatal("too many file arguments\n");
538 			filearg[filec] = xstrdup(optarg);
539 			break;
540 		case 'l':
541 			canonicalize = true;
542 			break;
543 		case 'n':
544 			diff_type = NORMAL_DIFF;
545 			break;
546 		case 'N':
547 			noreverse = true;
548 			break;
549 		case 'o':
550 			outname = xstrdup(optarg);
551 			break;
552 		case 'p':
553 			strippath = atoi(optarg);
554 			break;
555 		case 'r':
556 			if (strlcpy(rejname, optarg,
557 			    sizeof(rejname)) >= sizeof(rejname))
558 				fatal("argument for -r is too long\n");
559 			break;
560 		case 'R':
561 			reverse = true;
562 			reverse_flag_specified = true;
563 			break;
564 		case 's':
565 			verbose = false;
566 			break;
567 		case 't':
568 			batch = true;
569 			break;
570 		case 'u':
571 			diff_type = UNI_DIFF;
572 			break;
573 		case 'v':
574 			version();
575 			break;
576 		case 'V':
577 			backup_type = get_version(optarg);
578 			break;
579 #ifdef DEBUGGING
580 		case 'x':
581 			debug = atoi(optarg);
582 			break;
583 #endif
584 		default:
585 			if (ch != '\0')
586 				usage();
587 			break;
588 		}
589 	}
590 	Argc -= optind;
591 	Argv += optind;
592 
593 	if (Argc > 0) {
594 		filearg[0] = xstrdup(*Argv++);
595 		Argc--;
596 		while (Argc > 0) {
597 			if (++filec == MAXFILEC)
598 				fatal("too many file arguments\n");
599 			filearg[filec] = xstrdup(*Argv++);
600 			Argc--;
601 		}
602 	}
603 
604 	if (getenv("POSIXLY_CORRECT") != NULL)
605 		posix = 1;
606 }
607 
608 static __dead void
609 usage(void)
610 {
611 	fprintf(stderr,
612 "usage: patch [-bCcEeflNnRstuv] [-B backup-prefix] [-D symbol] [-d directory]\n"
613 "             [-F max-fuzz] [-i patchfile] [-o out-file] [-p strip-count]\n"
614 "             [-r rej-name] [-V t | nil | never] [-x number] [-z backup-ext]\n"
615 "             [--posix] [origfile [patchfile]]\n"
616 "       patch <patchfile\n");
617 	my_exit(EXIT_SUCCESS);
618 }
619 
620 /*
621  * Attempt to find the right place to apply this hunk of patch.
622  */
623 static LINENUM
624 locate_hunk(LINENUM fuzz)
625 {
626 	LINENUM	first_guess = pch_first() + last_offset;
627 	LINENUM	offset;
628 	LINENUM	pat_lines = pch_ptrn_lines();
629 	LINENUM	max_pos_offset = input_lines - first_guess - pat_lines + 1;
630 	LINENUM	max_neg_offset = first_guess - last_frozen_line - 1 + pch_context();
631 
632 	if (pat_lines == 0) {		/* null range matches always */
633 		if (verbose && fuzz == 0 && (diff_type == CONTEXT_DIFF
634 		    || diff_type == NEW_CONTEXT_DIFF
635 		    || diff_type == UNI_DIFF)) {
636 			say("Empty context always matches.\n");
637 		}
638 		return (first_guess);
639 	}
640 	if (max_neg_offset >= first_guess)	/* do not try lines < 0 */
641 		max_neg_offset = first_guess - 1;
642 	if (first_guess <= input_lines && patch_match(first_guess, 0, fuzz))
643 		return first_guess;
644 	for (offset = 1; ; offset++) {
645 		bool	check_after = (offset <= max_pos_offset);
646 		bool	check_before = (offset <= max_neg_offset);
647 
648 		if (check_after && patch_match(first_guess, offset, fuzz)) {
649 #ifdef DEBUGGING
650 			if (debug & 1)
651 				say("Offset changing from %ld to %ld\n",
652 				    last_offset, offset);
653 #endif
654 			last_offset = offset;
655 			return first_guess + offset;
656 		} else if (check_before && patch_match(first_guess, -offset, fuzz)) {
657 #ifdef DEBUGGING
658 			if (debug & 1)
659 				say("Offset changing from %ld to %ld\n",
660 				    last_offset, -offset);
661 #endif
662 			last_offset = -offset;
663 			return first_guess - offset;
664 		} else if (!check_before && !check_after)
665 			return 0;
666 	}
667 }
668 
669 /* We did not find the pattern, dump out the hunk so they can handle it. */
670 
671 static void
672 abort_context_hunk(void)
673 {
674 	LINENUM	i;
675 	const LINENUM	pat_end = pch_end();
676 	/*
677 	 * add in last_offset to guess the same as the previous successful
678 	 * hunk
679 	 */
680 	const LINENUM	oldfirst = pch_first() + last_offset;
681 	const LINENUM	newfirst = pch_newfirst() + last_offset;
682 	const LINENUM	oldlast = oldfirst + pch_ptrn_lines() - 1;
683 	const LINENUM	newlast = newfirst + pch_repl_lines() - 1;
684 	const char	*stars = (diff_type >= NEW_CONTEXT_DIFF ? " ****" : "");
685 	const char	*minuses = (diff_type >= NEW_CONTEXT_DIFF ? " ----" : " -----");
686 
687 	fprintf(rejfp, "***************\n");
688 	for (i = 0; i <= pat_end; i++) {
689 		switch (pch_char(i)) {
690 		case '*':
691 			if (oldlast < oldfirst)
692 				fprintf(rejfp, "*** 0%s\n", stars);
693 			else if (oldlast == oldfirst)
694 				fprintf(rejfp, "*** %ld%s\n", oldfirst, stars);
695 			else
696 				fprintf(rejfp, "*** %ld,%ld%s\n", oldfirst,
697 				    oldlast, stars);
698 			break;
699 		case '=':
700 			if (newlast < newfirst)
701 				fprintf(rejfp, "--- 0%s\n", minuses);
702 			else if (newlast == newfirst)
703 				fprintf(rejfp, "--- %ld%s\n", newfirst, minuses);
704 			else
705 				fprintf(rejfp, "--- %ld,%ld%s\n", newfirst,
706 				    newlast, minuses);
707 			break;
708 		case '\n':
709 			fprintf(rejfp, "%s", pfetch(i));
710 			break;
711 		case ' ':
712 		case '-':
713 		case '+':
714 		case '!':
715 			fprintf(rejfp, "%c %s", pch_char(i), pfetch(i));
716 			break;
717 		default:
718 			fatal("fatal internal error in abort_context_hunk\n");
719 		}
720 	}
721 }
722 
723 static void
724 rej_line(int ch, LINENUM i)
725 {
726 	size_t len;
727 	const char *line = pfetch(i);
728 
729 	len = strlen(line);
730 
731 	fprintf(rejfp, "%c%s", ch, line);
732 	if (len == 0 || line[len-1] != '\n')
733 		fprintf(rejfp, "\n\\ No newline at end of file\n");
734 }
735 
736 static void
737 abort_hunk(void)
738 {
739 	LINENUM		i, j, split;
740 	int		ch1, ch2;
741 	const LINENUM	pat_end = pch_end();
742 	const LINENUM	oldfirst = pch_first() + last_offset;
743 	const LINENUM	newfirst = pch_newfirst() + last_offset;
744 
745 	if (diff_type != UNI_DIFF) {
746 		abort_context_hunk();
747 		return;
748 	}
749 	split = -1;
750 	for (i = 0; i <= pat_end; i++) {
751 		if (pch_char(i) == '=') {
752 			split = i;
753 			break;
754 		}
755 	}
756 	if (split == -1) {
757 		fprintf(rejfp, "malformed hunk: no split found\n");
758 		return;
759 	}
760 	i = 0;
761 	j = split + 1;
762 	fprintf(rejfp, "@@ -%ld,%ld +%ld,%ld @@\n",
763 	    pch_ptrn_lines() ? oldfirst : 0,
764 	    pch_ptrn_lines(), newfirst, pch_repl_lines());
765 	while (i < split || j <= pat_end) {
766 		ch1 = i < split ? pch_char(i) : -1;
767 		ch2 = j <= pat_end ? pch_char(j) : -1;
768 		if (ch1 == '-') {
769 			rej_line('-', i);
770 			i++;
771 		} else if (ch1 == ' ' && ch2 == ' ') {
772 			rej_line(' ', i);
773 			i++;
774 			j++;
775 		} else if (ch1 == '!' && ch2 == '!') {
776 			while (i < split && ch1 == '!') {
777 				rej_line('-', i);
778 				i++;
779 				ch1 = i < split ? pch_char(i) : -1;
780 			}
781 			while (j <= pat_end && ch2 == '!') {
782 				rej_line('+', j);
783 				j++;
784 				ch2 = j <= pat_end ? pch_char(j) : -1;
785 			}
786 		} else if (ch1 == '*') {
787 			i++;
788 		} else if (ch2 == '+' || ch2 == ' ') {
789 			rej_line(ch2, j);
790 			j++;
791 		} else {
792 			fprintf(rejfp, "internal error on (%ld %ld %ld)\n",
793 			    i, split, j);
794 			rej_line(ch1, i);
795 			rej_line(ch2, j);
796 			return;
797 		}
798 	}
799 }
800 
801 /* We found where to apply it (we hope), so do it. */
802 
803 static void
804 apply_hunk(LINENUM where)
805 {
806 	LINENUM		old = 1;
807 	const LINENUM	lastline = pch_ptrn_lines();
808 	LINENUM		new = lastline + 1;
809 #define OUTSIDE 0
810 #define IN_IFNDEF 1
811 #define IN_IFDEF 2
812 #define IN_ELSE 3
813 	int		def_state = OUTSIDE;
814 	const LINENUM	pat_end = pch_end();
815 
816 	where--;
817 	while (pch_char(new) == '=' || pch_char(new) == '\n')
818 		new++;
819 
820 	while (old <= lastline) {
821 		if (pch_char(old) == '-') {
822 			copy_till(where + old - 1, false);
823 			if (do_defines) {
824 				if (def_state == OUTSIDE) {
825 					fputs(not_defined, ofp);
826 					def_state = IN_IFNDEF;
827 				} else if (def_state == IN_IFDEF) {
828 					fputs(else_defined, ofp);
829 					def_state = IN_ELSE;
830 				}
831 				fputs(pfetch(old), ofp);
832 			}
833 			last_frozen_line++;
834 			old++;
835 		} else if (new > pat_end) {
836 			break;
837 		} else if (pch_char(new) == '+') {
838 			copy_till(where + old - 1, false);
839 			if (do_defines) {
840 				if (def_state == IN_IFNDEF) {
841 					fputs(else_defined, ofp);
842 					def_state = IN_ELSE;
843 				} else if (def_state == OUTSIDE) {
844 					fputs(if_defined, ofp);
845 					def_state = IN_IFDEF;
846 				}
847 			}
848 			fputs(pfetch(new), ofp);
849 			new++;
850 		} else if (pch_char(new) != pch_char(old)) {
851 			say("Out-of-sync patch, lines %ld,%ld--mangled text or line numbers, maybe?\n",
852 			    pch_hunk_beg() + old,
853 			    pch_hunk_beg() + new);
854 #ifdef DEBUGGING
855 			say("oldchar = '%c', newchar = '%c'\n",
856 			    pch_char(old), pch_char(new));
857 #endif
858 			my_exit(2);
859 		} else if (pch_char(new) == '!') {
860 			copy_till(where + old - 1, false);
861 			if (do_defines) {
862 				fputs(not_defined, ofp);
863 				def_state = IN_IFNDEF;
864 			}
865 			while (pch_char(old) == '!') {
866 				if (do_defines) {
867 					fputs(pfetch(old), ofp);
868 				}
869 				last_frozen_line++;
870 				old++;
871 			}
872 			if (do_defines) {
873 				fputs(else_defined, ofp);
874 				def_state = IN_ELSE;
875 			}
876 			while (pch_char(new) == '!') {
877 				fputs(pfetch(new), ofp);
878 				new++;
879 			}
880 		} else {
881 			if (pch_char(new) != ' ')
882 				fatal("Internal error: expected ' '\n");
883 			old++;
884 			new++;
885 			if (do_defines && def_state != OUTSIDE) {
886 				fputs(end_defined, ofp);
887 				def_state = OUTSIDE;
888 			}
889 		}
890 	}
891 	if (new <= pat_end && pch_char(new) == '+') {
892 		copy_till(where + old - 1, false);
893 		if (do_defines) {
894 			if (def_state == OUTSIDE) {
895 				fputs(if_defined, ofp);
896 				def_state = IN_IFDEF;
897 			} else if (def_state == IN_IFNDEF) {
898 				fputs(else_defined, ofp);
899 				def_state = IN_ELSE;
900 			}
901 		}
902 		while (new <= pat_end && pch_char(new) == '+') {
903 			fputs(pfetch(new), ofp);
904 			new++;
905 		}
906 	}
907 	if (do_defines && def_state != OUTSIDE) {
908 		fputs(end_defined, ofp);
909 	}
910 }
911 
912 /*
913  * Open the new file.
914  */
915 static void
916 init_output(const char *name)
917 {
918 	ofp = fopen(name, "w");
919 	if (ofp == NULL)
920 		pfatal("can't create %s", name);
921 }
922 
923 /*
924  * Open a file to put hunks we can't locate.
925  */
926 static void
927 init_reject(const char *name)
928 {
929 	rejfp = fopen(name, "w");
930 	if (rejfp == NULL)
931 		pfatal("can't create %s", name);
932 }
933 
934 /*
935  * Copy input file to output, up to wherever hunk is to be applied.
936  * If endoffile is true, treat the last line specially since it may
937  * lack a newline.
938  */
939 static void
940 copy_till(LINENUM lastline, bool endoffile)
941 {
942 	if (last_frozen_line > lastline)
943 		fatal("misordered hunks! output would be garbled\n");
944 	while (last_frozen_line < lastline) {
945 		if (++last_frozen_line == lastline && endoffile)
946 			dump_line(last_frozen_line, !last_line_missing_eol);
947 		else
948 			dump_line(last_frozen_line, true);
949 	}
950 }
951 
952 /*
953  * Finish copying the input file to the output file.
954  */
955 static void
956 spew_output(void)
957 {
958 #ifdef DEBUGGING
959 	if (debug & 256)
960 		say("il=%ld lfl=%ld\n", input_lines, last_frozen_line);
961 #endif
962 	if (input_lines)
963 		copy_till(input_lines, true);	/* dump remainder of file */
964 	fclose(ofp);
965 	ofp = NULL;
966 }
967 
968 /*
969  * Copy one line from input to output.
970  */
971 static void
972 dump_line(LINENUM line, bool write_newline)
973 {
974 	char	*s;
975 
976 	s = ifetch(line, 0);
977 	if (s == NULL)
978 		return;
979 	/* Note: string is not NUL terminated. */
980 	for (; *s != '\n'; s++)
981 		putc(*s, ofp);
982 	if (write_newline)
983 		putc('\n', ofp);
984 }
985 
986 /*
987  * Does the patch pattern match at line base+offset?
988  */
989 static bool
990 patch_match(LINENUM base, LINENUM offset, LINENUM fuzz)
991 {
992 	LINENUM		pline = 1 + fuzz;
993 	LINENUM		iline;
994 	LINENUM		pat_lines = pch_ptrn_lines() - fuzz;
995 	const char	*ilineptr;
996 	const char	*plineptr;
997 	short		plinelen;
998 
999 	for (iline = base + offset + fuzz; pline <= pat_lines; pline++, iline++) {
1000 		ilineptr = ifetch(iline, offset >= 0);
1001 		if (ilineptr == NULL)
1002 			return false;
1003 		plineptr = pfetch(pline);
1004 		plinelen = pch_line_len(pline);
1005 		if (canonicalize) {
1006 			if (!similar(ilineptr, plineptr, plinelen))
1007 				return false;
1008 		} else if (strnNE(ilineptr, plineptr, plinelen))
1009 			return false;
1010 		if (iline == input_lines) {
1011 			/*
1012 			 * We are looking at the last line of the file.
1013 			 * If the file has no eol, the patch line should
1014 			 * not have one either and vice-versa. Note that
1015 			 * plinelen > 0.
1016 			 */
1017 			if (last_line_missing_eol) {
1018 				if (plineptr[plinelen - 1] == '\n')
1019 					return false;
1020 			} else {
1021 				if (plineptr[plinelen - 1] != '\n')
1022 					return false;
1023 			}
1024 		}
1025 	}
1026 	return true;
1027 }
1028 
1029 /*
1030  * Do two lines match with canonicalized white space?
1031  */
1032 static bool
1033 similar(const char *a, const char *b, int len)
1034 {
1035 	while (len) {
1036 		if (isspace((unsigned char)*b)) { /* whitespace (or \n) to match? */
1037 			if (!isspace((unsigned char)*a))
1038 				return false;	/* no corresponding whitespace */
1039 			while (len && isspace((unsigned char)*b) && *b != '\n')
1040 				b++, len--;	/* skip pattern whitespace */
1041 			while (isspace((unsigned char)*a) && *a != '\n')
1042 				a++;	/* skip target whitespace */
1043 			if (*a == '\n' || *b == '\n')
1044 				return (*a == *b);	/* should end in sync */
1045 		} else if (*a++ != *b++)	/* match non-whitespace chars */
1046 			return false;
1047 		else
1048 			len--;	/* probably not necessary */
1049 	}
1050 	return true;		/* actually, this is not reached */
1051 	/* since there is always a \n */
1052 }
1053