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: pch.c,v 1.43 2014/11/18 17:03:35 tobias Exp $
27 */
28
29#include <sys/types.h>
30#include <sys/stat.h>
31
32#include <ctype.h>
33#include <libgen.h>
34#include <limits.h>
35#include <stdint.h>
36#include <stdio.h>
37#include <stdlib.h>
38#include <string.h>
39#include <unistd.h>
40
41#include "common.h"
42#include "util.h"
43#include "pch.h"
44#include "pathnames.h"
45
46/* Patch (diff listing) abstract type. */
47
48static off_t	p_filesize;	/* size of the patch file */
49static LINENUM	p_first;	/* 1st line number */
50static LINENUM	p_newfirst;	/* 1st line number of replacement */
51static LINENUM	p_ptrn_lines;	/* # lines in pattern */
52static LINENUM	p_repl_lines;	/* # lines in replacement text */
53static LINENUM	p_end = -1;	/* last line in hunk */
54static LINENUM	p_max;		/* max allowed value of p_end */
55static LINENUM	p_context = 3;	/* # of context lines */
56static LINENUM	p_input_line = 0;	/* current line # from patch file */
57static char	**p_line = NULL;/* the text of the hunk */
58static size_t	*p_len = NULL;	/* length of each line */
59static char	*p_char = NULL;	/* +, -, and ! */
60static int	hunkmax = INITHUNKMAX;	/* size of above arrays to begin with */
61static int	p_indent;	/* indent to patch */
62static off_t	p_base;		/* where to intuit this time */
63static LINENUM	p_bline;	/* line # of p_base */
64static off_t	p_start;	/* where intuit found a patch */
65static LINENUM	p_sline;	/* and the line number for it */
66static LINENUM	p_hunk_beg;	/* line number of current hunk */
67static LINENUM	p_efake = -1;	/* end of faked up lines--don't free */
68static LINENUM	p_bfake = -1;	/* beg of faked up lines */
69static FILE	*pfp = NULL;	/* patch file pointer */
70static char	*bestguess = NULL;	/* guess at correct filename */
71
72char		*source_file;
73
74static void	grow_hunkmax(void);
75static int	intuit_diff_type(void);
76static void	next_intuit_at(off_t, LINENUM);
77static void	skip_to(off_t, LINENUM);
78static size_t	pgets(bool _do_indent);
79static char	*best_name(const struct file_name *, bool);
80static char	*posix_name(const struct file_name *, bool);
81static size_t	num_components(const char *);
82static LINENUM	strtolinenum(char *, char **);
83
84/*
85 * Prepare to look for the next patch in the patch file.
86 */
87void
88re_patch(void)
89{
90	p_first = 0;
91	p_newfirst = 0;
92	p_ptrn_lines = 0;
93	p_repl_lines = 0;
94	p_end = (LINENUM) - 1;
95	p_max = 0;
96	p_indent = 0;
97}
98
99/*
100 * Open the patch file at the beginning of time.
101 */
102void
103open_patch_file(const char *filename)
104{
105	struct stat filestat;
106	int nr, nw;
107
108	if (filename == NULL || *filename == '\0' || strEQ(filename, "-")) {
109		pfp = fopen(TMPPATNAME, "w");
110		if (pfp == NULL)
111			pfatal("can't create %s", TMPPATNAME);
112		while ((nr = fread(buf, 1, buf_size, stdin)) > 0) {
113			nw = fwrite(buf, 1, nr, pfp);
114			if (nr != nw)
115				pfatal("write error to %s", TMPPATNAME);
116		}
117		if (ferror(pfp) || fclose(pfp))
118			pfatal("can't write %s", TMPPATNAME);
119		filename = TMPPATNAME;
120	}
121	pfp = fopen(filename, "r");
122	if (pfp == NULL)
123		pfatal("patch file %s not found", filename);
124	if (fstat(fileno(pfp), &filestat))
125		pfatal("can't stat %s", filename);
126	p_filesize = filestat.st_size;
127	next_intuit_at(0, 1L);	/* start at the beginning */
128	set_hunkmax();
129}
130
131/*
132 * Make sure our dynamically realloced tables are malloced to begin with.
133 */
134void
135set_hunkmax(void)
136{
137	if (p_line == NULL)
138		p_line = malloc(hunkmax * sizeof(char *));
139	if (p_len == NULL)
140		p_len = malloc(hunkmax * sizeof(size_t));
141	if (p_char == NULL)
142		p_char = malloc(hunkmax * sizeof(char));
143}
144
145/*
146 * Enlarge the arrays containing the current hunk of patch.
147 */
148static void
149grow_hunkmax(void)
150{
151	int new_hunkmax = hunkmax * 2;
152
153	if (p_line == NULL || p_len == NULL || p_char == NULL)
154		fatal("Internal memory allocation error\n");
155
156	p_line = reallocf(p_line, new_hunkmax * sizeof(char *));
157	p_len = reallocf(p_len, new_hunkmax * sizeof(size_t));
158	p_char = reallocf(p_char, new_hunkmax * sizeof(char));
159
160	if (p_line != NULL && p_len != NULL && p_char != NULL) {
161		hunkmax = new_hunkmax;
162		return;
163	}
164
165	if (!using_plan_a)
166		fatal("out of memory\n");
167	out_of_mem = true;	/* whatever is null will be allocated again */
168				/* from within plan_a(), of all places */
169}
170
171/* True if the remainder of the patch file contains a diff of some sort. */
172
173bool
174there_is_another_patch(void)
175{
176	bool exists = false;
177
178	if (p_base != 0 && p_base >= p_filesize) {
179		if (verbose)
180			say("done\n");
181		return false;
182	}
183	if (p_filesize == 0)
184		return false;
185	nonempty_patchf_seen = true;
186	if (verbose)
187		say("Hmm...");
188	diff_type = intuit_diff_type();
189	if (!diff_type) {
190		if (p_base != 0) {
191			if (verbose)
192				say("  Ignoring the trailing garbage.\ndone\n");
193		} else
194			say("  I can't seem to find a patch in there anywhere.\n");
195		return false;
196	}
197	if (verbose)
198		say("  %sooks like %s to me...\n",
199		    (p_base == 0 ? "L" : "The next patch l"),
200		    diff_type == UNI_DIFF ? "a unified diff" :
201		    diff_type == CONTEXT_DIFF ? "a context diff" :
202		diff_type == NEW_CONTEXT_DIFF ? "a new-style context diff" :
203		    diff_type == NORMAL_DIFF ? "a normal diff" :
204		    "an ed script");
205	if (p_indent && verbose)
206		say("(Patch is indented %d space%s.)\n", p_indent,
207		    p_indent == 1 ? "" : "s");
208	skip_to(p_start, p_sline);
209	while (filearg[0] == NULL) {
210		if (force || batch) {
211			say("No file to patch.  Skipping...\n");
212			filearg[0] = xstrdup(bestguess);
213			skip_rest_of_patch = true;
214			return true;
215		}
216		ask("File to patch: ");
217		if (*buf != '\n') {
218			free(bestguess);
219			bestguess = xstrdup(buf);
220			filearg[0] = fetchname(buf, &exists, 0);
221		}
222		/*
223		 * fetchname can now return buf = NULL, exists = true, to
224		 * indicate to the caller that /dev/null was specified.  Retain
225		 * previous behavior for now until this can be better evaluted.
226		 */
227		if (filearg[0] == NULL || !exists) {
228			int def_skip = *bestguess == '\0';
229			ask("No file found--skip this patch? [%c] ",
230			    def_skip  ? 'y' : 'n');
231			if (*buf == 'n' || (!def_skip && *buf != 'y'))
232				continue;
233			if (verbose)
234				say("Skipping patch...\n");
235			free(filearg[0]);
236			filearg[0] = fetchname(bestguess, &exists, 0);
237			skip_rest_of_patch = true;
238			return true;
239		}
240	}
241	return true;
242}
243
244static void
245p4_fetchname(struct file_name *name, char *str)
246{
247	char *t, *h;
248
249	/* Skip leading whitespace. */
250	while (isspace((unsigned char)*str))
251		str++;
252
253	/* Remove the file revision number. */
254	for (t = str, h = NULL; *t != '\0' && !isspace((unsigned char)*t); t++)
255		if (*t == '#')
256			h = t;
257	if (h != NULL)
258		*h = '\0';
259
260	name->path = fetchname(str, &name->exists, strippath);
261}
262
263/* Determine what kind of diff is in the remaining part of the patch file. */
264
265static int
266intuit_diff_type(void)
267{
268	off_t	this_line = 0, previous_line;
269	off_t	first_command_line = -1;
270	LINENUM	fcl_line = -1;
271	bool	last_line_was_command = false, this_is_a_command = false;
272	bool	stars_last_line = false, stars_this_line = false;
273	char	*s, *t;
274	int	indent, retval;
275	struct file_name names[MAX_FILE];
276	int	piece_of_git = 0;
277
278	memset(names, 0, sizeof(names));
279	ok_to_create_file = false;
280	fseeko(pfp, p_base, SEEK_SET);
281	p_input_line = p_bline - 1;
282	for (;;) {
283		previous_line = this_line;
284		last_line_was_command = this_is_a_command;
285		stars_last_line = stars_this_line;
286		this_line = ftello(pfp);
287		indent = 0;
288		p_input_line++;
289		if (pgets(false) == 0) {
290			if (first_command_line >= 0) {
291				/* nothing but deletes!? */
292				p_start = first_command_line;
293				p_sline = fcl_line;
294				retval = ED_DIFF;
295				goto scan_exit;
296			} else {
297				p_start = this_line;
298				p_sline = p_input_line;
299				retval = 0;
300				goto scan_exit;
301			}
302		}
303		for (s = buf; *s == ' ' || *s == '\t' || *s == 'X'; s++) {
304			if (*s == '\t')
305				indent += 8 - (indent % 8);
306			else
307				indent++;
308		}
309		for (t = s; isdigit((unsigned char)*t) || *t == ','; t++)
310			;
311		this_is_a_command = (isdigit((unsigned char)*s) &&
312		    (*t == 'd' || *t == 'c' || *t == 'a'));
313		if (first_command_line < 0 && this_is_a_command) {
314			first_command_line = this_line;
315			fcl_line = p_input_line;
316			p_indent = indent;	/* assume this for now */
317		}
318		if (!stars_last_line && strnEQ(s, "*** ", 4))
319			names[OLD_FILE].path = fetchname(s + 4,
320			    &names[OLD_FILE].exists, strippath);
321		else if (strnEQ(s, "--- ", 4)) {
322			size_t off = 4;
323			if (piece_of_git && strippath == 957 &&
324			    strnEQ(s, "--- a/", 6))
325				off = 6;
326			names[NEW_FILE].path = fetchname(s + off,
327			    &names[NEW_FILE].exists, strippath);
328		} else if (strnEQ(s, "+++ ", 4)) {
329			/* pretend it is the old name */
330			size_t off = 4;
331			if (piece_of_git && strippath == 957 &&
332			    strnEQ(s, "+++ b/", 6))
333				off = 6;
334			names[OLD_FILE].path = fetchname(s + off,
335			    &names[OLD_FILE].exists, strippath);
336		} else if (strnEQ(s, "Index:", 6))
337			names[INDEX_FILE].path = fetchname(s + 6,
338			    &names[INDEX_FILE].exists, strippath);
339		else if (strnEQ(s, "Prereq:", 7)) {
340			for (t = s + 7; isspace((unsigned char)*t); t++)
341				;
342			revision = xstrdup(t);
343			for (t = revision;
344			     *t && !isspace((unsigned char)*t); t++)
345				;
346			*t = '\0';
347			if (*revision == '\0') {
348				free(revision);
349				revision = NULL;
350			}
351		} else if (strnEQ(s, "diff --git a/", 13)) {
352			/* Git-style diffs. */
353			piece_of_git = 1;
354		} else if (strnEQ(s, "==== ", 5)) {
355			/* Perforce-style diffs. */
356			if ((t = strstr(s + 5, " - ")) != NULL)
357				p4_fetchname(&names[NEW_FILE], t + 3);
358			p4_fetchname(&names[OLD_FILE], s + 5);
359		}
360		if ((!diff_type || diff_type == ED_DIFF) &&
361		    first_command_line >= 0 &&
362		    strEQ(s, ".\n")) {
363			p_indent = indent;
364			p_start = first_command_line;
365			p_sline = fcl_line;
366			retval = ED_DIFF;
367			goto scan_exit;
368		}
369		if ((!diff_type || diff_type == UNI_DIFF) && strnEQ(s, "@@ -", 4)) {
370			if (strnEQ(s + 4, "0,0", 3))
371				ok_to_create_file = true;
372			p_indent = indent;
373			p_start = this_line;
374			p_sline = p_input_line;
375			retval = UNI_DIFF;
376			goto scan_exit;
377		}
378		stars_this_line = strnEQ(s, "********", 8);
379		if ((!diff_type || diff_type == CONTEXT_DIFF) && stars_last_line &&
380		    strnEQ(s, "*** ", 4)) {
381			if (strtolinenum(s + 4, &s) == 0)
382				ok_to_create_file = true;
383			/*
384			 * If this is a new context diff the character just
385			 * at the end of the line is a '*'.
386			 */
387			while (*s && *s != '\n')
388				s++;
389			p_indent = indent;
390			p_start = previous_line;
391			p_sline = p_input_line - 1;
392			retval = (*(s - 1) == '*' ? NEW_CONTEXT_DIFF : CONTEXT_DIFF);
393			goto scan_exit;
394		}
395		if ((!diff_type || diff_type == NORMAL_DIFF) &&
396		    last_line_was_command &&
397		    (strnEQ(s, "< ", 2) || strnEQ(s, "> ", 2))) {
398			p_start = previous_line;
399			p_sline = p_input_line - 1;
400			p_indent = indent;
401			retval = NORMAL_DIFF;
402			goto scan_exit;
403		}
404	}
405scan_exit:
406	if (retval == UNI_DIFF) {
407		/* unswap old and new */
408		struct file_name tmp = names[OLD_FILE];
409		names[OLD_FILE] = names[NEW_FILE];
410		names[NEW_FILE] = tmp;
411	}
412
413	/* Invalidated */
414	free(source_file);
415	source_file = NULL;
416
417	if (retval != 0) {
418		/*
419		 * If we've successfully determined a diff type, stored in
420		 * retval, path == NULL means _PATH_DEVNULL if exists is set.
421		 * Explicitly specify it here to make it easier to detect later
422		 * on that we're actually creating a file and not that we've
423		 * just goofed something up.
424		 */
425		if (names[OLD_FILE].path != NULL)
426			source_file = xstrdup(names[OLD_FILE].path);
427		else if (names[OLD_FILE].exists)
428			source_file = xstrdup(_PATH_DEVNULL);
429	}
430	if (filearg[0] == NULL) {
431		if (posix)
432			filearg[0] = posix_name(names, ok_to_create_file);
433		else {
434			/* Ignore the Index: name for context diffs, like GNU */
435			if (names[OLD_FILE].path != NULL ||
436			    names[NEW_FILE].path != NULL) {
437				free(names[INDEX_FILE].path);
438				names[INDEX_FILE].path = NULL;
439			}
440			filearg[0] = best_name(names, ok_to_create_file);
441		}
442	}
443
444	free(bestguess);
445	bestguess = NULL;
446	if (filearg[0] != NULL)
447		bestguess = xstrdup(filearg[0]);
448	else if (!ok_to_create_file) {
449		/*
450		 * We don't want to create a new file but we need a
451		 * filename to set bestguess.  Avoid setting filearg[0]
452		 * so the file is not created automatically.
453		 */
454		if (posix)
455			bestguess = posix_name(names, true);
456		else
457			bestguess = best_name(names, true);
458	}
459	free(names[OLD_FILE].path);
460	free(names[NEW_FILE].path);
461	free(names[INDEX_FILE].path);
462	return retval;
463}
464
465/*
466 * Remember where this patch ends so we know where to start up again.
467 */
468static void
469next_intuit_at(off_t file_pos, LINENUM file_line)
470{
471	p_base = file_pos;
472	p_bline = file_line;
473}
474
475/*
476 * Basically a verbose fseeko() to the actual diff listing.
477 */
478static void
479skip_to(off_t file_pos, LINENUM file_line)
480{
481	size_t	len;
482
483	if (p_base > file_pos)
484		fatal("Internal error: seek %lld>%lld\n",
485		   (long long)p_base, (long long)file_pos);
486	if (verbose && p_base < file_pos) {
487		fseeko(pfp, p_base, SEEK_SET);
488		say("The text leading up to this was:\n--------------------------\n");
489		while (ftello(pfp) < file_pos) {
490			len = pgets(false);
491			if (len == 0)
492				fatal("Unexpected end of file\n");
493			say("|%s", buf);
494		}
495		say("--------------------------\n");
496	} else
497		fseeko(pfp, file_pos, SEEK_SET);
498	p_input_line = file_line - 1;
499}
500
501/* Make this a function for better debugging.  */
502static void
503malformed(void)
504{
505	fatal("malformed patch at line %ld: %s", p_input_line, buf);
506	/* about as informative as "Syntax error" in C */
507}
508
509/*
510 * True if the line has been discarded (i.e. it is a line saying
511 *  "\ No newline at end of file".)
512 */
513static bool
514remove_special_line(void)
515{
516	int	c;
517
518	c = fgetc(pfp);
519	if (c == '\\') {
520		do {
521			c = fgetc(pfp);
522		} while (c != EOF && c != '\n');
523
524		return true;
525	}
526	if (c != EOF)
527		fseeko(pfp, -1, SEEK_CUR);
528
529	return false;
530}
531
532/*
533 * True if there is more of the current diff listing to process.
534 */
535bool
536another_hunk(void)
537{
538	off_t	line_beginning;			/* file pos of the current line */
539	LINENUM	repl_beginning;			/* index of --- line */
540	LINENUM	fillcnt;			/* #lines of missing ptrn or repl */
541	LINENUM	fillsrc;			/* index of first line to copy */
542	LINENUM	filldst;			/* index of first missing line */
543	bool	ptrn_spaces_eaten;		/* ptrn was slightly malformed */
544	bool	repl_could_be_missing;		/* no + or ! lines in this hunk */
545	bool	repl_missing;			/* we are now backtracking */
546	off_t	repl_backtrack_position;	/* file pos of first repl line */
547	LINENUM	repl_patch_line;		/* input line number for same */
548	LINENUM	ptrn_copiable;			/* # of copiable lines in ptrn */
549	char	*s;
550	size_t	len;
551	int	context = 0;
552
553	while (p_end >= 0) {
554		if (p_end == p_efake)
555			p_end = p_bfake;	/* don't free twice */
556		else
557			free(p_line[p_end]);
558		p_end--;
559	}
560	p_efake = -1;
561
562	p_max = hunkmax;	/* gets reduced when --- found */
563	if (diff_type == CONTEXT_DIFF || diff_type == NEW_CONTEXT_DIFF) {
564		line_beginning = ftello(pfp);
565		repl_beginning = 0;
566		fillcnt = 0;
567		fillsrc = 0;
568		filldst = 0;
569		ptrn_spaces_eaten = false;
570		repl_could_be_missing = true;
571		repl_missing = false;
572		repl_backtrack_position = 0;
573		repl_patch_line = 0;
574		ptrn_copiable = 0;
575
576		len = pgets(true);
577		p_input_line++;
578		if (len == 0 || strnNE(buf, "********", 8)) {
579			next_intuit_at(line_beginning, p_input_line);
580			return false;
581		}
582		p_context = 100;
583		p_hunk_beg = p_input_line + 1;
584		while (p_end < p_max) {
585			line_beginning = ftello(pfp);
586			len = pgets(true);
587			p_input_line++;
588			if (len == 0) {
589				if (repl_beginning && repl_could_be_missing) {
590					repl_missing = true;
591					goto hunk_done;
592				}
593				fatal("unexpected end of file in patch\n");
594			}
595			p_end++;
596			if (p_end >= hunkmax)
597				fatal("Internal error: hunk larger than hunk "
598				    "buffer size");
599			p_char[p_end] = *buf;
600			p_line[p_end] = NULL;
601			switch (*buf) {
602			case '*':
603				if (strnEQ(buf, "********", 8)) {
604					if (repl_beginning && repl_could_be_missing) {
605						repl_missing = true;
606						goto hunk_done;
607					} else
608						fatal("unexpected end of hunk "
609						    "at line %ld\n",
610						    p_input_line);
611				}
612				if (p_end != 0) {
613					if (repl_beginning && repl_could_be_missing) {
614						repl_missing = true;
615						goto hunk_done;
616					}
617					fatal("unexpected *** at line %ld: %s",
618					    p_input_line, buf);
619				}
620				context = 0;
621				p_line[p_end] = savestr(buf);
622				if (out_of_mem) {
623					p_end--;
624					return false;
625				}
626				for (s = buf;
627				     *s && !isdigit((unsigned char)*s); s++)
628					;
629				if (!*s)
630					malformed();
631				if (strnEQ(s, "0,0", 3))
632					memmove(s, s + 2, strlen(s + 2) + 1);
633				p_first = strtolinenum(s, &s);
634				if (*s == ',') {
635					for (;
636					     *s && !isdigit((unsigned char)*s); s++)
637						;
638					if (!*s)
639						malformed();
640					p_ptrn_lines = strtolinenum(s, &s) - p_first + 1;
641					if (p_ptrn_lines < 0)
642						malformed();
643				} else if (p_first)
644					p_ptrn_lines = 1;
645				else {
646					p_ptrn_lines = 0;
647					p_first = 1;
648				}
649				if (p_first >= LINENUM_MAX - p_ptrn_lines ||
650				    p_ptrn_lines >= LINENUM_MAX - 6)
651					malformed();
652
653				/* we need this much at least */
654				p_max = p_ptrn_lines + 6;
655				while (p_max >= hunkmax)
656					grow_hunkmax();
657				p_max = hunkmax;
658				break;
659			case '-':
660				if (buf[1] == '-') {
661					if (repl_beginning ||
662					    (p_end != p_ptrn_lines + 1 +
663					    (p_char[p_end - 1] == '\n'))) {
664						if (p_end == 1) {
665							/*
666							 * `old' lines were omitted;
667							 * set up to fill them in
668							 * from 'new' context lines.
669							 */
670							p_end = p_ptrn_lines + 1;
671							fillsrc = p_end + 1;
672							filldst = 1;
673							fillcnt = p_ptrn_lines;
674						} else {
675							if (repl_beginning) {
676								if (repl_could_be_missing) {
677									repl_missing = true;
678									goto hunk_done;
679								}
680								fatal("duplicate \"---\" at line %ld--check line numbers at line %ld\n",
681								    p_input_line, p_hunk_beg + repl_beginning);
682							} else {
683								fatal("%s \"---\" at line %ld--check line numbers at line %ld\n",
684								    (p_end <= p_ptrn_lines
685								    ? "Premature"
686								    : "Overdue"),
687								    p_input_line, p_hunk_beg);
688							}
689						}
690					}
691					repl_beginning = p_end;
692					repl_backtrack_position = ftello(pfp);
693					repl_patch_line = p_input_line;
694					p_line[p_end] = savestr(buf);
695					if (out_of_mem) {
696						p_end--;
697						return false;
698					}
699					p_char[p_end] = '=';
700					for (s = buf; *s && !isdigit((unsigned char)*s); s++)
701						;
702					if (!*s)
703						malformed();
704					p_newfirst = strtolinenum(s, &s);
705					if (*s == ',') {
706						for (; *s && !isdigit((unsigned char)*s); s++)
707							;
708						if (!*s)
709							malformed();
710						p_repl_lines = strtolinenum(s, &s) -
711						    p_newfirst + 1;
712						if (p_repl_lines < 0)
713							malformed();
714					} else if (p_newfirst)
715						p_repl_lines = 1;
716					else {
717						p_repl_lines = 0;
718						p_newfirst = 1;
719					}
720					if (p_newfirst >= LINENUM_MAX - p_repl_lines ||
721					    p_repl_lines >= LINENUM_MAX - p_end)
722						malformed();
723					p_max = p_repl_lines + p_end;
724					if (p_max > MAXHUNKSIZE)
725						fatal("hunk too large (%ld lines) at line %ld: %s",
726						    p_max, p_input_line, buf);
727					while (p_max >= hunkmax)
728						grow_hunkmax();
729					if (p_repl_lines != ptrn_copiable &&
730					    (p_context != 0 || p_repl_lines != 1))
731						repl_could_be_missing = false;
732					break;
733				}
734				goto change_line;
735			case '+':
736			case '!':
737				repl_could_be_missing = false;
738		change_line:
739				if (buf[1] == '\n' && canonicalize)
740					strlcpy(buf + 1, " \n", buf_size - 1);
741				if (!isspace((unsigned char)buf[1]) &&
742				    buf[1] != '>' && buf[1] != '<' &&
743				    repl_beginning && repl_could_be_missing) {
744					repl_missing = true;
745					goto hunk_done;
746				}
747				if (context >= 0) {
748					if (context < p_context)
749						p_context = context;
750					context = -1000;
751				}
752				p_line[p_end] = savestr(buf + 2);
753				if (out_of_mem) {
754					p_end--;
755					return false;
756				}
757				if (p_end == p_ptrn_lines) {
758					if (remove_special_line()) {
759						int	l;
760
761						l = strlen(p_line[p_end]) - 1;
762						(p_line[p_end])[l] = 0;
763					}
764				}
765				break;
766			case '\t':
767			case '\n':	/* assume the 2 spaces got eaten */
768				if (repl_beginning && repl_could_be_missing &&
769				    (!ptrn_spaces_eaten ||
770				    diff_type == NEW_CONTEXT_DIFF)) {
771					repl_missing = true;
772					goto hunk_done;
773				}
774				p_line[p_end] = savestr(buf);
775				if (out_of_mem) {
776					p_end--;
777					return false;
778				}
779				if (p_end != p_ptrn_lines + 1) {
780					ptrn_spaces_eaten |= (repl_beginning != 0);
781					context++;
782					if (!repl_beginning)
783						ptrn_copiable++;
784					p_char[p_end] = ' ';
785				}
786				break;
787			case ' ':
788				if (!isspace((unsigned char)buf[1]) &&
789				    repl_beginning && repl_could_be_missing) {
790					repl_missing = true;
791					goto hunk_done;
792				}
793				context++;
794				if (!repl_beginning)
795					ptrn_copiable++;
796				p_line[p_end] = savestr(buf + 2);
797				if (out_of_mem) {
798					p_end--;
799					return false;
800				}
801				break;
802			default:
803				if (repl_beginning && repl_could_be_missing) {
804					repl_missing = true;
805					goto hunk_done;
806				}
807				malformed();
808			}
809			/* set up p_len for strncmp() so we don't have to */
810			/* assume null termination */
811			if (p_line[p_end])
812				p_len[p_end] = strlen(p_line[p_end]);
813			else
814				p_len[p_end] = 0;
815		}
816
817hunk_done:
818		if (p_end >= 0 && !repl_beginning)
819			fatal("no --- found in patch at line %ld\n", pch_hunk_beg());
820
821		if (repl_missing) {
822
823			/* reset state back to just after --- */
824			p_input_line = repl_patch_line;
825			for (p_end--; p_end > repl_beginning; p_end--)
826				free(p_line[p_end]);
827			fseeko(pfp, repl_backtrack_position, SEEK_SET);
828
829			/* redundant 'new' context lines were omitted - set */
830			/* up to fill them in from the old file context */
831			if (!p_context && p_repl_lines == 1) {
832				p_repl_lines = 0;
833				p_max--;
834			}
835			fillsrc = 1;
836			filldst = repl_beginning + 1;
837			fillcnt = p_repl_lines;
838			p_end = p_max;
839		} else if (!p_context && fillcnt == 1) {
840			/* the first hunk was a null hunk with no context */
841			/* and we were expecting one line -- fix it up. */
842			while (filldst < p_end) {
843				p_line[filldst] = p_line[filldst + 1];
844				p_char[filldst] = p_char[filldst + 1];
845				p_len[filldst] = p_len[filldst + 1];
846				filldst++;
847			}
848#if 0
849			repl_beginning--;	/* this doesn't need to be fixed */
850#endif
851			p_end--;
852			p_first++;	/* do append rather than insert */
853			fillcnt = 0;
854			p_ptrn_lines = 0;
855		}
856		if (diff_type == CONTEXT_DIFF &&
857		    (fillcnt || (p_first > 1 && ptrn_copiable > 2 * p_context))) {
858			if (verbose)
859				say("%s\n%s\n%s\n",
860				    "(Fascinating--this is really a new-style context diff but without",
861				    "the telltale extra asterisks on the *** line that usually indicate",
862				    "the new style...)");
863			diff_type = NEW_CONTEXT_DIFF;
864		}
865		/* if there were omitted context lines, fill them in now */
866		if (fillcnt) {
867			p_bfake = filldst;	/* remember where not to free() */
868			p_efake = filldst + fillcnt - 1;
869			while (fillcnt-- > 0) {
870				while (fillsrc <= p_end && p_char[fillsrc] != ' ')
871					fillsrc++;
872				if (fillsrc > p_end)
873					fatal("replacement text or line numbers mangled in hunk at line %ld\n",
874					    p_hunk_beg);
875				p_line[filldst] = p_line[fillsrc];
876				p_char[filldst] = p_char[fillsrc];
877				p_len[filldst] = p_len[fillsrc];
878				fillsrc++;
879				filldst++;
880			}
881			while (fillsrc <= p_end && fillsrc != repl_beginning &&
882			    p_char[fillsrc] != ' ')
883				fillsrc++;
884#ifdef DEBUGGING
885			if (debug & 64)
886				printf("fillsrc %ld, filldst %ld, rb %ld, e+1 %ld\n",
887				fillsrc, filldst, repl_beginning, p_end + 1);
888#endif
889			if (fillsrc != p_end + 1 && fillsrc != repl_beginning)
890				malformed();
891			if (filldst != p_end + 1 && filldst != repl_beginning)
892				malformed();
893		}
894		if (p_line[p_end] != NULL) {
895			if (remove_special_line()) {
896				p_len[p_end] -= 1;
897				(p_line[p_end])[p_len[p_end]] = 0;
898			}
899		}
900	} else if (diff_type == UNI_DIFF) {
901		LINENUM	fillold;	/* index of old lines */
902		LINENUM	fillnew;	/* index of new lines */
903		char	ch;
904
905		line_beginning = ftello(pfp); /* file pos of the current line */
906		len = pgets(true);
907		p_input_line++;
908		if (len == 0 || strnNE(buf, "@@ -", 4)) {
909			next_intuit_at(line_beginning, p_input_line);
910			return false;
911		}
912		s = buf + 4;
913		if (!*s)
914			malformed();
915		p_first = strtolinenum(s, &s);
916		if (*s == ',') {
917			p_ptrn_lines = strtolinenum(s + 1, &s);
918		} else
919			p_ptrn_lines = 1;
920		if (*s == ' ')
921			s++;
922		if (*s != '+' || !*++s)
923			malformed();
924		p_newfirst = strtolinenum(s, &s);
925		if (*s == ',') {
926			p_repl_lines = strtolinenum(s + 1, &s);
927		} else
928			p_repl_lines = 1;
929		if (*s == ' ')
930			s++;
931		if (*s != '@')
932			malformed();
933		if (p_first >= LINENUM_MAX - p_ptrn_lines ||
934		    p_newfirst > LINENUM_MAX - p_repl_lines ||
935		    p_ptrn_lines >= LINENUM_MAX - p_repl_lines - 1)
936			malformed();
937		if (!p_ptrn_lines)
938			p_first++;	/* do append rather than insert */
939		p_max = p_ptrn_lines + p_repl_lines + 1;
940		while (p_max >= hunkmax)
941			grow_hunkmax();
942		fillold = 1;
943		fillnew = fillold + p_ptrn_lines;
944		p_end = fillnew + p_repl_lines;
945		snprintf(buf, buf_size, "*** %ld,%ld ****\n", p_first,
946		    p_first + p_ptrn_lines - 1);
947		p_line[0] = savestr(buf);
948		if (out_of_mem) {
949			p_end = -1;
950			return false;
951		}
952		p_char[0] = '*';
953		snprintf(buf, buf_size, "--- %ld,%ld ----\n", p_newfirst,
954		    p_newfirst + p_repl_lines - 1);
955		p_line[fillnew] = savestr(buf);
956		if (out_of_mem) {
957			p_end = 0;
958			return false;
959		}
960		p_char[fillnew++] = '=';
961		p_context = 100;
962		context = 0;
963		p_hunk_beg = p_input_line + 1;
964		while (fillold <= p_ptrn_lines || fillnew <= p_end) {
965			line_beginning = ftello(pfp);
966			len = pgets(true);
967			p_input_line++;
968			if (len == 0) {
969				if (p_max - fillnew < 3) {
970					/* assume blank lines got chopped */
971					strlcpy(buf, " \n", buf_size);
972				} else {
973					fatal("unexpected end of file in patch\n");
974				}
975			}
976			if (*buf == '\t' || *buf == '\n') {
977				ch = ' ';	/* assume the space got eaten */
978				s = savestr(buf);
979			} else {
980				ch = *buf;
981				s = savestr(buf + 1);
982			}
983			if (out_of_mem) {
984				while (--fillnew > p_ptrn_lines)
985					free(p_line[fillnew]);
986				p_end = fillold - 1;
987				return false;
988			}
989			switch (ch) {
990			case '-':
991				if (fillold > p_ptrn_lines) {
992					free(s);
993					p_end = fillnew - 1;
994					malformed();
995				}
996				p_char[fillold] = ch;
997				p_line[fillold] = s;
998				p_len[fillold++] = strlen(s);
999				if (fillold > p_ptrn_lines) {
1000					if (remove_special_line()) {
1001						p_len[fillold - 1] -= 1;
1002						s[p_len[fillold - 1]] = 0;
1003					}
1004				}
1005				break;
1006			case '=':
1007				ch = ' ';
1008				/* FALL THROUGH */
1009			case ' ':
1010				if (fillold > p_ptrn_lines) {
1011					free(s);
1012					while (--fillnew > p_ptrn_lines)
1013						free(p_line[fillnew]);
1014					p_end = fillold - 1;
1015					malformed();
1016				}
1017				context++;
1018				p_char[fillold] = ch;
1019				p_line[fillold] = s;
1020				p_len[fillold++] = strlen(s);
1021				s = savestr(s);
1022				if (out_of_mem) {
1023					while (--fillnew > p_ptrn_lines)
1024						free(p_line[fillnew]);
1025					p_end = fillold - 1;
1026					return false;
1027				}
1028				if (fillold > p_ptrn_lines) {
1029					if (remove_special_line()) {
1030						p_len[fillold - 1] -= 1;
1031						s[p_len[fillold - 1]] = 0;
1032					}
1033				}
1034				/* FALL THROUGH */
1035			case '+':
1036				if (fillnew > p_end) {
1037					free(s);
1038					while (--fillnew > p_ptrn_lines)
1039						free(p_line[fillnew]);
1040					p_end = fillold - 1;
1041					malformed();
1042				}
1043				p_char[fillnew] = ch;
1044				p_line[fillnew] = s;
1045				p_len[fillnew++] = strlen(s);
1046				if (fillold > p_ptrn_lines) {
1047					if (remove_special_line()) {
1048						p_len[fillnew - 1] -= 1;
1049						s[p_len[fillnew - 1]] = 0;
1050					}
1051				}
1052				break;
1053			default:
1054				p_end = fillnew;
1055				malformed();
1056			}
1057			if (ch != ' ' && context > 0) {
1058				if (context < p_context)
1059					p_context = context;
1060				context = -1000;
1061			}
1062		}		/* while */
1063	} else {		/* normal diff--fake it up */
1064		char	hunk_type;
1065		int	i;
1066		LINENUM	min, max;
1067
1068		line_beginning = ftello(pfp);
1069		p_context = 0;
1070		len = pgets(true);
1071		p_input_line++;
1072		if (len == 0 || !isdigit((unsigned char)*buf)) {
1073			next_intuit_at(line_beginning, p_input_line);
1074			return false;
1075		}
1076		p_first = strtolinenum(buf, &s);
1077		if (*s == ',') {
1078			p_ptrn_lines = strtolinenum(s + 1, &s) - p_first + 1;
1079			if (p_ptrn_lines < 0)
1080				malformed();
1081		} else
1082			p_ptrn_lines = (*s != 'a');
1083		hunk_type = *s;
1084		if (hunk_type == 'a')
1085			p_first++;	/* do append rather than insert */
1086		min = strtolinenum(s + 1, &s);
1087		if (*s == ',')
1088			max = strtolinenum(s + 1, &s);
1089		else
1090			max = min;
1091		if (min < 0 || min > max || max - min == LINENUM_MAX)
1092			malformed();
1093		if (hunk_type == 'd')
1094			min++;
1095		p_newfirst = min;
1096		p_repl_lines = max - min + 1;
1097		if (p_newfirst > LINENUM_MAX - p_repl_lines ||
1098		    p_ptrn_lines >= LINENUM_MAX - p_repl_lines - 1)
1099			malformed();
1100		p_end = p_ptrn_lines + p_repl_lines + 1;
1101		if (p_end > MAXHUNKSIZE)
1102			fatal("hunk too large (%ld lines) at line %ld: %s",
1103			    p_end, p_input_line, buf);
1104		while (p_end >= hunkmax)
1105			grow_hunkmax();
1106		snprintf(buf, buf_size, "*** %ld,%ld\n", p_first,
1107		    p_first + p_ptrn_lines - 1);
1108		p_line[0] = savestr(buf);
1109		if (out_of_mem) {
1110			p_end = -1;
1111			return false;
1112		}
1113		p_char[0] = '*';
1114		for (i = 1; i <= p_ptrn_lines; i++) {
1115			len = pgets(true);
1116			p_input_line++;
1117			if (len == 0)
1118				fatal("unexpected end of file in patch at line %ld\n",
1119				    p_input_line);
1120			if (*buf != '<')
1121				fatal("< expected at line %ld of patch\n",
1122				    p_input_line);
1123			p_line[i] = savestr(buf + 2);
1124			if (out_of_mem) {
1125				p_end = i - 1;
1126				return false;
1127			}
1128			p_len[i] = strlen(p_line[i]);
1129			p_char[i] = '-';
1130		}
1131
1132		if (remove_special_line()) {
1133			p_len[i - 1] -= 1;
1134			(p_line[i - 1])[p_len[i - 1]] = 0;
1135		}
1136		if (hunk_type == 'c') {
1137			len = pgets(true);
1138			p_input_line++;
1139			if (len == 0)
1140				fatal("unexpected end of file in patch at line %ld\n",
1141				    p_input_line);
1142			if (*buf != '-')
1143				fatal("--- expected at line %ld of patch\n",
1144				    p_input_line);
1145		}
1146		snprintf(buf, buf_size, "--- %ld,%ld\n", min, max);
1147		p_line[i] = savestr(buf);
1148		if (out_of_mem) {
1149			p_end = i - 1;
1150			return false;
1151		}
1152		p_char[i] = '=';
1153		for (i++; i <= p_end; i++) {
1154			len = pgets(true);
1155			p_input_line++;
1156			if (len == 0)
1157				fatal("unexpected end of file in patch at line %ld\n",
1158				    p_input_line);
1159			if (*buf != '>')
1160				fatal("> expected at line %ld of patch\n",
1161				    p_input_line);
1162			/* Don't overrun if we don't have enough line */
1163			if (len > 2)
1164				p_line[i] = savestr(buf + 2);
1165			else
1166				p_line[i] = savestr("");
1167
1168			if (out_of_mem) {
1169				p_end = i - 1;
1170				return false;
1171			}
1172			p_len[i] = strlen(p_line[i]);
1173			p_char[i] = '+';
1174		}
1175
1176		if (remove_special_line()) {
1177			p_len[i - 1] -= 1;
1178			(p_line[i - 1])[p_len[i - 1]] = 0;
1179		}
1180	}
1181	if (reverse)		/* backwards patch? */
1182		if (!pch_swap())
1183			say("Not enough memory to swap next hunk!\n");
1184#ifdef DEBUGGING
1185	if (debug & 2) {
1186		LINENUM	i;
1187		char	special;
1188
1189		for (i = 0; i <= p_end; i++) {
1190			if (i == p_ptrn_lines)
1191				special = '^';
1192			else
1193				special = ' ';
1194			fprintf(stderr, "%3ld %c %c %s", i, p_char[i],
1195			    special, p_line[i]);
1196			fflush(stderr);
1197		}
1198	}
1199#endif
1200	if (p_end + 1 < hunkmax)/* paranoia reigns supreme... */
1201		p_char[p_end + 1] = '^';	/* add a stopper for apply_hunk */
1202	return true;
1203}
1204
1205/*
1206 * Input a line from the patch file.
1207 * Worry about indentation if do_indent is true.
1208 * The line is read directly into the buf global variable which
1209 * is resized if necessary in order to hold the complete line.
1210 * Returns the number of characters read including the terminating
1211 * '\n', if any.
1212 */
1213size_t
1214pgets(bool do_indent)
1215{
1216	char *line = NULL;
1217	ssize_t len = 0;
1218	size_t buflen = 0;
1219	int indent = 0, skipped = 0;
1220
1221	if ((len = getline(&line, &buflen, pfp)) >= 0) {
1222		char *linep = line;
1223		if ((size_t)(len + 1) > buf_size) {
1224			while ((size_t)(len + 1) > buf_size)
1225				buf_size *= 2;
1226			free(buf);
1227			buf = malloc(buf_size);
1228			if (buf == NULL)
1229				fatal("out of memory\n");
1230		}
1231		if (do_indent == 1 && p_indent) {
1232			for (;
1233			    indent < p_indent && (*line == ' ' || *line == '\t' || *line == 'X');
1234			    line++, skipped++) {
1235				if (*line == '\t')
1236					indent += 8 - (indent %7);
1237				else
1238					indent++;
1239			}
1240		}
1241		memcpy(buf, line, len - skipped);
1242		buf[len - skipped] = '\0';
1243		line = linep;
1244	}
1245	free(line);
1246	return (len > 0) ? len : 0;
1247}
1248
1249
1250/*
1251 * Reverse the old and new portions of the current hunk.
1252 */
1253bool
1254pch_swap(void)
1255{
1256	char	**tp_line;	/* the text of the hunk */
1257	size_t	*tp_len;	/* length of each line */
1258	char	*tp_char;	/* +, -, and ! */
1259	LINENUM	i;
1260	LINENUM	n;
1261	bool	blankline = false;
1262	char	*s;
1263
1264	i = p_first;
1265	p_first = p_newfirst;
1266	p_newfirst = i;
1267
1268	/* make a scratch copy */
1269
1270	tp_line = p_line;
1271	tp_len = p_len;
1272	tp_char = p_char;
1273	p_line = NULL;	/* force set_hunkmax to allocate again */
1274	p_len = NULL;
1275	p_char = NULL;
1276	set_hunkmax();
1277	if (p_line == NULL || p_len == NULL || p_char == NULL) {
1278
1279		free(p_line);
1280		p_line = tp_line;
1281		free(p_len);
1282		p_len = tp_len;
1283		free(p_char);
1284		p_char = tp_char;
1285		return false;	/* not enough memory to swap hunk! */
1286	}
1287	/* now turn the new into the old */
1288
1289	i = p_ptrn_lines + 1;
1290	if (tp_char[i] == '\n') {	/* account for possible blank line */
1291		blankline = true;
1292		i++;
1293	}
1294	if (p_efake >= 0) {	/* fix non-freeable ptr range */
1295		if (p_efake <= i)
1296			n = p_end - i + 1;
1297		else
1298			n = -i;
1299		p_efake += n;
1300		p_bfake += n;
1301	}
1302	for (n = 0; i <= p_end; i++, n++) {
1303		p_line[n] = tp_line[i];
1304		p_char[n] = tp_char[i];
1305		if (p_char[n] == '+')
1306			p_char[n] = '-';
1307		p_len[n] = tp_len[i];
1308	}
1309	if (blankline) {
1310		i = p_ptrn_lines + 1;
1311		p_line[n] = tp_line[i];
1312		p_char[n] = tp_char[i];
1313		p_len[n] = tp_len[i];
1314		n++;
1315	}
1316	if (p_char[0] != '=')
1317		fatal("Malformed patch at line %ld: expected '=' found '%c'\n",
1318		    p_input_line, p_char[0]);
1319	p_char[0] = '*';
1320	for (s = p_line[0]; *s; s++)
1321		if (*s == '-')
1322			*s = '*';
1323
1324	/* now turn the old into the new */
1325
1326	if (p_char[0] != '*')
1327		fatal("Malformed patch at line %ld: expected '*' found '%c'\n",
1328		    p_input_line, p_char[0]);
1329	tp_char[0] = '=';
1330	for (s = tp_line[0]; *s; s++)
1331		if (*s == '*')
1332			*s = '-';
1333	for (i = 0; n <= p_end; i++, n++) {
1334		p_line[n] = tp_line[i];
1335		p_char[n] = tp_char[i];
1336		if (p_char[n] == '-')
1337			p_char[n] = '+';
1338		p_len[n] = tp_len[i];
1339	}
1340
1341	if (i != p_ptrn_lines + 1)
1342		fatal("Malformed patch at line %ld: expected %ld lines, "
1343		    "got %ld\n",
1344		    p_input_line, p_ptrn_lines + 1, i);
1345
1346	i = p_ptrn_lines;
1347	p_ptrn_lines = p_repl_lines;
1348	p_repl_lines = i;
1349
1350	free(tp_line);
1351	free(tp_len);
1352	free(tp_char);
1353
1354	return true;
1355}
1356
1357/*
1358 * Return the specified line position in the old file of the old context.
1359 */
1360LINENUM
1361pch_first(void)
1362{
1363	return p_first;
1364}
1365
1366/*
1367 * Return the number of lines of old context.
1368 */
1369LINENUM
1370pch_ptrn_lines(void)
1371{
1372	return p_ptrn_lines;
1373}
1374
1375/*
1376 * Return the probable line position in the new file of the first line.
1377 */
1378LINENUM
1379pch_newfirst(void)
1380{
1381	return p_newfirst;
1382}
1383
1384/*
1385 * Return the number of lines in the replacement text including context.
1386 */
1387LINENUM
1388pch_repl_lines(void)
1389{
1390	return p_repl_lines;
1391}
1392
1393/*
1394 * Return the number of lines in the whole hunk.
1395 */
1396LINENUM
1397pch_end(void)
1398{
1399	return p_end;
1400}
1401
1402/*
1403 * Return the number of context lines before the first changed line.
1404 */
1405LINENUM
1406pch_context(void)
1407{
1408	return p_context;
1409}
1410
1411/*
1412 * Return the length of a particular patch line.
1413 */
1414size_t
1415pch_line_len(LINENUM line)
1416{
1417	return p_len[line];
1418}
1419
1420/*
1421 * Return the control character (+, -, *, !, etc) for a patch line.
1422 */
1423char
1424pch_char(LINENUM line)
1425{
1426	return p_char[line];
1427}
1428
1429/*
1430 * Return a pointer to a particular patch line.
1431 */
1432char *
1433pfetch(LINENUM line)
1434{
1435	return p_line[line];
1436}
1437
1438/*
1439 * Return where in the patch file this hunk began, for error messages.
1440 */
1441LINENUM
1442pch_hunk_beg(void)
1443{
1444	return p_hunk_beg;
1445}
1446
1447/*
1448 * Apply an ed script by feeding ed itself.
1449 */
1450void
1451do_ed_script(void)
1452{
1453	char	*t;
1454	off_t	beginning_of_this_line;
1455	FILE	*pipefp = NULL;
1456	int	continuation;
1457
1458	if (!skip_rest_of_patch) {
1459		if (copy_file(filearg[0], TMPOUTNAME) < 0) {
1460			unlink(TMPOUTNAME);
1461			fatal("can't create temp file %s", TMPOUTNAME);
1462		}
1463		snprintf(buf, buf_size, "%s%s%s", _PATH_RED,
1464		    verbose ? " " : " -s ", TMPOUTNAME);
1465		pipefp = popen(buf, "w");
1466	}
1467	for (;;) {
1468		beginning_of_this_line = ftello(pfp);
1469		if (pgets(true) == 0) {
1470			next_intuit_at(beginning_of_this_line, p_input_line);
1471			break;
1472		}
1473		p_input_line++;
1474		for (t = buf; isdigit((unsigned char)*t) || *t == ','; t++)
1475			;
1476		/* POSIX defines allowed commands as {a,c,d,i,s} */
1477		if (isdigit((unsigned char)*buf) &&
1478		    (*t == 'a' || *t == 'c' || *t == 'd' || *t == 'i' || *t == 's')) {
1479			if (pipefp != NULL)
1480				fputs(buf, pipefp);
1481			if (*t == 's') {
1482				for (;;) {
1483					continuation = 0;
1484					t = strchr(buf, '\0') - 1;
1485					while (--t >= buf && *t == '\\')
1486						continuation = !continuation;
1487					if (!continuation ||
1488					    pgets(true) == 0)
1489						break;
1490					if (pipefp != NULL)
1491						fputs(buf, pipefp);
1492				}
1493			} else if (*t != 'd') {
1494				while (pgets(true)) {
1495					p_input_line++;
1496					if (pipefp != NULL)
1497						fputs(buf, pipefp);
1498					if (strEQ(buf, ".\n"))
1499						break;
1500				}
1501			}
1502		} else {
1503			next_intuit_at(beginning_of_this_line, p_input_line);
1504			break;
1505		}
1506	}
1507	if (pipefp == NULL)
1508		return;
1509	fprintf(pipefp, "w\n");
1510	fprintf(pipefp, "q\n");
1511	fflush(pipefp);
1512	pclose(pipefp);
1513	ignore_signals();
1514	if (!check_only) {
1515		if (move_file(TMPOUTNAME, outname) < 0) {
1516			toutkeep = true;
1517			chmod(TMPOUTNAME, filemode);
1518		} else
1519			chmod(outname, filemode);
1520	}
1521	set_signals(1);
1522}
1523
1524/*
1525 * Choose the name of the file to be patched based on POSIX rules.
1526 * NOTE: the POSIX rules are amazingly stupid and we only follow them
1527 *       if the user specified --posix or set POSIXLY_CORRECT.
1528 */
1529static char *
1530posix_name(const struct file_name *names, bool assume_exists)
1531{
1532	char *path = NULL;
1533	int i;
1534
1535	/*
1536	 * POSIX states that the filename will be chosen from one
1537	 * of the old, new and index names (in that order) if
1538	 * the file exists relative to CWD after -p stripping.
1539	 */
1540	for (i = 0; i < MAX_FILE; i++) {
1541		if (names[i].path != NULL && names[i].exists) {
1542			path = names[i].path;
1543			break;
1544		}
1545	}
1546	if (path == NULL && !assume_exists) {
1547		/*
1548		 * No files found, check to see if the diff could be
1549		 * creating a new file.
1550		 */
1551		if (path == NULL && ok_to_create_file &&
1552		    names[NEW_FILE].path != NULL)
1553			path = names[NEW_FILE].path;
1554	}
1555
1556	return path ? xstrdup(path) : NULL;
1557}
1558
1559static char *
1560compare_names(const struct file_name *names, bool assume_exists)
1561{
1562	size_t min_components, min_baselen, min_len, tmp;
1563	char *best = NULL;
1564	char *path;
1565	int i;
1566
1567	/*
1568	 * The "best" name is the one with the fewest number of path
1569	 * components, the shortest basename length, and the shortest
1570	 * overall length (in that order).  We only use the Index: file
1571	 * if neither of the old or new files could be intuited from
1572	 * the diff header.
1573	 */
1574	min_components = min_baselen = min_len = SIZE_MAX;
1575	for (i = INDEX_FILE; i >= OLD_FILE; i--) {
1576		path = names[i].path;
1577		if (path == NULL || (!names[i].exists && !assume_exists))
1578			continue;
1579		if ((tmp = num_components(path)) > min_components)
1580			continue;
1581		if (tmp < min_components) {
1582			min_components = tmp;
1583			best = path;
1584		}
1585		if ((tmp = strlen(basename(path))) > min_baselen)
1586			continue;
1587		if (tmp < min_baselen) {
1588			min_baselen = tmp;
1589			best = path;
1590		}
1591		if ((tmp = strlen(path)) > min_len)
1592			continue;
1593		min_len = tmp;
1594		best = path;
1595	}
1596	return best;
1597}
1598
1599/*
1600 * Choose the name of the file to be patched based the "best" one
1601 * available.
1602 */
1603static char *
1604best_name(const struct file_name *names, bool assume_exists)
1605{
1606	char *best;
1607
1608	best = compare_names(names, assume_exists);
1609
1610	/* No match?  Check to see if the diff could be creating a new file. */
1611	if (best == NULL && ok_to_create_file)
1612		best = names[NEW_FILE].path;
1613
1614	return best ? xstrdup(best) : NULL;
1615}
1616
1617static size_t
1618num_components(const char *path)
1619{
1620	size_t n;
1621	const char *cp;
1622
1623	for (n = 0, cp = path; (cp = strchr(cp, '/')) != NULL; n++) {
1624		cp++;
1625		while (*cp == '/')
1626			cp++;		/* skip consecutive slashes */
1627	}
1628	return n;
1629}
1630
1631/*
1632 * Convert number at NPTR into LINENUM and save address of first
1633 * character that is not a digit in ENDPTR.  If conversion is not
1634 * possible, call fatal.
1635 */
1636static LINENUM
1637strtolinenum(char *nptr, char **endptr)
1638{
1639	LINENUM rv;
1640	char c;
1641	char *p;
1642	const char *errstr;
1643
1644	for (p = nptr; isdigit((unsigned char)*p); p++)
1645		;
1646
1647	if (p == nptr)
1648		malformed();
1649
1650	c = *p;
1651	*p = '\0';
1652
1653	rv = strtonum(nptr, 0, LINENUM_MAX, &errstr);
1654	if (errstr != NULL)
1655		fatal("invalid line number at line %ld: `%s' is %s\n",
1656		    p_input_line, nptr, errstr);
1657
1658	*p = c;
1659	*endptr = p;
1660
1661	return rv;
1662}
1663