xref: /freebsd/usr.bin/patch/patch.c (revision fcb560670601b2a4d87bb31d7531c8dcc37ee71b)
1 /*-
2  * Copyright 1986, Larry Wall
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following condition is met:
6  * 1. Redistributions of source code must retain the above copyright notice,
7  * this condition and the following disclaimer.
8  *
9  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
10  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
11  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
12  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
13  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
14  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
15  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
16  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
17  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
18  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
19  * SUCH DAMAGE.
20  *
21  * patch - a program to apply diffs to original files
22  *
23  * -C option added in 1998, original code by Marc Espie, based on FreeBSD
24  * behaviour
25  *
26  * $OpenBSD: patch.c,v 1.54 2014/12/13 10:31:07 tobias Exp $
27  * $FreeBSD$
28  *
29  */
30 
31 #include <sys/types.h>
32 #include <sys/stat.h>
33 
34 #include <ctype.h>
35 #include <getopt.h>
36 #include <limits.h>
37 #include <stdio.h>
38 #include <string.h>
39 #include <stdlib.h>
40 #include <unistd.h>
41 
42 #include "common.h"
43 #include "util.h"
44 #include "pch.h"
45 #include "inp.h"
46 #include "backupfile.h"
47 #include "pathnames.h"
48 
49 mode_t		filemode = 0644;
50 
51 char		*buf;			/* general purpose buffer */
52 size_t		buf_size;		/* size of the general purpose buffer */
53 
54 bool		using_plan_a = true;	/* try to keep everything in memory */
55 bool		out_of_mem = false;	/* ran out of memory in plan a */
56 
57 #define MAXFILEC 2
58 
59 char		*filearg[MAXFILEC];
60 bool		ok_to_create_file = false;
61 char		*outname = NULL;
62 char		*origprae = NULL;
63 char		*TMPOUTNAME;
64 char		*TMPINNAME;
65 char		*TMPREJNAME;
66 char		*TMPPATNAME;
67 bool		toutkeep = false;
68 bool		trejkeep = false;
69 bool		warn_on_invalid_line;
70 bool		last_line_missing_eol;
71 
72 #ifdef DEBUGGING
73 int		debug = 0;
74 #endif
75 
76 bool		force = false;
77 bool		batch = false;
78 bool		verbose = true;
79 bool		reverse = false;
80 bool		noreverse = false;
81 bool		skip_rest_of_patch = false;
82 int		strippath = 957;
83 bool		canonicalize = false;
84 bool		check_only = false;
85 int		diff_type = 0;
86 char		*revision = NULL;	/* prerequisite revision, if any */
87 LINENUM		input_lines = 0;	/* how long is input file in lines */
88 int		posix = 0;		/* strict POSIX mode? */
89 
90 static void	reinitialize_almost_everything(void);
91 static void	get_some_switches(void);
92 static LINENUM	locate_hunk(LINENUM);
93 static void	abort_context_hunk(void);
94 static void	rej_line(int, LINENUM);
95 static void	abort_hunk(void);
96 static void	apply_hunk(LINENUM);
97 static void	init_output(const char *);
98 static void	init_reject(const char *);
99 static void	copy_till(LINENUM, bool);
100 static bool	spew_output(void);
101 static void	dump_line(LINENUM, bool);
102 static bool	patch_match(LINENUM, LINENUM, LINENUM);
103 static bool	similar(const char *, const char *, int);
104 static void	usage(void);
105 
106 /* true if -E was specified on command line.  */
107 static bool	remove_empty_files = false;
108 
109 /* true if -R was specified on command line.  */
110 static bool	reverse_flag_specified = false;
111 
112 /* buffer holding the name of the rejected patch file. */
113 static char	rejname[NAME_MAX + 1];
114 
115 /* how many input lines have been irretractibly output */
116 static LINENUM	last_frozen_line = 0;
117 
118 static int	Argc;		/* guess */
119 static char	**Argv;
120 static int	Argc_last;	/* for restarting plan_b */
121 static char	**Argv_last;
122 
123 static FILE	*ofp = NULL;	/* output file pointer */
124 static FILE	*rejfp = NULL;	/* reject file pointer */
125 
126 static int	filec = 0;	/* how many file arguments? */
127 static LINENUM	last_offset = 0;
128 static LINENUM	maxfuzz = 2;
129 
130 /* patch using ifdef, ifndef, etc. */
131 static bool		do_defines = false;
132 /* #ifdef xyzzy */
133 static char		if_defined[128];
134 /* #ifndef xyzzy */
135 static char		not_defined[128];
136 /* #else */
137 static const char	else_defined[] = "#else\n";
138 /* #endif xyzzy */
139 static char		end_defined[128];
140 
141 
142 /* Apply a set of diffs as appropriate. */
143 
144 int
145 main(int argc, char *argv[])
146 {
147 	int	error = 0, hunk, failed, i, fd;
148 	bool	patch_seen, reverse_seen;
149 	LINENUM	where = 0, newwhere, fuzz, mymaxfuzz;
150 	const	char *tmpdir;
151 	char	*v;
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 	buf_size = INITLINELEN;
159 	buf = malloc((unsigned)(buf_size));
160 	if (buf == NULL)
161 		fatal("out of memory\n");
162 
163 	/* Cons up the names of the temporary files.  */
164 	if ((tmpdir = getenv("TMPDIR")) == NULL || *tmpdir == '\0')
165 		tmpdir = _PATH_TMP;
166 	for (i = strlen(tmpdir) - 1; i > 0 && tmpdir[i] == '/'; i--)
167 		;
168 	i++;
169 	if (asprintf(&TMPOUTNAME, "%.*s/patchoXXXXXXXXXX", i, tmpdir) == -1)
170 		fatal("cannot allocate memory");
171 	if ((fd = mkstemp(TMPOUTNAME)) < 0)
172 		pfatal("can't create %s", TMPOUTNAME);
173 	close(fd);
174 
175 	if (asprintf(&TMPINNAME, "%.*s/patchiXXXXXXXXXX", i, tmpdir) == -1)
176 		fatal("cannot allocate memory");
177 	if ((fd = mkstemp(TMPINNAME)) < 0)
178 		pfatal("can't create %s", TMPINNAME);
179 	close(fd);
180 
181 	if (asprintf(&TMPREJNAME, "%.*s/patchrXXXXXXXXXX", i, tmpdir) == -1)
182 		fatal("cannot allocate memory");
183 	if ((fd = mkstemp(TMPREJNAME)) < 0)
184 		pfatal("can't create %s", TMPREJNAME);
185 	close(fd);
186 
187 	if (asprintf(&TMPPATNAME, "%.*s/patchpXXXXXXXXXX", i, tmpdir) == -1)
188 		fatal("cannot allocate memory");
189 	if ((fd = mkstemp(TMPPATNAME)) < 0)
190 		pfatal("can't create %s", TMPPATNAME);
191 	close(fd);
192 
193 	v = getenv("SIMPLE_BACKUP_SUFFIX");
194 	if (v)
195 		simple_backup_suffix = v;
196 	else
197 		simple_backup_suffix = ORIGEXT;
198 
199 	/* parse switches */
200 	Argc = argc;
201 	Argv = argv;
202 	get_some_switches();
203 
204 	if (backup_type == none) {
205 		if ((v = getenv("PATCH_VERSION_CONTROL")) == NULL)
206 			v = getenv("VERSION_CONTROL");
207 		if (v != NULL || !posix)
208 			backup_type = get_version(v);	/* OK to pass NULL. */
209 	}
210 
211 	/* make sure we clean up /tmp in case of disaster */
212 	set_signals(0);
213 
214 	patch_seen = false;
215 	for (open_patch_file(filearg[1]); there_is_another_patch();
216 	    reinitialize_almost_everything()) {
217 		/* for each patch in patch file */
218 
219 		patch_seen = true;
220 
221 		warn_on_invalid_line = true;
222 
223 		if (outname == NULL)
224 			outname = xstrdup(filearg[0]);
225 
226 		/* for ed script just up and do it and exit */
227 		if (diff_type == ED_DIFF) {
228 			do_ed_script();
229 			continue;
230 		}
231 		/* initialize the patched file */
232 		if (!skip_rest_of_patch)
233 			init_output(TMPOUTNAME);
234 
235 		/* initialize reject file */
236 		init_reject(TMPREJNAME);
237 
238 		/* find out where all the lines are */
239 		if (!skip_rest_of_patch)
240 			scan_input(filearg[0]);
241 
242 		/*
243 		 * from here on, open no standard i/o files, because
244 		 * malloc might misfire and we can't catch it easily
245 		 */
246 
247 		/* apply each hunk of patch */
248 		hunk = 0;
249 		failed = 0;
250 		reverse_seen = false;
251 		out_of_mem = false;
252 		while (another_hunk()) {
253 			hunk++;
254 			fuzz = 0;
255 			mymaxfuzz = pch_context();
256 			if (maxfuzz < mymaxfuzz)
257 				mymaxfuzz = maxfuzz;
258 			if (!skip_rest_of_patch) {
259 				do {
260 					where = locate_hunk(fuzz);
261 					if (hunk == 1 && where == 0 && !force && !reverse_seen) {
262 						/* dwim for reversed patch? */
263 						if (!pch_swap()) {
264 							if (fuzz == 0)
265 								say("Not enough memory to try swapped hunk!  Assuming unswapped.\n");
266 							continue;
267 						}
268 						reverse = !reverse;
269 						/* try again */
270 						where = locate_hunk(fuzz);
271 						if (where == 0) {
272 							/* didn't find it swapped */
273 							if (!pch_swap())
274 								/* put it back to normal */
275 								fatal("lost hunk on alloc error!\n");
276 							reverse = !reverse;
277 						} else if (noreverse) {
278 							if (!pch_swap())
279 								/* put it back to normal */
280 								fatal("lost hunk on alloc error!\n");
281 							reverse = !reverse;
282 							say("Ignoring previously applied (or reversed) patch.\n");
283 							skip_rest_of_patch = true;
284 						} else if (batch) {
285 							if (verbose)
286 								say("%seversed (or previously applied) patch detected!  %s -R.",
287 								    reverse ? "R" : "Unr",
288 								    reverse ? "Assuming" : "Ignoring");
289 						} else {
290 							ask("%seversed (or previously applied) patch detected!  %s -R? [y] ",
291 							    reverse ? "R" : "Unr",
292 							    reverse ? "Assume" : "Ignore");
293 							if (*buf == 'n') {
294 								ask("Apply anyway? [n] ");
295 								if (*buf != 'y')
296 									skip_rest_of_patch = true;
297 								else
298 									reverse_seen = true;
299 								where = 0;
300 								reverse = !reverse;
301 								if (!pch_swap())
302 									/* put it back to normal */
303 									fatal("lost hunk on alloc error!\n");
304 							}
305 						}
306 					}
307 				} while (!skip_rest_of_patch && where == 0 &&
308 				    ++fuzz <= mymaxfuzz);
309 
310 				if (skip_rest_of_patch) {	/* just got decided */
311 					if (ferror(ofp) || fclose(ofp)) {
312 						say("Error writing %s\n",
313 						    TMPOUTNAME);
314 						error = 1;
315 					}
316 					ofp = NULL;
317 				}
318 			}
319 			newwhere = pch_newfirst() + last_offset;
320 			if (skip_rest_of_patch) {
321 				abort_hunk();
322 				failed++;
323 				if (verbose)
324 					say("Hunk #%d ignored at %ld.\n",
325 					    hunk, newwhere);
326 			} else if (where == 0) {
327 				abort_hunk();
328 				failed++;
329 				if (verbose)
330 					say("Hunk #%d failed at %ld.\n",
331 					    hunk, newwhere);
332 			} else {
333 				apply_hunk(where);
334 				if (verbose) {
335 					say("Hunk #%d succeeded at %ld",
336 					    hunk, newwhere);
337 					if (fuzz != 0)
338 						say(" with fuzz %ld", fuzz);
339 					if (last_offset)
340 						say(" (offset %ld line%s)",
341 						    last_offset,
342 						    last_offset == 1L ? "" : "s");
343 					say(".\n");
344 				}
345 			}
346 		}
347 
348 		if (out_of_mem && using_plan_a) {
349 			Argc = Argc_last;
350 			Argv = Argv_last;
351 			say("\n\nRan out of memory using Plan A--trying again...\n\n");
352 			if (ofp)
353 				fclose(ofp);
354 			ofp = NULL;
355 			if (rejfp)
356 				fclose(rejfp);
357 			rejfp = NULL;
358 			continue;
359 		}
360 		if (hunk == 0)
361 			fatal("Internal error: hunk should not be 0\n");
362 
363 		/* finish spewing out the new file */
364 		if (!skip_rest_of_patch && !spew_output()) {
365 			say("Can't write %s\n", TMPOUTNAME);
366 			error = 1;
367 		}
368 
369 		/* and put the output where desired */
370 		ignore_signals();
371 		if (!skip_rest_of_patch) {
372 			struct stat	statbuf;
373 			char	*realout = outname;
374 
375 			if (!check_only) {
376 				if (move_file(TMPOUTNAME, outname) < 0) {
377 					toutkeep = true;
378 					realout = TMPOUTNAME;
379 					chmod(TMPOUTNAME, filemode);
380 				} else
381 					chmod(outname, filemode);
382 
383 				if (remove_empty_files &&
384 				    stat(realout, &statbuf) == 0 &&
385 				    statbuf.st_size == 0) {
386 					if (verbose)
387 						say("Removing %s (empty after patching).\n",
388 						    realout);
389 					unlink(realout);
390 				}
391 			}
392 		}
393 		if (ferror(rejfp) || fclose(rejfp)) {
394 			say("Error writing %s\n", rejname);
395 			error = 1;
396 		}
397 		rejfp = NULL;
398 		if (failed) {
399 			error = 1;
400 			if (*rejname == '\0') {
401 				if (strlcpy(rejname, outname,
402 				    sizeof(rejname)) >= sizeof(rejname))
403 					fatal("filename %s is too long\n", outname);
404 				if (strlcat(rejname, REJEXT,
405 				    sizeof(rejname)) >= sizeof(rejname))
406 					fatal("filename %s is too long\n", outname);
407 			}
408 			if (!check_only)
409 				say("%d out of %d hunks %s--saving rejects to %s\n",
410 				    failed, hunk, skip_rest_of_patch ? "ignored" : "failed", rejname);
411 			else
412 				say("%d out of %d hunks %s while patching %s\n",
413 				    failed, hunk, skip_rest_of_patch ? "ignored" : "failed", filearg[0]);
414 			if (!check_only && move_file(TMPREJNAME, rejname) < 0)
415 				trejkeep = true;
416 		}
417 		set_signals(1);
418 	}
419 
420 	if (!patch_seen)
421 		error = 2;
422 
423 	my_exit(error);
424 	/* NOTREACHED */
425 }
426 
427 /* Prepare to find the next patch to do in the patch file. */
428 
429 static void
430 reinitialize_almost_everything(void)
431 {
432 	re_patch();
433 	re_input();
434 
435 	input_lines = 0;
436 	last_frozen_line = 0;
437 
438 	filec = 0;
439 	if (!out_of_mem) {
440 		free(filearg[0]);
441 		filearg[0] = NULL;
442 	}
443 
444 	free(outname);
445 	outname = NULL;
446 
447 	last_offset = 0;
448 	diff_type = 0;
449 
450 	free(revision);
451 	revision = NULL;
452 
453 	reverse = reverse_flag_specified;
454 	skip_rest_of_patch = false;
455 
456 	get_some_switches();
457 }
458 
459 /* Process switches and filenames. */
460 
461 static void
462 get_some_switches(void)
463 {
464 	const char *options = "b::B:cCd:D:eEfF:i:lnNo:p:r:RstuvV:x:z:";
465 	static struct option longopts[] = {
466 		{"backup",		no_argument,		0,	'b'},
467 		{"batch",		no_argument,		0,	't'},
468 		{"check",		no_argument,		0,	'C'},
469 		{"context",		no_argument,		0,	'c'},
470 		{"debug",		required_argument,	0,	'x'},
471 		{"directory",		required_argument,	0,	'd'},
472 		{"dry-run",		no_argument,		0,	'C'},
473 		{"ed",			no_argument,		0,	'e'},
474 		{"force",		no_argument,		0,	'f'},
475 		{"forward",		no_argument,		0,	'N'},
476 		{"fuzz",		required_argument,	0,	'F'},
477 		{"ifdef",		required_argument,	0,	'D'},
478 		{"input",		required_argument,	0,	'i'},
479 		{"ignore-whitespace",	no_argument,		0,	'l'},
480 		{"normal",		no_argument,		0,	'n'},
481 		{"output",		required_argument,	0,	'o'},
482 		{"prefix",		required_argument,	0,	'B'},
483 		{"quiet",		no_argument,		0,	's'},
484 		{"reject-file",		required_argument,	0,	'r'},
485 		{"remove-empty-files",	no_argument,		0,	'E'},
486 		{"reverse",		no_argument,		0,	'R'},
487 		{"silent",		no_argument,		0,	's'},
488 		{"strip",		required_argument,	0,	'p'},
489 		{"suffix",		required_argument,	0,	'z'},
490 		{"unified",		no_argument,		0,	'u'},
491 		{"version",		no_argument,		0,	'v'},
492 		{"version-control",	required_argument,	0,	'V'},
493 		{"posix",		no_argument,		&posix,	1},
494 		{NULL,			0,			0,	0}
495 	};
496 	int ch;
497 
498 	rejname[0] = '\0';
499 	Argc_last = Argc;
500 	Argv_last = Argv;
501 	if (!Argc)
502 		return;
503 	optreset = optind = 1;
504 	while ((ch = getopt_long(Argc, Argv, options, longopts, NULL)) != -1) {
505 		switch (ch) {
506 		case 'b':
507 			if (backup_type == none)
508 				backup_type = numbered_existing;
509 			if (optarg == NULL)
510 				break;
511 			if (verbose)
512 				say("Warning, the ``-b suffix'' option has been"
513 				    " obsoleted by the -z option.\n");
514 			/* FALLTHROUGH */
515 		case 'z':
516 			/* must directly follow 'b' case for backwards compat */
517 			simple_backup_suffix = xstrdup(optarg);
518 			break;
519 		case 'B':
520 			origprae = xstrdup(optarg);
521 			break;
522 		case 'c':
523 			diff_type = CONTEXT_DIFF;
524 			break;
525 		case 'C':
526 			check_only = true;
527 			break;
528 		case 'd':
529 			if (chdir(optarg) < 0)
530 				pfatal("can't cd to %s", optarg);
531 			break;
532 		case 'D':
533 			do_defines = true;
534 			if (!isalpha((unsigned char)*optarg) && *optarg != '_')
535 				fatal("argument to -D is not an identifier\n");
536 			snprintf(if_defined, sizeof if_defined,
537 			    "#ifdef %s\n", optarg);
538 			snprintf(not_defined, sizeof not_defined,
539 			    "#ifndef %s\n", optarg);
540 			snprintf(end_defined, sizeof end_defined,
541 			    "#endif /* %s */\n", optarg);
542 			break;
543 		case 'e':
544 			diff_type = ED_DIFF;
545 			break;
546 		case 'E':
547 			remove_empty_files = true;
548 			break;
549 		case 'f':
550 			force = true;
551 			break;
552 		case 'F':
553 			maxfuzz = atoi(optarg);
554 			break;
555 		case 'i':
556 			if (++filec == MAXFILEC)
557 				fatal("too many file arguments\n");
558 			filearg[filec] = xstrdup(optarg);
559 			break;
560 		case 'l':
561 			canonicalize = true;
562 			break;
563 		case 'n':
564 			diff_type = NORMAL_DIFF;
565 			break;
566 		case 'N':
567 			noreverse = true;
568 			break;
569 		case 'o':
570 			outname = xstrdup(optarg);
571 			break;
572 		case 'p':
573 			strippath = atoi(optarg);
574 			break;
575 		case 'r':
576 			if (strlcpy(rejname, optarg,
577 			    sizeof(rejname)) >= sizeof(rejname))
578 				fatal("argument for -r is too long\n");
579 			break;
580 		case 'R':
581 			reverse = true;
582 			reverse_flag_specified = true;
583 			break;
584 		case 's':
585 			verbose = false;
586 			break;
587 		case 't':
588 			batch = true;
589 			break;
590 		case 'u':
591 			diff_type = UNI_DIFF;
592 			break;
593 		case 'v':
594 			version();
595 			break;
596 		case 'V':
597 			backup_type = get_version(optarg);
598 			break;
599 #ifdef DEBUGGING
600 		case 'x':
601 			debug = atoi(optarg);
602 			break;
603 #endif
604 		default:
605 			if (ch != '\0')
606 				usage();
607 			break;
608 		}
609 	}
610 	Argc -= optind;
611 	Argv += optind;
612 
613 	if (Argc > 0) {
614 		filearg[0] = xstrdup(*Argv++);
615 		Argc--;
616 		while (Argc > 0) {
617 			if (++filec == MAXFILEC)
618 				fatal("too many file arguments\n");
619 			filearg[filec] = xstrdup(*Argv++);
620 			Argc--;
621 		}
622 	}
623 
624 	if (getenv("POSIXLY_CORRECT") != NULL)
625 		posix = 1;
626 }
627 
628 static void
629 usage(void)
630 {
631 	fprintf(stderr,
632 "usage: patch [-bCcEeflNnRstuv] [-B backup-prefix] [-D symbol] [-d directory]\n"
633 "             [-F max-fuzz] [-i patchfile] [-o out-file] [-p strip-count]\n"
634 "             [-r rej-name] [-V t | nil | never] [-x number] [-z backup-ext]\n"
635 "             [--posix] [origfile [patchfile]]\n"
636 "       patch <patchfile\n");
637 	my_exit(EXIT_FAILURE);
638 }
639 
640 /*
641  * Attempt to find the right place to apply this hunk of patch.
642  */
643 static LINENUM
644 locate_hunk(LINENUM fuzz)
645 {
646 	LINENUM	first_guess = pch_first() + last_offset;
647 	LINENUM	offset;
648 	LINENUM	pat_lines = pch_ptrn_lines();
649 	LINENUM	max_pos_offset = input_lines - first_guess - pat_lines + 1;
650 	LINENUM	max_neg_offset = first_guess - last_frozen_line - 1 + pch_context();
651 
652 	if (pat_lines == 0) {		/* null range matches always */
653 		if (verbose && fuzz == 0 && (diff_type == CONTEXT_DIFF
654 		    || diff_type == NEW_CONTEXT_DIFF
655 		    || diff_type == UNI_DIFF)) {
656 			say("Empty context always matches.\n");
657 		}
658 		return (first_guess);
659 	}
660 	if (max_neg_offset >= first_guess)	/* do not try lines < 0 */
661 		max_neg_offset = first_guess - 1;
662 	if (first_guess <= input_lines && patch_match(first_guess, 0, fuzz))
663 		return first_guess;
664 	for (offset = 1; ; offset++) {
665 		bool	check_after = (offset <= max_pos_offset);
666 		bool	check_before = (offset <= max_neg_offset);
667 
668 		if (check_after && patch_match(first_guess, offset, fuzz)) {
669 #ifdef DEBUGGING
670 			if (debug & 1)
671 				say("Offset changing from %ld to %ld\n",
672 				    last_offset, offset);
673 #endif
674 			last_offset = offset;
675 			return first_guess + offset;
676 		} else if (check_before && patch_match(first_guess, -offset, fuzz)) {
677 #ifdef DEBUGGING
678 			if (debug & 1)
679 				say("Offset changing from %ld to %ld\n",
680 				    last_offset, -offset);
681 #endif
682 			last_offset = -offset;
683 			return first_guess - offset;
684 		} else if (!check_before && !check_after)
685 			return 0;
686 	}
687 }
688 
689 /* We did not find the pattern, dump out the hunk so they can handle it. */
690 
691 static void
692 abort_context_hunk(void)
693 {
694 	LINENUM	i;
695 	const LINENUM	pat_end = pch_end();
696 	/*
697 	 * add in last_offset to guess the same as the previous successful
698 	 * hunk
699 	 */
700 	const LINENUM	oldfirst = pch_first() + last_offset;
701 	const LINENUM	newfirst = pch_newfirst() + last_offset;
702 	const LINENUM	oldlast = oldfirst + pch_ptrn_lines() - 1;
703 	const LINENUM	newlast = newfirst + pch_repl_lines() - 1;
704 	const char	*stars = (diff_type >= NEW_CONTEXT_DIFF ? " ****" : "");
705 	const char	*minuses = (diff_type >= NEW_CONTEXT_DIFF ? " ----" : " -----");
706 
707 	fprintf(rejfp, "***************\n");
708 	for (i = 0; i <= pat_end; i++) {
709 		switch (pch_char(i)) {
710 		case '*':
711 			if (oldlast < oldfirst)
712 				fprintf(rejfp, "*** 0%s\n", stars);
713 			else if (oldlast == oldfirst)
714 				fprintf(rejfp, "*** %ld%s\n", oldfirst, stars);
715 			else
716 				fprintf(rejfp, "*** %ld,%ld%s\n", oldfirst,
717 				    oldlast, stars);
718 			break;
719 		case '=':
720 			if (newlast < newfirst)
721 				fprintf(rejfp, "--- 0%s\n", minuses);
722 			else if (newlast == newfirst)
723 				fprintf(rejfp, "--- %ld%s\n", newfirst, minuses);
724 			else
725 				fprintf(rejfp, "--- %ld,%ld%s\n", newfirst,
726 				    newlast, minuses);
727 			break;
728 		case '\n':
729 			fprintf(rejfp, "%s", pfetch(i));
730 			break;
731 		case ' ':
732 		case '-':
733 		case '+':
734 		case '!':
735 			fprintf(rejfp, "%c %s", pch_char(i), pfetch(i));
736 			break;
737 		default:
738 			fatal("fatal internal error in abort_context_hunk\n");
739 		}
740 	}
741 }
742 
743 static void
744 rej_line(int ch, LINENUM i)
745 {
746 	unsigned short len;
747 	const char *line = pfetch(i);
748 
749 	len = strnlen(line, USHRT_MAX);
750 
751 	fprintf(rejfp, "%c%s", ch, line);
752 	if (len == 0 || line[len-1] != '\n') {
753 		if (len >= USHRT_MAX)
754 			fprintf(rejfp, "\n\\ Line too long\n");
755 		else
756 			fprintf(rejfp, "\n\\ No newline at end of line\n");
757 	}
758 }
759 
760 static void
761 abort_hunk(void)
762 {
763 	LINENUM		i, j, split;
764 	int		ch1, ch2;
765 	const LINENUM	pat_end = pch_end();
766 	const LINENUM	oldfirst = pch_first() + last_offset;
767 	const LINENUM	newfirst = pch_newfirst() + last_offset;
768 
769 	if (diff_type != UNI_DIFF) {
770 		abort_context_hunk();
771 		return;
772 	}
773 	split = -1;
774 	for (i = 0; i <= pat_end; i++) {
775 		if (pch_char(i) == '=') {
776 			split = i;
777 			break;
778 		}
779 	}
780 	if (split == -1) {
781 		fprintf(rejfp, "malformed hunk: no split found\n");
782 		return;
783 	}
784 	i = 0;
785 	j = split + 1;
786 	fprintf(rejfp, "@@ -%ld,%ld +%ld,%ld @@\n",
787 	    pch_ptrn_lines() ? oldfirst : 0,
788 	    pch_ptrn_lines(), newfirst, pch_repl_lines());
789 	while (i < split || j <= pat_end) {
790 		ch1 = i < split ? pch_char(i) : -1;
791 		ch2 = j <= pat_end ? pch_char(j) : -1;
792 		if (ch1 == '-') {
793 			rej_line('-', i);
794 			i++;
795 		} else if (ch1 == ' ' && ch2 == ' ') {
796 			rej_line(' ', i);
797 			i++;
798 			j++;
799 		} else if (ch1 == '!' && ch2 == '!') {
800 			while (i < split && ch1 == '!') {
801 				rej_line('-', i);
802 				i++;
803 				ch1 = i < split ? pch_char(i) : -1;
804 			}
805 			while (j <= pat_end && ch2 == '!') {
806 				rej_line('+', j);
807 				j++;
808 				ch2 = j <= pat_end ? pch_char(j) : -1;
809 			}
810 		} else if (ch1 == '*') {
811 			i++;
812 		} else if (ch2 == '+' || ch2 == ' ') {
813 			rej_line(ch2, j);
814 			j++;
815 		} else {
816 			fprintf(rejfp, "internal error on (%ld %ld %ld)\n",
817 			    i, split, j);
818 			rej_line(ch1, i);
819 			rej_line(ch2, j);
820 			return;
821 		}
822 	}
823 }
824 
825 /* We found where to apply it (we hope), so do it. */
826 
827 static void
828 apply_hunk(LINENUM where)
829 {
830 	LINENUM		old = 1;
831 	const LINENUM	lastline = pch_ptrn_lines();
832 	LINENUM		new = lastline + 1;
833 #define OUTSIDE 0
834 #define IN_IFNDEF 1
835 #define IN_IFDEF 2
836 #define IN_ELSE 3
837 	int		def_state = OUTSIDE;
838 	const LINENUM	pat_end = pch_end();
839 
840 	where--;
841 	while (pch_char(new) == '=' || pch_char(new) == '\n')
842 		new++;
843 
844 	while (old <= lastline) {
845 		if (pch_char(old) == '-') {
846 			copy_till(where + old - 1, false);
847 			if (do_defines) {
848 				if (def_state == OUTSIDE) {
849 					fputs(not_defined, ofp);
850 					def_state = IN_IFNDEF;
851 				} else if (def_state == IN_IFDEF) {
852 					fputs(else_defined, ofp);
853 					def_state = IN_ELSE;
854 				}
855 				fputs(pfetch(old), ofp);
856 			}
857 			last_frozen_line++;
858 			old++;
859 		} else if (new > pat_end) {
860 			break;
861 		} else if (pch_char(new) == '+') {
862 			copy_till(where + old - 1, false);
863 			if (do_defines) {
864 				if (def_state == IN_IFNDEF) {
865 					fputs(else_defined, ofp);
866 					def_state = IN_ELSE;
867 				} else if (def_state == OUTSIDE) {
868 					fputs(if_defined, ofp);
869 					def_state = IN_IFDEF;
870 				}
871 			}
872 			fputs(pfetch(new), ofp);
873 			new++;
874 		} else if (pch_char(new) != pch_char(old)) {
875 			say("Out-of-sync patch, lines %ld,%ld--mangled text or line numbers, maybe?\n",
876 			    pch_hunk_beg() + old,
877 			    pch_hunk_beg() + new);
878 #ifdef DEBUGGING
879 			say("oldchar = '%c', newchar = '%c'\n",
880 			    pch_char(old), pch_char(new));
881 #endif
882 			my_exit(2);
883 		} else if (pch_char(new) == '!') {
884 			copy_till(where + old - 1, false);
885 			if (do_defines) {
886 				fputs(not_defined, ofp);
887 				def_state = IN_IFNDEF;
888 			}
889 			while (pch_char(old) == '!') {
890 				if (do_defines) {
891 					fputs(pfetch(old), ofp);
892 				}
893 				last_frozen_line++;
894 				old++;
895 			}
896 			if (do_defines) {
897 				fputs(else_defined, ofp);
898 				def_state = IN_ELSE;
899 			}
900 			while (pch_char(new) == '!') {
901 				fputs(pfetch(new), ofp);
902 				new++;
903 			}
904 		} else {
905 			if (pch_char(new) != ' ')
906 				fatal("Internal error: expected ' '\n");
907 			old++;
908 			new++;
909 			if (do_defines && def_state != OUTSIDE) {
910 				fputs(end_defined, ofp);
911 				def_state = OUTSIDE;
912 			}
913 		}
914 	}
915 	if (new <= pat_end && pch_char(new) == '+') {
916 		copy_till(where + old - 1, false);
917 		if (do_defines) {
918 			if (def_state == OUTSIDE) {
919 				fputs(if_defined, ofp);
920 				def_state = IN_IFDEF;
921 			} else if (def_state == IN_IFNDEF) {
922 				fputs(else_defined, ofp);
923 				def_state = IN_ELSE;
924 			}
925 		}
926 		while (new <= pat_end && pch_char(new) == '+') {
927 			fputs(pfetch(new), ofp);
928 			new++;
929 		}
930 	}
931 	if (do_defines && def_state != OUTSIDE) {
932 		fputs(end_defined, ofp);
933 	}
934 }
935 
936 /*
937  * Open the new file.
938  */
939 static void
940 init_output(const char *name)
941 {
942 	ofp = fopen(name, "w");
943 	if (ofp == NULL)
944 		pfatal("can't create %s", name);
945 }
946 
947 /*
948  * Open a file to put hunks we can't locate.
949  */
950 static void
951 init_reject(const char *name)
952 {
953 	rejfp = fopen(name, "w");
954 	if (rejfp == NULL)
955 		pfatal("can't create %s", name);
956 }
957 
958 /*
959  * Copy input file to output, up to wherever hunk is to be applied.
960  * If endoffile is true, treat the last line specially since it may
961  * lack a newline.
962  */
963 static void
964 copy_till(LINENUM lastline, bool endoffile)
965 {
966 	if (last_frozen_line > lastline)
967 		fatal("misordered hunks! output would be garbled\n");
968 	while (last_frozen_line < lastline) {
969 		if (++last_frozen_line == lastline && endoffile)
970 			dump_line(last_frozen_line, !last_line_missing_eol);
971 		else
972 			dump_line(last_frozen_line, true);
973 	}
974 }
975 
976 /*
977  * Finish copying the input file to the output file.
978  */
979 static bool
980 spew_output(void)
981 {
982 	int rv;
983 
984 #ifdef DEBUGGING
985 	if (debug & 256)
986 		say("il=%ld lfl=%ld\n", input_lines, last_frozen_line);
987 #endif
988 	if (input_lines)
989 		copy_till(input_lines, true);	/* dump remainder of file */
990 	rv = ferror(ofp) == 0 && fclose(ofp) == 0;
991 	ofp = NULL;
992 	return rv;
993 }
994 
995 /*
996  * Copy one line from input to output.
997  */
998 static void
999 dump_line(LINENUM line, bool write_newline)
1000 {
1001 	char	*s;
1002 
1003 	s = ifetch(line, 0);
1004 	if (s == NULL)
1005 		return;
1006 	/* Note: string is not NUL terminated. */
1007 	for (; *s != '\n'; s++)
1008 		putc(*s, ofp);
1009 	if (write_newline)
1010 		putc('\n', ofp);
1011 }
1012 
1013 /*
1014  * Does the patch pattern match at line base+offset?
1015  */
1016 static bool
1017 patch_match(LINENUM base, LINENUM offset, LINENUM fuzz)
1018 {
1019 	LINENUM		pline = 1 + fuzz;
1020 	LINENUM		iline;
1021 	LINENUM		pat_lines = pch_ptrn_lines() - fuzz;
1022 	const char	*ilineptr;
1023 	const char	*plineptr;
1024 	unsigned short	plinelen;
1025 
1026 	for (iline = base + offset + fuzz; pline <= pat_lines; pline++, iline++) {
1027 		ilineptr = ifetch(iline, offset >= 0);
1028 		if (ilineptr == NULL)
1029 			return false;
1030 		plineptr = pfetch(pline);
1031 		plinelen = pch_line_len(pline);
1032 		if (canonicalize) {
1033 			if (!similar(ilineptr, plineptr, plinelen))
1034 				return false;
1035 		} else if (strnNE(ilineptr, plineptr, plinelen))
1036 			return false;
1037 		if (iline == input_lines) {
1038 			/*
1039 			 * We are looking at the last line of the file.
1040 			 * If the file has no eol, the patch line should
1041 			 * not have one either and vice-versa. Note that
1042 			 * plinelen > 0.
1043 			 */
1044 			if (last_line_missing_eol) {
1045 				if (plineptr[plinelen - 1] == '\n')
1046 					return false;
1047 			} else {
1048 				if (plineptr[plinelen - 1] != '\n')
1049 					return false;
1050 			}
1051 		}
1052 	}
1053 	return true;
1054 }
1055 
1056 /*
1057  * Do two lines match with canonicalized white space?
1058  */
1059 static bool
1060 similar(const char *a, const char *b, int len)
1061 {
1062 	while (len) {
1063 		if (isspace((unsigned char)*b)) {	/* whitespace (or \n) to match? */
1064 			if (!isspace((unsigned char)*a))	/* no corresponding whitespace? */
1065 				return false;
1066 			while (len && isspace((unsigned char)*b) && *b != '\n')
1067 				b++, len--;	/* skip pattern whitespace */
1068 			while (isspace((unsigned char)*a) && *a != '\n')
1069 				a++;	/* skip target whitespace */
1070 			if (*a == '\n' || *b == '\n')
1071 				return (*a == *b);	/* should end in sync */
1072 		} else if (*a++ != *b++)	/* match non-whitespace chars */
1073 			return false;
1074 		else
1075 			len--;	/* probably not necessary */
1076 	}
1077 	return true;		/* actually, this is not reached */
1078 	/* since there is always a \n */
1079 }
1080