1/*
2 * $OpenBSD: pch.c,v 1.37 2007/09/02 15:19:33 deraadt Exp $
3 * $DragonFly: src/usr.bin/patch/pch.c,v 1.6 2008/08/10 23:35:40 joerg Exp $
4 * $NetBSD: pch.c,v 1.33 2023/06/16 23:31:53 wiz Exp $
5 */
6
7/*
8 * patch - a program to apply diffs to original files
9 *
10 * Copyright 1986, Larry Wall
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following condition is met:
14 * 1. Redistributions of source code must retain the above copyright notice,
15 * this condition and the following disclaimer.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
21 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
23 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
24 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * -C option added in 1998, original code by Marc Espie, based on FreeBSD
30 * behaviour
31 */
32
33#include <sys/cdefs.h>
34__RCSID("$NetBSD: pch.c,v 1.33 2023/06/16 23:31:53 wiz Exp $");
35
36#include <sys/types.h>
37#include <sys/stat.h>
38
39#include <ctype.h>
40#include <libgen.h>
41#include <limits.h>
42#include <stdio.h>
43#include <stdlib.h>
44#include <string.h>
45#include <unistd.h>
46
47#include "common.h"
48#include "util.h"
49#include "pch.h"
50#include "pathnames.h"
51
52/* Patch (diff listing) abstract type. */
53
54static long	p_filesize;	/* size of the patch file */
55static LINENUM	p_first;	/* 1st line number */
56static LINENUM	p_newfirst;	/* 1st line number of replacement */
57static LINENUM	p_ptrn_lines;	/* # lines in pattern */
58static LINENUM	p_repl_lines;	/* # lines in replacement text */
59static LINENUM	p_end = -1;	/* last line in hunk */
60static LINENUM	p_max;		/* max allowed value of p_end */
61static LINENUM	p_context = 3;	/* # of context lines */
62static LINENUM	p_input_line = 0;	/* current line # from patch file */
63static char	**p_line = NULL;/* the text of the hunk */
64static short	*p_len = NULL;	/* length of each line */
65static char	*p_char = NULL;	/* +, -, and ! */
66static int	hunkmax = INITHUNKMAX;	/* size of above arrays to begin with */
67static int	p_indent;	/* indent to patch */
68static LINENUM	p_base;		/* where to intuit this time */
69static LINENUM	p_bline;	/* line # of p_base */
70static LINENUM	p_start;	/* where intuit found a patch */
71static LINENUM	p_sline;	/* and the line number for it */
72static LINENUM	p_hunk_beg;	/* line number of current hunk */
73static LINENUM	p_efake = -1;	/* end of faked up lines--don't free */
74static LINENUM	p_bfake = -1;	/* beg of faked up lines */
75static FILE	*pfp = NULL;	/* patch file pointer */
76static char	*bestguess = NULL;	/* guess at correct filename */
77
78static void	grow_hunkmax(void);
79static int	intuit_diff_type(void);
80static void	next_intuit_at(LINENUM, LINENUM);
81static void	skip_to(LINENUM, LINENUM);
82static int	pgetline(char **, size_t *, FILE *);
83static char	*best_name(const struct file_name *, bool);
84static char	*posix_name(const struct file_name *, bool);
85static size_t	num_components(const char *);
86
87/*
88 * Prepare to look for the next patch in the patch file.
89 */
90void
91re_patch(void)
92{
93	p_first = 0;
94	p_newfirst = 0;
95	p_ptrn_lines = 0;
96	p_repl_lines = 0;
97	p_end = (LINENUM) - 1;
98	p_max = 0;
99	p_indent = 0;
100}
101
102/*
103 * Open the patch file at the beginning of time.
104 */
105void
106open_patch_file(const char *filename)
107{
108	struct stat filestat;
109
110	if (filename == NULL || *filename == '\0' || strEQ(filename, "-")) {
111		pfp = fopen(TMPPATNAME, "w");
112		if (pfp == NULL)
113			pfatal("can't create %s", TMPPATNAME);
114		while (getline(&buf, &bufsz, stdin) != -1)
115			fprintf(pfp, "%s", buf);
116		if (ferror(pfp) || fclose(pfp))
117			pfatal("can't write %s", TMPPATNAME);
118		filename = TMPPATNAME;
119	}
120	pfp = fopen(filename, "r");
121	if (pfp == NULL)
122		pfatal("patch file %s not found", filename);
123	fstat(fileno(pfp), &filestat);
124	p_filesize = filestat.st_size;
125	next_intuit_at(0L, 1L);	/* start at the beginning */
126	set_hunkmax();
127}
128
129/*
130 * Make sure our dynamically realloced tables are malloced to begin with.
131 */
132void
133set_hunkmax(void)
134{
135	if (p_line == NULL)
136		p_line = calloc((size_t) hunkmax, sizeof(char *));
137	if (p_len == NULL)
138		p_len = calloc((size_t) hunkmax, sizeof(short));
139	if (p_char == NULL)
140		p_char = calloc((size_t) hunkmax, sizeof(char));
141}
142
143/*
144 * Enlarge the arrays containing the current hunk of patch.
145 */
146static void
147grow_hunkmax(void)
148{
149	int		new_hunkmax;
150	char		**new_p_line;
151	short		*new_p_len;
152	char		*new_p_char;
153
154	new_hunkmax = hunkmax * 2;
155
156	if (p_line == NULL || p_len == NULL || p_char == NULL)
157		fatal("Internal memory allocation error\n");
158
159	new_p_line = pch_realloc(p_line, new_hunkmax, sizeof(char *));
160	if (new_p_line == NULL)
161		free(p_line);
162
163	new_p_len = pch_realloc(p_len, new_hunkmax, sizeof(short));
164	if (new_p_len == NULL)
165		free(p_len);
166
167	new_p_char = pch_realloc(p_char, new_hunkmax, sizeof(char));
168	if (new_p_char == NULL)
169		free(p_char);
170
171	p_char = new_p_char;
172	p_len = new_p_len;
173	p_line = new_p_line;
174
175	if (p_line != NULL && p_len != NULL && p_char != NULL) {
176		hunkmax = new_hunkmax;
177		return;
178	}
179
180	if (!using_plan_a)
181		fatal("out of memory\n");
182	out_of_mem = true;	/* whatever is null will be allocated again */
183				/* from within plan_a(), of all places */
184}
185
186/* True if the remainder of the patch file contains a diff of some sort. */
187
188bool
189there_is_another_patch(void)
190{
191	bool exists = false;
192
193	if (p_base != 0L && p_base >= p_filesize) {
194		if (verbose)
195			say("done\n");
196		return false;
197	}
198	if (verbose)
199		say("Hmm...");
200	diff_type = intuit_diff_type();
201	if (!diff_type) {
202		if (p_base != 0L) {
203			if (verbose)
204				say("  Ignoring the trailing garbage.\ndone\n");
205		} else
206			say("  I can't seem to find a patch in there anywhere.\n");
207		return false;
208	}
209	if (verbose)
210		say("  %sooks like %s to me...\n",
211		    (p_base == 0L ? "L" : "The next patch l"),
212		    diff_type == UNI_DIFF ? "a unified diff" :
213		    diff_type == CONTEXT_DIFF ? "a context diff" :
214		diff_type == NEW_CONTEXT_DIFF ? "a new-style context diff" :
215		    diff_type == NORMAL_DIFF ? "a normal diff" :
216		    "an ed script");
217	if (p_indent && verbose)
218		say("(Patch is indented %d space%s.)\n", p_indent,
219		    p_indent == 1 ? "" : "s");
220	skip_to(p_start, p_sline);
221	while (filearg[0] == NULL) {
222		if (force || batch) {
223			say("No file to patch.  Skipping...\n");
224			filearg[0] = savestr(bestguess);
225			skip_rest_of_patch = true;
226			return true;
227		}
228		ask("File to patch: ");
229		if (*buf != '\n') {
230			free(bestguess);
231			bestguess = savestr(buf);
232			filearg[0] = fetchname(buf, &exists, 0);
233		}
234		if (!exists) {
235			ask("No file found--skip this patch? [n] ");
236			if (*buf != 'y')
237				continue;
238			if (verbose)
239				say("Skipping patch...\n");
240			free(filearg[0]);
241			filearg[0] = fetchname(bestguess, &exists, 0);
242			skip_rest_of_patch = true;
243			return true;
244		}
245	}
246	return true;
247}
248
249/* Determine what kind of diff is in the remaining part of the patch file. */
250
251static int
252intuit_diff_type(void)
253{
254	long	this_line = 0, previous_line;
255	long	first_command_line = -1;
256	LINENUM	fcl_line = -1;
257	bool	last_line_was_command = false, this_is_a_command = false;
258	bool	stars_last_line = false, stars_this_line = false;
259	char	*s, *t;
260	int	indent, retval;
261	struct file_name names[MAX_FILE];
262
263	memset(names, 0, sizeof(names));
264	ok_to_create_file = false;
265	fseek(pfp, p_base, SEEK_SET);
266	p_input_line = p_bline - 1;
267	for (;;) {
268		previous_line = this_line;
269		last_line_was_command = this_is_a_command;
270		stars_last_line = stars_this_line;
271		this_line = ftell(pfp);
272		indent = 0;
273		p_input_line++;
274		if (getline(&buf, &bufsz, pfp) == -1) {
275			if (first_command_line >= 0L) {
276				/* nothing but deletes!? */
277				p_start = first_command_line;
278				p_sline = fcl_line;
279				retval = ED_DIFF;
280				goto scan_exit;
281			} else {
282				p_start = this_line;
283				p_sline = p_input_line;
284				retval = 0;
285				goto scan_exit;
286			}
287		}
288		for (s = buf; *s == ' ' || *s == '\t' || *s == 'X'; s++) {
289			if (*s == '\t')
290				indent += 8 - (indent % 8);
291			else
292				indent++;
293		}
294		for (t = s; isdigit((unsigned char)*t) || *t == ','; t++)
295			;
296		this_is_a_command = (isdigit((unsigned char)*s) &&
297		    (*t == 'd' || *t == 'c' || *t == 'a'));
298		if (first_command_line < 0L && this_is_a_command) {
299			first_command_line = this_line;
300			fcl_line = p_input_line;
301			p_indent = indent;	/* assume this for now */
302		}
303		if (!stars_last_line && strnEQ(s, "*** ", 4))
304			names[OLD_FILE].path = fetchname(s + 4,
305			    &names[OLD_FILE].exists, strippath);
306		else if (strnEQ(s, "--- ", 4))
307			names[NEW_FILE].path = fetchname(s + 4,
308			    &names[NEW_FILE].exists, strippath);
309		else if (strnEQ(s, "+++ ", 4))
310			/* pretend it is the old name */
311			names[OLD_FILE].path = fetchname(s + 4,
312			    &names[OLD_FILE].exists, strippath);
313		else if (strnEQ(s, "Index:", 6))
314			names[INDEX_FILE].path = fetchname(s + 6,
315			    &names[INDEX_FILE].exists, strippath);
316		else if (strnEQ(s, "Prereq:", 7)) {
317			for (t = s + 7; isspace((unsigned char)*t); t++)
318				;
319			revision = savestr(t);
320			for (t = revision; *t && !isspace((unsigned char)*t); t++)
321				;
322			*t = '\0';
323			if (*revision == '\0') {
324				free(revision);
325				revision = NULL;
326			}
327		}
328		if ((!diff_type || diff_type == ED_DIFF) &&
329		    first_command_line >= 0L &&
330		    strEQ(s, ".\n")) {
331			p_indent = indent;
332			p_start = first_command_line;
333			p_sline = fcl_line;
334			retval = ED_DIFF;
335			goto scan_exit;
336		}
337		if ((!diff_type || diff_type == UNI_DIFF) && strnEQ(s, "@@ -", 4)) {
338			if (strnEQ(s + 4, "0,0", 3))
339				ok_to_create_file = true;
340			p_indent = indent;
341			p_start = this_line;
342			p_sline = p_input_line;
343			retval = UNI_DIFF;
344			goto scan_exit;
345		}
346		stars_this_line = strnEQ(s, "********", 8);
347		if ((!diff_type || diff_type == CONTEXT_DIFF) && stars_last_line &&
348		    strnEQ(s, "*** ", 4)) {
349			if (atol(s + 4) == 0)
350				ok_to_create_file = true;
351			/*
352			 * If this is a new context diff the character just
353			 * before the newline is a '*'.
354			 */
355			while (*s != '\n')
356				s++;
357			p_indent = indent;
358			p_start = previous_line;
359			p_sline = p_input_line - 1;
360			retval = (*(s - 1) == '*' ? NEW_CONTEXT_DIFF : CONTEXT_DIFF);
361			goto scan_exit;
362		}
363		if ((!diff_type || diff_type == NORMAL_DIFF) &&
364		    last_line_was_command &&
365		    (strnEQ(s, "< ", 2) || strnEQ(s, "> ", 2))) {
366			p_start = previous_line;
367			p_sline = p_input_line - 1;
368			p_indent = indent;
369			retval = NORMAL_DIFF;
370			goto scan_exit;
371		}
372	}
373scan_exit:
374	if (retval == UNI_DIFF) {
375		/* unswap old and new */
376		struct file_name tmp = names[OLD_FILE];
377		names[OLD_FILE] = names[NEW_FILE];
378		names[NEW_FILE] = tmp;
379	}
380	if (filearg[0] == NULL) {
381		if (posix)
382			filearg[0] = posix_name(names, ok_to_create_file);
383		else {
384			/* Ignore the Index: name for context diffs, like GNU */
385			if (names[OLD_FILE].path != NULL ||
386			    names[NEW_FILE].path != NULL) {
387				free(names[INDEX_FILE].path);
388				names[INDEX_FILE].path = NULL;
389			}
390			filearg[0] = best_name(names, ok_to_create_file);
391		}
392	}
393
394	free(bestguess);
395	bestguess = NULL;
396	if (filearg[0] != NULL)
397		bestguess = savestr(filearg[0]);
398	else if (!ok_to_create_file) {
399		/*
400		 * We don't want to create a new file but we need a
401		 * filename to set bestguess.  Avoid setting filearg[0]
402		 * so the file is not created automatically.
403		 */
404		if (posix)
405			bestguess = posix_name(names, true);
406		else
407			bestguess = best_name(names, true);
408	}
409	free(names[OLD_FILE].path);
410	free(names[NEW_FILE].path);
411	free(names[INDEX_FILE].path);
412	return retval;
413}
414
415/*
416 * Remember where this patch ends so we know where to start up again.
417 */
418static void
419next_intuit_at(LINENUM file_pos, LINENUM file_line)
420{
421	p_base = file_pos;
422	p_bline = file_line;
423}
424
425/*
426 * Basically a verbose fseek() to the actual diff listing.
427 */
428static void
429skip_to(LINENUM file_pos, LINENUM file_line)
430{
431	int	ret;
432
433	if (p_base > file_pos)
434		fatal("Internal error: seek %ld>%ld\n", p_base, file_pos);
435	if (verbose && p_base < file_pos) {
436		fseek(pfp, p_base, SEEK_SET);
437		say("The text leading up to this was:\n--------------------------\n");
438		while (ftell(pfp) < file_pos) {
439			ret = getline(&buf, &bufsz, pfp);
440			if (ret == -1)
441				fatal("Unexpected end of file\n");
442			say("|%s", buf);
443		}
444		say("--------------------------\n");
445	} else
446		fseek(pfp, file_pos, SEEK_SET);
447	p_input_line = file_line - 1;
448}
449
450/* Make this a function for better debugging.  */
451__dead static void
452malformed(void)
453{
454	fatal("malformed patch at line %ld: %s", p_input_line, buf);
455	/* about as informative as "Syntax error" in C */
456}
457
458static LINENUM
459getlinenum(const char *s)
460{
461	LINENUM l = (LINENUM)atol(s);
462	if (l < 0) {
463		l = 0;
464		malformed();
465	}
466	return l;
467}
468
469static LINENUM
470getskiplinenum(char **p)
471{
472	char *s = *p;
473	LINENUM l = getlinenum(s);
474	while (isdigit((unsigned char)*s))
475		s++;
476	*p = s;
477	return l;
478}
479
480/*
481 * True if the line has been discarded (i.e., it is a line saying
482 *  "\ No newline at end of file".)
483 */
484static bool
485remove_special_line(void)
486{
487	int	c;
488
489	c = fgetc(pfp);
490	if (c == '\\') {
491		do {
492			c = fgetc(pfp);
493		} while (c != EOF && c != '\n');
494
495		return true;
496	}
497	if (c != EOF)
498		fseek(pfp, -1L, SEEK_CUR);
499
500	return false;
501}
502
503/*
504 * True if there is more of the current diff listing to process.
505 */
506bool
507another_hunk(void)
508{
509	long	line_beginning;			/* file pos of the current line */
510	LINENUM	repl_beginning;			/* index of --- line */
511	LINENUM	fillcnt;			/* #lines of missing ptrn or repl */
512	LINENUM	fillsrc;			/* index of first line to copy */
513	LINENUM	filldst;			/* index of first missing line */
514	bool	ptrn_spaces_eaten;		/* ptrn was slightly misformed */
515	bool	repl_could_be_missing;		/* no + or ! lines in this hunk */
516	bool	repl_missing;			/* we are now backtracking */
517	long	repl_backtrack_position;	/* file pos of first repl line */
518	LINENUM	repl_patch_line;		/* input line number for same */
519	LINENUM	ptrn_copiable;			/* # of copiable lines in ptrn */
520	char	*s;
521	int	context = 0;
522	int	ret;
523
524	while (p_end >= 0) {
525		if (p_end == p_efake)
526			p_end = p_bfake;	/* don't free twice */
527		else
528			free(p_line[p_end]);
529		p_end--;
530	}
531	p_efake = -1;
532
533	p_max = hunkmax;	/* gets reduced when --- found */
534	if (diff_type == CONTEXT_DIFF || diff_type == NEW_CONTEXT_DIFF) {
535		line_beginning = ftell(pfp);
536		repl_beginning = 0;
537		fillcnt = 0;
538		fillsrc = 0;
539		filldst = 0;
540		ptrn_spaces_eaten = false;
541		repl_could_be_missing = true;
542		repl_missing = false;
543		repl_backtrack_position = 0;
544		repl_patch_line = 0;
545		ptrn_copiable = 0;
546
547		ret = pgetline(&buf, &bufsz, pfp);
548		p_input_line++;
549		if (ret == -1 || strnNE(buf, "********", 8)) {
550			next_intuit_at(line_beginning, p_input_line);
551			return false;
552		}
553		p_context = 100;
554		p_hunk_beg = p_input_line + 1;
555		while (p_end < p_max) {
556			// line_beginning = ftell(pfp);
557			ret = pgetline(&buf, &bufsz, pfp);
558			p_input_line++;
559			if (ret == -1) {
560				if (repl_beginning && repl_could_be_missing) {
561					repl_missing = true;
562					goto hunk_done;
563				}
564				fatal("unexpected end of file in patch\n");
565			}
566			p_end++;
567			if (p_end >= hunkmax)
568				fatal("Internal error: hunk larger than hunk "
569				    "buffer size");
570			p_char[p_end] = *buf;
571			p_line[p_end] = NULL;
572			switch (*buf) {
573			case '*':
574				if (strnEQ(buf, "********", 8)) {
575					if (repl_beginning && repl_could_be_missing) {
576						repl_missing = true;
577						goto hunk_done;
578					} else
579						fatal("unexpected end of hunk "
580						    "at line %ld\n",
581						    p_input_line);
582				}
583				if (p_end != 0) {
584					if (repl_beginning && repl_could_be_missing) {
585						repl_missing = true;
586						goto hunk_done;
587					}
588					fatal("unexpected *** at line %ld: %s",
589					    p_input_line, buf);
590				}
591				context = 0;
592				p_line[p_end] = savestr(buf);
593				if (out_of_mem) {
594					p_end--;
595					return false;
596				}
597				for (s = buf; *s && !isdigit((unsigned char)*s); s++)
598					;
599				if (!*s)
600					malformed();
601				if (strnEQ(s, "0,0", 3))
602					memmove(s, s + 2, strlen(s + 2) + 1);
603				p_first = getskiplinenum(&s);
604				if (*s == ',') {
605					for (; *s && !isdigit((unsigned char)*s); s++)
606						;
607					if (!*s)
608						malformed();
609					p_ptrn_lines = (getlinenum(s)) - p_first + 1;
610					if (p_ptrn_lines < 0)
611						malformed();
612				} else if (p_first)
613					p_ptrn_lines = 1;
614				else {
615					p_ptrn_lines = 0;
616					p_first = 1;
617				}
618				if (p_first >= LINENUM_MAX - p_ptrn_lines ||
619				    p_ptrn_lines >= LINENUM_MAX - 6)
620					malformed();
621
622				/* we need this much at least */
623				p_max = p_ptrn_lines + 6;
624				while (p_max >= hunkmax)
625					grow_hunkmax();
626				p_max = hunkmax;
627				break;
628			case '-':
629				if (buf[1] == '-') {
630					if (repl_beginning ||
631					    (p_end != p_ptrn_lines + 1 +
632					    (p_char[p_end - 1] == '\n'))) {
633						if (p_end == 1) {
634							/*
635							 * `old' lines were omitted;
636							 * set up to fill them in
637							 * from 'new' context lines.
638							 */
639							p_end = p_ptrn_lines + 1;
640							fillsrc = p_end + 1;
641							filldst = 1;
642							fillcnt = p_ptrn_lines;
643						} else {
644							if (repl_beginning) {
645								if (repl_could_be_missing) {
646									repl_missing = true;
647									goto hunk_done;
648								}
649								fatal("duplicate \"---\" at line %ld--check line numbers at line %ld\n",
650								    p_input_line, p_hunk_beg + repl_beginning);
651							} else {
652								fatal("%s \"---\" at line %ld--check line numbers at line %ld\n",
653								    (p_end <= p_ptrn_lines
654								    ? "Premature"
655								    : "Overdue"),
656								    p_input_line, p_hunk_beg);
657							}
658						}
659					}
660					repl_beginning = p_end;
661					repl_backtrack_position = ftell(pfp);
662					repl_patch_line = p_input_line;
663					p_line[p_end] = savestr(buf);
664					if (out_of_mem) {
665						p_end--;
666						return false;
667					}
668					p_char[p_end] = '=';
669					for (s = buf; *s && !isdigit((unsigned char)*s); s++)
670						;
671					if (!*s)
672						malformed();
673					p_newfirst = getskiplinenum(&s);
674					if (*s == ',') {
675						for (; *s && !isdigit((unsigned char)*s); s++)
676							;
677						if (!*s)
678							malformed();
679						p_repl_lines = (getlinenum(s)) -
680						    p_newfirst + 1;
681						if (p_repl_lines < 0)
682							malformed();
683					} else if (p_newfirst)
684						p_repl_lines = 1;
685					else {
686						p_repl_lines = 0;
687						p_newfirst = 1;
688					}
689					if (p_newfirst >= LINENUM_MAX - p_repl_lines ||
690					    p_repl_lines >= LINENUM_MAX - p_end)
691						malformed();
692					p_max = p_repl_lines + p_end;
693					if (p_max > MAXHUNKSIZE)
694						fatal("hunk too large (%ld lines) at line %ld: %s",
695						    p_max, p_input_line, buf);
696					while (p_max >= hunkmax)
697						grow_hunkmax();
698					if (p_repl_lines != ptrn_copiable &&
699					    (p_context != 0 || p_repl_lines != 1))
700						repl_could_be_missing = false;
701					break;
702				}
703				goto change_line;
704			case '+':
705			case '!':
706				repl_could_be_missing = false;
707		change_line:
708				if (buf[1] == '\n' && canonicalize)
709					strlcpy(buf + 1, " \n", bufsz - 1);
710				if (!isspace((unsigned char)buf[1]) && buf[1] != '>' &&
711				    buf[1] != '<' &&
712				    repl_beginning && repl_could_be_missing) {
713					repl_missing = true;
714					goto hunk_done;
715				}
716				if (context >= 0) {
717					if (context < p_context)
718						p_context = context;
719					context = -1000;
720				}
721				p_line[p_end] = savestr(buf + 2);
722				if (out_of_mem) {
723					p_end--;
724					return false;
725				}
726				if (p_end == p_ptrn_lines) {
727					if (remove_special_line()) {
728						int	len;
729
730						len = strlen(p_line[p_end]) - 1;
731						(p_line[p_end])[len] = 0;
732					}
733				}
734				break;
735			case '\t':
736			case '\n':	/* assume the 2 spaces got eaten */
737				if (repl_beginning && repl_could_be_missing &&
738				    (!ptrn_spaces_eaten ||
739				    diff_type == NEW_CONTEXT_DIFF)) {
740					repl_missing = true;
741					goto hunk_done;
742				}
743				p_line[p_end] = savestr(buf);
744				if (out_of_mem) {
745					p_end--;
746					return false;
747				}
748				if (p_end != p_ptrn_lines + 1) {
749					ptrn_spaces_eaten |= (repl_beginning != 0);
750					context++;
751					if (!repl_beginning)
752						ptrn_copiable++;
753					p_char[p_end] = ' ';
754				}
755				break;
756			case ' ':
757				if (!isspace((unsigned char)buf[1]) &&
758				    repl_beginning && repl_could_be_missing) {
759					repl_missing = true;
760					goto hunk_done;
761				}
762				context++;
763				if (!repl_beginning)
764					ptrn_copiable++;
765				p_line[p_end] = savestr(buf + 2);
766				if (out_of_mem) {
767					p_end--;
768					return false;
769				}
770				break;
771			default:
772				if (repl_beginning && repl_could_be_missing) {
773					repl_missing = true;
774					goto hunk_done;
775				}
776				malformed();
777			}
778			/* set up p_len for strncmp() so we don't have to */
779			/* assume null termination */
780			if (p_line[p_end])
781				p_len[p_end] = strlen(p_line[p_end]);
782			else
783				p_len[p_end] = 0;
784		}
785
786hunk_done:
787		if (p_end >= 0 && !repl_beginning)
788			fatal("no --- found in patch at line %ld\n", pch_hunk_beg());
789
790		if (repl_missing) {
791
792			/* reset state back to just after --- */
793			p_input_line = repl_patch_line;
794			for (p_end--; p_end > repl_beginning; p_end--)
795				free(p_line[p_end]);
796			fseek(pfp, repl_backtrack_position, SEEK_SET);
797
798			/* redundant 'new' context lines were omitted - set */
799			/* up to fill them in from the old file context */
800			if (!p_context && p_repl_lines == 1) {
801				p_repl_lines = 0;
802				p_max--;
803			}
804			fillsrc = 1;
805			filldst = repl_beginning + 1;
806			fillcnt = p_repl_lines;
807			p_end = p_max;
808		} else if (!p_context && fillcnt == 1) {
809			/* the first hunk was a null hunk with no context */
810			/* and we were expecting one line -- fix it up. */
811			while (filldst < p_end) {
812				p_line[filldst] = p_line[filldst + 1];
813				p_char[filldst] = p_char[filldst + 1];
814				p_len[filldst] = p_len[filldst + 1];
815				filldst++;
816			}
817#if 0
818			repl_beginning--;	/* this doesn't need to be fixed */
819#endif
820			p_end--;
821			p_first++;	/* do append rather than insert */
822			fillcnt = 0;
823			p_ptrn_lines = 0;
824		}
825		if (diff_type == CONTEXT_DIFF &&
826		    (fillcnt || (p_first > 1 && ptrn_copiable > 2 * p_context))) {
827			if (verbose)
828				say("%s\n%s\n%s\n",
829				    "(Fascinating--this is really a new-style context diff but without",
830				    "the telltale extra asterisks on the *** line that usually indicate",
831				    "the new style...)");
832			diff_type = NEW_CONTEXT_DIFF;
833		}
834		/* if there were omitted context lines, fill them in now */
835		if (fillcnt) {
836			p_bfake = filldst;	/* remember where not to free() */
837			p_efake = filldst + fillcnt - 1;
838			while (fillcnt-- > 0) {
839				while (fillsrc <= p_end && p_char[fillsrc] != ' ')
840					fillsrc++;
841				if (fillsrc > p_end)
842					fatal("replacement text or line numbers mangled in hunk at line %ld\n",
843					    p_hunk_beg);
844				p_line[filldst] = p_line[fillsrc];
845				p_char[filldst] = p_char[fillsrc];
846				p_len[filldst] = p_len[fillsrc];
847				fillsrc++;
848				filldst++;
849			}
850			while (fillsrc <= p_end && fillsrc != repl_beginning &&
851			    p_char[fillsrc] != ' ')
852				fillsrc++;
853#ifdef DEBUGGING
854			if (debug & 64)
855				printf("fillsrc %ld, filldst %ld, rb %ld, e+1 %ld\n",
856				fillsrc, filldst, repl_beginning, p_end + 1);
857#endif
858			if (fillsrc != p_end + 1 && fillsrc != repl_beginning)
859				malformed();
860			if (filldst != p_end + 1 && filldst != repl_beginning)
861				malformed();
862		}
863		if (p_line[p_end] != NULL) {
864			if (remove_special_line()) {
865				p_len[p_end] -= 1;
866				(p_line[p_end])[p_len[p_end]] = 0;
867			}
868		}
869	} else if (diff_type == UNI_DIFF) {
870		LINENUM	fillold;	/* index of old lines */
871		LINENUM	fillnew;	/* index of new lines */
872		char	ch;
873
874		line_beginning = ftell(pfp); /* file pos of the current line */
875		ret = pgetline(&buf, &bufsz, pfp);
876		p_input_line++;
877		if (ret == -1 || strnNE(buf, "@@ -", 4)) {
878			next_intuit_at(line_beginning, p_input_line);
879			return false;
880		}
881		s = buf + 4;
882		if (!*s)
883			malformed();
884		p_first = getskiplinenum(&s);
885		if (*s == ',') {
886			s++;
887			p_ptrn_lines = getskiplinenum(&s);
888		} else
889			p_ptrn_lines = 1;
890		if (p_first >= LINENUM_MAX - p_ptrn_lines)
891			malformed();
892		if (*s == ' ')
893			s++;
894		if (*s != '+' || !*++s)
895			malformed();
896		p_newfirst = getskiplinenum(&s);
897		if (*s == ',') {
898			s++;
899			p_repl_lines = getskiplinenum(&s);
900		} else
901			p_repl_lines = 1;
902		if (*s == ' ')
903			s++;
904		if (*s != '@')
905			malformed();
906		if (p_first >= LINENUM_MAX - p_ptrn_lines ||
907		    p_newfirst > LINENUM_MAX - p_repl_lines ||
908		    p_ptrn_lines >= LINENUM_MAX - p_repl_lines - 1)
909			malformed();
910		if (!p_ptrn_lines)
911			p_first++;	/* do append rather than insert */
912		p_max = p_ptrn_lines + p_repl_lines + 1;
913		while (p_max >= hunkmax)
914			grow_hunkmax();
915		fillold = 1;
916		fillnew = fillold + p_ptrn_lines;
917		p_end = fillnew + p_repl_lines;
918		snprintf(buf, bufsz, "*** %ld,%ld ****\n", p_first,
919		    p_first + p_ptrn_lines - 1);
920		p_line[0] = savestr(buf);
921		if (out_of_mem) {
922			p_end = -1;
923			return false;
924		}
925		p_char[0] = '*';
926		snprintf(buf, bufsz, "--- %ld,%ld ----\n", p_newfirst,
927		    p_newfirst + p_repl_lines - 1);
928		p_line[fillnew] = savestr(buf);
929		if (out_of_mem) {
930			p_end = 0;
931			return false;
932		}
933		p_char[fillnew++] = '=';
934		p_context = 100;
935		context = 0;
936		p_hunk_beg = p_input_line + 1;
937		while (fillold <= p_ptrn_lines || fillnew <= p_end) {
938			// line_beginning = ftell(pfp);
939			ret = pgetline(&buf, &bufsz, pfp);
940			p_input_line++;
941			if (ret == -1) {
942				if (p_max - fillnew < 3) {
943					/* assume blank lines got chopped */
944					strlcpy(buf, " \n", bufsz);
945				} else {
946					fatal("unexpected end of file in patch\n");
947				}
948			}
949			if (*buf == '\t' || *buf == '\n') {
950				ch = ' ';	/* assume the space got eaten */
951				s = savestr(buf);
952			} else {
953				ch = *buf;
954				s = savestr(buf + 1);
955			}
956			if (out_of_mem) {
957				while (--fillnew > p_ptrn_lines)
958					free(p_line[fillnew]);
959				p_end = fillold - 1;
960				return false;
961			}
962			switch (ch) {
963			case '-':
964				if (fillold > p_ptrn_lines) {
965					free(s);
966					p_end = fillnew - 1;
967					malformed();
968				}
969				p_char[fillold] = ch;
970				p_line[fillold] = s;
971				p_len[fillold++] = strlen(s);
972				if (fillold > p_ptrn_lines) {
973					if (remove_special_line()) {
974						p_len[fillold - 1] -= 1;
975						s[p_len[fillold - 1]] = 0;
976					}
977				}
978				break;
979			case '=':
980				ch = ' ';
981				/* FALL THROUGH */
982			case ' ':
983				if (fillold > p_ptrn_lines) {
984					free(s);
985					while (--fillnew > p_ptrn_lines)
986						free(p_line[fillnew]);
987					p_end = fillold - 1;
988					malformed();
989				}
990				context++;
991				p_char[fillold] = ch;
992				p_line[fillold] = s;
993				p_len[fillold++] = strlen(s);
994				s = savestr(s);
995				if (out_of_mem) {
996					while (--fillnew > p_ptrn_lines)
997						free(p_line[fillnew]);
998					p_end = fillold - 1;
999					return false;
1000				}
1001				if (fillold > p_ptrn_lines) {
1002					if (remove_special_line()) {
1003						p_len[fillold - 1] -= 1;
1004						s[p_len[fillold - 1]] = 0;
1005					}
1006				}
1007				/* FALL THROUGH */
1008			case '+':
1009				if (fillnew > p_end) {
1010					free(s);
1011					while (--fillnew > p_ptrn_lines)
1012						free(p_line[fillnew]);
1013					p_end = fillold - 1;
1014					malformed();
1015				}
1016				p_char[fillnew] = ch;
1017				p_line[fillnew] = s;
1018				p_len[fillnew++] = strlen(s);
1019				if (fillold > p_ptrn_lines) {
1020					if (remove_special_line()) {
1021						p_len[fillnew - 1] -= 1;
1022						s[p_len[fillnew - 1]] = 0;
1023					}
1024				}
1025				break;
1026			default:
1027				p_end = fillnew;
1028				malformed();
1029			}
1030			if (ch != ' ' && context > 0) {
1031				if (context < p_context)
1032					p_context = context;
1033				context = -1000;
1034			}
1035		}		/* while */
1036	} else {		/* normal diff--fake it up */
1037		char	hunk_type;
1038		int	i;
1039		LINENUM	min, max;
1040
1041		line_beginning = ftell(pfp);
1042		p_context = 0;
1043		ret = pgetline(&buf, &bufsz, pfp);
1044		p_input_line++;
1045		if (ret == -1 || !isdigit((unsigned char)*buf)) {
1046			next_intuit_at(line_beginning, p_input_line);
1047			return false;
1048		}
1049		s = buf;
1050		p_first = getskiplinenum(&s);
1051		if (*s == ',') {
1052			s++;
1053			p_ptrn_lines = getskiplinenum(&s) - p_first + 1;
1054		} else
1055			p_ptrn_lines = (*s != 'a');
1056		if (p_first >= LINENUM_MAX - p_ptrn_lines)
1057			malformed();
1058		hunk_type = *s++;
1059		if (hunk_type == 'a')
1060			p_first++;	/* do append rather than insert */
1061		min = getskiplinenum(&s);
1062		if (*s == ',')
1063			max = getlinenum(++s);
1064		else
1065			max = min;
1066		if (min < 0 || min > max || max - min == LINENUM_MAX)
1067			malformed();
1068		if (hunk_type == 'd')
1069			min++;
1070		p_end = p_ptrn_lines + 1 + max - min + 1;
1071		p_newfirst = min;
1072		p_repl_lines = max - min + 1;
1073		if (p_newfirst > LINENUM_MAX - p_repl_lines ||
1074		    p_ptrn_lines >= LINENUM_MAX - p_repl_lines - 1)
1075			malformed();
1076		p_end = p_ptrn_lines + p_repl_lines + 1;
1077		if (p_end > MAXHUNKSIZE)
1078			fatal("hunk too large (%ld lines) at line %ld: %s",
1079			    p_end, p_input_line, buf);
1080		while (p_end >= hunkmax)
1081			grow_hunkmax();
1082		snprintf(buf, bufsz, "*** %ld,%ld\n", p_first,
1083		    p_first + p_ptrn_lines - 1);
1084		p_line[0] = savestr(buf);
1085		if (out_of_mem) {
1086			p_end = -1;
1087			return false;
1088		}
1089		p_char[0] = '*';
1090		for (i = 1; i <= p_ptrn_lines; i++) {
1091			ret = pgetline(&buf, &bufsz, pfp);
1092			p_input_line++;
1093			if (ret == -1)
1094				fatal("unexpected end of file in patch at line %ld\n",
1095				    p_input_line);
1096			if (*buf != '<')
1097				fatal("< expected at line %ld of patch\n",
1098				    p_input_line);
1099			p_line[i] = savestr(buf + 2);
1100			if (out_of_mem) {
1101				p_end = i - 1;
1102				return false;
1103			}
1104			p_len[i] = strlen(p_line[i]);
1105			p_char[i] = '-';
1106		}
1107
1108		if (remove_special_line()) {
1109			p_len[i - 1] -= 1;
1110			(p_line[i - 1])[p_len[i - 1]] = 0;
1111		}
1112		if (hunk_type == 'c') {
1113			ret = pgetline(&buf, &bufsz, pfp);
1114			p_input_line++;
1115			if (ret == -1)
1116				fatal("unexpected end of file in patch at line %ld\n",
1117				    p_input_line);
1118			if (*buf != '-')
1119				fatal("--- expected at line %ld of patch\n",
1120				    p_input_line);
1121		}
1122		snprintf(buf, bufsz, "--- %ld,%ld\n", min, max);
1123		p_line[i] = savestr(buf);
1124		if (out_of_mem) {
1125			p_end = i - 1;
1126			return false;
1127		}
1128		p_char[i] = '=';
1129		for (i++; i <= p_end; i++) {
1130			ret = pgetline(&buf, &bufsz, pfp);
1131			p_input_line++;
1132			if (ret == -1)
1133				fatal("unexpected end of file in patch at line %ld\n",
1134				    p_input_line);
1135			if (*buf != '>')
1136				fatal("> expected at line %ld of patch\n",
1137				    p_input_line);
1138			p_line[i] = savestr(buf + 2);
1139			if (out_of_mem) {
1140				p_end = i - 1;
1141				return false;
1142			}
1143			p_len[i] = strlen(p_line[i]);
1144			p_char[i] = '+';
1145		}
1146
1147		if (remove_special_line()) {
1148			p_len[i - 1] -= 1;
1149			(p_line[i - 1])[p_len[i - 1]] = 0;
1150		}
1151	}
1152	if (reverse)		/* backwards patch? */
1153		if (!pch_swap())
1154			say("Not enough memory to swap next hunk!\n");
1155#ifdef DEBUGGING
1156	if (debug & 2) {
1157		int	i;
1158		char	special;
1159
1160		for (i = 0; i <= p_end; i++) {
1161			if (i == p_ptrn_lines)
1162				special = '^';
1163			else
1164				special = ' ';
1165			fprintf(stderr, "%3d %c %c %s", i, p_char[i],
1166			    special, p_line[i]);
1167			fflush(stderr);
1168		}
1169	}
1170#endif
1171	if (p_end + 1 < hunkmax)/* paranoia reigns supreme... */
1172		p_char[p_end + 1] = '^';	/* add a stopper for apply_hunk */
1173	return true;
1174}
1175
1176/*
1177 * Input a line from the patch file, worrying about indentation.
1178 */
1179int
1180pgetline(char **bf, size_t *sz, FILE *fp)
1181{
1182	char	*s;
1183	int	indent = 0;
1184	int	ret;
1185
1186	ret = getline(bf, sz, fp);
1187
1188	if (p_indent && ret != -1) {
1189		for (s = buf;
1190		    indent < p_indent && (*s == ' ' || *s == '\t' || *s == 'X');
1191		    s++) {
1192			if (*s == '\t')
1193				indent += 8 - (indent % 7);
1194			else
1195				indent++;
1196		}
1197		if (buf != s && strlcpy(buf, s, bufsz) >= bufsz)
1198			fatal("buffer too small in pgetline()\n");
1199	}
1200	return ret;
1201}
1202
1203/*
1204 * Reverse the old and new portions of the current hunk.
1205 */
1206bool
1207pch_swap(void)
1208{
1209	char	**tp_line;	/* the text of the hunk */
1210	short	*tp_len;	/* length of each line */
1211	char	*tp_char;	/* +, -, and ! */
1212	LINENUM	i;
1213	LINENUM	n;
1214	bool	blankline = false;
1215	char	*s;
1216
1217	i = p_first;
1218	p_first = p_newfirst;
1219	p_newfirst = i;
1220
1221	/* make a scratch copy */
1222
1223	tp_line = p_line;
1224	tp_len = p_len;
1225	tp_char = p_char;
1226	p_line = NULL;	/* force set_hunkmax to allocate again */
1227	p_len = NULL;
1228	p_char = NULL;
1229	set_hunkmax();
1230	if (p_line == NULL || p_len == NULL || p_char == NULL) {
1231
1232		free(p_line);
1233		p_line = tp_line;
1234		free(p_len);
1235		p_len = tp_len;
1236		free(p_char);
1237		p_char = tp_char;
1238		return false;	/* not enough memory to swap hunk! */
1239	}
1240	/* now turn the new into the old */
1241
1242	i = p_ptrn_lines + 1;
1243	if (tp_char[i] == '\n') {	/* account for possible blank line */
1244		blankline = true;
1245		i++;
1246	}
1247	if (p_efake >= 0) {	/* fix non-freeable ptr range */
1248		if (p_efake <= i)
1249			n = p_end - i + 1;
1250		else
1251			n = -i;
1252		p_efake += n;
1253		p_bfake += n;
1254	}
1255	for (n = 0; i <= p_end; i++, n++) {
1256		p_line[n] = tp_line[i];
1257		p_char[n] = tp_char[i];
1258		if (p_char[n] == '+')
1259			p_char[n] = '-';
1260		p_len[n] = tp_len[i];
1261	}
1262	if (blankline) {
1263		i = p_ptrn_lines + 1;
1264		p_line[n] = tp_line[i];
1265		p_char[n] = tp_char[i];
1266		p_len[n] = tp_len[i];
1267		n++;
1268	}
1269	if (p_char[0] != '=')
1270		fatal("Malformed patch at line %ld: expected '=' found '%c'\n",
1271		    p_input_line, p_char[0]);
1272	p_char[0] = '*';
1273	for (s = p_line[0]; *s; s++)
1274		if (*s == '-')
1275			*s = '*';
1276
1277	/* now turn the old into the new */
1278
1279	if (p_char[0] != '*')
1280		fatal("Malformed patch at line %ld: expected '*' found '%c'\n",
1281		    p_input_line, p_char[0]);
1282	tp_char[0] = '=';
1283	for (s = tp_line[0]; *s; s++)
1284		if (*s == '*')
1285			*s = '-';
1286	for (i = 0; n <= p_end; i++, n++) {
1287		p_line[n] = tp_line[i];
1288		p_char[n] = tp_char[i];
1289		if (p_char[n] == '-')
1290			p_char[n] = '+';
1291		p_len[n] = tp_len[i];
1292	}
1293
1294	if (i != p_ptrn_lines + 1)
1295		fatal("Malformed patch at line %ld: expected %ld lines, "
1296		    "got %ld\n",
1297		    p_input_line, p_ptrn_lines + 1, i);
1298
1299	i = p_ptrn_lines;
1300	p_ptrn_lines = p_repl_lines;
1301	p_repl_lines = i;
1302
1303	free(tp_line);
1304	free(tp_len);
1305	free(tp_char);
1306
1307	return true;
1308}
1309
1310/*
1311 * Return the specified line position in the old file of the old context.
1312 */
1313LINENUM
1314pch_first(void)
1315{
1316	return p_first;
1317}
1318
1319/*
1320 * Return the number of lines of old context.
1321 */
1322LINENUM
1323pch_ptrn_lines(void)
1324{
1325	return p_ptrn_lines;
1326}
1327
1328/*
1329 * Return the probable line position in the new file of the first line.
1330 */
1331LINENUM
1332pch_newfirst(void)
1333{
1334	return p_newfirst;
1335}
1336
1337/*
1338 * Return the number of lines in the replacement text including context.
1339 */
1340LINENUM
1341pch_repl_lines(void)
1342{
1343	return p_repl_lines;
1344}
1345
1346/*
1347 * Return the number of lines in the whole hunk.
1348 */
1349LINENUM
1350pch_end(void)
1351{
1352	return p_end;
1353}
1354
1355/*
1356 * Return the number of context lines before the first changed line.
1357 */
1358LINENUM
1359pch_context(void)
1360{
1361	return p_context;
1362}
1363
1364/*
1365 * Return the length of a particular patch line.
1366 */
1367short
1368pch_line_len(LINENUM line)
1369{
1370	return p_len[line];
1371}
1372
1373/*
1374 * Return the control character (+, -, *, !, etc) for a patch line.
1375 */
1376char
1377pch_char(LINENUM line)
1378{
1379	return p_char[line];
1380}
1381
1382/*
1383 * Return a pointer to a particular patch line.
1384 */
1385char *
1386pfetch(LINENUM line)
1387{
1388	return p_line[line];
1389}
1390
1391/*
1392 * Return where in the patch file this hunk began, for error messages.
1393 */
1394LINENUM
1395pch_hunk_beg(void)
1396{
1397	return p_hunk_beg;
1398}
1399
1400/*
1401 * Apply an ed script by feeding ed itself.
1402 */
1403void
1404do_ed_script(void)
1405{
1406	char	*t;
1407	long	beginning_of_this_line;
1408	FILE	*pipefp = NULL;
1409	int	continuation;
1410
1411	if (!skip_rest_of_patch) {
1412		if (copy_file(filearg[0], TMPOUTNAME) < 0) {
1413			unlink(TMPOUTNAME);
1414			fatal("can't create temp file %s", TMPOUTNAME);
1415		}
1416		snprintf(buf, bufsz, "%s -S%s %s", _PATH_ED,
1417		    verbose ? "" : "s", TMPOUTNAME);
1418		pipefp = popen(buf, "w");
1419	}
1420	for (;;) {
1421		beginning_of_this_line = ftell(pfp);
1422		if (pgetline(&buf, &bufsz, pfp) == -1) {
1423			next_intuit_at(beginning_of_this_line, p_input_line);
1424			break;
1425		}
1426		p_input_line++;
1427		for (t = buf; isdigit((unsigned char)*t) || *t == ','; t++)
1428			;
1429		/* POSIX defines allowed commands as {a,c,d,i,s} */
1430		if (isdigit((unsigned char)*buf) && (*t == 'a' || *t == 'c' ||
1431		    *t == 'd' || *t == 'i' || *t == 's')) {
1432			if (pipefp != NULL)
1433				fprintf(pipefp, "%s", buf);
1434			if (*t == 's') {
1435				for (;;) {
1436					continuation = 0;
1437					t = strchr(buf, '\0') - 1;
1438					while (--t >= buf && *t == '\\')
1439						continuation = !continuation;
1440					if (!continuation ||
1441					    pgetline(&buf, &bufsz, pfp) == -1)
1442						break;
1443					if (pipefp != NULL)
1444						fprintf(pipefp, "%s", buf);
1445				}
1446			} else if (*t != 'd') {
1447				while (pgetline(&buf, &bufsz, pfp) != -1) {
1448					p_input_line++;
1449					if (pipefp != NULL)
1450						fprintf(pipefp, "%s", buf);
1451					if (strEQ(buf, ".\n"))
1452						break;
1453				}
1454			}
1455		} else {
1456			next_intuit_at(beginning_of_this_line, p_input_line);
1457			break;
1458		}
1459	}
1460	if (pipefp == NULL)
1461		return;
1462	fprintf(pipefp, "w\n");
1463	fprintf(pipefp, "q\n");
1464	fflush(pipefp);
1465	pclose(pipefp);
1466	ignore_signals();
1467	if (!check_only) {
1468		if (move_file(TMPOUTNAME, outname) < 0) {
1469			toutkeep = true;
1470			chmod(TMPOUTNAME, filemode);
1471		} else
1472			chmod(outname, filemode);
1473	}
1474	set_signals(1);
1475}
1476
1477/*
1478 * Choose the name of the file to be patched based on POSIX rules.
1479 * NOTE: the POSIX rules are amazingly stupid and we only follow them
1480 *       if the user specified --posix or set POSIXLY_CORRECT.
1481 */
1482static char *
1483posix_name(const struct file_name *names, bool assume_exists)
1484{
1485	char *path = NULL;
1486	int i;
1487
1488	/*
1489	 * POSIX states that the filename will be chosen from one
1490	 * of the old, new and index names (in that order) if
1491	 * the file exists relative to CWD after -p stripping.
1492	 */
1493	for (i = 0; i < MAX_FILE; i++) {
1494		if (names[i].path != NULL && names[i].exists) {
1495			path = names[i].path;
1496			break;
1497		}
1498	}
1499	if (path == NULL && !assume_exists) {
1500		/*
1501		 * No files found, look for something we can checkout from
1502		 * RCS/SCCS dirs.  Same order as above.
1503		 */
1504		for (i = 0; i < MAX_FILE; i++) {
1505			if (names[i].path != NULL &&
1506			    (path = checked_in(names[i].path)) != NULL)
1507				break;
1508		}
1509		/*
1510		 * Still no match?  Check to see if the diff could be creating
1511		 * a new file.
1512		 */
1513		if (path == NULL && ok_to_create_file &&
1514		    names[NEW_FILE].path != NULL)
1515			path = names[NEW_FILE].path;
1516	}
1517
1518	return path ? savestr(path) : NULL;
1519}
1520
1521/*
1522 * Choose the name of the file to be patched based the "best" one
1523 * available.
1524 */
1525static char *
1526best_name(const struct file_name *names, bool assume_exists)
1527{
1528	size_t min_components, min_baselen, min_len, tmp;
1529	char *best = NULL;
1530	int i;
1531
1532	/*
1533	 * The "best" name is the one with the fewest number of path
1534	 * components, the shortest basename length, and the shortest
1535	 * overall length (in that order).  We only use the Index: file
1536	 * if neither of the old or new files could be intuited from
1537	 * the diff header.
1538	 */
1539	min_components = min_baselen = min_len = SIZE_MAX;
1540	for (i = INDEX_FILE; i >= OLD_FILE; i--) {
1541		if (names[i].path == NULL ||
1542		    (!names[i].exists && !assume_exists))
1543			continue;
1544		if ((tmp = num_components(names[i].path)) > min_components)
1545			continue;
1546		min_components = tmp;
1547		if ((tmp = strlen(basename(names[i].path))) > min_baselen)
1548			continue;
1549		min_baselen = tmp;
1550		if ((tmp = strlen(names[i].path)) > min_len)
1551			continue;
1552		min_len = tmp;
1553		best = names[i].path;
1554	}
1555	if (best == NULL) {
1556		/*
1557		 * No files found, look for something we can checkout from
1558		 * RCS/SCCS dirs.  Logic is identical to that above...
1559		 */
1560		min_components = min_baselen = min_len = SIZE_MAX;
1561		for (i = INDEX_FILE; i >= OLD_FILE; i--) {
1562			if (names[i].path == NULL ||
1563			    checked_in(names[i].path) == NULL)
1564				continue;
1565			if ((tmp = num_components(names[i].path)) > min_components)
1566				continue;
1567			min_components = tmp;
1568			if ((tmp = strlen(basename(names[i].path))) > min_baselen)
1569				continue;
1570			min_baselen = tmp;
1571			if ((tmp = strlen(names[i].path)) > min_len)
1572				continue;
1573			min_len = tmp;
1574			best = names[i].path;
1575		}
1576		/*
1577		 * Still no match?  Check to see if the diff could be creating
1578		 * a new file.
1579		 */
1580		if (best == NULL && ok_to_create_file &&
1581		    names[NEW_FILE].path != NULL)
1582			best = names[NEW_FILE].path;
1583	}
1584
1585	return best ? savestr(best) : NULL;
1586}
1587
1588static size_t
1589num_components(const char *path)
1590{
1591	size_t n;
1592	const char *cp;
1593
1594	for (n = 0, cp = path; (cp = strchr(cp, '/')) != NULL; n++, cp++) {
1595		while (*cp == '/')
1596			cp++;		/* skip consecutive slashes */
1597	}
1598	return n;
1599}
1600