xref: /freebsd/usr.bin/patch/patch.c (revision ab0b9f6b3073e6c4d1dfbf07444d7db67a189a96)
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 1.50 2012/05/15 19:32:02 millert 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 	setlinebuf(stdout);
154 	setlinebuf(stderr);
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 = savestr(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 		{"ed",			no_argument,		0,	'e'},
473 		{"force",		no_argument,		0,	'f'},
474 		{"forward",		no_argument,		0,	'N'},
475 		{"fuzz",		required_argument,	0,	'F'},
476 		{"ifdef",		required_argument,	0,	'D'},
477 		{"input",		required_argument,	0,	'i'},
478 		{"ignore-whitespace",	no_argument,		0,	'l'},
479 		{"normal",		no_argument,		0,	'n'},
480 		{"output",		required_argument,	0,	'o'},
481 		{"prefix",		required_argument,	0,	'B'},
482 		{"quiet",		no_argument,		0,	's'},
483 		{"reject-file",		required_argument,	0,	'r'},
484 		{"remove-empty-files",	no_argument,		0,	'E'},
485 		{"reverse",		no_argument,		0,	'R'},
486 		{"silent",		no_argument,		0,	's'},
487 		{"strip",		required_argument,	0,	'p'},
488 		{"suffix",		required_argument,	0,	'z'},
489 		{"unified",		no_argument,		0,	'u'},
490 		{"version",		no_argument,		0,	'v'},
491 		{"version-control",	required_argument,	0,	'V'},
492 		{"posix",		no_argument,		&posix,	1},
493 		{NULL,			0,			0,	0}
494 	};
495 	int ch;
496 
497 	rejname[0] = '\0';
498 	Argc_last = Argc;
499 	Argv_last = Argv;
500 	if (!Argc)
501 		return;
502 	optreset = optind = 1;
503 	while ((ch = getopt_long(Argc, Argv, options, longopts, NULL)) != -1) {
504 		switch (ch) {
505 		case 'b':
506 			if (backup_type == none)
507 				backup_type = numbered_existing;
508 			if (optarg == NULL)
509 				break;
510 			if (verbose)
511 				say("Warning, the ``-b suffix'' option has been"
512 				    " obsoleted by the -z option.\n");
513 			/* FALLTHROUGH */
514 		case 'z':
515 			/* must directly follow 'b' case for backwards compat */
516 			simple_backup_suffix = savestr(optarg);
517 			break;
518 		case 'B':
519 			origprae = savestr(optarg);
520 			break;
521 		case 'c':
522 			diff_type = CONTEXT_DIFF;
523 			break;
524 		case 'C':
525 			check_only = true;
526 			break;
527 		case 'd':
528 			if (chdir(optarg) < 0)
529 				pfatal("can't cd to %s", optarg);
530 			break;
531 		case 'D':
532 			do_defines = true;
533 			if (!isalpha((unsigned char)*optarg) && *optarg != '_')
534 				fatal("argument to -D is not an identifier\n");
535 			snprintf(if_defined, sizeof if_defined,
536 			    "#ifdef %s\n", optarg);
537 			snprintf(not_defined, sizeof not_defined,
538 			    "#ifndef %s\n", optarg);
539 			snprintf(end_defined, sizeof end_defined,
540 			    "#endif /* %s */\n", optarg);
541 			break;
542 		case 'e':
543 			diff_type = ED_DIFF;
544 			break;
545 		case 'E':
546 			remove_empty_files = true;
547 			break;
548 		case 'f':
549 			force = true;
550 			break;
551 		case 'F':
552 			maxfuzz = atoi(optarg);
553 			break;
554 		case 'i':
555 			if (++filec == MAXFILEC)
556 				fatal("too many file arguments\n");
557 			filearg[filec] = savestr(optarg);
558 			break;
559 		case 'l':
560 			canonicalize = true;
561 			break;
562 		case 'n':
563 			diff_type = NORMAL_DIFF;
564 			break;
565 		case 'N':
566 			noreverse = true;
567 			break;
568 		case 'o':
569 			outname = savestr(optarg);
570 			break;
571 		case 'p':
572 			strippath = atoi(optarg);
573 			break;
574 		case 'r':
575 			if (strlcpy(rejname, optarg,
576 			    sizeof(rejname)) >= sizeof(rejname))
577 				fatal("argument for -r is too long\n");
578 			break;
579 		case 'R':
580 			reverse = true;
581 			reverse_flag_specified = true;
582 			break;
583 		case 's':
584 			verbose = false;
585 			break;
586 		case 't':
587 			batch = true;
588 			break;
589 		case 'u':
590 			diff_type = UNI_DIFF;
591 			break;
592 		case 'v':
593 			version();
594 			break;
595 		case 'V':
596 			backup_type = get_version(optarg);
597 			break;
598 #ifdef DEBUGGING
599 		case 'x':
600 			debug = atoi(optarg);
601 			break;
602 #endif
603 		default:
604 			if (ch != '\0')
605 				usage();
606 			break;
607 		}
608 	}
609 	Argc -= optind;
610 	Argv += optind;
611 
612 	if (Argc > 0) {
613 		filearg[0] = savestr(*Argv++);
614 		Argc--;
615 		while (Argc > 0) {
616 			if (++filec == MAXFILEC)
617 				fatal("too many file arguments\n");
618 			filearg[filec] = savestr(*Argv++);
619 			Argc--;
620 		}
621 	}
622 
623 	if (getenv("POSIXLY_CORRECT") != NULL)
624 		posix = 1;
625 }
626 
627 static void
628 usage(void)
629 {
630 	fprintf(stderr,
631 "usage: patch [-bCcEeflNnRstuv] [-B backup-prefix] [-D symbol] [-d directory]\n"
632 "             [-F max-fuzz] [-i patchfile] [-o out-file] [-p strip-count]\n"
633 "             [-r rej-name] [-V t | nil | never] [-x number] [-z backup-ext]\n"
634 "             [--posix] [origfile [patchfile]]\n"
635 "       patch <patchfile\n");
636 	my_exit(EXIT_SUCCESS);
637 }
638 
639 /*
640  * Attempt to find the right place to apply this hunk of patch.
641  */
642 static LINENUM
643 locate_hunk(LINENUM fuzz)
644 {
645 	LINENUM	first_guess = pch_first() + last_offset;
646 	LINENUM	offset;
647 	LINENUM	pat_lines = pch_ptrn_lines();
648 	LINENUM	max_pos_offset = input_lines - first_guess - pat_lines + 1;
649 	LINENUM	max_neg_offset = first_guess - last_frozen_line - 1 + pch_context();
650 
651 	if (pat_lines == 0) {		/* null range matches always */
652 		if (verbose && fuzz == 0 && (diff_type == CONTEXT_DIFF
653 		    || diff_type == NEW_CONTEXT_DIFF
654 		    || diff_type == UNI_DIFF)) {
655 			say("Empty context always matches.\n");
656 		}
657 		return (first_guess);
658 	}
659 	if (max_neg_offset >= first_guess)	/* do not try lines < 0 */
660 		max_neg_offset = first_guess - 1;
661 	if (first_guess <= input_lines && patch_match(first_guess, 0, fuzz))
662 		return first_guess;
663 	for (offset = 1; ; offset++) {
664 		bool	check_after = (offset <= max_pos_offset);
665 		bool	check_before = (offset <= max_neg_offset);
666 
667 		if (check_after && patch_match(first_guess, offset, fuzz)) {
668 #ifdef DEBUGGING
669 			if (debug & 1)
670 				say("Offset changing from %ld to %ld\n",
671 				    last_offset, offset);
672 #endif
673 			last_offset = offset;
674 			return first_guess + offset;
675 		} else if (check_before && patch_match(first_guess, -offset, fuzz)) {
676 #ifdef DEBUGGING
677 			if (debug & 1)
678 				say("Offset changing from %ld to %ld\n",
679 				    last_offset, -offset);
680 #endif
681 			last_offset = -offset;
682 			return first_guess - offset;
683 		} else if (!check_before && !check_after)
684 			return 0;
685 	}
686 }
687 
688 /* We did not find the pattern, dump out the hunk so they can handle it. */
689 
690 static void
691 abort_context_hunk(void)
692 {
693 	LINENUM	i;
694 	const LINENUM	pat_end = pch_end();
695 	/*
696 	 * add in last_offset to guess the same as the previous successful
697 	 * hunk
698 	 */
699 	const LINENUM	oldfirst = pch_first() + last_offset;
700 	const LINENUM	newfirst = pch_newfirst() + last_offset;
701 	const LINENUM	oldlast = oldfirst + pch_ptrn_lines() - 1;
702 	const LINENUM	newlast = newfirst + pch_repl_lines() - 1;
703 	const char	*stars = (diff_type >= NEW_CONTEXT_DIFF ? " ****" : "");
704 	const char	*minuses = (diff_type >= NEW_CONTEXT_DIFF ? " ----" : " -----");
705 
706 	fprintf(rejfp, "***************\n");
707 	for (i = 0; i <= pat_end; i++) {
708 		switch (pch_char(i)) {
709 		case '*':
710 			if (oldlast < oldfirst)
711 				fprintf(rejfp, "*** 0%s\n", stars);
712 			else if (oldlast == oldfirst)
713 				fprintf(rejfp, "*** %ld%s\n", oldfirst, stars);
714 			else
715 				fprintf(rejfp, "*** %ld,%ld%s\n", oldfirst,
716 				    oldlast, stars);
717 			break;
718 		case '=':
719 			if (newlast < newfirst)
720 				fprintf(rejfp, "--- 0%s\n", minuses);
721 			else if (newlast == newfirst)
722 				fprintf(rejfp, "--- %ld%s\n", newfirst, minuses);
723 			else
724 				fprintf(rejfp, "--- %ld,%ld%s\n", newfirst,
725 				    newlast, minuses);
726 			break;
727 		case '\n':
728 			fprintf(rejfp, "%s", pfetch(i));
729 			break;
730 		case ' ':
731 		case '-':
732 		case '+':
733 		case '!':
734 			fprintf(rejfp, "%c %s", pch_char(i), pfetch(i));
735 			break;
736 		default:
737 			fatal("fatal internal error in abort_context_hunk\n");
738 		}
739 	}
740 }
741 
742 static void
743 rej_line(int ch, LINENUM i)
744 {
745 	size_t len;
746 	const char *line = pfetch(i);
747 
748 	len = strlen(line);
749 
750 	fprintf(rejfp, "%c%s", ch, line);
751 	if (len == 0 || line[len-1] != '\n')
752 		fprintf(rejfp, "\n\\ No newline at end of file\n");
753 }
754 
755 static void
756 abort_hunk(void)
757 {
758 	LINENUM		i, j, split;
759 	int		ch1, ch2;
760 	const LINENUM	pat_end = pch_end();
761 	const LINENUM	oldfirst = pch_first() + last_offset;
762 	const LINENUM	newfirst = pch_newfirst() + last_offset;
763 
764 	if (diff_type != UNI_DIFF) {
765 		abort_context_hunk();
766 		return;
767 	}
768 	split = -1;
769 	for (i = 0; i <= pat_end; i++) {
770 		if (pch_char(i) == '=') {
771 			split = i;
772 			break;
773 		}
774 	}
775 	if (split == -1) {
776 		fprintf(rejfp, "malformed hunk: no split found\n");
777 		return;
778 	}
779 	i = 0;
780 	j = split + 1;
781 	fprintf(rejfp, "@@ -%ld,%ld +%ld,%ld @@\n",
782 	    pch_ptrn_lines() ? oldfirst : 0,
783 	    pch_ptrn_lines(), newfirst, pch_repl_lines());
784 	while (i < split || j <= pat_end) {
785 		ch1 = i < split ? pch_char(i) : -1;
786 		ch2 = j <= pat_end ? pch_char(j) : -1;
787 		if (ch1 == '-') {
788 			rej_line('-', i);
789 			i++;
790 		} else if (ch1 == ' ' && ch2 == ' ') {
791 			rej_line(' ', i);
792 			i++;
793 			j++;
794 		} else if (ch1 == '!' && ch2 == '!') {
795 			while (i < split && ch1 == '!') {
796 				rej_line('-', i);
797 				i++;
798 				ch1 = i < split ? pch_char(i) : -1;
799 			}
800 			while (j <= pat_end && ch2 == '!') {
801 				rej_line('+', j);
802 				j++;
803 				ch2 = j <= pat_end ? pch_char(j) : -1;
804 			}
805 		} else if (ch1 == '*') {
806 			i++;
807 		} else if (ch2 == '+' || ch2 == ' ') {
808 			rej_line(ch2, j);
809 			j++;
810 		} else {
811 			fprintf(rejfp, "internal error on (%ld %ld %ld)\n",
812 			    i, split, j);
813 			rej_line(ch1, i);
814 			rej_line(ch2, j);
815 			return;
816 		}
817 	}
818 }
819 
820 /* We found where to apply it (we hope), so do it. */
821 
822 static void
823 apply_hunk(LINENUM where)
824 {
825 	LINENUM		old = 1;
826 	const LINENUM	lastline = pch_ptrn_lines();
827 	LINENUM		new = lastline + 1;
828 #define OUTSIDE 0
829 #define IN_IFNDEF 1
830 #define IN_IFDEF 2
831 #define IN_ELSE 3
832 	int		def_state = OUTSIDE;
833 	const LINENUM	pat_end = pch_end();
834 
835 	where--;
836 	while (pch_char(new) == '=' || pch_char(new) == '\n')
837 		new++;
838 
839 	while (old <= lastline) {
840 		if (pch_char(old) == '-') {
841 			copy_till(where + old - 1, false);
842 			if (do_defines) {
843 				if (def_state == OUTSIDE) {
844 					fputs(not_defined, ofp);
845 					def_state = IN_IFNDEF;
846 				} else if (def_state == IN_IFDEF) {
847 					fputs(else_defined, ofp);
848 					def_state = IN_ELSE;
849 				}
850 				fputs(pfetch(old), ofp);
851 			}
852 			last_frozen_line++;
853 			old++;
854 		} else if (new > pat_end) {
855 			break;
856 		} else if (pch_char(new) == '+') {
857 			copy_till(where + old - 1, false);
858 			if (do_defines) {
859 				if (def_state == IN_IFNDEF) {
860 					fputs(else_defined, ofp);
861 					def_state = IN_ELSE;
862 				} else if (def_state == OUTSIDE) {
863 					fputs(if_defined, ofp);
864 					def_state = IN_IFDEF;
865 				}
866 			}
867 			fputs(pfetch(new), ofp);
868 			new++;
869 		} else if (pch_char(new) != pch_char(old)) {
870 			say("Out-of-sync patch, lines %ld,%ld--mangled text or line numbers, maybe?\n",
871 			    pch_hunk_beg() + old,
872 			    pch_hunk_beg() + new);
873 #ifdef DEBUGGING
874 			say("oldchar = '%c', newchar = '%c'\n",
875 			    pch_char(old), pch_char(new));
876 #endif
877 			my_exit(2);
878 		} else if (pch_char(new) == '!') {
879 			copy_till(where + old - 1, false);
880 			if (do_defines) {
881 				fputs(not_defined, ofp);
882 				def_state = IN_IFNDEF;
883 			}
884 			while (pch_char(old) == '!') {
885 				if (do_defines) {
886 					fputs(pfetch(old), ofp);
887 				}
888 				last_frozen_line++;
889 				old++;
890 			}
891 			if (do_defines) {
892 				fputs(else_defined, ofp);
893 				def_state = IN_ELSE;
894 			}
895 			while (pch_char(new) == '!') {
896 				fputs(pfetch(new), ofp);
897 				new++;
898 			}
899 		} else {
900 			if (pch_char(new) != ' ')
901 				fatal("Internal error: expected ' '\n");
902 			old++;
903 			new++;
904 			if (do_defines && def_state != OUTSIDE) {
905 				fputs(end_defined, ofp);
906 				def_state = OUTSIDE;
907 			}
908 		}
909 	}
910 	if (new <= pat_end && pch_char(new) == '+') {
911 		copy_till(where + old - 1, false);
912 		if (do_defines) {
913 			if (def_state == OUTSIDE) {
914 				fputs(if_defined, ofp);
915 				def_state = IN_IFDEF;
916 			} else if (def_state == IN_IFNDEF) {
917 				fputs(else_defined, ofp);
918 				def_state = IN_ELSE;
919 			}
920 		}
921 		while (new <= pat_end && pch_char(new) == '+') {
922 			fputs(pfetch(new), ofp);
923 			new++;
924 		}
925 	}
926 	if (do_defines && def_state != OUTSIDE) {
927 		fputs(end_defined, ofp);
928 	}
929 }
930 
931 /*
932  * Open the new file.
933  */
934 static void
935 init_output(const char *name)
936 {
937 	ofp = fopen(name, "w");
938 	if (ofp == NULL)
939 		pfatal("can't create %s", name);
940 }
941 
942 /*
943  * Open a file to put hunks we can't locate.
944  */
945 static void
946 init_reject(const char *name)
947 {
948 	rejfp = fopen(name, "w");
949 	if (rejfp == NULL)
950 		pfatal("can't create %s", name);
951 }
952 
953 /*
954  * Copy input file to output, up to wherever hunk is to be applied.
955  * If endoffile is true, treat the last line specially since it may
956  * lack a newline.
957  */
958 static void
959 copy_till(LINENUM lastline, bool endoffile)
960 {
961 	if (last_frozen_line > lastline)
962 		fatal("misordered hunks! output would be garbled\n");
963 	while (last_frozen_line < lastline) {
964 		if (++last_frozen_line == lastline && endoffile)
965 			dump_line(last_frozen_line, !last_line_missing_eol);
966 		else
967 			dump_line(last_frozen_line, true);
968 	}
969 }
970 
971 /*
972  * Finish copying the input file to the output file.
973  */
974 static bool
975 spew_output(void)
976 {
977 	int rv;
978 
979 #ifdef DEBUGGING
980 	if (debug & 256)
981 		say("il=%ld lfl=%ld\n", input_lines, last_frozen_line);
982 #endif
983 	if (input_lines)
984 		copy_till(input_lines, true);	/* dump remainder of file */
985 	rv = ferror(ofp) == 0 && fclose(ofp) == 0;
986 	ofp = NULL;
987 	return rv;
988 }
989 
990 /*
991  * Copy one line from input to output.
992  */
993 static void
994 dump_line(LINENUM line, bool write_newline)
995 {
996 	char	*s;
997 
998 	s = ifetch(line, 0);
999 	if (s == NULL)
1000 		return;
1001 	/* Note: string is not NUL terminated. */
1002 	for (; *s != '\n'; s++)
1003 		putc(*s, ofp);
1004 	if (write_newline)
1005 		putc('\n', ofp);
1006 }
1007 
1008 /*
1009  * Does the patch pattern match at line base+offset?
1010  */
1011 static bool
1012 patch_match(LINENUM base, LINENUM offset, LINENUM fuzz)
1013 {
1014 	LINENUM		pline = 1 + fuzz;
1015 	LINENUM		iline;
1016 	LINENUM		pat_lines = pch_ptrn_lines() - fuzz;
1017 	const char	*ilineptr;
1018 	const char	*plineptr;
1019 	short		plinelen;
1020 
1021 	for (iline = base + offset + fuzz; pline <= pat_lines; pline++, iline++) {
1022 		ilineptr = ifetch(iline, offset >= 0);
1023 		if (ilineptr == NULL)
1024 			return false;
1025 		plineptr = pfetch(pline);
1026 		plinelen = pch_line_len(pline);
1027 		if (canonicalize) {
1028 			if (!similar(ilineptr, plineptr, plinelen))
1029 				return false;
1030 		} else if (strnNE(ilineptr, plineptr, plinelen))
1031 			return false;
1032 		if (iline == input_lines) {
1033 			/*
1034 			 * We are looking at the last line of the file.
1035 			 * If the file has no eol, the patch line should
1036 			 * not have one either and vice-versa. Note that
1037 			 * plinelen > 0.
1038 			 */
1039 			if (last_line_missing_eol) {
1040 				if (plineptr[plinelen - 1] == '\n')
1041 					return false;
1042 			} else {
1043 				if (plineptr[plinelen - 1] != '\n')
1044 					return false;
1045 			}
1046 		}
1047 	}
1048 	return true;
1049 }
1050 
1051 /*
1052  * Do two lines match with canonicalized white space?
1053  */
1054 static bool
1055 similar(const char *a, const char *b, int len)
1056 {
1057 	while (len) {
1058 		if (isspace((unsigned char)*b)) {	/* whitespace (or \n) to match? */
1059 			if (!isspace((unsigned char)*a))	/* no corresponding whitespace? */
1060 				return false;
1061 			while (len && isspace((unsigned char)*b) && *b != '\n')
1062 				b++, len--;	/* skip pattern whitespace */
1063 			while (isspace((unsigned char)*a) && *a != '\n')
1064 				a++;	/* skip target whitespace */
1065 			if (*a == '\n' || *b == '\n')
1066 				return (*a == *b);	/* should end in sync */
1067 		} else if (*a++ != *b++)	/* match non-whitespace chars */
1068 			return false;
1069 		else
1070 			len--;	/* probably not necessary */
1071 	}
1072 	return true;		/* actually, this is not reached */
1073 	/* since there is always a \n */
1074 }
1075