xref: /netbsd-src/usr.bin/patch/patch.c (revision 53d1339bf7f9c7367b35a9e1ebe693f9b047a47b)
1 /*
2  * $OpenBSD: patch.c,v 1.45 2007/04/18 21:52:24 sobrado Exp $
3  * $DragonFly: src/usr.bin/patch/patch.c,v 1.10 2008/08/10 23:39:56 joerg Exp $
4  * $NetBSD: patch.c,v 1.32 2021/05/25 11:25:59 cjep Exp $
5  */
6 
7 /*
8  * patch - a program to apply diffs to original files
9  *
10  * Copyright 1986, Larry Wall
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following condition is met:
14  * 1. Redistributions of source code must retain the above copyright notice,
15  * this condition and the following disclaimer.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
21  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
23  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
24  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * -C option added in 1998, original code by Marc Espie, based on FreeBSD
30  * behaviour
31  */
32 
33 #include <sys/cdefs.h>
34 __RCSID("$NetBSD: patch.c,v 1.32 2021/05/25 11:25:59 cjep Exp $");
35 
36 #include <sys/types.h>
37 #include <sys/stat.h>
38 
39 #include <ctype.h>
40 #include <getopt.h>
41 #include <limits.h>
42 #include <stdio.h>
43 #include <string.h>
44 #include <stdlib.h>
45 #include <unistd.h>
46 
47 #include "common.h"
48 #include "util.h"
49 #include "pch.h"
50 #include "inp.h"
51 #include "backupfile.h"
52 #include "pathnames.h"
53 
54 mode_t		filemode = 0644;
55 
56 char		*buf;			/* general purpose buffer */
57 size_t		bufsz;			/* general purpose buffer size */
58 
59 bool		using_plan_a = true;	/* try to keep everything in memory */
60 bool		out_of_mem = false;	/* ran out of memory in plan a */
61 
62 #define MAXFILEC 2
63 
64 char		*filearg[MAXFILEC];
65 bool		ok_to_create_file = false;
66 char		*outname = NULL;
67 char		*origprae = NULL;
68 char		*TMPOUTNAME;
69 char		*TMPINNAME;
70 char		*TMPREJNAME;
71 char		*TMPPATNAME;
72 bool		toutkeep = false;
73 bool		trejkeep = false;
74 bool		warn_on_invalid_line;
75 bool		last_line_missing_eol;
76 
77 #ifdef DEBUGGING
78 int		debug = 0;
79 #endif
80 
81 bool		force = false;
82 bool		batch = false;
83 bool		verbose = true;
84 bool		reverse = false;
85 bool		noreverse = false;
86 bool		skip_rest_of_patch = false;
87 int		strippath = 957;
88 bool		canonicalize = false;
89 bool		check_only = false;
90 int		diff_type = 0;
91 char		*revision = NULL;	/* prerequisite revision, if any */
92 LINENUM		input_lines = 0;	/* how long is input file in lines */
93 int		posix = 0;		/* strict POSIX mode? */
94 
95 static void	reinitialize_almost_everything(void);
96 static void	get_some_switches(void);
97 static LINENUM	locate_hunk(LINENUM);
98 static void	abort_context_hunk(void);
99 static void	rej_line(int, LINENUM);
100 static void	abort_hunk(void);
101 static void	apply_hunk(LINENUM);
102 static void	init_output(const char *);
103 static void	init_reject(const char *);
104 static void	copy_till(LINENUM, bool);
105 static bool	spew_output(void);
106 static void	dump_line(LINENUM, bool);
107 static bool	patch_match(LINENUM, LINENUM, LINENUM);
108 static bool	similar(const char *, const char *, int);
109 __dead static void	usage(void);
110 
111 /* true if -E was specified on command line.  */
112 static bool	remove_empty_files = false;
113 
114 /* true if -R was specified on command line.  */
115 static bool	reverse_flag_specified = false;
116 
117 /* buffer holding the name of the rejected patch file. */
118 static char	rejname[PATH_MAX];
119 
120 /* buffer for stderr */
121 static char	serrbuf[BUFSIZ];
122 
123 /* how many input lines have been irretractibly output */
124 static LINENUM	last_frozen_line = 0;
125 
126 static int	Argc;		/* guess */
127 static char	**Argv;
128 static int	Argc_last;	/* for restarting plan_b */
129 static char	**Argv_last;
130 
131 static FILE	*ofp = NULL;	/* output file pointer */
132 static FILE	*rejfp = NULL;	/* reject file pointer */
133 
134 static int	filec = 0;	/* how many file arguments? */
135 static LINENUM	last_offset = 0;
136 static LINENUM	maxfuzz = 2;
137 
138 /* patch using ifdef, ifndef, etc. */
139 static bool		do_defines = false;
140 /* #ifdef xyzzy */
141 static char		if_defined[128];
142 /* #ifndef xyzzy */
143 static char		not_defined[128];
144 /* #else */
145 static const char	else_defined[] = "#else\n";
146 /* #endif xyzzy */
147 static char		end_defined[128];
148 
149 
150 /* Apply a set of diffs as appropriate. */
151 
152 int
153 main(int argc, char *argv[])
154 {
155 	int	error = 0, hunk, failed, i, fd;
156 	LINENUM	where = 0, newwhere, fuzz, mymaxfuzz;
157 	const	char *tmpdir;
158 	char	*v;
159 
160 	bufsz = INITLINELEN;
161 	if ((buf = malloc(bufsz)) == NULL)
162 		pfatal("allocating input buffer");
163 	buf[0] = '\0';
164 
165 	setbuf(stderr, serrbuf);
166 	for (i = 0; i < MAXFILEC; i++)
167 		filearg[i] = NULL;
168 
169 	/* Cons up the names of the temporary files.  */
170 	if ((tmpdir = getenv("TMPDIR")) == NULL || *tmpdir == '\0')
171 		tmpdir = _PATH_TMP;
172 	for (i = strlen(tmpdir) - 1; i > 0 && tmpdir[i] == '/'; i--)
173 		;
174 	i++;
175 	if (asprintf(&TMPOUTNAME, "%.*s/patchoXXXXXXXXXX", i, tmpdir) == -1)
176 		fatal("cannot allocate memory");
177 	if ((fd = mkstemp(TMPOUTNAME)) < 0)
178 		pfatal("can't create %s", TMPOUTNAME);
179 	close(fd);
180 
181 	if (asprintf(&TMPINNAME, "%.*s/patchiXXXXXXXXXX", i, tmpdir) == -1)
182 		fatal("cannot allocate memory");
183 	if ((fd = mkstemp(TMPINNAME)) < 0)
184 		pfatal("can't create %s", TMPINNAME);
185 	close(fd);
186 
187 	if (asprintf(&TMPREJNAME, "%.*s/patchrXXXXXXXXXX", i, tmpdir) == -1)
188 		fatal("cannot allocate memory");
189 	if ((fd = mkstemp(TMPREJNAME)) < 0)
190 		pfatal("can't create %s", TMPREJNAME);
191 	close(fd);
192 
193 	if (asprintf(&TMPPATNAME, "%.*s/patchpXXXXXXXXXX", i, tmpdir) == -1)
194 		fatal("cannot allocate memory");
195 	if ((fd = mkstemp(TMPPATNAME)) < 0)
196 		pfatal("can't create %s", TMPPATNAME);
197 	close(fd);
198 
199 	v = getenv("SIMPLE_BACKUP_SUFFIX");
200 	if (v)
201 		simple_backup_suffix = v;
202 	else
203 		simple_backup_suffix = ORIGEXT;
204 
205 	if ((v = getenv("PATCH_VERSION_CONTROL")) == NULL)
206 		v = getenv("VERSION_CONTROL");
207 	if (v != NULL)
208 		backup_type = get_version(v);
209 
210 	/* parse switches */
211 	Argc = argc;
212 	Argv = argv;
213 	get_some_switches();
214 
215 	if (backup_type == undefined)
216 		backup_type = posix ? none : numbered_existing;
217 
218 	/* make sure we clean up /tmp in case of disaster */
219 	set_signals(0);
220 
221 	for (open_patch_file(filearg[1]); there_is_another_patch();
222 	    reinitialize_almost_everything()) {
223 		/* for each patch in patch file */
224 
225 		warn_on_invalid_line = true;
226 
227 		if (outname == NULL)
228 			outname = savestr(filearg[0]);
229 
230 		/* for ed script just up and do it and exit */
231 		if (diff_type == ED_DIFF) {
232 			do_ed_script();
233 			continue;
234 		}
235 		/* initialize the patched file */
236 		if (!skip_rest_of_patch)
237 			init_output(TMPOUTNAME);
238 
239 		/* initialize reject file */
240 		init_reject(TMPREJNAME);
241 
242 		/* find out where all the lines are */
243 		if (!skip_rest_of_patch)
244 			scan_input(filearg[0]);
245 
246 		/* from here on, open no standard i/o files, because malloc */
247 		/* might misfire and we can't catch it easily */
248 
249 		/* apply each hunk of patch */
250 		hunk = 0;
251 		failed = 0;
252 		out_of_mem = false;
253 		while (another_hunk()) {
254 			hunk++;
255 			fuzz = 0;
256 			mymaxfuzz = pch_context();
257 			if (maxfuzz < mymaxfuzz)
258 				mymaxfuzz = maxfuzz;
259 			if (!skip_rest_of_patch) {
260 				do {
261 					where = locate_hunk(fuzz);
262 					if (hunk == 1 && where == 0 && !force) {
263 						/* dwim for reversed patch? */
264 						if (!pch_swap()) {
265 							if (fuzz == 0)
266 								say("Not enough memory to try swapped hunk!  Assuming unswapped.\n");
267 							continue;
268 						}
269 						reverse = !reverse;
270 						/* try again */
271 						where = locate_hunk(fuzz);
272 						if (where == 0) {
273 							/* didn't find it swapped */
274 							if (!pch_swap())
275 								/* put it back to normal */
276 								fatal("lost hunk on alloc error!\n");
277 							reverse = !reverse;
278 						} else if (noreverse) {
279 							if (!pch_swap())
280 								/* put it back to normal */
281 								fatal("lost hunk on alloc error!\n");
282 							reverse = !reverse;
283 							say("Ignoring previously applied (or reversed) patch.\n");
284 							skip_rest_of_patch = true;
285 						} else if (batch) {
286 							if (verbose)
287 								say("%seversed (or previously applied) patch detected!  %s -R.",
288 								    reverse ? "R" : "Unr",
289 								    reverse ? "Assuming" : "Ignoring");
290 						} else {
291 							ask("%seversed (or previously applied) patch detected!  %s -R? [y] ",
292 							    reverse ? "R" : "Unr",
293 							    reverse ? "Assume" : "Ignore");
294 							if (*buf == 'n') {
295 								ask("Apply anyway? [n] ");
296 								if (*buf != 'y')
297 									skip_rest_of_patch = true;
298 								where = 0;
299 								reverse = !reverse;
300 								if (!pch_swap())
301 									/* put it back to normal */
302 									fatal("lost hunk on alloc error!\n");
303 							}
304 						}
305 					}
306 				} while (!skip_rest_of_patch && where == 0 &&
307 				    ++fuzz <= mymaxfuzz);
308 
309 				if (skip_rest_of_patch) {	/* just got decided */
310 					if (ferror(ofp) || fclose(ofp)) {
311 						say("Error writing %s\n",
312 						    TMPOUTNAME);
313 						error = 1;
314 					}
315 					ofp = NULL;
316 				}
317 			}
318 			newwhere = pch_newfirst() + last_offset;
319 			if (skip_rest_of_patch) {
320 				abort_hunk();
321 				failed++;
322 				if (verbose)
323 					say("Hunk #%d ignored at %ld.\n",
324 					    hunk, newwhere);
325 			} else if (where == 0) {
326 				abort_hunk();
327 				failed++;
328 				if (verbose)
329 					say("Hunk #%d failed at %ld.\n",
330 					    hunk, newwhere);
331 			} else {
332 				apply_hunk(where);
333 				if (verbose) {
334 					say("Hunk #%d succeeded at %ld",
335 					    hunk, newwhere);
336 					if (fuzz != 0)
337 						say(" with fuzz %ld", fuzz);
338 					if (last_offset)
339 						say(" (offset %ld line%s)",
340 						    last_offset,
341 						    last_offset == 1L ? "" : "s");
342 					say(".\n");
343 				}
344 			}
345 		}
346 
347 		if (out_of_mem && using_plan_a) {
348 			Argc = Argc_last;
349 			Argv = Argv_last;
350 			say("\n\nRan out of memory using Plan A--trying again...\n\n");
351 			if (ofp)
352 				fclose(ofp);
353 			ofp = NULL;
354 			if (rejfp)
355 				fclose(rejfp);
356 			rejfp = NULL;
357 			continue;
358 		}
359 		if (hunk == 0)
360 			fatal("Internal error: hunk should not be 0\n");
361 
362 		/* finish spewing out the new file */
363 		if (!skip_rest_of_patch && !spew_output()) {
364 			say("Can't write %s\n", TMPOUTNAME);
365 			error = 1;
366 		}
367 
368 		/* and put the output where desired */
369 		ignore_signals();
370 		if (!skip_rest_of_patch) {
371 			struct stat	statbuf;
372 			char	*realout = outname;
373 
374 			if (!check_only) {
375 				if (move_file(TMPOUTNAME, outname) < 0) {
376 					toutkeep = true;
377 					realout = TMPOUTNAME;
378 					chmod(TMPOUTNAME, filemode);
379 				} else
380 					chmod(outname, filemode);
381 
382 				if (remove_empty_files &&
383 				    stat(realout, &statbuf) == 0 &&
384 				    statbuf.st_size == 0) {
385 					if (verbose)
386 						say("Removing %s (empty after patching).\n",
387 						    realout);
388 					unlink(realout);
389 				}
390 			}
391 		}
392 		if (ferror(rejfp) || fclose(rejfp)) {
393 			say("Error writing %s\n", rejname);
394 			error = 1;
395 		}
396 		rejfp = NULL;
397 		if (failed) {
398 			error = 1;
399 			if (*rejname == '\0') {
400 				if (strlcpy(rejname, outname,
401 				    sizeof(rejname)) >= sizeof(rejname))
402 					fatal("filename %s is too long\n", outname);
403 				if (strlcat(rejname, REJEXT,
404 				    sizeof(rejname)) >= sizeof(rejname))
405 					fatal("filename %s is too long\n", outname);
406 			}
407 			if (skip_rest_of_patch) {
408 				say("%d out of %d hunks ignored--saving rejects to %s\n",
409 				    failed, hunk, rejname);
410 			} else {
411 				say("%d out of %d hunks failed--saving rejects to %s\n",
412 				    failed, hunk, rejname);
413 			}
414 			if (!check_only && move_file(TMPREJNAME, rejname) < 0)
415 				trejkeep = true;
416 		}
417 		set_signals(1);
418 	}
419 	my_exit(error);
420 	/* NOTREACHED */
421 }
422 
423 /* Prepare to find the next patch to do in the patch file. */
424 
425 static void
426 reinitialize_almost_everything(void)
427 {
428 	re_patch();
429 	re_input();
430 
431 	input_lines = 0;
432 	last_frozen_line = 0;
433 
434 	filec = 0;
435 	if (!out_of_mem) {
436 		free(filearg[0]);
437 		filearg[0] = NULL;
438 	}
439 
440 	free(outname);
441 	outname = NULL;
442 
443 	last_offset = 0;
444 	diff_type = 0;
445 
446 	free(revision);
447 	revision = NULL;
448 
449 	reverse = reverse_flag_specified;
450 	skip_rest_of_patch = false;
451 
452 	get_some_switches();
453 }
454 
455 /* Process switches and filenames. */
456 
457 static void
458 get_some_switches(void)
459 {
460 	const char *options = "b::B:cCd:D:eEfF:i:lnNo:p:r:RstuvV:x:z:";
461 	static struct option longopts[] = {
462 		{"backup",		no_argument,		0,	'b'},
463 		{"batch",		no_argument,		0,	't'},
464 		{"check",		no_argument,		0,	'C'},
465 		{"context",		no_argument,		0,	'c'},
466 		{"debug",		required_argument,	0,	'x'},
467 		{"directory",		required_argument,	0,	'd'},
468 		{"ed",			no_argument,		0,	'e'},
469 		{"force",		no_argument,		0,	'f'},
470 		{"forward",		no_argument,		0,	'N'},
471 		{"fuzz",		required_argument,	0,	'F'},
472 		{"ifdef",		required_argument,	0,	'D'},
473 		{"input",		required_argument,	0,	'i'},
474 		{"ignore-whitespace",	no_argument,		0,	'l'},
475 		{"normal",		no_argument,		0,	'n'},
476 		{"output",		required_argument,	0,	'o'},
477 		{"prefix",		required_argument,	0,	'B'},
478 		{"quiet",		no_argument,		0,	's'},
479 		{"reject-file",		required_argument,	0,	'r'},
480 		{"remove-empty-files",	no_argument,		0,	'E'},
481 		{"reverse",		no_argument,		0,	'R'},
482 		{"silent",		no_argument,		0,	's'},
483 		{"strip",		required_argument,	0,	'p'},
484 		{"suffix",		required_argument,	0,	'z'},
485 		{"unified",		no_argument,		0,	'u'},
486 		{"version",		no_argument,		0,	'v'},
487 		{"version-control",	required_argument,	0,	'V'},
488 		{"posix",		no_argument,		&posix,	1},
489 		{NULL,			0,			0,	0}
490 	};
491 	int ch;
492 
493 	rejname[0] = '\0';
494 	Argc_last = Argc;
495 	Argv_last = Argv;
496 	if (!Argc)
497 		return;
498 	optreset = optind = 1;
499 	while ((ch = getopt_long(Argc, Argv, options, longopts, NULL)) != -1) {
500 		switch (ch) {
501 		case 'b':
502 			if (backup_type == undefined)
503 				backup_type = numbered_existing;
504 			if (optarg == NULL)
505 				break;
506 			if (verbose)
507 				say("Warning, the ``-b suffix'' option has been"
508 				    " obsoleted by the -z option.\n");
509 			/* FALLTHROUGH */
510 		case 'z':
511 			/* must directly follow 'b' case for backwards compat */
512 			simple_backup_suffix = savestr(optarg);
513 			break;
514 		case 'B':
515 			origprae = savestr(optarg);
516 			break;
517 		case 'c':
518 			diff_type = CONTEXT_DIFF;
519 			break;
520 		case 'C':
521 			check_only = true;
522 			break;
523 		case 'd':
524 			if (chdir(optarg) < 0)
525 				pfatal("can't cd to %s", optarg);
526 			break;
527 		case 'D':
528 			do_defines = true;
529 			if (!isalpha((unsigned char)*optarg) && *optarg != '_')
530 				fatal("argument to -D is not an identifier\n");
531 			snprintf(if_defined, sizeof if_defined,
532 			    "#ifdef %s\n", optarg);
533 			snprintf(not_defined, sizeof not_defined,
534 			    "#ifndef %s\n", optarg);
535 			snprintf(end_defined, sizeof end_defined,
536 			    "#endif /* %s */\n", optarg);
537 			break;
538 		case 'e':
539 			diff_type = ED_DIFF;
540 			break;
541 		case 'E':
542 			remove_empty_files = true;
543 			break;
544 		case 'f':
545 			force = true;
546 			break;
547 		case 'F':
548 			maxfuzz = atoi(optarg);
549 			break;
550 		case 'i':
551 			if (++filec == MAXFILEC)
552 				fatal("too many file arguments\n");
553 			filearg[filec] = savestr(optarg);
554 			break;
555 		case 'l':
556 			canonicalize = true;
557 			break;
558 		case 'n':
559 			diff_type = NORMAL_DIFF;
560 			break;
561 		case 'N':
562 			noreverse = true;
563 			break;
564 		case 'o':
565 			outname = savestr(optarg);
566 			break;
567 		case 'p':
568 			strippath = atoi(optarg);
569 			break;
570 		case 'r':
571 			if (strlcpy(rejname, optarg,
572 			    sizeof(rejname)) >= sizeof(rejname))
573 				fatal("argument for -r is too long\n");
574 			break;
575 		case 'R':
576 			reverse = true;
577 			reverse_flag_specified = true;
578 			break;
579 		case 's':
580 			verbose = false;
581 			break;
582 		case 't':
583 			batch = true;
584 			break;
585 		case 'u':
586 			diff_type = UNI_DIFF;
587 			break;
588 		case 'v':
589 			version();
590 			break;
591 		case 'V':
592 			backup_type = get_version(optarg);
593 			break;
594 #ifdef DEBUGGING
595 		case 'x':
596 			debug = atoi(optarg);
597 			break;
598 #endif
599 		default:
600 			if (ch != '\0')
601 				usage();
602 			break;
603 		}
604 	}
605 	Argc -= optind;
606 	Argv += optind;
607 
608 	if (Argc > 0) {
609 		filearg[0] = savestr(*Argv++);
610 		Argc--;
611 		while (Argc > 0) {
612 			if (++filec == MAXFILEC)
613 				fatal("too many file arguments\n");
614 			filearg[filec] = savestr(*Argv++);
615 			Argc--;
616 		}
617 	}
618 
619 	if (getenv("POSIXLY_CORRECT") != NULL)
620 		posix = 1;
621 }
622 
623 static void
624 usage(void)
625 {
626 	fprintf(stderr,
627 "usage: patch [-bCcEeflNnRstuv] [-B backup-prefix] [-D symbol] [-d directory]\n"
628 "             [-F max-fuzz] [-i patchfile] [-o out-file] [-p strip-count]\n"
629 "             [-r rej-name] [-V t | nil | never] [-x number] [-z backup-ext]\n"
630 "             [--posix] [origfile [patchfile]]\n"
631 "       patch <patchfile\n");
632 	my_exit(EXIT_FAILURE);
633 }
634 
635 /*
636  * Attempt to find the right place to apply this hunk of patch.
637  */
638 static LINENUM
639 locate_hunk(LINENUM fuzz)
640 {
641 	LINENUM	first_guess = pch_first() + last_offset;
642 	LINENUM	offset;
643 	LINENUM	pat_lines = pch_ptrn_lines();
644 	LINENUM	max_pos_offset = input_lines - first_guess - pat_lines + 1;
645 	LINENUM	max_neg_offset = first_guess - last_frozen_line - 1 + pch_context();
646 
647 	if (pat_lines == 0) {		/* null range matches always */
648 		if (verbose && fuzz == 0 && (diff_type == CONTEXT_DIFF
649 		    || diff_type == NEW_CONTEXT_DIFF
650 		    || diff_type == UNI_DIFF)) {
651 			say("Empty context always matches.\n");
652 		}
653 		return (first_guess);
654 	}
655 	if (max_neg_offset >= first_guess)	/* do not try lines < 0 */
656 		max_neg_offset = first_guess - 1;
657 	if (first_guess <= input_lines && patch_match(first_guess, 0, fuzz))
658 		return first_guess;
659 	for (offset = 1; ; offset++) {
660 		bool	check_after = (offset <= max_pos_offset);
661 		bool	check_before = (offset <= max_neg_offset);
662 
663 		if (check_after && patch_match(first_guess, offset, fuzz)) {
664 #ifdef DEBUGGING
665 			if (debug & 1)
666 				say("Offset changing from %ld to %ld\n",
667 				    last_offset, offset);
668 #endif
669 			last_offset = offset;
670 			return first_guess + offset;
671 		} else if (check_before && patch_match(first_guess, -offset, fuzz)) {
672 #ifdef DEBUGGING
673 			if (debug & 1)
674 				say("Offset changing from %ld to %ld\n",
675 				    last_offset, -offset);
676 #endif
677 			last_offset = -offset;
678 			return first_guess - offset;
679 		} else if (!check_before && !check_after)
680 			return 0;
681 	}
682 }
683 
684 /* We did not find the pattern, dump out the hunk so they can handle it. */
685 
686 static void
687 abort_context_hunk(void)
688 {
689 	LINENUM	i;
690 	const LINENUM	pat_end = pch_end();
691 	/*
692 	 * add in last_offset to guess the same as the previous successful
693 	 * hunk
694 	 */
695 	const LINENUM	oldfirst = pch_first() + last_offset;
696 	const LINENUM	newfirst = pch_newfirst() + last_offset;
697 	const LINENUM	oldlast = oldfirst + pch_ptrn_lines() - 1;
698 	const LINENUM	newlast = newfirst + pch_repl_lines() - 1;
699 	const char	*stars = (diff_type >= NEW_CONTEXT_DIFF ? " ****" : "");
700 	const char	*minuses = (diff_type >= NEW_CONTEXT_DIFF ? " ----" : " -----");
701 
702 	fprintf(rejfp, "***************\n");
703 	for (i = 0; i <= pat_end; i++) {
704 		switch (pch_char(i)) {
705 		case '*':
706 			if (oldlast < oldfirst)
707 				fprintf(rejfp, "*** 0%s\n", stars);
708 			else if (oldlast == oldfirst)
709 				fprintf(rejfp, "*** %ld%s\n", oldfirst, stars);
710 			else
711 				fprintf(rejfp, "*** %ld,%ld%s\n", oldfirst,
712 				    oldlast, stars);
713 			break;
714 		case '=':
715 			if (newlast < newfirst)
716 				fprintf(rejfp, "--- 0%s\n", minuses);
717 			else if (newlast == newfirst)
718 				fprintf(rejfp, "--- %ld%s\n", newfirst, minuses);
719 			else
720 				fprintf(rejfp, "--- %ld,%ld%s\n", newfirst,
721 				    newlast, minuses);
722 			break;
723 		case '\n':
724 			fprintf(rejfp, "%s", pfetch(i));
725 			break;
726 		case ' ':
727 		case '-':
728 		case '+':
729 		case '!':
730 			fprintf(rejfp, "%c %s", pch_char(i), pfetch(i));
731 			break;
732 		default:
733 			fatal("fatal internal error in abort_context_hunk\n");
734 		}
735 	}
736 }
737 
738 static void
739 rej_line(int ch, LINENUM i)
740 {
741 	size_t len;
742 	const char *line = pfetch(i);
743 
744 	len = strlen(line);
745 
746 	fprintf(rejfp, "%c%s", ch, line);
747 	if (len == 0 || line[len-1] != '\n')
748 		fprintf(rejfp, "\n\\ No newline at end of file\n");
749 }
750 
751 static void
752 abort_hunk(void)
753 {
754 	LINENUM		i, j, split;
755 	int		ch1, ch2;
756 	const LINENUM	pat_end = pch_end();
757 	const LINENUM	oldfirst = pch_first() + last_offset;
758 	const LINENUM	newfirst = pch_newfirst() + last_offset;
759 
760 	if (diff_type != UNI_DIFF) {
761 		abort_context_hunk();
762 		return;
763 	}
764 	split = -1;
765 	for (i = 0; i <= pat_end; i++) {
766 		if (pch_char(i) == '=') {
767 			split = i;
768 			break;
769 		}
770 	}
771 	if (split == -1) {
772 		fprintf(rejfp, "malformed hunk: no split found\n");
773 		return;
774 	}
775 	i = 0;
776 	j = split + 1;
777 	fprintf(rejfp, "@@ -%ld,%ld +%ld,%ld @@\n",
778 	    pch_ptrn_lines() ? oldfirst : 0,
779 	    pch_ptrn_lines(), newfirst, pch_repl_lines());
780 	while (i < split || j <= pat_end) {
781 		ch1 = i < split ? pch_char(i) : -1;
782 		ch2 = j <= pat_end ? pch_char(j) : -1;
783 		if (ch1 == '-') {
784 			rej_line('-', i);
785 			i++;
786 		} else if (ch1 == ' ' && ch2 == ' ') {
787 			rej_line(' ', i);
788 			i++;
789 			j++;
790 		} else if (ch1 == '!' && ch2 == '!') {
791 			while (i < split && ch1 == '!') {
792 				rej_line('-', i);
793 				i++;
794 				ch1 = i < split ? pch_char(i) : -1;
795 			}
796 			while (j <= pat_end && ch2 == '!') {
797 				rej_line('+', j);
798 				j++;
799 				ch2 = j <= pat_end ? pch_char(j) : -1;
800 			}
801 		} else if (ch1 == '*') {
802 			i++;
803 		} else if (ch2 == '+' || ch2 == ' ') {
804 			rej_line(ch2, j);
805 			j++;
806 		} else {
807 			fprintf(rejfp, "internal error on (%ld %ld %ld)\n",
808 			    i, split, j);
809 			rej_line(ch1, i);
810 			rej_line(ch2, j);
811 			return;
812 		}
813 	}
814 }
815 
816 /* We found where to apply it (we hope), so do it. */
817 
818 static void
819 apply_hunk(LINENUM where)
820 {
821 	LINENUM		old = 1;
822 	const LINENUM	lastline = pch_ptrn_lines();
823 	LINENUM		new = lastline + 1;
824 #define OUTSIDE 0
825 #define IN_IFNDEF 1
826 #define IN_IFDEF 2
827 #define IN_ELSE 3
828 	int		def_state = OUTSIDE;
829 	const LINENUM	pat_end = pch_end();
830 
831 	where--;
832 	while (pch_char(new) == '=' || pch_char(new) == '\n')
833 		new++;
834 
835 	while (old <= lastline) {
836 		if (pch_char(old) == '-') {
837 			copy_till(where + old - 1, false);
838 			if (do_defines) {
839 				if (def_state == OUTSIDE) {
840 					fputs(not_defined, ofp);
841 					def_state = IN_IFNDEF;
842 				} else if (def_state == IN_IFDEF) {
843 					fputs(else_defined, ofp);
844 					def_state = IN_ELSE;
845 				}
846 				fputs(pfetch(old), ofp);
847 			}
848 			last_frozen_line++;
849 			old++;
850 		} else if (new > pat_end) {
851 			break;
852 		} else if (pch_char(new) == '+') {
853 			copy_till(where + old - 1, false);
854 			if (do_defines) {
855 				if (def_state == IN_IFNDEF) {
856 					fputs(else_defined, ofp);
857 					def_state = IN_ELSE;
858 				} else if (def_state == OUTSIDE) {
859 					fputs(if_defined, ofp);
860 					def_state = IN_IFDEF;
861 				}
862 			}
863 			fputs(pfetch(new), ofp);
864 			new++;
865 		} else if (pch_char(new) != pch_char(old)) {
866 			say("Out-of-sync patch, lines %ld,%ld--mangled text or line numbers, maybe?\n",
867 			    pch_hunk_beg() + old,
868 			    pch_hunk_beg() + new);
869 #ifdef DEBUGGING
870 			say("oldchar = '%c', newchar = '%c'\n",
871 			    pch_char(old), pch_char(new));
872 #endif
873 			my_exit(2);
874 		} else if (pch_char(new) == '!') {
875 			copy_till(where + old - 1, false);
876 			if (do_defines) {
877 				fputs(not_defined, ofp);
878 				def_state = IN_IFNDEF;
879 			}
880 			while (pch_char(old) == '!') {
881 				if (do_defines) {
882 					fputs(pfetch(old), ofp);
883 				}
884 				last_frozen_line++;
885 				old++;
886 			}
887 			if (do_defines) {
888 				fputs(else_defined, ofp);
889 				def_state = IN_ELSE;
890 			}
891 			while (pch_char(new) == '!') {
892 				fputs(pfetch(new), ofp);
893 				new++;
894 			}
895 		} else {
896 			if (pch_char(new) != ' ')
897 				fatal("Internal error: expected ' '\n");
898 			old++;
899 			new++;
900 			if (do_defines && def_state != OUTSIDE) {
901 				fputs(end_defined, ofp);
902 				def_state = OUTSIDE;
903 			}
904 		}
905 	}
906 	if (new <= pat_end && pch_char(new) == '+') {
907 		copy_till(where + old - 1, false);
908 		if (do_defines) {
909 			if (def_state == OUTSIDE) {
910 				fputs(if_defined, ofp);
911 				def_state = IN_IFDEF;
912 			} else if (def_state == IN_IFNDEF) {
913 				fputs(else_defined, ofp);
914 				def_state = IN_ELSE;
915 			}
916 		}
917 		while (new <= pat_end && pch_char(new) == '+') {
918 			fputs(pfetch(new), ofp);
919 			new++;
920 		}
921 	}
922 	if (do_defines && def_state != OUTSIDE) {
923 		fputs(end_defined, ofp);
924 	}
925 }
926 
927 /*
928  * Open the new file.
929  */
930 static void
931 init_output(const char *name)
932 {
933 	ofp = fopen(name, "w");
934 	if (ofp == NULL)
935 		pfatal("can't create %s", name);
936 }
937 
938 /*
939  * Open a file to put hunks we can't locate.
940  */
941 static void
942 init_reject(const char *name)
943 {
944 	rejfp = fopen(name, "w");
945 	if (rejfp == NULL)
946 		pfatal("can't create %s", name);
947 }
948 
949 /*
950  * Copy input file to output, up to wherever hunk is to be applied.
951  * If endoffile is true, treat the last line specially since it may
952  * lack a newline.
953  */
954 static void
955 copy_till(LINENUM lastline, bool endoffile)
956 {
957 	if (last_frozen_line > lastline)
958 		fatal("misordered hunks! output would be garbled\n");
959 	while (last_frozen_line < lastline) {
960 		if (++last_frozen_line == lastline && endoffile)
961 			dump_line(last_frozen_line, !last_line_missing_eol);
962 		else
963 			dump_line(last_frozen_line, true);
964 	}
965 }
966 
967 /*
968  * Finish copying the input file to the output file.
969  */
970 static bool
971 spew_output(void)
972 {
973 	int rv;
974 
975 #ifdef DEBUGGING
976 	if (debug & 256)
977 		say("il=%ld lfl=%ld\n", input_lines, last_frozen_line);
978 #endif
979 	if (input_lines)
980 		copy_till(input_lines, true);	/* dump remainder of file */
981 	rv = ferror(ofp) == 0 && fclose(ofp) == 0;
982 	ofp = NULL;
983 	return rv;
984 }
985 
986 /*
987  * Copy one line from input to output.
988  */
989 static void
990 dump_line(LINENUM line, bool write_newline)
991 {
992 	char	*s;
993 
994 	s = ifetch(line, 0);
995 	if (s == NULL)
996 		return;
997 	/* Note: string is not NUL terminated. */
998 	for (; *s != '\n'; s++)
999 		putc(*s, ofp);
1000 	if (write_newline)
1001 		putc('\n', ofp);
1002 }
1003 
1004 /*
1005  * Does the patch pattern match at line base+offset?
1006  */
1007 static bool
1008 patch_match(LINENUM base, LINENUM offset, LINENUM fuzz)
1009 {
1010 	LINENUM		pline = 1 + fuzz;
1011 	LINENUM		iline;
1012 	LINENUM		pat_lines = pch_ptrn_lines() - fuzz;
1013 	const char	*ilineptr;
1014 	const char	*plineptr;
1015 	short		plinelen;
1016 
1017 	for (iline = base + offset + fuzz; pline <= pat_lines; pline++, iline++) {
1018 		ilineptr = ifetch(iline, offset >= 0);
1019 		if (ilineptr == NULL)
1020 			return false;
1021 		plineptr = pfetch(pline);
1022 		plinelen = pch_line_len(pline);
1023 		if (canonicalize) {
1024 			if (!similar(ilineptr, plineptr, plinelen))
1025 				return false;
1026 		} else if (strnNE(ilineptr, plineptr, plinelen))
1027 			return false;
1028 		if (iline == input_lines) {
1029 			/*
1030 			 * We are looking at the last line of the file.
1031 			 * If the file has no eol, the patch line should
1032 			 * not have one either and vice-versa. Note that
1033 			 * plinelen > 0.
1034 			 */
1035 			if (last_line_missing_eol) {
1036 				if (plineptr[plinelen - 1] == '\n')
1037 					return false;
1038 			} else {
1039 				if (plineptr[plinelen - 1] != '\n')
1040 					return false;
1041 			}
1042 		}
1043 	}
1044 	return true;
1045 }
1046 
1047 /*
1048  * Do two lines match with canonicalized white space?
1049  */
1050 static bool
1051 similar(const char *a, const char *b, int len)
1052 {
1053 	while (len) {
1054 		if (isspace((unsigned char)*b)) {	/* whitespace (or \n) to match? */
1055 			if (!isspace((unsigned char)*a))	/* no corresponding whitespace? */
1056 				return false;
1057 			while (len && isspace((unsigned char)*b) && *b != '\n')
1058 				b++, len--;	/* skip pattern whitespace */
1059 			while (isspace((unsigned char)*a) && *a != '\n')
1060 				a++;	/* skip target whitespace */
1061 			if (*a == '\n' || *b == '\n')
1062 				return (*a == *b);	/* should end in sync */
1063 		} else if (*a++ != *b++)	/* match non-whitespace chars */
1064 			return false;
1065 		else
1066 			len--;	/* probably not necessary */
1067 	}
1068 	return true;		/* actually, this is not reached */
1069 	/* since there is always a \n */
1070 }
1071