xref: /dragonfly/usr.bin/patch/pch.c (revision 5dfd06ac)
1 /*
2  * $OpenBSD: pch.c,v 1.35 2004/08/05 21:47:24 deraadt Exp $
3  * $DragonFly: src/usr.bin/patch/pch.c,v 1.4 2006/04/18 22:11:35 joerg Exp $
4  */
5 
6 /*
7  * patch - a program to apply diffs to original files
8  *
9  * Copyright 1986, Larry Wall
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following condition is met:
13  * 1. Redistributions of source code must retain the above copyright notice,
14  * this condition and the following disclaimer.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
17  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
20  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
23  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * -C option added in 1998, original code by Marc Espie, based on FreeBSD
29  * behaviour
30  */
31 
32 #include <sys/types.h>
33 #include <sys/stat.h>
34 
35 #include <ctype.h>
36 #include <libgen.h>
37 #include <limits.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <unistd.h>
42 
43 #include "common.h"
44 #include "util.h"
45 #include "pch.h"
46 #include "pathnames.h"
47 
48 /* Patch (diff listing) abstract type. */
49 
50 static long	p_filesize;	/* size of the patch file */
51 static LINENUM	p_first;	/* 1st line number */
52 static LINENUM	p_newfirst;	/* 1st line number of replacement */
53 static LINENUM	p_ptrn_lines;	/* # lines in pattern */
54 static LINENUM	p_repl_lines;	/* # lines in replacement text */
55 static LINENUM	p_end = -1;	/* last line in hunk */
56 static LINENUM	p_max;		/* max allowed value of p_end */
57 static LINENUM	p_context = 3;	/* # of context lines */
58 static LINENUM	p_input_line = 0;	/* current line # from patch file */
59 static char	**p_line = NULL;/* the text of the hunk */
60 static short	*p_len = NULL;	/* length of each line */
61 static char	*p_char = NULL;	/* +, -, and ! */
62 static int	hunkmax = INITHUNKMAX;	/* size of above arrays to begin with */
63 static int	p_indent;	/* indent to patch */
64 static LINENUM	p_base;		/* where to intuit this time */
65 static LINENUM	p_bline;	/* line # of p_base */
66 static LINENUM	p_start;	/* where intuit found a patch */
67 static LINENUM	p_sline;	/* and the line number for it */
68 static LINENUM	p_hunk_beg;	/* line number of current hunk */
69 static LINENUM	p_efake = -1;	/* end of faked up lines--don't free */
70 static LINENUM	p_bfake = -1;	/* beg of faked up lines */
71 static FILE	*pfp = NULL;	/* patch file pointer */
72 static char	*bestguess = NULL;	/* guess at correct filename */
73 
74 static void	grow_hunkmax(void);
75 static int	intuit_diff_type(void);
76 static void	next_intuit_at(LINENUM, LINENUM);
77 static void	skip_to(LINENUM, LINENUM);
78 static char	*pgets(char *, int, FILE *);
79 static char	*best_name(const struct file_name *, bool);
80 static char	*posix_name(const struct file_name *, bool);
81 static size_t	num_components(const char *);
82 
83 /*
84  * Prepare to look for the next patch in the patch file.
85  */
86 void
87 re_patch(void)
88 {
89 	p_first = 0;
90 	p_newfirst = 0;
91 	p_ptrn_lines = 0;
92 	p_repl_lines = 0;
93 	p_end = (LINENUM) - 1;
94 	p_max = 0;
95 	p_indent = 0;
96 }
97 
98 /*
99  * Open the patch file at the beginning of time.
100  */
101 void
102 open_patch_file(const char *filename)
103 {
104 	struct stat filestat;
105 
106 	if (filename == NULL || *filename == '\0' || strEQ(filename, "-")) {
107 		pfp = fopen(TMPPATNAME, "w");
108 		if (pfp == NULL)
109 			pfatal("can't create %s", TMPPATNAME);
110 		while (fgets(buf, buf_len, stdin) != NULL)
111 			fputs(buf, pfp);
112 		fclose(pfp);
113 		filename = TMPPATNAME;
114 	}
115 	pfp = fopen(filename, "r");
116 	if (pfp == NULL)
117 		pfatal("patch file %s not found", filename);
118 	fstat(fileno(pfp), &filestat);
119 	p_filesize = filestat.st_size;
120 	next_intuit_at(0L, 1L);	/* start at the beginning */
121 	set_hunkmax();
122 }
123 
124 /*
125  * Make sure our dynamically realloced tables are malloced to begin with.
126  */
127 void
128 set_hunkmax(void)
129 {
130 	if (p_line == NULL)
131 		p_line = malloc((size_t) hunkmax * sizeof(char *));
132 	if (p_len == NULL)
133 		p_len = malloc((size_t) hunkmax * sizeof(short));
134 	if (p_char == NULL)
135 		p_char = malloc((size_t) hunkmax * sizeof(char));
136 }
137 
138 /*
139  * Enlarge the arrays containing the current hunk of patch.
140  */
141 static void
142 grow_hunkmax(void)
143 {
144 	int		new_hunkmax;
145 	char		**new_p_line;
146 	short		*new_p_len;
147 	char		*new_p_char;
148 
149 	new_hunkmax = hunkmax * 2;
150 
151 	if (p_line == NULL || p_len == NULL || p_char == NULL)
152 		fatal("Internal memory allocation error\n");
153 
154 	new_p_line = realloc(p_line, new_hunkmax * sizeof(char *));
155 	if (new_p_line == NULL)
156 		free(p_line);
157 
158 	new_p_len = realloc(p_len, new_hunkmax * sizeof(short));
159 	if (new_p_len == NULL)
160 		free(p_len);
161 
162 	new_p_char = realloc(p_char, new_hunkmax * sizeof(char));
163 	if (new_p_char == NULL)
164 		free(p_char);
165 
166 	p_char = new_p_char;
167 	p_len = new_p_len;
168 	p_line = new_p_line;
169 
170 	if (p_line != NULL && p_len != NULL && p_char != NULL) {
171 		hunkmax = new_hunkmax;
172 		return;
173 	}
174 
175 	if (!using_plan_a)
176 		fatal("out of memory\n");
177 	out_of_mem = true;	/* whatever is null will be allocated again */
178 				/* from within plan_a(), of all places */
179 }
180 
181 /* True if the remainder of the patch file contains a diff of some sort. */
182 
183 bool
184 there_is_another_patch(void)
185 {
186 	bool exists = false;
187 
188 	if (p_base != 0L && p_base >= p_filesize) {
189 		if (verbose)
190 			say("done\n");
191 		return false;
192 	}
193 	if (verbose)
194 		say("Hmm...");
195 	diff_type = intuit_diff_type();
196 	if (!diff_type) {
197 		if (p_base != 0L) {
198 			if (verbose)
199 				say("  Ignoring the trailing garbage.\ndone\n");
200 		} else
201 			say("  I can't seem to find a patch in there anywhere.\n");
202 		return false;
203 	}
204 	if (verbose)
205 		say("  %sooks like %s to me...\n",
206 		    (p_base == 0L ? "L" : "The next patch l"),
207 		    diff_type == UNI_DIFF ? "a unified diff" :
208 		    diff_type == CONTEXT_DIFF ? "a context diff" :
209 		diff_type == NEW_CONTEXT_DIFF ? "a new-style context diff" :
210 		    diff_type == NORMAL_DIFF ? "a normal diff" :
211 		    "an ed script");
212 	if (p_indent && verbose)
213 		say("(Patch is indented %d space%s.)\n", p_indent,
214 		    p_indent == 1 ? "" : "s");
215 	skip_to(p_start, p_sline);
216 	while (filearg[0] == NULL) {
217 		if (force || batch) {
218 			say("No file to patch.  Skipping...\n");
219 			filearg[0] = savestr(bestguess);
220 			skip_rest_of_patch = true;
221 			return true;
222 		}
223 		ask("File to patch: ");
224 		if (*buf != '\n') {
225 			free(bestguess);
226 			bestguess = savestr(buf);
227 			filearg[0] = fetchname(buf, &exists, 0);
228 		}
229 		if (!exists) {
230 			ask("No file found--skip this patch? [n] ");
231 			if (*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 
244 /* Determine what kind of diff is in the remaining part of the patch file. */
245 
246 static int
247 intuit_diff_type(void)
248 {
249 	long	this_line = 0, previous_line;
250 	long	first_command_line = -1;
251 	LINENUM	fcl_line = -1;
252 	bool	last_line_was_command = false, this_is_a_command = false;
253 	bool	stars_last_line = false, stars_this_line = false;
254 	char	*s, *t;
255 	int	indent, retval;
256 	struct file_name names[MAX_FILE];
257 
258 	memset(names, 0, sizeof(names));
259 	ok_to_create_file = false;
260 	fseek(pfp, p_base, SEEK_SET);
261 	p_input_line = p_bline - 1;
262 	for (;;) {
263 		previous_line = this_line;
264 		last_line_was_command = this_is_a_command;
265 		stars_last_line = stars_this_line;
266 		this_line = ftell(pfp);
267 		indent = 0;
268 		p_input_line++;
269 		if (fgets(buf, buf_len, pfp) == NULL) {
270 			if (first_command_line >= 0L) {
271 				/* nothing but deletes!? */
272 				p_start = first_command_line;
273 				p_sline = fcl_line;
274 				retval = ED_DIFF;
275 				goto scan_exit;
276 			} else {
277 				p_start = this_line;
278 				p_sline = p_input_line;
279 				retval = 0;
280 				goto scan_exit;
281 			}
282 		}
283 		for (s = buf; *s == ' ' || *s == '\t' || *s == 'X'; s++) {
284 			if (*s == '\t')
285 				indent += 8 - (indent % 8);
286 			else
287 				indent++;
288 		}
289 		for (t = s; isdigit((unsigned char)*t) || *t == ','; t++)
290 			;
291 		this_is_a_command = (isdigit((unsigned char)*s) &&
292 		    (*t == 'd' || *t == 'c' || *t == 'a'));
293 		if (first_command_line < 0L && this_is_a_command) {
294 			first_command_line = this_line;
295 			fcl_line = p_input_line;
296 			p_indent = indent;	/* assume this for now */
297 		}
298 		if (!stars_last_line && strnEQ(s, "*** ", 4))
299 			names[OLD_FILE].path = fetchname(s + 4,
300 			    &names[OLD_FILE].exists, strippath);
301 		else if (strnEQ(s, "--- ", 4))
302 			names[NEW_FILE].path = fetchname(s + 4,
303 			    &names[NEW_FILE].exists, strippath);
304 		else if (strnEQ(s, "+++ ", 4))
305 			/* pretend it is the old name */
306 			names[OLD_FILE].path = fetchname(s + 4,
307 			    &names[OLD_FILE].exists, strippath);
308 		else if (strnEQ(s, "Index:", 6))
309 			names[INDEX_FILE].path = fetchname(s + 6,
310 			    &names[INDEX_FILE].exists, strippath);
311 		else if (strnEQ(s, "Prereq:", 7)) {
312 			for (t = s + 7; isspace((unsigned char)*t); t++)
313 				;
314 			revision = savestr(t);
315 			for (t = revision; *t && !isspace((unsigned char)*t); t++)
316 				;
317 			*t = '\0';
318 			if (*revision == '\0') {
319 				free(revision);
320 				revision = NULL;
321 			}
322 		}
323 		if ((!diff_type || diff_type == ED_DIFF) &&
324 		    first_command_line >= 0L &&
325 		    strEQ(s, ".\n")) {
326 			p_indent = indent;
327 			p_start = first_command_line;
328 			p_sline = fcl_line;
329 			retval = ED_DIFF;
330 			goto scan_exit;
331 		}
332 		if ((!diff_type || diff_type == UNI_DIFF) && strnEQ(s, "@@ -", 4)) {
333 			if (strnEQ(s + 4, "0,0", 3))
334 				ok_to_create_file = true;
335 			p_indent = indent;
336 			p_start = this_line;
337 			p_sline = p_input_line;
338 			retval = UNI_DIFF;
339 			goto scan_exit;
340 		}
341 		stars_this_line = strnEQ(s, "********", 8);
342 		if ((!diff_type || diff_type == CONTEXT_DIFF) && stars_last_line &&
343 		    strnEQ(s, "*** ", 4)) {
344 			if (atol(s + 4) == 0)
345 				ok_to_create_file = true;
346 			/*
347 			 * If this is a new context diff the character just
348 			 * before the newline is a '*'.
349 			 */
350 			while (*s != '\n')
351 				s++;
352 			p_indent = indent;
353 			p_start = previous_line;
354 			p_sline = p_input_line - 1;
355 			retval = (*(s - 1) == '*' ? NEW_CONTEXT_DIFF : CONTEXT_DIFF);
356 			goto scan_exit;
357 		}
358 		if ((!diff_type || diff_type == NORMAL_DIFF) &&
359 		    last_line_was_command &&
360 		    (strnEQ(s, "< ", 2) || strnEQ(s, "> ", 2))) {
361 			p_start = previous_line;
362 			p_sline = p_input_line - 1;
363 			p_indent = indent;
364 			retval = NORMAL_DIFF;
365 			goto scan_exit;
366 		}
367 	}
368 scan_exit:
369 	if (retval == UNI_DIFF) {
370 		/* unswap old and new */
371 		struct file_name tmp = names[OLD_FILE];
372 		names[OLD_FILE] = names[NEW_FILE];
373 		names[NEW_FILE] = tmp;
374 	}
375 	if (filearg[0] == NULL) {
376 		if (posix)
377 			filearg[0] = posix_name(names, ok_to_create_file);
378 		else {
379 			/* Ignore the Index: name for context diffs, like GNU */
380 			if (names[OLD_FILE].path != NULL ||
381 			    names[NEW_FILE].path != NULL) {
382 				free(names[INDEX_FILE].path);
383 				names[INDEX_FILE].path = NULL;
384 			}
385 			filearg[0] = best_name(names, ok_to_create_file);
386 		}
387 	}
388 
389 	free(bestguess);
390 	bestguess = NULL;
391 	if (filearg[0] != NULL)
392 		bestguess = savestr(filearg[0]);
393 	else if (!ok_to_create_file) {
394 		/*
395 		 * We don't want to create a new file but we need a
396 		 * filename to set bestguess.  Avoid setting filearg[0]
397 		 * so the file is not created automatically.
398 		 */
399 		if (posix)
400 			bestguess = posix_name(names, true);
401 		else
402 			bestguess = best_name(names, true);
403 	}
404 	free(names[OLD_FILE].path);
405 	free(names[NEW_FILE].path);
406 	free(names[INDEX_FILE].path);
407 	return retval;
408 }
409 
410 /*
411  * Remember where this patch ends so we know where to start up again.
412  */
413 static void
414 next_intuit_at(LINENUM file_pos, LINENUM file_line)
415 {
416 	p_base = file_pos;
417 	p_bline = file_line;
418 }
419 
420 /*
421  * Basically a verbose fseek() to the actual diff listing.
422  */
423 static void
424 skip_to(LINENUM file_pos, LINENUM file_line)
425 {
426 	char	*ret;
427 
428 	if (p_base > file_pos)
429 		fatal("Internal error: seek %ld>%ld\n", p_base, file_pos);
430 	if (verbose && p_base < file_pos) {
431 		fseek(pfp, p_base, SEEK_SET);
432 		say("The text leading up to this was:\n--------------------------\n");
433 		while (ftell(pfp) < file_pos) {
434 			ret = fgets(buf, buf_len, pfp);
435 			if (ret == NULL)
436 				fatal("Unexpected end of file\n");
437 			say("|%s", buf);
438 		}
439 		say("--------------------------\n");
440 	} else
441 		fseek(pfp, file_pos, SEEK_SET);
442 	p_input_line = file_line - 1;
443 }
444 
445 /* Make this a function for better debugging.  */
446 static void
447 malformed(void)
448 {
449 	fatal("malformed patch at line %ld: %s", p_input_line, buf);
450 	/* about as informative as "Syntax error" in C */
451 }
452 
453 /*
454  * True if the line has been discarded (i.e. it is a line saying
455  *  "\ No newline at end of file".)
456  */
457 static bool
458 remove_special_line(void)
459 {
460 	int	c;
461 
462 	c = fgetc(pfp);
463 	if (c == '\\') {
464 		do {
465 			c = fgetc(pfp);
466 		} while (c != EOF && c != '\n');
467 
468 		return true;
469 	}
470 	if (c != EOF)
471 		fseek(pfp, -1L, SEEK_CUR);
472 
473 	return false;
474 }
475 
476 /*
477  * True if there is more of the current diff listing to process.
478  */
479 bool
480 another_hunk(void)
481 {
482 	long	line_beginning;			/* file pos of the current line */
483 	LINENUM	repl_beginning;			/* index of --- line */
484 	LINENUM	fillcnt;			/* #lines of missing ptrn or repl */
485 	LINENUM	fillsrc;			/* index of first line to copy */
486 	LINENUM	filldst;			/* index of first missing line */
487 	bool	ptrn_spaces_eaten;		/* ptrn was slightly misformed */
488 	bool	repl_could_be_missing;		/* no + or ! lines in this hunk */
489 	bool	repl_missing;			/* we are now backtracking */
490 	long	repl_backtrack_position;	/* file pos of first repl line */
491 	LINENUM	repl_patch_line;		/* input line number for same */
492 	LINENUM	ptrn_copiable;			/* # of copiable lines in ptrn */
493 	char	*s, *ret;
494 	int	context = 0;
495 
496 	while (p_end >= 0) {
497 		if (p_end == p_efake)
498 			p_end = p_bfake;	/* don't free twice */
499 		else
500 			free(p_line[p_end]);
501 		p_end--;
502 	}
503 	p_efake = -1;
504 
505 	p_max = hunkmax;	/* gets reduced when --- found */
506 	if (diff_type == CONTEXT_DIFF || diff_type == NEW_CONTEXT_DIFF) {
507 		line_beginning = ftell(pfp);
508 		repl_beginning = 0;
509 		fillcnt = 0;
510 		fillsrc = 0;
511 		filldst = 0;
512 		ptrn_spaces_eaten = false;
513 		repl_could_be_missing = true;
514 		repl_missing = false;
515 		repl_backtrack_position = 0;
516 		repl_patch_line = 0;
517 		ptrn_copiable = 0;
518 
519 		ret = pgets(buf, buf_len, pfp);
520 		p_input_line++;
521 		if (ret == NULL || strnNE(buf, "********", 8)) {
522 			next_intuit_at(line_beginning, p_input_line);
523 			return false;
524 		}
525 		p_context = 100;
526 		p_hunk_beg = p_input_line + 1;
527 		while (p_end < p_max) {
528 			line_beginning = ftell(pfp);
529 			ret = pgets(buf, buf_len, pfp);
530 			p_input_line++;
531 			if (ret == NULL) {
532 				if (p_max - p_end < 4) {
533 					/* assume blank lines got chopped */
534 					strlcpy(buf, "  \n", buf_len);
535 				} else {
536 					if (repl_beginning && repl_could_be_missing) {
537 						repl_missing = true;
538 						goto hunk_done;
539 					}
540 					fatal("unexpected end of file in patch\n");
541 				}
542 			}
543 			p_end++;
544 			if (p_end >= hunkmax)
545 				fatal("Internal error: hunk larger than hunk "
546 				    "buffer size");
547 			p_char[p_end] = *buf;
548 			p_line[p_end] = NULL;
549 			switch (*buf) {
550 			case '*':
551 				if (strnEQ(buf, "********", 8)) {
552 					if (repl_beginning && repl_could_be_missing) {
553 						repl_missing = true;
554 						goto hunk_done;
555 					} else
556 						fatal("unexpected end of hunk "
557 						    "at line %ld\n",
558 						    p_input_line);
559 				}
560 				if (p_end != 0) {
561 					if (repl_beginning && repl_could_be_missing) {
562 						repl_missing = true;
563 						goto hunk_done;
564 					}
565 					fatal("unexpected *** at line %ld: %s",
566 					    p_input_line, buf);
567 				}
568 				context = 0;
569 				p_line[p_end] = savestr(buf);
570 				if (out_of_mem) {
571 					p_end--;
572 					return false;
573 				}
574 				for (s = buf; *s && !isdigit((unsigned char)*s); s++)
575 					;
576 				if (!*s)
577 					malformed();
578 				if (strnEQ(s, "0,0", 3))
579 					memmove(s, s + 2, strlen(s + 2) + 1);
580 				p_first = (LINENUM) atol(s);
581 				while (isdigit((unsigned char)*s))
582 					s++;
583 				if (*s == ',') {
584 					for (; *s && !isdigit((unsigned char)*s); s++)
585 						;
586 					if (!*s)
587 						malformed();
588 					p_ptrn_lines = ((LINENUM) atol(s)) - p_first + 1;
589 				} else if (p_first)
590 					p_ptrn_lines = 1;
591 				else {
592 					p_ptrn_lines = 0;
593 					p_first = 1;
594 				}
595 
596 				/* we need this much at least */
597 				p_max = p_ptrn_lines + 6;
598 				while (p_max >= hunkmax)
599 					grow_hunkmax();
600 				p_max = hunkmax;
601 				break;
602 			case '-':
603 				if (buf[1] == '-') {
604 					if (repl_beginning ||
605 					    (p_end != p_ptrn_lines + 1 +
606 					    (p_char[p_end - 1] == '\n'))) {
607 						if (p_end == 1) {
608 							/*
609 							 * `old' lines were omitted;
610 							 * set up to fill them in
611 							 * from 'new' context lines.
612 							 */
613 							p_end = p_ptrn_lines + 1;
614 							fillsrc = p_end + 1;
615 							filldst = 1;
616 							fillcnt = p_ptrn_lines;
617 						} else {
618 							if (repl_beginning) {
619 								if (repl_could_be_missing) {
620 									repl_missing = true;
621 									goto hunk_done;
622 								}
623 								fatal("duplicate \"---\" at line %ld--check line numbers at line %ld\n",
624 								    p_input_line, p_hunk_beg + repl_beginning);
625 							} else {
626 								fatal("%s \"---\" at line %ld--check line numbers at line %ld\n",
627 								    (p_end <= p_ptrn_lines
628 								    ? "Premature"
629 								    : "Overdue"),
630 								    p_input_line, p_hunk_beg);
631 							}
632 						}
633 					}
634 					repl_beginning = p_end;
635 					repl_backtrack_position = ftell(pfp);
636 					repl_patch_line = p_input_line;
637 					p_line[p_end] = savestr(buf);
638 					if (out_of_mem) {
639 						p_end--;
640 						return false;
641 					}
642 					p_char[p_end] = '=';
643 					for (s = buf; *s && !isdigit((unsigned char)*s); s++)
644 						;
645 					if (!*s)
646 						malformed();
647 					p_newfirst = (LINENUM) atol(s);
648 					while (isdigit((unsigned char)*s))
649 						s++;
650 					if (*s == ',') {
651 						for (; *s && !isdigit((unsigned char)*s); s++)
652 							;
653 						if (!*s)
654 							malformed();
655 						p_repl_lines = ((LINENUM) atol(s)) -
656 						    p_newfirst + 1;
657 					} else if (p_newfirst)
658 						p_repl_lines = 1;
659 					else {
660 						p_repl_lines = 0;
661 						p_newfirst = 1;
662 					}
663 					p_max = p_repl_lines + p_end;
664 					if (p_max > MAXHUNKSIZE)
665 						fatal("hunk too large (%ld lines) at line %ld: %s",
666 						    p_max, p_input_line, buf);
667 					while (p_max >= hunkmax)
668 						grow_hunkmax();
669 					if (p_repl_lines != ptrn_copiable &&
670 					    (p_context != 0 || p_repl_lines != 1))
671 						repl_could_be_missing = false;
672 					break;
673 				}
674 				goto change_line;
675 			case '+':
676 			case '!':
677 				repl_could_be_missing = false;
678 		change_line:
679 				if (buf[1] == '\n' && canonicalize)
680 					strlcpy(buf + 1, " \n", buf_len - 1);
681 				if (!isspace((unsigned char)buf[1]) && buf[1] != '>' &&
682 				    buf[1] != '<' &&
683 				    repl_beginning && repl_could_be_missing) {
684 					repl_missing = true;
685 					goto hunk_done;
686 				}
687 				if (context >= 0) {
688 					if (context < p_context)
689 						p_context = context;
690 					context = -1000;
691 				}
692 				p_line[p_end] = savestr(buf + 2);
693 				if (out_of_mem) {
694 					p_end--;
695 					return false;
696 				}
697 				if (p_end == p_ptrn_lines) {
698 					if (remove_special_line()) {
699 						int	len;
700 
701 						len = strlen(p_line[p_end]) - 1;
702 						(p_line[p_end])[len] = 0;
703 					}
704 				}
705 				break;
706 			case '\t':
707 			case '\n':	/* assume the 2 spaces got eaten */
708 				if (repl_beginning && repl_could_be_missing &&
709 				    (!ptrn_spaces_eaten ||
710 				    diff_type == NEW_CONTEXT_DIFF)) {
711 					repl_missing = true;
712 					goto hunk_done;
713 				}
714 				p_line[p_end] = savestr(buf);
715 				if (out_of_mem) {
716 					p_end--;
717 					return false;
718 				}
719 				if (p_end != p_ptrn_lines + 1) {
720 					ptrn_spaces_eaten |= (repl_beginning != 0);
721 					context++;
722 					if (!repl_beginning)
723 						ptrn_copiable++;
724 					p_char[p_end] = ' ';
725 				}
726 				break;
727 			case ' ':
728 				if (!isspace((unsigned char)buf[1]) &&
729 				    repl_beginning && repl_could_be_missing) {
730 					repl_missing = true;
731 					goto hunk_done;
732 				}
733 				context++;
734 				if (!repl_beginning)
735 					ptrn_copiable++;
736 				p_line[p_end] = savestr(buf + 2);
737 				if (out_of_mem) {
738 					p_end--;
739 					return false;
740 				}
741 				break;
742 			default:
743 				if (repl_beginning && repl_could_be_missing) {
744 					repl_missing = true;
745 					goto hunk_done;
746 				}
747 				malformed();
748 			}
749 			/* set up p_len for strncmp() so we don't have to */
750 			/* assume null termination */
751 			if (p_line[p_end])
752 				p_len[p_end] = strlen(p_line[p_end]);
753 			else
754 				p_len[p_end] = 0;
755 		}
756 
757 hunk_done:
758 		if (p_end >= 0 && !repl_beginning)
759 			fatal("no --- found in patch at line %ld\n", pch_hunk_beg());
760 
761 		if (repl_missing) {
762 
763 			/* reset state back to just after --- */
764 			p_input_line = repl_patch_line;
765 			for (p_end--; p_end > repl_beginning; p_end--)
766 				free(p_line[p_end]);
767 			fseek(pfp, repl_backtrack_position, SEEK_SET);
768 
769 			/* redundant 'new' context lines were omitted - set */
770 			/* up to fill them in from the old file context */
771 			if (!p_context && p_repl_lines == 1) {
772 				p_repl_lines = 0;
773 				p_max--;
774 			}
775 			fillsrc = 1;
776 			filldst = repl_beginning + 1;
777 			fillcnt = p_repl_lines;
778 			p_end = p_max;
779 		} else if (!p_context && fillcnt == 1) {
780 			/* the first hunk was a null hunk with no context */
781 			/* and we were expecting one line -- fix it up. */
782 			while (filldst < p_end) {
783 				p_line[filldst] = p_line[filldst + 1];
784 				p_char[filldst] = p_char[filldst + 1];
785 				p_len[filldst] = p_len[filldst + 1];
786 				filldst++;
787 			}
788 #if 0
789 			repl_beginning--;	/* this doesn't need to be fixed */
790 #endif
791 			p_end--;
792 			p_first++;	/* do append rather than insert */
793 			fillcnt = 0;
794 			p_ptrn_lines = 0;
795 		}
796 		if (diff_type == CONTEXT_DIFF &&
797 		    (fillcnt || (p_first > 1 && ptrn_copiable > 2 * p_context))) {
798 			if (verbose)
799 				say("%s\n%s\n%s\n",
800 				    "(Fascinating--this is really a new-style context diff but without",
801 				    "the telltale extra asterisks on the *** line that usually indicate",
802 				    "the new style...)");
803 			diff_type = NEW_CONTEXT_DIFF;
804 		}
805 		/* if there were omitted context lines, fill them in now */
806 		if (fillcnt) {
807 			p_bfake = filldst;	/* remember where not to free() */
808 			p_efake = filldst + fillcnt - 1;
809 			while (fillcnt-- > 0) {
810 				while (fillsrc <= p_end && p_char[fillsrc] != ' ')
811 					fillsrc++;
812 				if (fillsrc > p_end)
813 					fatal("replacement text or line numbers mangled in hunk at line %ld\n",
814 					    p_hunk_beg);
815 				p_line[filldst] = p_line[fillsrc];
816 				p_char[filldst] = p_char[fillsrc];
817 				p_len[filldst] = p_len[fillsrc];
818 				fillsrc++;
819 				filldst++;
820 			}
821 			while (fillsrc <= p_end && fillsrc != repl_beginning &&
822 			    p_char[fillsrc] != ' ')
823 				fillsrc++;
824 #ifdef DEBUGGING
825 			if (debug & 64)
826 				printf("fillsrc %ld, filldst %ld, rb %ld, e+1 %ld\n",
827 				fillsrc, filldst, repl_beginning, p_end + 1);
828 #endif
829 			if (fillsrc != p_end + 1 && fillsrc != repl_beginning)
830 				malformed();
831 			if (filldst != p_end + 1 && filldst != repl_beginning)
832 				malformed();
833 		}
834 		if (p_line[p_end] != NULL) {
835 			if (remove_special_line()) {
836 				p_len[p_end] -= 1;
837 				(p_line[p_end])[p_len[p_end]] = 0;
838 			}
839 		}
840 	} else if (diff_type == UNI_DIFF) {
841 		LINENUM	fillold;	/* index of old lines */
842 		LINENUM	fillnew;	/* index of new lines */
843 		char	ch;
844 
845 		line_beginning = ftell(pfp); /* file pos of the current line */
846 		ret = pgets(buf, buf_len, pfp);
847 		p_input_line++;
848 		if (ret == NULL || strnNE(buf, "@@ -", 4)) {
849 			next_intuit_at(line_beginning, p_input_line);
850 			return false;
851 		}
852 		s = buf + 4;
853 		if (!*s)
854 			malformed();
855 		p_first = (LINENUM) atol(s);
856 		while (isdigit((unsigned char)*s))
857 			s++;
858 		if (*s == ',') {
859 			p_ptrn_lines = (LINENUM) atol(++s);
860 			while (isdigit((unsigned char)*s))
861 				s++;
862 		} else
863 			p_ptrn_lines = 1;
864 		if (*s == ' ')
865 			s++;
866 		if (*s != '+' || !*++s)
867 			malformed();
868 		p_newfirst = (LINENUM) atol(s);
869 		while (isdigit((unsigned char)*s))
870 			s++;
871 		if (*s == ',') {
872 			p_repl_lines = (LINENUM) atol(++s);
873 			while (isdigit((unsigned char)*s))
874 				s++;
875 		} else
876 			p_repl_lines = 1;
877 		if (*s == ' ')
878 			s++;
879 		if (*s != '@')
880 			malformed();
881 		if (!p_ptrn_lines)
882 			p_first++;	/* do append rather than insert */
883 		p_max = p_ptrn_lines + p_repl_lines + 1;
884 		while (p_max >= hunkmax)
885 			grow_hunkmax();
886 		fillold = 1;
887 		fillnew = fillold + p_ptrn_lines;
888 		p_end = fillnew + p_repl_lines;
889 		snprintf(buf, buf_len, "*** %ld,%ld ****\n", p_first,
890 		    p_first + p_ptrn_lines - 1);
891 		p_line[0] = savestr(buf);
892 		if (out_of_mem) {
893 			p_end = -1;
894 			return false;
895 		}
896 		p_char[0] = '*';
897 		snprintf(buf, buf_len, "--- %ld,%ld ----\n", p_newfirst,
898 		    p_newfirst + p_repl_lines - 1);
899 		p_line[fillnew] = savestr(buf);
900 		if (out_of_mem) {
901 			p_end = 0;
902 			return false;
903 		}
904 		p_char[fillnew++] = '=';
905 		p_context = 100;
906 		context = 0;
907 		p_hunk_beg = p_input_line + 1;
908 		while (fillold <= p_ptrn_lines || fillnew <= p_end) {
909 			line_beginning = ftell(pfp);
910 			ret = pgets(buf, buf_len, pfp);
911 			p_input_line++;
912 			if (ret == NULL) {
913 				if (p_max - fillnew < 3) {
914 					/* assume blank lines got chopped */
915 					strlcpy(buf, " \n", buf_len);
916 				} else {
917 					fatal("unexpected end of file in patch\n");
918 				}
919 			}
920 			if (*buf == '\t' || *buf == '\n') {
921 				ch = ' ';	/* assume the space got eaten */
922 				s = savestr(buf);
923 			} else {
924 				ch = *buf;
925 				s = savestr(buf + 1);
926 			}
927 			if (out_of_mem) {
928 				while (--fillnew > p_ptrn_lines)
929 					free(p_line[fillnew]);
930 				p_end = fillold - 1;
931 				return false;
932 			}
933 			switch (ch) {
934 			case '-':
935 				if (fillold > p_ptrn_lines) {
936 					free(s);
937 					p_end = fillnew - 1;
938 					malformed();
939 				}
940 				p_char[fillold] = ch;
941 				p_line[fillold] = s;
942 				p_len[fillold++] = strlen(s);
943 				if (fillold > p_ptrn_lines) {
944 					if (remove_special_line()) {
945 						p_len[fillold - 1] -= 1;
946 						s[p_len[fillold - 1]] = 0;
947 					}
948 				}
949 				break;
950 			case '=':
951 				ch = ' ';
952 				/* FALL THROUGH */
953 			case ' ':
954 				if (fillold > p_ptrn_lines) {
955 					free(s);
956 					while (--fillnew > p_ptrn_lines)
957 						free(p_line[fillnew]);
958 					p_end = fillold - 1;
959 					malformed();
960 				}
961 				context++;
962 				p_char[fillold] = ch;
963 				p_line[fillold] = s;
964 				p_len[fillold++] = strlen(s);
965 				s = savestr(s);
966 				if (out_of_mem) {
967 					while (--fillnew > p_ptrn_lines)
968 						free(p_line[fillnew]);
969 					p_end = fillold - 1;
970 					return false;
971 				}
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 				/* FALL THROUGH */
979 			case '+':
980 				if (fillnew > p_end) {
981 					free(s);
982 					while (--fillnew > p_ptrn_lines)
983 						free(p_line[fillnew]);
984 					p_end = fillold - 1;
985 					malformed();
986 				}
987 				p_char[fillnew] = ch;
988 				p_line[fillnew] = s;
989 				p_len[fillnew++] = strlen(s);
990 				if (fillold > p_ptrn_lines) {
991 					if (remove_special_line()) {
992 						p_len[fillnew - 1] -= 1;
993 						s[p_len[fillnew - 1]] = 0;
994 					}
995 				}
996 				break;
997 			default:
998 				p_end = fillnew;
999 				malformed();
1000 			}
1001 			if (ch != ' ' && context > 0) {
1002 				if (context < p_context)
1003 					p_context = context;
1004 				context = -1000;
1005 			}
1006 		}		/* while */
1007 	} else {		/* normal diff--fake it up */
1008 		char	hunk_type;
1009 		int	i;
1010 		LINENUM	min, max;
1011 
1012 		line_beginning = ftell(pfp);
1013 		p_context = 0;
1014 		ret = pgets(buf, buf_len, pfp);
1015 		p_input_line++;
1016 		if (ret == NULL || !isdigit((unsigned char)*buf)) {
1017 			next_intuit_at(line_beginning, p_input_line);
1018 			return false;
1019 		}
1020 		p_first = (LINENUM) atol(buf);
1021 		for (s = buf; isdigit((unsigned char)*s); s++)
1022 			;
1023 		if (*s == ',') {
1024 			p_ptrn_lines = (LINENUM) atol(++s) - p_first + 1;
1025 			while (isdigit((unsigned char)*s))
1026 				s++;
1027 		} else
1028 			p_ptrn_lines = (*s != 'a');
1029 		hunk_type = *s;
1030 		if (hunk_type == 'a')
1031 			p_first++;	/* do append rather than insert */
1032 		min = (LINENUM) atol(++s);
1033 		for (; isdigit((unsigned char)*s); s++)
1034 			;
1035 		if (*s == ',')
1036 			max = (LINENUM) atol(++s);
1037 		else
1038 			max = min;
1039 		if (hunk_type == 'd')
1040 			min++;
1041 		p_end = p_ptrn_lines + 1 + max - min + 1;
1042 		if (p_end > MAXHUNKSIZE)
1043 			fatal("hunk too large (%ld lines) at line %ld: %s",
1044 			    p_end, p_input_line, buf);
1045 		while (p_end >= hunkmax)
1046 			grow_hunkmax();
1047 		p_newfirst = min;
1048 		p_repl_lines = max - min + 1;
1049 		snprintf(buf, buf_len, "*** %ld,%ld\n", p_first,
1050 		    p_first + p_ptrn_lines - 1);
1051 		p_line[0] = savestr(buf);
1052 		if (out_of_mem) {
1053 			p_end = -1;
1054 			return false;
1055 		}
1056 		p_char[0] = '*';
1057 		for (i = 1; i <= p_ptrn_lines; i++) {
1058 			ret = pgets(buf, buf_len, pfp);
1059 			p_input_line++;
1060 			if (ret == NULL)
1061 				fatal("unexpected end of file in patch at line %ld\n",
1062 				    p_input_line);
1063 			if (*buf != '<')
1064 				fatal("< expected at line %ld of patch\n",
1065 				    p_input_line);
1066 			p_line[i] = savestr(buf + 2);
1067 			if (out_of_mem) {
1068 				p_end = i - 1;
1069 				return false;
1070 			}
1071 			p_len[i] = strlen(p_line[i]);
1072 			p_char[i] = '-';
1073 		}
1074 
1075 		if (remove_special_line()) {
1076 			p_len[i - 1] -= 1;
1077 			(p_line[i - 1])[p_len[i - 1]] = 0;
1078 		}
1079 		if (hunk_type == 'c') {
1080 			ret = pgets(buf, buf_len, pfp);
1081 			p_input_line++;
1082 			if (ret == NULL)
1083 				fatal("unexpected end of file in patch at line %ld\n",
1084 				    p_input_line);
1085 			if (*buf != '-')
1086 				fatal("--- expected at line %ld of patch\n",
1087 				    p_input_line);
1088 		}
1089 		snprintf(buf, buf_len, "--- %ld,%ld\n", min, max);
1090 		p_line[i] = savestr(buf);
1091 		if (out_of_mem) {
1092 			p_end = i - 1;
1093 			return false;
1094 		}
1095 		p_char[i] = '=';
1096 		for (i++; i <= p_end; i++) {
1097 			ret = pgets(buf, buf_len, pfp);
1098 			p_input_line++;
1099 			if (ret == NULL)
1100 				fatal("unexpected end of file in patch at line %ld\n",
1101 				    p_input_line);
1102 			if (*buf != '>')
1103 				fatal("> expected at line %ld of patch\n",
1104 				    p_input_line);
1105 			p_line[i] = savestr(buf + 2);
1106 			if (out_of_mem) {
1107 				p_end = i - 1;
1108 				return false;
1109 			}
1110 			p_len[i] = strlen(p_line[i]);
1111 			p_char[i] = '+';
1112 		}
1113 
1114 		if (remove_special_line()) {
1115 			p_len[i - 1] -= 1;
1116 			(p_line[i - 1])[p_len[i - 1]] = 0;
1117 		}
1118 	}
1119 	if (reverse)		/* backwards patch? */
1120 		if (!pch_swap())
1121 			say("Not enough memory to swap next hunk!\n");
1122 #ifdef DEBUGGING
1123 	if (debug & 2) {
1124 		int	i;
1125 		char	special;
1126 
1127 		for (i = 0; i <= p_end; i++) {
1128 			if (i == p_ptrn_lines)
1129 				special = '^';
1130 			else
1131 				special = ' ';
1132 			fprintf(stderr, "%3d %c %c %s", i, p_char[i],
1133 			    special, p_line[i]);
1134 			fflush(stderr);
1135 		}
1136 	}
1137 #endif
1138 	if (p_end + 1 < hunkmax)/* paranoia reigns supreme... */
1139 		p_char[p_end + 1] = '^';	/* add a stopper for apply_hunk */
1140 	return true;
1141 }
1142 
1143 /*
1144  * Input a line from the patch file, worrying about indentation.
1145  */
1146 static char *
1147 pgets(char *bf, int sz, FILE *fp)
1148 {
1149 	char	*s, *ret = fgets(bf, sz, fp);
1150 	int	indent = 0;
1151 
1152 	if (p_indent && ret != NULL) {
1153 		for (s = buf;
1154 		    indent < p_indent && (*s == ' ' || *s == '\t' || *s == 'X');
1155 		    s++) {
1156 			if (*s == '\t')
1157 				indent += 8 - (indent % 7);
1158 			else
1159 				indent++;
1160 		}
1161 		if (buf != s && strlcpy(buf, s, buf_len) >= buf_len)
1162 			fatal("buffer too small in pgets()\n");
1163 	}
1164 	return ret;
1165 }
1166 
1167 /*
1168  * Reverse the old and new portions of the current hunk.
1169  */
1170 bool
1171 pch_swap(void)
1172 {
1173 	char	**tp_line;	/* the text of the hunk */
1174 	short	*tp_len;	/* length of each line */
1175 	char	*tp_char;	/* +, -, and ! */
1176 	LINENUM	i;
1177 	LINENUM	n;
1178 	bool	blankline = false;
1179 	char	*s;
1180 
1181 	i = p_first;
1182 	p_first = p_newfirst;
1183 	p_newfirst = i;
1184 
1185 	/* make a scratch copy */
1186 
1187 	tp_line = p_line;
1188 	tp_len = p_len;
1189 	tp_char = p_char;
1190 	p_line = NULL;	/* force set_hunkmax to allocate again */
1191 	p_len = NULL;
1192 	p_char = NULL;
1193 	set_hunkmax();
1194 	if (p_line == NULL || p_len == NULL || p_char == NULL) {
1195 
1196 		free(p_line);
1197 		p_line = tp_line;
1198 		free(p_len);
1199 		p_len = tp_len;
1200 		free(p_char);
1201 		p_char = tp_char;
1202 		return false;	/* not enough memory to swap hunk! */
1203 	}
1204 	/* now turn the new into the old */
1205 
1206 	i = p_ptrn_lines + 1;
1207 	if (tp_char[i] == '\n') {	/* account for possible blank line */
1208 		blankline = true;
1209 		i++;
1210 	}
1211 	if (p_efake >= 0) {	/* fix non-freeable ptr range */
1212 		if (p_efake <= i)
1213 			n = p_end - i + 1;
1214 		else
1215 			n = -i;
1216 		p_efake += n;
1217 		p_bfake += n;
1218 	}
1219 	for (n = 0; i <= p_end; i++, n++) {
1220 		p_line[n] = tp_line[i];
1221 		p_char[n] = tp_char[i];
1222 		if (p_char[n] == '+')
1223 			p_char[n] = '-';
1224 		p_len[n] = tp_len[i];
1225 	}
1226 	if (blankline) {
1227 		i = p_ptrn_lines + 1;
1228 		p_line[n] = tp_line[i];
1229 		p_char[n] = tp_char[i];
1230 		p_len[n] = tp_len[i];
1231 		n++;
1232 	}
1233 	if (p_char[0] != '=')
1234 		fatal("Malformed patch at line %ld: expected '=' found '%c'\n",
1235 		    p_input_line, p_char[0]);
1236 	p_char[0] = '*';
1237 	for (s = p_line[0]; *s; s++)
1238 		if (*s == '-')
1239 			*s = '*';
1240 
1241 	/* now turn the old into the new */
1242 
1243 	if (p_char[0] != '*')
1244 		fatal("Malformed patch at line %ld: expected '*' found '%c'\n",
1245 		    p_input_line, p_char[0]);
1246 	tp_char[0] = '=';
1247 	for (s = tp_line[0]; *s; s++)
1248 		if (*s == '*')
1249 			*s = '-';
1250 	for (i = 0; n <= p_end; i++, n++) {
1251 		p_line[n] = tp_line[i];
1252 		p_char[n] = tp_char[i];
1253 		if (p_char[n] == '-')
1254 			p_char[n] = '+';
1255 		p_len[n] = tp_len[i];
1256 	}
1257 
1258 	if (i != p_ptrn_lines + 1)
1259 		fatal("Malformed patch at line %ld: expected %ld lines, "
1260 		    "got %ld\n",
1261 		    p_input_line, p_ptrn_lines + 1, i);
1262 
1263 	i = p_ptrn_lines;
1264 	p_ptrn_lines = p_repl_lines;
1265 	p_repl_lines = i;
1266 
1267 	free(tp_line);
1268 	free(tp_len);
1269 	free(tp_char);
1270 
1271 	return true;
1272 }
1273 
1274 /*
1275  * Return the specified line position in the old file of the old context.
1276  */
1277 LINENUM
1278 pch_first(void)
1279 {
1280 	return p_first;
1281 }
1282 
1283 /*
1284  * Return the number of lines of old context.
1285  */
1286 LINENUM
1287 pch_ptrn_lines(void)
1288 {
1289 	return p_ptrn_lines;
1290 }
1291 
1292 /*
1293  * Return the probable line position in the new file of the first line.
1294  */
1295 LINENUM
1296 pch_newfirst(void)
1297 {
1298 	return p_newfirst;
1299 }
1300 
1301 /*
1302  * Return the number of lines in the replacement text including context.
1303  */
1304 LINENUM
1305 pch_repl_lines(void)
1306 {
1307 	return p_repl_lines;
1308 }
1309 
1310 /*
1311  * Return the number of lines in the whole hunk.
1312  */
1313 LINENUM
1314 pch_end(void)
1315 {
1316 	return p_end;
1317 }
1318 
1319 /*
1320  * Return the number of context lines before the first changed line.
1321  */
1322 LINENUM
1323 pch_context(void)
1324 {
1325 	return p_context;
1326 }
1327 
1328 /*
1329  * Return the length of a particular patch line.
1330  */
1331 short
1332 pch_line_len(LINENUM line)
1333 {
1334 	return p_len[line];
1335 }
1336 
1337 /*
1338  * Return the control character (+, -, *, !, etc) for a patch line.
1339  */
1340 char
1341 pch_char(LINENUM line)
1342 {
1343 	return p_char[line];
1344 }
1345 
1346 /*
1347  * Return a pointer to a particular patch line.
1348  */
1349 char *
1350 pfetch(LINENUM line)
1351 {
1352 	return p_line[line];
1353 }
1354 
1355 /*
1356  * Return where in the patch file this hunk began, for error messages.
1357  */
1358 LINENUM
1359 pch_hunk_beg(void)
1360 {
1361 	return p_hunk_beg;
1362 }
1363 
1364 /*
1365  * Apply an ed script by feeding ed itself.
1366  */
1367 void
1368 do_ed_script(void)
1369 {
1370 	char	*t;
1371 	long	beginning_of_this_line;
1372 	FILE	*pipefp;
1373 
1374 	pipefp = NULL;
1375 	if (!skip_rest_of_patch) {
1376 		if (copy_file(filearg[0], TMPOUTNAME) < 0) {
1377 			unlink(TMPOUTNAME);
1378 			fatal("can't create temp file %s", TMPOUTNAME);
1379 		}
1380 		snprintf(buf, buf_len, "%s%s%s", _PATH_ED,
1381 		    verbose ? " " : " -s ", TMPOUTNAME);
1382 		pipefp = popen(buf, "w");
1383 	}
1384 	for (;;) {
1385 		beginning_of_this_line = ftell(pfp);
1386 		if (pgets(buf, buf_len, pfp) == NULL) {
1387 			next_intuit_at(beginning_of_this_line, p_input_line);
1388 			break;
1389 		}
1390 		p_input_line++;
1391 		for (t = buf; isdigit((unsigned char)*t) || *t == ','; t++)
1392 			;
1393 		/* POSIX defines allowed commands as {a,c,d,i,s} */
1394 		if (isdigit((unsigned char)*buf) && (*t == 'a' || *t == 'c' ||
1395 		    *t == 'd' || *t == 'i' || *t == 's')) {
1396 			if (pipefp != NULL)
1397 				fputs(buf, pipefp);
1398 			if (*t != 'd') {
1399 				while (pgets(buf, buf_len, pfp) != NULL) {
1400 					p_input_line++;
1401 					if (pipefp != NULL)
1402 						fputs(buf, pipefp);
1403 					if (strEQ(buf, ".\n"))
1404 						break;
1405 				}
1406 			}
1407 		} else {
1408 			next_intuit_at(beginning_of_this_line, p_input_line);
1409 			break;
1410 		}
1411 	}
1412 	if (pipefp == NULL)
1413 		return;
1414 	fprintf(pipefp, "w\n");
1415 	fprintf(pipefp, "q\n");
1416 	fflush(pipefp);
1417 	pclose(pipefp);
1418 	ignore_signals();
1419 	if (!check_only) {
1420 		if (move_file(TMPOUTNAME, outname) < 0) {
1421 			toutkeep = true;
1422 			chmod(TMPOUTNAME, filemode);
1423 		} else
1424 			chmod(outname, filemode);
1425 	}
1426 	set_signals(1);
1427 }
1428 
1429 /*
1430  * Choose the name of the file to be patched based on POSIX rules.
1431  * NOTE: the POSIX rules are amazingly stupid and we only follow them
1432  *       if the user specified --posix or set POSIXLY_CORRECT.
1433  */
1434 static char *
1435 posix_name(const struct file_name *names, bool assume_exists)
1436 {
1437 	char *path = NULL;
1438 	int i;
1439 
1440 	/*
1441 	 * POSIX states that the filename will be chosen from one
1442 	 * of the old, new and index names (in that order) if
1443 	 * the file exists relative to CWD after -p stripping.
1444 	 */
1445 	for (i = 0; i < MAX_FILE; i++) {
1446 		if (names[i].path != NULL && names[i].exists) {
1447 			path = names[i].path;
1448 			break;
1449 		}
1450 	}
1451 	if (path == NULL && !assume_exists) {
1452 		/*
1453 		 * No files found, look for something we can checkout from
1454 		 * RCS/SCCS dirs.  Same order as above.
1455 		 */
1456 		for (i = 0; i < MAX_FILE; i++) {
1457 			if (names[i].path != NULL &&
1458 			    (path = checked_in(names[i].path)) != NULL)
1459 				break;
1460 		}
1461 		/*
1462 		 * Still no match?  Check to see if the diff could be creating
1463 		 * a new file.
1464 		 */
1465 		if (path == NULL && ok_to_create_file &&
1466 		    names[NEW_FILE].path != NULL)
1467 			path = names[NEW_FILE].path;
1468 	}
1469 
1470 	return path ? savestr(path) : NULL;
1471 }
1472 
1473 /*
1474  * Choose the name of the file to be patched based the "best" one
1475  * available.
1476  */
1477 static char *
1478 best_name(const struct file_name *names, bool assume_exists)
1479 {
1480 	size_t min_components, min_baselen, min_len, tmp;
1481 	char *best = NULL;
1482 	int i;
1483 
1484 	/*
1485 	 * The "best" name is the one with the fewest number of path
1486 	 * components, the shortest basename length, and the shortest
1487 	 * overall length (in that order).  We only use the Index: file
1488 	 * if neither of the old or new files could be intuited from
1489 	 * the diff header.
1490 	 */
1491 	min_components = min_baselen = min_len = SIZE_MAX;
1492 	for (i = INDEX_FILE; i >= OLD_FILE; i--) {
1493 		if (names[i].path == NULL ||
1494 		    (!names[i].exists && !assume_exists))
1495 			continue;
1496 		if ((tmp = num_components(names[i].path)) > min_components)
1497 			continue;
1498 		min_components = tmp;
1499 		if ((tmp = strlen(basename(names[i].path))) > min_baselen)
1500 			continue;
1501 		min_baselen = tmp;
1502 		if ((tmp = strlen(names[i].path)) > min_len)
1503 			continue;
1504 		min_len = tmp;
1505 		best = names[i].path;
1506 	}
1507 	if (best == NULL) {
1508 		/*
1509 		 * No files found, look for something we can checkout from
1510 		 * RCS/SCCS dirs.  Logic is identical to that above...
1511 		 */
1512 		min_components = min_baselen = min_len = SIZE_MAX;
1513 		for (i = INDEX_FILE; i >= OLD_FILE; i--) {
1514 			if (names[i].path == NULL ||
1515 			    checked_in(names[i].path) == NULL)
1516 				continue;
1517 			if ((tmp = num_components(names[i].path)) > min_components)
1518 				continue;
1519 			min_components = tmp;
1520 			if ((tmp = strlen(basename(names[i].path))) > min_baselen)
1521 				continue;
1522 			min_baselen = tmp;
1523 			if ((tmp = strlen(names[i].path)) > min_len)
1524 				continue;
1525 			min_len = tmp;
1526 			best = names[i].path;
1527 		}
1528 		/*
1529 		 * Still no match?  Check to see if the diff could be creating
1530 		 * a new file.
1531 		 */
1532 		if (best == NULL && ok_to_create_file &&
1533 		    names[NEW_FILE].path != NULL)
1534 			best = names[NEW_FILE].path;
1535 	}
1536 
1537 	return best ? savestr(best) : NULL;
1538 }
1539 
1540 static size_t
1541 num_components(const char *path)
1542 {
1543 	size_t n;
1544 	const char *cp;
1545 
1546 	for (n = 0, cp = path; (cp = strchr(cp, '/')) != NULL; n++, cp++) {
1547 		while (*cp == '/')
1548 			cp++;		/* skip consecutive slashes */
1549 	}
1550 	return n;
1551 }
1552