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 *
28 */
29
30#include <sys/types.h>
31#include <sys/stat.h>
32
33#include <assert.h>
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
49mode_t		filemode = 0644;
50
51char		*buf;			/* general purpose buffer */
52size_t		buf_size;		/* size of the general purpose buffer */
53
54bool		using_plan_a = true;	/* try to keep everything in memory */
55bool		out_of_mem = false;	/* ran out of memory in plan a */
56bool		nonempty_patchf_seen = false;	/* seen nonempty patch file? */
57
58#define MAXFILEC 2
59
60char		*filearg[MAXFILEC];
61bool		ok_to_create_file = false;
62char		*outname = NULL;
63char		*origprae = NULL;
64char		*TMPOUTNAME;
65char		*TMPINNAME;
66char		*TMPREJNAME;
67char		*TMPPATNAME;
68bool		toutkeep = false;
69bool		trejkeep = false;
70bool		warn_on_invalid_line;
71bool		last_line_missing_eol;
72
73#ifdef DEBUGGING
74int		debug = 0;
75#endif
76
77bool		force = false;
78bool		batch = false;
79bool		verbose = true;
80bool		reverse = false;
81bool		noreverse = false;
82bool		skip_rest_of_patch = false;
83int		strippath = 957;
84bool		canonicalize = false;
85bool		check_only = false;
86int		diff_type = 0;
87char		*revision = NULL;	/* prerequisite revision, if any */
88LINENUM		input_lines = 0;	/* how long is input file in lines */
89int		posix = 0;		/* strict POSIX mode? */
90
91static void	reinitialize_almost_everything(void);
92static void	get_some_switches(void);
93static LINENUM	locate_hunk(LINENUM);
94static void	abort_context_hunk(void);
95static void	rej_line(int, LINENUM);
96static void	abort_hunk(void);
97static void	apply_hunk(LINENUM);
98static void	init_output(const char *);
99static void	init_reject(const char *);
100static void	copy_till(LINENUM, bool);
101static bool	spew_output(void);
102static void	dump_line(LINENUM, bool);
103static bool	patch_match(LINENUM, LINENUM, LINENUM);
104static bool	similar(const char *, const char *, int);
105static void	usage(void);
106static bool	handle_creation(bool, bool *);
107
108/* true if -E was specified on command line.  */
109static bool	remove_empty_files = false;
110
111/* true if -R was specified on command line.  */
112static bool	reverse_flag_specified = false;
113
114static bool	Vflag = false;
115
116/* buffer holding the name of the rejected patch file. */
117static char	rejname[PATH_MAX];
118
119/* how many input lines have been irretractibly output */
120static LINENUM	last_frozen_line = 0;
121
122static int	Argc;		/* guess */
123static char	**Argv;
124static int	Argc_last;	/* for restarting plan_b */
125static char	**Argv_last;
126
127static FILE	*ofp = NULL;	/* output file pointer */
128static FILE	*rejfp = NULL;	/* reject file pointer */
129
130static int	filec = 0;	/* how many file arguments? */
131static LINENUM	last_offset = 0;
132static LINENUM	maxfuzz = 2;
133
134/* patch using ifdef, ifndef, etc. */
135static bool		do_defines = false;
136/* #ifdef xyzzy */
137static char		if_defined[128];
138/* #ifndef xyzzy */
139static char		not_defined[128];
140/* #else */
141static const char	else_defined[] = "#else\n";
142/* #endif xyzzy */
143static char		end_defined[128];
144
145
146/* Apply a set of diffs as appropriate. */
147
148int
149main(int argc, char *argv[])
150{
151	struct stat statbuf;
152	int	error = 0, hunk, failed, i, fd;
153	bool	out_creating, out_existed, patch_seen, remove_file;
154	bool	reverse_seen;
155	LINENUM	where = 0, newwhere, fuzz, mymaxfuzz;
156	const	char *tmpdir;
157	char	*v;
158
159	setvbuf(stdout, NULL, _IOLBF, 0);
160	setvbuf(stderr, NULL, _IOLBF, 0);
161	for (i = 0; i < MAXFILEC; i++)
162		filearg[i] = NULL;
163
164	buf_size = INITLINELEN;
165	buf = malloc((unsigned)(buf_size));
166	if (buf == NULL)
167		fatal("out of memory\n");
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	/* parse switches */
206	Argc = argc;
207	Argv = argv;
208	get_some_switches();
209
210	if (!Vflag) {
211		if ((v = getenv("PATCH_VERSION_CONTROL")) == NULL)
212			v = getenv("VERSION_CONTROL");
213		if (v != NULL || !posix)
214			backup_type = get_version(v);	/* OK to pass NULL. */
215	}
216
217	/* make sure we clean up /tmp in case of disaster */
218	set_signals(0);
219
220	patch_seen = false;
221	for (open_patch_file(filearg[1]); there_is_another_patch();
222	    reinitialize_almost_everything()) {
223		/* for each patch in patch file */
224
225		if (source_file != NULL && (diff_type == CONTEXT_DIFF ||
226		    diff_type == NEW_CONTEXT_DIFF ||
227		    diff_type == UNI_DIFF))
228			out_creating = strcmp(source_file, _PATH_DEVNULL) == 0;
229		else
230			out_creating = false;
231		patch_seen = true;
232
233		warn_on_invalid_line = true;
234
235		if (outname == NULL)
236			outname = xstrdup(filearg[0]);
237
238		/*
239		 * At this point, we know if we're supposed to be creating the
240		 * file and we know if we should be trying to handle a conflict
241		 * between the patch and the file already existing.  We defer
242		 * handling it until hunk processing because we want to swap
243		 * the hunk if they opt to reverse it, but we want to make sure
244		 * we *can* swap the hunk without running into memory issues
245		 * before we offer it.  We also want to be verbose if flags or
246		 * user decision cause us to skip -- this is explained a little
247		 * more later.
248		 */
249		out_existed = stat(outname, &statbuf) == 0;
250
251		/* for ed script just up and do it and exit */
252		if (diff_type == ED_DIFF) {
253			do_ed_script();
254			continue;
255		}
256		/* initialize the patched file */
257		if (!skip_rest_of_patch)
258			init_output(TMPOUTNAME);
259
260		/* initialize reject file */
261		init_reject(TMPREJNAME);
262
263		/* find out where all the lines are */
264		if (!skip_rest_of_patch)
265			scan_input(filearg[0]);
266
267		/*
268		 * from here on, open no standard i/o files, because
269		 * malloc might misfire and we can't catch it easily
270		 */
271
272		/* apply each hunk of patch */
273		hunk = 0;
274		failed = 0;
275		reverse_seen = false;
276		out_of_mem = false;
277		remove_file = false;
278		while (another_hunk()) {
279			assert(!out_creating || hunk == 0);
280			hunk++;
281			fuzz = 0;
282
283			/*
284			 * There are only three cases in handle_creation() that
285			 * results in us skipping hunk location, in order:
286			 *
287			 * 1.) Potentially reversed but -f/--force'd,
288			 * 2.) Potentially reversed but -N/--forward'd
289			 * 3.) Reversed and the user's opted to not apply it.
290			 *
291			 * In all three cases, we still want to inform the user
292			 * that we're ignoring it in the standard way, which is
293			 * also tied to this hunk processing loop.
294			 */
295			if (out_creating)
296				reverse_seen = handle_creation(out_existed,
297				    &remove_file);
298
299			mymaxfuzz = pch_context();
300			if (maxfuzz < mymaxfuzz)
301				mymaxfuzz = maxfuzz;
302			if (!skip_rest_of_patch) {
303				do {
304					where = locate_hunk(fuzz);
305					if (hunk == 1 && where == 0 && !force && !reverse_seen) {
306						/* dwim for reversed patch? */
307						if (!pch_swap()) {
308							if (fuzz == 0)
309								say("Not enough memory to try swapped hunk!  Assuming unswapped.\n");
310							continue;
311						}
312						reverse = !reverse;
313						/* try again */
314						where = locate_hunk(fuzz);
315						if (where == 0) {
316							/* didn't find it swapped */
317							if (!pch_swap())
318								/* put it back to normal */
319								fatal("lost hunk on alloc error!\n");
320							reverse = !reverse;
321						} else if (noreverse) {
322							if (!pch_swap())
323								/* put it back to normal */
324								fatal("lost hunk on alloc error!\n");
325							reverse = !reverse;
326							say("Ignoring previously applied (or reversed) patch.\n");
327							skip_rest_of_patch = true;
328						} else if (batch) {
329							if (verbose)
330								say("%seversed (or previously applied) patch detected!  %s -R.",
331								    reverse ? "R" : "Unr",
332								    reverse ? "Assuming" : "Ignoring");
333						} else {
334							ask("%seversed (or previously applied) patch detected!  %s -R? [y] ",
335							    reverse ? "R" : "Unr",
336							    reverse ? "Assume" : "Ignore");
337							if (*buf == 'n') {
338								ask("Apply anyway? [n] ");
339								if (*buf != 'y')
340									skip_rest_of_patch = true;
341								else
342									reverse_seen = true;
343								where = 0;
344								reverse = !reverse;
345								if (!pch_swap())
346									/* put it back to normal */
347									fatal("lost hunk on alloc error!\n");
348							}
349						}
350					}
351				} while (!skip_rest_of_patch && where == 0 &&
352				    ++fuzz <= mymaxfuzz);
353
354				if (skip_rest_of_patch) {	/* just got decided */
355					if (ferror(ofp) || fclose(ofp)) {
356						say("Error writing %s\n",
357						    TMPOUTNAME);
358						error = 1;
359					}
360					ofp = NULL;
361				}
362			}
363			newwhere = pch_newfirst() + last_offset;
364			if (skip_rest_of_patch) {
365				abort_hunk();
366				failed++;
367				if (verbose)
368					say("Hunk #%d ignored at %ld.\n",
369					    hunk, newwhere);
370			} else if (where == 0) {
371				abort_hunk();
372				failed++;
373				if (verbose)
374					say("Hunk #%d failed at %ld.\n",
375					    hunk, newwhere);
376			} else {
377				apply_hunk(where);
378				if (verbose) {
379					say("Hunk #%d succeeded at %ld",
380					    hunk, newwhere);
381					if (fuzz != 0)
382						say(" with fuzz %ld", fuzz);
383					if (last_offset)
384						say(" (offset %ld line%s)",
385						    last_offset,
386						    last_offset == 1L ? "" : "s");
387					say(".\n");
388				}
389			}
390		}
391
392		if (out_of_mem && using_plan_a) {
393			Argc = Argc_last;
394			Argv = Argv_last;
395			say("\n\nRan out of memory using Plan A--trying again...\n\n");
396			if (ofp)
397				fclose(ofp);
398			ofp = NULL;
399			if (rejfp)
400				fclose(rejfp);
401			rejfp = NULL;
402			continue;
403		}
404		if (hunk == 0)
405			fatal("Internal error: hunk should not be 0\n");
406
407		/* finish spewing out the new file */
408		if (!skip_rest_of_patch && !spew_output()) {
409			say("Can't write %s\n", TMPOUTNAME);
410			error = 1;
411		}
412
413		/* and put the output where desired */
414		ignore_signals();
415		if (!skip_rest_of_patch) {
416			char	*realout = outname;
417
418			if (!check_only) {
419				if (move_file(TMPOUTNAME, outname) < 0) {
420					toutkeep = true;
421					realout = TMPOUTNAME;
422					chmod(TMPOUTNAME, filemode);
423				} else
424					chmod(outname, filemode);
425
426				/*
427				 * remove_file is a per-patch flag indicating
428				 * whether it's OK to remove the empty file.
429				 * This is specifically set when we're reversing
430				 * the creation of a file and it ends up empty.
431				 * This is an exception to the global policy
432				 * (remove_empty_files) because the user would
433				 * likely not expect the reverse of file
434				 * creation to leave an empty file laying
435				 * around.
436				 */
437				if ((remove_empty_files || remove_file) &&
438				    stat(realout, &statbuf) == 0 &&
439				    statbuf.st_size == 0) {
440					if (verbose)
441						say("Removing %s (empty after patching).\n",
442						    realout);
443					unlink(realout);
444				}
445			}
446		}
447		if (ferror(rejfp) || fclose(rejfp)) {
448			say("Error writing %s\n", rejname);
449			error = 1;
450		}
451		rejfp = NULL;
452		if (failed) {
453			error = 1;
454			if (*rejname == '\0') {
455				if (strlcpy(rejname, outname,
456				    sizeof(rejname)) >= sizeof(rejname))
457					fatal("filename %s is too long\n", outname);
458				if (strlcat(rejname, REJEXT,
459				    sizeof(rejname)) >= sizeof(rejname))
460					fatal("filename %s is too long\n", outname);
461			}
462			if (!check_only)
463				say("%d out of %d hunks %s--saving rejects to %s\n",
464				    failed, hunk, skip_rest_of_patch ? "ignored" : "failed", rejname);
465			else if (filearg[0] != NULL)
466				say("%d out of %d hunks %s while patching %s\n",
467				    failed, hunk, skip_rest_of_patch ? "ignored" : "failed", filearg[0]);
468			else
469				/* File prompt ignored, just note # hunks. */
470				say("%d out of %d hunks %s\n",
471				    failed, hunk, skip_rest_of_patch ? "ignored" : "failed");
472			if (!check_only && move_file(TMPREJNAME, rejname) < 0)
473				trejkeep = true;
474		}
475		set_signals(1);
476	}
477
478	if (!patch_seen && nonempty_patchf_seen)
479		error = 2;
480
481	my_exit(error);
482	/* NOTREACHED */
483}
484
485/* Prepare to find the next patch to do in the patch file. */
486
487static void
488reinitialize_almost_everything(void)
489{
490	re_patch();
491	re_input();
492
493	input_lines = 0;
494	last_frozen_line = 0;
495
496	filec = 0;
497	if (!out_of_mem) {
498		free(filearg[0]);
499		filearg[0] = NULL;
500	}
501
502	free(source_file);
503	source_file = NULL;
504
505	free(outname);
506	outname = NULL;
507
508	last_offset = 0;
509	diff_type = 0;
510
511	free(revision);
512	revision = NULL;
513
514	reverse = reverse_flag_specified;
515	skip_rest_of_patch = false;
516
517	get_some_switches();
518}
519
520/* Process switches and filenames. */
521
522static void
523get_some_switches(void)
524{
525	const char *options = "b::B:cCd:D:eEfF:i:lnNo:p:r:RstuvV:x:z:";
526	static struct option longopts[] = {
527		{"backup",		no_argument,		0,	'b'},
528		{"batch",		no_argument,		0,	't'},
529		{"check",		no_argument,		0,	'C'},
530		{"context",		no_argument,		0,	'c'},
531		{"debug",		required_argument,	0,	'x'},
532		{"directory",		required_argument,	0,	'd'},
533		{"dry-run",		no_argument,		0,	'C'},
534		{"ed",			no_argument,		0,	'e'},
535		{"force",		no_argument,		0,	'f'},
536		{"forward",		no_argument,		0,	'N'},
537		{"fuzz",		required_argument,	0,	'F'},
538		{"ifdef",		required_argument,	0,	'D'},
539		{"input",		required_argument,	0,	'i'},
540		{"ignore-whitespace",	no_argument,		0,	'l'},
541		{"normal",		no_argument,		0,	'n'},
542		{"output",		required_argument,	0,	'o'},
543		{"prefix",		required_argument,	0,	'B'},
544		{"quiet",		no_argument,		0,	's'},
545		{"reject-file",		required_argument,	0,	'r'},
546		{"remove-empty-files",	no_argument,		0,	'E'},
547		{"reverse",		no_argument,		0,	'R'},
548		{"silent",		no_argument,		0,	's'},
549		{"strip",		required_argument,	0,	'p'},
550		{"suffix",		required_argument,	0,	'z'},
551		{"unified",		no_argument,		0,	'u'},
552		{"version",		no_argument,		0,	'v'},
553		{"version-control",	required_argument,	0,	'V'},
554		{"posix",		no_argument,		&posix,	1},
555		{NULL,			0,			0,	0}
556	};
557	int ch;
558
559	rejname[0] = '\0';
560	Argc_last = Argc;
561	Argv_last = Argv;
562	if (!Argc)
563		return;
564	optreset = optind = 1;
565	while ((ch = getopt_long(Argc, Argv, options, longopts, NULL)) != -1) {
566		switch (ch) {
567		case 'b':
568			if (backup_type == none)
569				backup_type = numbered_existing;
570			if (optarg == NULL)
571				break;
572			if (verbose)
573				say("Warning, the ``-b suffix'' option has been"
574				    " obsoleted by the -z option.\n");
575			/* FALLTHROUGH */
576		case 'z':
577			/* must directly follow 'b' case for backwards compat */
578			simple_backup_suffix = xstrdup(optarg);
579			break;
580		case 'B':
581			origprae = xstrdup(optarg);
582			break;
583		case 'c':
584			diff_type = CONTEXT_DIFF;
585			break;
586		case 'C':
587			check_only = true;
588			break;
589		case 'd':
590			if (chdir(optarg) < 0)
591				pfatal("can't cd to %s", optarg);
592			break;
593		case 'D':
594			do_defines = true;
595			if (!isalpha((unsigned char)*optarg) && *optarg != '_')
596				fatal("argument to -D is not an identifier\n");
597			snprintf(if_defined, sizeof if_defined,
598			    "#ifdef %s\n", optarg);
599			snprintf(not_defined, sizeof not_defined,
600			    "#ifndef %s\n", optarg);
601			snprintf(end_defined, sizeof end_defined,
602			    "#endif /* %s */\n", optarg);
603			break;
604		case 'e':
605			diff_type = ED_DIFF;
606			break;
607		case 'E':
608			remove_empty_files = true;
609			break;
610		case 'f':
611			force = true;
612			break;
613		case 'F':
614			maxfuzz = atoi(optarg);
615			break;
616		case 'i':
617			if (++filec == MAXFILEC)
618				fatal("too many file arguments\n");
619			filearg[filec] = xstrdup(optarg);
620			break;
621		case 'l':
622			canonicalize = true;
623			break;
624		case 'n':
625			diff_type = NORMAL_DIFF;
626			break;
627		case 'N':
628			noreverse = true;
629			break;
630		case 'o':
631			outname = xstrdup(optarg);
632			break;
633		case 'p':
634			strippath = atoi(optarg);
635			break;
636		case 'r':
637			if (strlcpy(rejname, optarg,
638			    sizeof(rejname)) >= sizeof(rejname))
639				fatal("argument for -r is too long\n");
640			break;
641		case 'R':
642			reverse = true;
643			reverse_flag_specified = true;
644			break;
645		case 's':
646			verbose = false;
647			break;
648		case 't':
649			batch = true;
650			break;
651		case 'u':
652			diff_type = UNI_DIFF;
653			break;
654		case 'v':
655			version();
656			break;
657		case 'V':
658			backup_type = get_version(optarg);
659			Vflag = true;
660			break;
661#ifdef DEBUGGING
662		case 'x':
663			debug = atoi(optarg);
664			break;
665#endif
666		default:
667			if (ch != '\0')
668				usage();
669			break;
670		}
671	}
672	Argc -= optind;
673	Argv += optind;
674
675	if (Argc > 0) {
676		filearg[0] = xstrdup(*Argv++);
677		Argc--;
678		while (Argc > 0) {
679			if (++filec == MAXFILEC)
680				fatal("too many file arguments\n");
681			filearg[filec] = xstrdup(*Argv++);
682			Argc--;
683		}
684	}
685
686	if (getenv("POSIXLY_CORRECT") != NULL)
687		posix = 1;
688}
689
690static void
691usage(void)
692{
693	fprintf(stderr,
694"usage: patch [-bCcEeflNnRstuv] [-B backup-prefix] [-D symbol] [-d directory]\n"
695"             [-F max-fuzz] [-i patchfile] [-o out-file] [-p strip-count]\n"
696"             [-r rej-name] [-V t | nil | never | none] [-x number]\n"
697"             [-z backup-ext] [--posix] [origfile [patchfile]]\n"
698"       patch <patchfile\n");
699	my_exit(EXIT_FAILURE);
700}
701
702/*
703 * Attempt to find the right place to apply this hunk of patch.
704 */
705static LINENUM
706locate_hunk(LINENUM fuzz)
707{
708	LINENUM	first_guess = pch_first() + last_offset;
709	LINENUM	offset;
710	LINENUM	pat_lines = pch_ptrn_lines();
711	LINENUM	max_pos_offset = input_lines - first_guess - pat_lines + 1;
712	LINENUM	max_neg_offset = first_guess - last_frozen_line - 1 + pch_context();
713
714	if (pat_lines == 0) {		/* null range matches always */
715		if (verbose && fuzz == 0 && (diff_type == CONTEXT_DIFF
716		    || diff_type == NEW_CONTEXT_DIFF
717		    || diff_type == UNI_DIFF)) {
718			say("Empty context always matches.\n");
719		}
720		if (first_guess == 0)	/* empty file */
721			return 1;
722		return (first_guess);
723	}
724	if (max_neg_offset >= first_guess)	/* do not try lines < 0 */
725		max_neg_offset = first_guess - 1;
726	if (first_guess <= input_lines && patch_match(first_guess, 0, fuzz))
727		return first_guess;
728	for (offset = 1; ; offset++) {
729		bool	check_after = (offset <= max_pos_offset);
730		bool	check_before = (offset <= max_neg_offset);
731
732		if (check_after && patch_match(first_guess, offset, fuzz)) {
733#ifdef DEBUGGING
734			if (debug & 1)
735				say("Offset changing from %ld to %ld\n",
736				    last_offset, offset);
737#endif
738			last_offset = offset;
739			return first_guess + offset;
740		} else if (check_before && patch_match(first_guess, -offset, fuzz)) {
741#ifdef DEBUGGING
742			if (debug & 1)
743				say("Offset changing from %ld to %ld\n",
744				    last_offset, -offset);
745#endif
746			last_offset = -offset;
747			return first_guess - offset;
748		} else if (!check_before && !check_after)
749			return 0;
750	}
751}
752
753/* We did not find the pattern, dump out the hunk so they can handle it. */
754
755static void
756abort_context_hunk(void)
757{
758	LINENUM	i;
759	const LINENUM	pat_end = pch_end();
760	/*
761	 * add in last_offset to guess the same as the previous successful
762	 * hunk
763	 */
764	const LINENUM	oldfirst = pch_first() + last_offset;
765	const LINENUM	newfirst = pch_newfirst() + last_offset;
766	const LINENUM	oldlast = oldfirst + pch_ptrn_lines() - 1;
767	const LINENUM	newlast = newfirst + pch_repl_lines() - 1;
768	const char	*stars = (diff_type >= NEW_CONTEXT_DIFF ? " ****" : "");
769	const char	*minuses = (diff_type >= NEW_CONTEXT_DIFF ? " ----" : " -----");
770
771	fprintf(rejfp, "***************\n");
772	for (i = 0; i <= pat_end; i++) {
773		switch (pch_char(i)) {
774		case '*':
775			if (oldlast < oldfirst)
776				fprintf(rejfp, "*** 0%s\n", stars);
777			else if (oldlast == oldfirst)
778				fprintf(rejfp, "*** %ld%s\n", oldfirst, stars);
779			else
780				fprintf(rejfp, "*** %ld,%ld%s\n", oldfirst,
781				    oldlast, stars);
782			break;
783		case '=':
784			if (newlast < newfirst)
785				fprintf(rejfp, "--- 0%s\n", minuses);
786			else if (newlast == newfirst)
787				fprintf(rejfp, "--- %ld%s\n", newfirst, minuses);
788			else
789				fprintf(rejfp, "--- %ld,%ld%s\n", newfirst,
790				    newlast, minuses);
791			break;
792		case '\n':
793			fprintf(rejfp, "%s", pfetch(i));
794			break;
795		case ' ':
796		case '-':
797		case '+':
798		case '!':
799			fprintf(rejfp, "%c %s", pch_char(i), pfetch(i));
800			break;
801		default:
802			fatal("fatal internal error in abort_context_hunk\n");
803		}
804	}
805}
806
807static void
808rej_line(int ch, LINENUM i)
809{
810	size_t len;
811	const char *line = pfetch(i);
812
813	len = strlen(line);
814
815	fprintf(rejfp, "%c%s", ch, line);
816	if (len == 0 || line[len - 1] != '\n') {
817		if (len >= USHRT_MAX)
818			fprintf(rejfp, "\n\\ Line too long\n");
819		else
820			fprintf(rejfp, "\n\\ No newline at end of line\n");
821	}
822}
823
824static void
825abort_hunk(void)
826{
827	LINENUM		i, j, split;
828	int		ch1, ch2;
829	const LINENUM	pat_end = pch_end();
830	const LINENUM	oldfirst = pch_first() + last_offset;
831	const LINENUM	newfirst = pch_newfirst() + last_offset;
832
833	if (diff_type != UNI_DIFF) {
834		abort_context_hunk();
835		return;
836	}
837	split = -1;
838	for (i = 0; i <= pat_end; i++) {
839		if (pch_char(i) == '=') {
840			split = i;
841			break;
842		}
843	}
844	if (split == -1) {
845		fprintf(rejfp, "malformed hunk: no split found\n");
846		return;
847	}
848	i = 0;
849	j = split + 1;
850	fprintf(rejfp, "@@ -%ld,%ld +%ld,%ld @@\n",
851	    pch_ptrn_lines() ? oldfirst : 0,
852	    pch_ptrn_lines(), newfirst, pch_repl_lines());
853	while (i < split || j <= pat_end) {
854		ch1 = i < split ? pch_char(i) : -1;
855		ch2 = j <= pat_end ? pch_char(j) : -1;
856		if (ch1 == '-') {
857			rej_line('-', i);
858			i++;
859		} else if (ch1 == ' ' && ch2 == ' ') {
860			rej_line(' ', i);
861			i++;
862			j++;
863		} else if (ch1 == '!' && ch2 == '!') {
864			while (i < split && ch1 == '!') {
865				rej_line('-', i);
866				i++;
867				ch1 = i < split ? pch_char(i) : -1;
868			}
869			while (j <= pat_end && ch2 == '!') {
870				rej_line('+', j);
871				j++;
872				ch2 = j <= pat_end ? pch_char(j) : -1;
873			}
874		} else if (ch1 == '*') {
875			i++;
876		} else if (ch2 == '+' || ch2 == ' ') {
877			rej_line(ch2, j);
878			j++;
879		} else {
880			fprintf(rejfp, "internal error on (%ld %ld %ld)\n",
881			    i, split, j);
882			rej_line(ch1, i);
883			rej_line(ch2, j);
884			return;
885		}
886	}
887}
888
889/* We found where to apply it (we hope), so do it. */
890
891static void
892apply_hunk(LINENUM where)
893{
894	LINENUM		old = 1;
895	const LINENUM	lastline = pch_ptrn_lines();
896	LINENUM		new = lastline + 1;
897#define OUTSIDE 0
898#define IN_IFNDEF 1
899#define IN_IFDEF 2
900#define IN_ELSE 3
901	int		def_state = OUTSIDE;
902	const LINENUM	pat_end = pch_end();
903
904	where--;
905	while (pch_char(new) == '=' || pch_char(new) == '\n')
906		new++;
907
908	while (old <= lastline) {
909		if (pch_char(old) == '-') {
910			copy_till(where + old - 1, false);
911			if (do_defines) {
912				if (def_state == OUTSIDE) {
913					fputs(not_defined, ofp);
914					def_state = IN_IFNDEF;
915				} else if (def_state == IN_IFDEF) {
916					fputs(else_defined, ofp);
917					def_state = IN_ELSE;
918				}
919				fputs(pfetch(old), ofp);
920			}
921			last_frozen_line++;
922			old++;
923		} else if (new > pat_end) {
924			break;
925		} else if (pch_char(new) == '+') {
926			copy_till(where + old - 1, false);
927			if (do_defines) {
928				if (def_state == IN_IFNDEF) {
929					fputs(else_defined, ofp);
930					def_state = IN_ELSE;
931				} else if (def_state == OUTSIDE) {
932					fputs(if_defined, ofp);
933					def_state = IN_IFDEF;
934				}
935			}
936			fputs(pfetch(new), ofp);
937			new++;
938		} else if (pch_char(new) != pch_char(old)) {
939			say("Out-of-sync patch, lines %ld,%ld--mangled text or line numbers, maybe?\n",
940			    pch_hunk_beg() + old,
941			    pch_hunk_beg() + new);
942#ifdef DEBUGGING
943			say("oldchar = '%c', newchar = '%c'\n",
944			    pch_char(old), pch_char(new));
945#endif
946			my_exit(2);
947		} else if (pch_char(new) == '!') {
948			copy_till(where + old - 1, false);
949			if (do_defines) {
950				fputs(not_defined, ofp);
951				def_state = IN_IFNDEF;
952			}
953			while (pch_char(old) == '!') {
954				if (do_defines) {
955					fputs(pfetch(old), ofp);
956				}
957				last_frozen_line++;
958				old++;
959			}
960			if (do_defines) {
961				fputs(else_defined, ofp);
962				def_state = IN_ELSE;
963			}
964			while (pch_char(new) == '!') {
965				fputs(pfetch(new), ofp);
966				new++;
967			}
968		} else {
969			if (pch_char(new) != ' ')
970				fatal("Internal error: expected ' '\n");
971			old++;
972			new++;
973			if (do_defines && def_state != OUTSIDE) {
974				fputs(end_defined, ofp);
975				def_state = OUTSIDE;
976			}
977		}
978	}
979	if (new <= pat_end && pch_char(new) == '+') {
980		copy_till(where + old - 1, false);
981		if (do_defines) {
982			if (def_state == OUTSIDE) {
983				fputs(if_defined, ofp);
984				def_state = IN_IFDEF;
985			} else if (def_state == IN_IFNDEF) {
986				fputs(else_defined, ofp);
987				def_state = IN_ELSE;
988			}
989		}
990		while (new <= pat_end && pch_char(new) == '+') {
991			fputs(pfetch(new), ofp);
992			new++;
993		}
994	}
995	if (do_defines && def_state != OUTSIDE) {
996		fputs(end_defined, ofp);
997	}
998}
999
1000/*
1001 * Open the new file.
1002 */
1003static void
1004init_output(const char *name)
1005{
1006	ofp = fopen(name, "w");
1007	if (ofp == NULL)
1008		pfatal("can't create %s", name);
1009}
1010
1011/*
1012 * Open a file to put hunks we can't locate.
1013 */
1014static void
1015init_reject(const char *name)
1016{
1017	rejfp = fopen(name, "w");
1018	if (rejfp == NULL)
1019		pfatal("can't create %s", name);
1020}
1021
1022/*
1023 * Copy input file to output, up to wherever hunk is to be applied.
1024 * If endoffile is true, treat the last line specially since it may
1025 * lack a newline.
1026 */
1027static void
1028copy_till(LINENUM lastline, bool endoffile)
1029{
1030	if (last_frozen_line > lastline)
1031		fatal("misordered hunks! output would be garbled\n");
1032	while (last_frozen_line < lastline) {
1033		if (++last_frozen_line == lastline && endoffile)
1034			dump_line(last_frozen_line, !last_line_missing_eol);
1035		else
1036			dump_line(last_frozen_line, true);
1037	}
1038}
1039
1040/*
1041 * Finish copying the input file to the output file.
1042 */
1043static bool
1044spew_output(void)
1045{
1046	int rv;
1047
1048#ifdef DEBUGGING
1049	if (debug & 256)
1050		say("il=%ld lfl=%ld\n", input_lines, last_frozen_line);
1051#endif
1052	if (input_lines)
1053		copy_till(input_lines, true);	/* dump remainder of file */
1054	rv = ferror(ofp) == 0 && fclose(ofp) == 0;
1055	ofp = NULL;
1056	return rv;
1057}
1058
1059/*
1060 * Copy one line from input to output.
1061 */
1062static void
1063dump_line(LINENUM line, bool write_newline)
1064{
1065	char	*s;
1066
1067	s = ifetch(line, 0);
1068	if (s == NULL)
1069		return;
1070	/* Note: string is not NUL terminated. */
1071	for (; *s != '\n'; s++)
1072		putc(*s, ofp);
1073	if (write_newline)
1074		putc('\n', ofp);
1075}
1076
1077/*
1078 * Does the patch pattern match at line base+offset?
1079 */
1080static bool
1081patch_match(LINENUM base, LINENUM offset, LINENUM fuzz)
1082{
1083	LINENUM		pline = 1 + fuzz;
1084	LINENUM		iline;
1085	LINENUM		pat_lines = pch_ptrn_lines() - fuzz;
1086	const char	*ilineptr;
1087	const char	*plineptr;
1088	size_t		plinelen;
1089
1090	/* Patch does not match if we don't have any more context to use */
1091	if (pline > pat_lines)
1092		return false;
1093	for (iline = base + offset + fuzz; pline <= pat_lines; pline++, iline++) {
1094		ilineptr = ifetch(iline, offset >= 0);
1095		if (ilineptr == NULL)
1096			return false;
1097		plineptr = pfetch(pline);
1098		plinelen = pch_line_len(pline);
1099		if (canonicalize) {
1100			if (!similar(ilineptr, plineptr, plinelen))
1101				return false;
1102		} else if (strnNE(ilineptr, plineptr, plinelen))
1103			return false;
1104		if (iline == input_lines) {
1105			/*
1106			 * We are looking at the last line of the file.
1107			 * If the file has no eol, the patch line should
1108			 * not have one either and vice-versa. Note that
1109			 * plinelen > 0.
1110			 */
1111			if (last_line_missing_eol) {
1112				if (plineptr[plinelen - 1] == '\n')
1113					return false;
1114			} else {
1115				if (plineptr[plinelen - 1] != '\n')
1116					return false;
1117			}
1118		}
1119	}
1120	return true;
1121}
1122
1123/*
1124 * Do two lines match with canonicalized white space?
1125 */
1126static bool
1127similar(const char *a, const char *b, int len)
1128{
1129	while (len) {
1130		if (isspace((unsigned char)*b)) {	/* whitespace (or \n) to match? */
1131			if (!isspace((unsigned char)*a))	/* no corresponding whitespace? */
1132				return false;
1133			while (len && isspace((unsigned char)*b) && *b != '\n')
1134				b++, len--;	/* skip pattern whitespace */
1135			while (isspace((unsigned char)*a) && *a != '\n')
1136				a++;	/* skip target whitespace */
1137			if (*a == '\n' || *b == '\n')
1138				return (*a == *b);	/* should end in sync */
1139		} else if (*a++ != *b++)	/* match non-whitespace chars */
1140			return false;
1141		else
1142			len--;	/* probably not necessary */
1143	}
1144	return true;		/* actually, this is not reached */
1145	/* since there is always a \n */
1146}
1147
1148static bool
1149handle_creation(bool out_existed, bool *remove)
1150{
1151	bool reverse_seen;
1152
1153	reverse_seen = false;
1154	if (reverse && out_existed) {
1155		/*
1156		 * If the patch creates the file and we're reversing the patch,
1157		 * then we need to indicate to the patch processor that it's OK
1158		 * to remove this file.
1159		 */
1160		*remove = true;
1161	} else if (!reverse && out_existed) {
1162		/*
1163		 * Otherwise, we need to blow the horn because the patch appears
1164		 * to be reversed/already applied.  For non-batch jobs, we'll
1165		 * prompt to figure out what we should be trying to do to raise
1166		 * awareness of the issue.  batch (-t) processing suppresses the
1167		 * questions and just assumes that we're reversed if it looks
1168		 * like we are, which is always the case if we've reached this
1169		 * branch.
1170		 */
1171		if (force) {
1172			skip_rest_of_patch = true;
1173			return (false);
1174		}
1175		if (noreverse) {
1176			/* If -N is supplied, however, we bail out/ignore. */
1177			say("Ignoring previously applied (or reversed) patch.\n");
1178			skip_rest_of_patch = true;
1179			return (false);
1180		}
1181
1182		/* Unreversed... suspicious if the file existed. */
1183		if (!pch_swap())
1184			fatal("lost hunk on alloc error!\n");
1185
1186		reverse = !reverse;
1187
1188		if (batch) {
1189			if (verbose)
1190				say("Patch creates file that already exists, %s %seversed",
1191				    reverse ? "Assuming" : "Ignoring",
1192				    reverse ? "R" : "Unr");
1193		} else {
1194			ask("Patch creates file that already exists!  %s -R? [y] ",
1195			    reverse ? "Assume" : "Ignore");
1196
1197			if (*buf == 'n') {
1198				ask("Apply anyway? [n]");
1199				if (*buf != 'y')
1200					/* Don't apply; error out. */
1201					skip_rest_of_patch = true;
1202				else
1203					/* Attempt to apply. */
1204					reverse_seen = true;
1205				reverse = !reverse;
1206				if (!pch_swap())
1207					fatal("lost hunk on alloc error!\n");
1208			} else {
1209				/*
1210				 * They've opted to assume -R; effectively the
1211				 * same as the first branch in this function,
1212				 * but the decision is here rather than in a
1213				 * prior patch/hunk as in that branch.
1214				 */
1215				*remove = true;
1216			}
1217		}
1218	}
1219
1220	/*
1221	 * The return value indicates if we offered a chance to reverse but the
1222	 * user declined.  This keeps the main patch processor in the loop since
1223	 * we've taken this out of the normal flow of hunk processing to
1224	 * simplify logic a little bit.
1225	 */
1226	return (reverse_seen);
1227}
1228