patch.c revision 250975 
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: head/usr.bin/patch/patch.c 250975 2013-05-25 07:17:16Z gjb $
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
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 */
56
57#define MAXFILEC 2
58
59char		*filearg[MAXFILEC];
60bool		ok_to_create_file = false;
61char		*outname = NULL;
62char		*origprae = NULL;
63char		*TMPOUTNAME;
64char		*TMPINNAME;
65char		*TMPREJNAME;
66char		*TMPPATNAME;
67bool		toutkeep = false;
68bool		trejkeep = false;
69bool		warn_on_invalid_line;
70bool		last_line_missing_eol;
71
72#ifdef DEBUGGING
73int		debug = 0;
74#endif
75
76bool		force = false;
77bool		batch = false;
78bool		verbose = true;
79bool		reverse = false;
80bool		noreverse = false;
81bool		skip_rest_of_patch = false;
82int		strippath = 957;
83bool		canonicalize = false;
84bool		check_only = false;
85int		diff_type = 0;
86char		*revision = NULL;	/* prerequisite revision, if any */
87LINENUM		input_lines = 0;	/* how long is input file in lines */
88int		posix = 0;		/* strict POSIX mode? */
89
90static void	reinitialize_almost_everything(void);
91static void	get_some_switches(void);
92static LINENUM	locate_hunk(LINENUM);
93static void	abort_context_hunk(void);
94static void	rej_line(int, LINENUM);
95static void	abort_hunk(void);
96static void	apply_hunk(LINENUM);
97static void	init_output(const char *);
98static void	init_reject(const char *);
99static void	copy_till(LINENUM, bool);
100static bool	spew_output(void);
101static void	dump_line(LINENUM, bool);
102static bool	patch_match(LINENUM, LINENUM, LINENUM);
103static bool	similar(const char *, const char *, int);
104static void	usage(void);
105
106/* true if -E was specified on command line.  */
107static bool	remove_empty_files = false;
108
109/* true if -R was specified on command line.  */
110static bool	reverse_flag_specified = false;
111
112/* buffer holding the name of the rejected patch file. */
113static char	rejname[NAME_MAX + 1];
114
115/* how many input lines have been irretractibly output */
116static LINENUM	last_frozen_line = 0;
117
118static int	Argc;		/* guess */
119static char	**Argv;
120static int	Argc_last;	/* for restarting plan_b */
121static char	**Argv_last;
122
123static FILE	*ofp = NULL;	/* output file pointer */
124static FILE	*rejfp = NULL;	/* reject file pointer */
125
126static int	filec = 0;	/* how many file arguments? */
127static LINENUM	last_offset = 0;
128static LINENUM	maxfuzz = 2;
129
130/* patch using ifdef, ifndef, etc. */
131static bool		do_defines = false;
132/* #ifdef xyzzy */
133static char		if_defined[128];
134/* #ifndef xyzzy */
135static char		not_defined[128];
136/* #else */
137static const char	else_defined[] = "#else\n";
138/* #endif xyzzy */
139static char		end_defined[128];
140
141
142/* Apply a set of diffs as appropriate. */
143
144int
145main(int argc, char *argv[])
146{
147	int	error = 0, hunk, failed, i, fd;
148	bool	patch_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		/* from here on, open no standard i/o files, because malloc */
243		/* might misfire and we can't catch it easily */
244
245		/* apply each hunk of patch */
246		hunk = 0;
247		failed = 0;
248		out_of_mem = false;
249		while (another_hunk()) {
250			hunk++;
251			fuzz = 0;
252			mymaxfuzz = pch_context();
253			if (maxfuzz < mymaxfuzz)
254				mymaxfuzz = maxfuzz;
255			if (!skip_rest_of_patch) {
256				do {
257					where = locate_hunk(fuzz);
258					if (hunk == 1 && where == 0 && !force) {
259						/* dwim for reversed patch? */
260						if (!pch_swap()) {
261							if (fuzz == 0)
262								say("Not enough memory to try swapped hunk!  Assuming unswapped.\n");
263							continue;
264						}
265						reverse = !reverse;
266						/* try again */
267						where = locate_hunk(fuzz);
268						if (where == 0) {
269							/* didn't find it swapped */
270							if (!pch_swap())
271								/* put it back to normal */
272								fatal("lost hunk on alloc error!\n");
273							reverse = !reverse;
274						} else if (noreverse) {
275							if (!pch_swap())
276								/* put it back to normal */
277								fatal("lost hunk on alloc error!\n");
278							reverse = !reverse;
279							say("Ignoring previously applied (or reversed) patch.\n");
280							skip_rest_of_patch = true;
281						} else if (batch) {
282							if (verbose)
283								say("%seversed (or previously applied) patch detected!  %s -R.",
284								    reverse ? "R" : "Unr",
285								    reverse ? "Assuming" : "Ignoring");
286						} else {
287							ask("%seversed (or previously applied) patch detected!  %s -R? [y] ",
288							    reverse ? "R" : "Unr",
289							    reverse ? "Assume" : "Ignore");
290							if (*buf == 'n') {
291								ask("Apply anyway? [n] ");
292								if (*buf != 'y')
293									skip_rest_of_patch = true;
294								where = 0;
295								reverse = !reverse;
296								if (!pch_swap())
297									/* put it back to normal */
298									fatal("lost hunk on alloc error!\n");
299							}
300						}
301					}
302				} while (!skip_rest_of_patch && where == 0 &&
303				    ++fuzz <= mymaxfuzz);
304
305				if (skip_rest_of_patch) {	/* just got decided */
306					if (ferror(ofp) || fclose(ofp)) {
307						say("Error writing %s\n",
308						    TMPOUTNAME);
309						error = 1;
310					}
311					ofp = NULL;
312				}
313			}
314			newwhere = pch_newfirst() + last_offset;
315			if (skip_rest_of_patch) {
316				abort_hunk();
317				failed++;
318				if (verbose)
319					say("Hunk #%d ignored at %ld.\n",
320					    hunk, newwhere);
321			} else if (where == 0) {
322				abort_hunk();
323				failed++;
324				if (verbose)
325					say("Hunk #%d failed at %ld.\n",
326					    hunk, newwhere);
327			} else {
328				apply_hunk(where);
329				if (verbose) {
330					say("Hunk #%d succeeded at %ld",
331					    hunk, newwhere);
332					if (fuzz != 0)
333						say(" with fuzz %ld", fuzz);
334					if (last_offset)
335						say(" (offset %ld line%s)",
336						    last_offset,
337						    last_offset == 1L ? "" : "s");
338					say(".\n");
339				}
340			}
341		}
342
343		if (out_of_mem && using_plan_a) {
344			Argc = Argc_last;
345			Argv = Argv_last;
346			say("\n\nRan out of memory using Plan A--trying again...\n\n");
347			if (ofp)
348				fclose(ofp);
349			ofp = NULL;
350			if (rejfp)
351				fclose(rejfp);
352			rejfp = NULL;
353			continue;
354		}
355		if (hunk == 0)
356			fatal("Internal error: hunk should not be 0\n");
357
358		/* finish spewing out the new file */
359		if (!skip_rest_of_patch && !spew_output()) {
360			say("Can't write %s\n", TMPOUTNAME);
361			error = 1;
362		}
363
364		/* and put the output where desired */
365		ignore_signals();
366		if (!skip_rest_of_patch) {
367			struct stat	statbuf;
368			char	*realout = outname;
369
370			if (!check_only) {
371				if (move_file(TMPOUTNAME, outname) < 0) {
372					toutkeep = true;
373					realout = TMPOUTNAME;
374					chmod(TMPOUTNAME, filemode);
375				} else
376					chmod(outname, filemode);
377
378				if (remove_empty_files &&
379				    stat(realout, &statbuf) == 0 &&
380				    statbuf.st_size == 0) {
381					if (verbose)
382						say("Removing %s (empty after patching).\n",
383						    realout);
384					unlink(realout);
385				}
386			}
387		}
388		if (ferror(rejfp) || fclose(rejfp)) {
389			say("Error writing %s\n", rejname);
390			error = 1;
391		}
392		rejfp = NULL;
393		if (failed) {
394			error = 1;
395			if (*rejname == '\0') {
396				if (strlcpy(rejname, outname,
397				    sizeof(rejname)) >= sizeof(rejname))
398					fatal("filename %s is too long\n", outname);
399				if (strlcat(rejname, REJEXT,
400				    sizeof(rejname)) >= sizeof(rejname))
401					fatal("filename %s is too long\n", outname);
402			}
403			if (!check_only)
404				say("%d out of %d hunks %s--saving rejects to %s\n",
405				    failed, hunk, skip_rest_of_patch ? "ignored" : "failed", rejname);
406			else
407				say("%d out of %d hunks %s\n",
408				    failed, hunk, skip_rest_of_patch ? "ignored" : "failed");
409			if (!check_only && move_file(TMPREJNAME, rejname) < 0)
410				trejkeep = true;
411		}
412		set_signals(1);
413	}
414
415	if (!patch_seen)
416		error = 2;
417
418	my_exit(error);
419	/* NOTREACHED */
420}
421
422/* Prepare to find the next patch to do in the patch file. */
423
424static void
425reinitialize_almost_everything(void)
426{
427	re_patch();
428	re_input();
429
430	input_lines = 0;
431	last_frozen_line = 0;
432
433	filec = 0;
434	if (!out_of_mem) {
435		free(filearg[0]);
436		filearg[0] = NULL;
437	}
438
439	free(outname);
440	outname = NULL;
441
442	last_offset = 0;
443	diff_type = 0;
444
445	free(revision);
446	revision = NULL;
447
448	reverse = reverse_flag_specified;
449	skip_rest_of_patch = false;
450
451	get_some_switches();
452}
453
454/* Process switches and filenames. */
455
456static void
457get_some_switches(void)
458{
459	const char *options = "b::B:cCd:D:eEfF:i:lnNo:p:r:RstuvV:x:z:";
460	static struct option longopts[] = {
461		{"backup",		no_argument,		0,	'b'},
462		{"batch",		no_argument,		0,	't'},
463		{"check",		no_argument,		0,	'C'},
464		{"context",		no_argument,		0,	'c'},
465		{"debug",		required_argument,	0,	'x'},
466		{"directory",		required_argument,	0,	'd'},
467		{"ed",			no_argument,		0,	'e'},
468		{"force",		no_argument,		0,	'f'},
469		{"forward",		no_argument,		0,	'N'},
470		{"fuzz",		required_argument,	0,	'F'},
471		{"ifdef",		required_argument,	0,	'D'},
472		{"input",		required_argument,	0,	'i'},
473		{"ignore-whitespace",	no_argument,		0,	'l'},
474		{"normal",		no_argument,		0,	'n'},
475		{"output",		required_argument,	0,	'o'},
476		{"prefix",		required_argument,	0,	'B'},
477		{"quiet",		no_argument,		0,	's'},
478		{"reject-file",		required_argument,	0,	'r'},
479		{"remove-empty-files",	no_argument,		0,	'E'},
480		{"reverse",		no_argument,		0,	'R'},
481		{"silent",		no_argument,		0,	's'},
482		{"strip",		required_argument,	0,	'p'},
483		{"suffix",		required_argument,	0,	'z'},
484		{"unified",		no_argument,		0,	'u'},
485		{"version",		no_argument,		0,	'v'},
486		{"version-control",	required_argument,	0,	'V'},
487		{"posix",		no_argument,		&posix,	1},
488		{NULL,			0,			0,	0}
489	};
490	int ch;
491
492	rejname[0] = '\0';
493	Argc_last = Argc;
494	Argv_last = Argv;
495	if (!Argc)
496		return;
497	optreset = optind = 1;
498	while ((ch = getopt_long(Argc, Argv, options, longopts, NULL)) != -1) {
499		switch (ch) {
500		case 'b':
501			if (backup_type == none)
502				backup_type = numbered_existing;
503			if (optarg == NULL)
504				break;
505			if (verbose)
506				say("Warning, the ``-b suffix'' option has been"
507				    " obsoleted by the -z option.\n");
508			/* FALLTHROUGH */
509		case 'z':
510			/* must directly follow 'b' case for backwards compat */
511			simple_backup_suffix = savestr(optarg);
512			break;
513		case 'B':
514			origprae = savestr(optarg);
515			break;
516		case 'c':
517			diff_type = CONTEXT_DIFF;
518			break;
519		case 'C':
520			check_only = true;
521			break;
522		case 'd':
523			if (chdir(optarg) < 0)
524				pfatal("can't cd to %s", optarg);
525			break;
526		case 'D':
527			do_defines = true;
528			if (!isalpha((unsigned char)*optarg) && *optarg != '_')
529				fatal("argument to -D is not an identifier\n");
530			snprintf(if_defined, sizeof if_defined,
531			    "#ifdef %s\n", optarg);
532			snprintf(not_defined, sizeof not_defined,
533			    "#ifndef %s\n", optarg);
534			snprintf(end_defined, sizeof end_defined,
535			    "#endif /* %s */\n", optarg);
536			break;
537		case 'e':
538			diff_type = ED_DIFF;
539			break;
540		case 'E':
541			remove_empty_files = true;
542			break;
543		case 'f':
544			force = true;
545			break;
546		case 'F':
547			maxfuzz = atoi(optarg);
548			break;
549		case 'i':
550			if (++filec == MAXFILEC)
551				fatal("too many file arguments\n");
552			filearg[filec] = savestr(optarg);
553			break;
554		case 'l':
555			canonicalize = true;
556			break;
557		case 'n':
558			diff_type = NORMAL_DIFF;
559			break;
560		case 'N':
561			noreverse = true;
562			break;
563		case 'o':
564			outname = savestr(optarg);
565			break;
566		case 'p':
567			strippath = atoi(optarg);
568			break;
569		case 'r':
570			if (strlcpy(rejname, optarg,
571			    sizeof(rejname)) >= sizeof(rejname))
572				fatal("argument for -r is too long\n");
573			break;
574		case 'R':
575			reverse = true;
576			reverse_flag_specified = true;
577			break;
578		case 's':
579			verbose = false;
580			break;
581		case 't':
582			batch = true;
583			break;
584		case 'u':
585			diff_type = UNI_DIFF;
586			break;
587		case 'v':
588			version();
589			break;
590		case 'V':
591			backup_type = get_version(optarg);
592			break;
593#ifdef DEBUGGING
594		case 'x':
595			debug = atoi(optarg);
596			break;
597#endif
598		default:
599			if (ch != '\0')
600				usage();
601			break;
602		}
603	}
604	Argc -= optind;
605	Argv += optind;
606
607	if (Argc > 0) {
608		filearg[0] = savestr(*Argv++);
609		Argc--;
610		while (Argc > 0) {
611			if (++filec == MAXFILEC)
612				fatal("too many file arguments\n");
613			filearg[filec] = savestr(*Argv++);
614			Argc--;
615		}
616	}
617
618	if (getenv("POSIXLY_CORRECT") != NULL)
619		posix = 1;
620}
621
622static void
623usage(void)
624{
625	fprintf(stderr,
626"usage: patch [-bCcEeflNnRstuv] [-B backup-prefix] [-D symbol] [-d directory]\n"
627"             [-F max-fuzz] [-i patchfile] [-o out-file] [-p strip-count]\n"
628"             [-r rej-name] [-V t | nil | never] [-x number] [-z backup-ext]\n"
629"             [--posix] [origfile [patchfile]]\n"
630"       patch <patchfile\n");
631	my_exit(EXIT_SUCCESS);
632}
633
634/*
635 * Attempt to find the right place to apply this hunk of patch.
636 */
637static LINENUM
638locate_hunk(LINENUM fuzz)
639{
640	LINENUM	first_guess = pch_first() + last_offset;
641	LINENUM	offset;
642	LINENUM	pat_lines = pch_ptrn_lines();
643	LINENUM	max_pos_offset = input_lines - first_guess - pat_lines + 1;
644	LINENUM	max_neg_offset = first_guess - last_frozen_line - 1 + pch_context();
645
646	if (pat_lines == 0) {		/* null range matches always */
647		if (verbose && fuzz == 0 && (diff_type == CONTEXT_DIFF
648		    || diff_type == NEW_CONTEXT_DIFF
649		    || diff_type == UNI_DIFF)) {
650			say("Empty context always matches.\n");
651		}
652		return (first_guess);
653	}
654	if (max_neg_offset >= first_guess)	/* do not try lines < 0 */
655		max_neg_offset = first_guess - 1;
656	if (first_guess <= input_lines && patch_match(first_guess, 0, fuzz))
657		return first_guess;
658	for (offset = 1; ; offset++) {
659		bool	check_after = (offset <= max_pos_offset);
660		bool	check_before = (offset <= max_neg_offset);
661
662		if (check_after && patch_match(first_guess, offset, fuzz)) {
663#ifdef DEBUGGING
664			if (debug & 1)
665				say("Offset changing from %ld to %ld\n",
666				    last_offset, offset);
667#endif
668			last_offset = offset;
669			return first_guess + offset;
670		} else if (check_before && patch_match(first_guess, -offset, fuzz)) {
671#ifdef DEBUGGING
672			if (debug & 1)
673				say("Offset changing from %ld to %ld\n",
674				    last_offset, -offset);
675#endif
676			last_offset = -offset;
677			return first_guess - offset;
678		} else if (!check_before && !check_after)
679			return 0;
680	}
681}
682
683/* We did not find the pattern, dump out the hunk so they can handle it. */
684
685static void
686abort_context_hunk(void)
687{
688	LINENUM	i;
689	const LINENUM	pat_end = pch_end();
690	/*
691	 * add in last_offset to guess the same as the previous successful
692	 * hunk
693	 */
694	const LINENUM	oldfirst = pch_first() + last_offset;
695	const LINENUM	newfirst = pch_newfirst() + last_offset;
696	const LINENUM	oldlast = oldfirst + pch_ptrn_lines() - 1;
697	const LINENUM	newlast = newfirst + pch_repl_lines() - 1;
698	const char	*stars = (diff_type >= NEW_CONTEXT_DIFF ? " ****" : "");
699	const char	*minuses = (diff_type >= NEW_CONTEXT_DIFF ? " ----" : " -----");
700
701	fprintf(rejfp, "***************\n");
702	for (i = 0; i <= pat_end; i++) {
703		switch (pch_char(i)) {
704		case '*':
705			if (oldlast < oldfirst)
706				fprintf(rejfp, "*** 0%s\n", stars);
707			else if (oldlast == oldfirst)
708				fprintf(rejfp, "*** %ld%s\n", oldfirst, stars);
709			else
710				fprintf(rejfp, "*** %ld,%ld%s\n", oldfirst,
711				    oldlast, stars);
712			break;
713		case '=':
714			if (newlast < newfirst)
715				fprintf(rejfp, "--- 0%s\n", minuses);
716			else if (newlast == newfirst)
717				fprintf(rejfp, "--- %ld%s\n", newfirst, minuses);
718			else
719				fprintf(rejfp, "--- %ld,%ld%s\n", newfirst,
720				    newlast, minuses);
721			break;
722		case '\n':
723			fprintf(rejfp, "%s", pfetch(i));
724			break;
725		case ' ':
726		case '-':
727		case '+':
728		case '!':
729			fprintf(rejfp, "%c %s", pch_char(i), pfetch(i));
730			break;
731		default:
732			fatal("fatal internal error in abort_context_hunk\n");
733		}
734	}
735}
736
737static void
738rej_line(int ch, LINENUM i)
739{
740	size_t len;
741	const char *line = pfetch(i);
742
743	len = strlen(line);
744
745	fprintf(rejfp, "%c%s", ch, line);
746	if (len == 0 || line[len-1] != '\n')
747		fprintf(rejfp, "\n\\ No newline at end of file\n");
748}
749
750static void
751abort_hunk(void)
752{
753	LINENUM		i, j, split;
754	int		ch1, ch2;
755	const LINENUM	pat_end = pch_end();
756	const LINENUM	oldfirst = pch_first() + last_offset;
757	const LINENUM	newfirst = pch_newfirst() + last_offset;
758
759	if (diff_type != UNI_DIFF) {
760		abort_context_hunk();
761		return;
762	}
763	split = -1;
764	for (i = 0; i <= pat_end; i++) {
765		if (pch_char(i) == '=') {
766			split = i;
767			break;
768		}
769	}
770	if (split == -1) {
771		fprintf(rejfp, "malformed hunk: no split found\n");
772		return;
773	}
774	i = 0;
775	j = split + 1;
776	fprintf(rejfp, "@@ -%ld,%ld +%ld,%ld @@\n",
777	    pch_ptrn_lines() ? oldfirst : 0,
778	    pch_ptrn_lines(), newfirst, pch_repl_lines());
779	while (i < split || j <= pat_end) {
780		ch1 = i < split ? pch_char(i) : -1;
781		ch2 = j <= pat_end ? pch_char(j) : -1;
782		if (ch1 == '-') {
783			rej_line('-', i);
784			i++;
785		} else if (ch1 == ' ' && ch2 == ' ') {
786			rej_line(' ', i);
787			i++;
788			j++;
789		} else if (ch1 == '!' && ch2 == '!') {
790			while (i < split && ch1 == '!') {
791				rej_line('-', i);
792				i++;
793				ch1 = i < split ? pch_char(i) : -1;
794			}
795			while (j <= pat_end && ch2 == '!') {
796				rej_line('+', j);
797				j++;
798				ch2 = j <= pat_end ? pch_char(j) : -1;
799			}
800		} else if (ch1 == '*') {
801			i++;
802		} else if (ch2 == '+' || ch2 == ' ') {
803			rej_line(ch2, j);
804			j++;
805		} else {
806			fprintf(rejfp, "internal error on (%ld %ld %ld)\n",
807			    i, split, j);
808			rej_line(ch1, i);
809			rej_line(ch2, j);
810			return;
811		}
812	}
813}
814
815/* We found where to apply it (we hope), so do it. */
816
817static void
818apply_hunk(LINENUM where)
819{
820	LINENUM		old = 1;
821	const LINENUM	lastline = pch_ptrn_lines();
822	LINENUM		new = lastline + 1;
823#define OUTSIDE 0
824#define IN_IFNDEF 1
825#define IN_IFDEF 2
826#define IN_ELSE 3
827	int		def_state = OUTSIDE;
828	const LINENUM	pat_end = pch_end();
829
830	where--;
831	while (pch_char(new) == '=' || pch_char(new) == '\n')
832		new++;
833
834	while (old <= lastline) {
835		if (pch_char(old) == '-') {
836			copy_till(where + old - 1, false);
837			if (do_defines) {
838				if (def_state == OUTSIDE) {
839					fputs(not_defined, ofp);
840					def_state = IN_IFNDEF;
841				} else if (def_state == IN_IFDEF) {
842					fputs(else_defined, ofp);
843					def_state = IN_ELSE;
844				}
845				fputs(pfetch(old), ofp);
846			}
847			last_frozen_line++;
848			old++;
849		} else if (new > pat_end) {
850			break;
851		} else if (pch_char(new) == '+') {
852			copy_till(where + old - 1, false);
853			if (do_defines) {
854				if (def_state == IN_IFNDEF) {
855					fputs(else_defined, ofp);
856					def_state = IN_ELSE;
857				} else if (def_state == OUTSIDE) {
858					fputs(if_defined, ofp);
859					def_state = IN_IFDEF;
860				}
861			}
862			fputs(pfetch(new), ofp);
863			new++;
864		} else if (pch_char(new) != pch_char(old)) {
865			say("Out-of-sync patch, lines %ld,%ld--mangled text or line numbers, maybe?\n",
866			    pch_hunk_beg() + old,
867			    pch_hunk_beg() + new);
868#ifdef DEBUGGING
869			say("oldchar = '%c', newchar = '%c'\n",
870			    pch_char(old), pch_char(new));
871#endif
872			my_exit(2);
873		} else if (pch_char(new) == '!') {
874			copy_till(where + old - 1, false);
875			if (do_defines) {
876				fputs(not_defined, ofp);
877				def_state = IN_IFNDEF;
878			}
879			while (pch_char(old) == '!') {
880				if (do_defines) {
881					fputs(pfetch(old), ofp);
882				}
883				last_frozen_line++;
884				old++;
885			}
886			if (do_defines) {
887				fputs(else_defined, ofp);
888				def_state = IN_ELSE;
889			}
890			while (pch_char(new) == '!') {
891				fputs(pfetch(new), ofp);
892				new++;
893			}
894		} else {
895			if (pch_char(new) != ' ')
896				fatal("Internal error: expected ' '\n");
897			old++;
898			new++;
899			if (do_defines && def_state != OUTSIDE) {
900				fputs(end_defined, ofp);
901				def_state = OUTSIDE;
902			}
903		}
904	}
905	if (new <= pat_end && pch_char(new) == '+') {
906		copy_till(where + old - 1, false);
907		if (do_defines) {
908			if (def_state == OUTSIDE) {
909				fputs(if_defined, ofp);
910				def_state = IN_IFDEF;
911			} else if (def_state == IN_IFNDEF) {
912				fputs(else_defined, ofp);
913				def_state = IN_ELSE;
914			}
915		}
916		while (new <= pat_end && pch_char(new) == '+') {
917			fputs(pfetch(new), ofp);
918			new++;
919		}
920	}
921	if (do_defines && def_state != OUTSIDE) {
922		fputs(end_defined, ofp);
923	}
924}
925
926/*
927 * Open the new file.
928 */
929static void
930init_output(const char *name)
931{
932	ofp = fopen(name, "w");
933	if (ofp == NULL)
934		pfatal("can't create %s", name);
935}
936
937/*
938 * Open a file to put hunks we can't locate.
939 */
940static void
941init_reject(const char *name)
942{
943	rejfp = fopen(name, "w");
944	if (rejfp == NULL)
945		pfatal("can't create %s", name);
946}
947
948/*
949 * Copy input file to output, up to wherever hunk is to be applied.
950 * If endoffile is true, treat the last line specially since it may
951 * lack a newline.
952 */
953static void
954copy_till(LINENUM lastline, bool endoffile)
955{
956	if (last_frozen_line > lastline)
957		fatal("misordered hunks! output would be garbled\n");
958	while (last_frozen_line < lastline) {
959		if (++last_frozen_line == lastline && endoffile)
960			dump_line(last_frozen_line, !last_line_missing_eol);
961		else
962			dump_line(last_frozen_line, true);
963	}
964}
965
966/*
967 * Finish copying the input file to the output file.
968 */
969static bool
970spew_output(void)
971{
972	int rv;
973
974#ifdef DEBUGGING
975	if (debug & 256)
976		say("il=%ld lfl=%ld\n", input_lines, last_frozen_line);
977#endif
978	if (input_lines)
979		copy_till(input_lines, true);	/* dump remainder of file */
980	rv = ferror(ofp) == 0 && fclose(ofp) == 0;
981	ofp = NULL;
982	return rv;
983}
984
985/*
986 * Copy one line from input to output.
987 */
988static void
989dump_line(LINENUM line, bool write_newline)
990{
991	char	*s;
992
993	s = ifetch(line, 0);
994	if (s == NULL)
995		return;
996	/* Note: string is not NUL terminated. */
997	for (; *s != '\n'; s++)
998		putc(*s, ofp);
999	if (write_newline)
1000		putc('\n', ofp);
1001}
1002
1003/*
1004 * Does the patch pattern match at line base+offset?
1005 */
1006static bool
1007patch_match(LINENUM base, LINENUM offset, LINENUM fuzz)
1008{
1009	LINENUM		pline = 1 + fuzz;
1010	LINENUM		iline;
1011	LINENUM		pat_lines = pch_ptrn_lines() - fuzz;
1012	const char	*ilineptr;
1013	const char	*plineptr;
1014	short		plinelen;
1015
1016	for (iline = base + offset + fuzz; pline <= pat_lines; pline++, iline++) {
1017		ilineptr = ifetch(iline, offset >= 0);
1018		if (ilineptr == NULL)
1019			return false;
1020		plineptr = pfetch(pline);
1021		plinelen = pch_line_len(pline);
1022		if (canonicalize) {
1023			if (!similar(ilineptr, plineptr, plinelen))
1024				return false;
1025		} else if (strnNE(ilineptr, plineptr, plinelen))
1026			return false;
1027		if (iline == input_lines) {
1028			/*
1029			 * We are looking at the last line of the file.
1030			 * If the file has no eol, the patch line should
1031			 * not have one either and vice-versa. Note that
1032			 * plinelen > 0.
1033			 */
1034			if (last_line_missing_eol) {
1035				if (plineptr[plinelen - 1] == '\n')
1036					return false;
1037			} else {
1038				if (plineptr[plinelen - 1] != '\n')
1039					return false;
1040			}
1041		}
1042	}
1043	return true;
1044}
1045
1046/*
1047 * Do two lines match with canonicalized white space?
1048 */
1049static bool
1050similar(const char *a, const char *b, int len)
1051{
1052	while (len) {
1053		if (isspace((unsigned char)*b)) {	/* whitespace (or \n) to match? */
1054			if (!isspace((unsigned char)*a))	/* no corresponding whitespace? */
1055				return false;
1056			while (len && isspace((unsigned char)*b) && *b != '\n')
1057				b++, len--;	/* skip pattern whitespace */
1058			while (isspace((unsigned char)*a) && *a != '\n')
1059				a++;	/* skip target whitespace */
1060			if (*a == '\n' || *b == '\n')
1061				return (*a == *b);	/* should end in sync */
1062		} else if (*a++ != *b++)	/* match non-whitespace chars */
1063			return false;
1064		else
1065			len--;	/* probably not necessary */
1066	}
1067	return true;		/* actually, this is not reached */
1068	/* since there is always a \n */
1069}
1070