xref: /freebsd/usr.bin/patch/pch.c (revision 12300d3aa0168f532d29242ce9a47afb630a348c)
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  * $FreeBSD$
28  */
29 
30 #include <sys/types.h>
31 #include <sys/stat.h>
32 
33 #include <ctype.h>
34 #include <libgen.h>
35 #include <limits.h>
36 #include <stdint.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <unistd.h>
41 
42 #include "common.h"
43 #include "util.h"
44 #include "pch.h"
45 #include "pathnames.h"
46 
47 /* Patch (diff listing) abstract type. */
48 
49 static off_t	p_filesize;	/* size of the patch file */
50 static LINENUM	p_first;	/* 1st line number */
51 static LINENUM	p_newfirst;	/* 1st line number of replacement */
52 static LINENUM	p_ptrn_lines;	/* # lines in pattern */
53 static LINENUM	p_repl_lines;	/* # lines in replacement text */
54 static LINENUM	p_end = -1;	/* last line in hunk */
55 static LINENUM	p_max;		/* max allowed value of p_end */
56 static LINENUM	p_context = 3;	/* # of context lines */
57 static LINENUM	p_input_line = 0;	/* current line # from patch file */
58 static char	**p_line = NULL;/* the text of the hunk */
59 static unsigned short	*p_len = NULL; /* length of each line */
60 static char	*p_char = NULL;	/* +, -, and ! */
61 static int	hunkmax = INITHUNKMAX;	/* size of above arrays to begin with */
62 static int	p_indent;	/* indent to patch */
63 static off_t	p_base;		/* where to intuit this time */
64 static LINENUM	p_bline;	/* line # of p_base */
65 static off_t	p_start;	/* where intuit found a patch */
66 static LINENUM	p_sline;	/* and the line number for it */
67 static LINENUM	p_hunk_beg;	/* line number of current hunk */
68 static LINENUM	p_efake = -1;	/* end of faked up lines--don't free */
69 static LINENUM	p_bfake = -1;	/* beg of faked up lines */
70 static FILE	*pfp = NULL;	/* patch file pointer */
71 static char	*bestguess = NULL;	/* guess at correct filename */
72 
73 static void	grow_hunkmax(void);
74 static int	intuit_diff_type(void);
75 static void	next_intuit_at(off_t, LINENUM);
76 static void	skip_to(off_t, LINENUM);
77 static size_t	pgets(bool _do_indent);
78 static char	*best_name(const struct file_name *, bool);
79 static char	*posix_name(const struct file_name *, bool);
80 static size_t	num_components(const char *);
81 static LINENUM	strtolinenum(char *, 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 	int nr, nw;
106 
107 	if (filename == NULL || *filename == '\0' || strEQ(filename, "-")) {
108 		pfp = fopen(TMPPATNAME, "w");
109 		if (pfp == NULL)
110 			pfatal("can't create %s", TMPPATNAME);
111 		while ((nr = fread(buf, 1, buf_size, stdin)) > 0) {
112 			nw = fwrite(buf, 1, nr, pfp);
113 			if (nr != nw)
114 				pfatal("write error to %s", TMPPATNAME);
115 		}
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 	if (fstat(fileno(pfp), &filestat))
124 		pfatal("can't stat %s", filename);
125 	p_filesize = filestat.st_size;
126 	next_intuit_at(0, 1L);	/* start at the beginning */
127 	set_hunkmax();
128 }
129 
130 /*
131  * Make sure our dynamically realloced tables are malloced to begin with.
132  */
133 void
134 set_hunkmax(void)
135 {
136 	if (p_line == NULL)
137 		p_line = malloc(hunkmax * sizeof(char *));
138 	if (p_len == NULL)
139 		p_len = malloc(hunkmax * sizeof(unsigned short));
140 	if (p_char == NULL)
141 		p_char = malloc(hunkmax * sizeof(char));
142 }
143 
144 /*
145  * Enlarge the arrays containing the current hunk of patch.
146  */
147 static void
148 grow_hunkmax(void)
149 {
150 	int new_hunkmax = hunkmax * 2;
151 
152 	if (p_line == NULL || p_len == NULL || p_char == NULL)
153 		fatal("Internal memory allocation error\n");
154 
155 	p_line = reallocf(p_line, new_hunkmax * sizeof(char *));
156 	p_len = reallocf(p_len, new_hunkmax * sizeof(unsigned short));
157 	p_char = reallocf(p_char, new_hunkmax * sizeof(char));
158 
159 	if (p_line != NULL && p_len != NULL && p_char != NULL) {
160 		hunkmax = new_hunkmax;
161 		return;
162 	}
163 
164 	if (!using_plan_a)
165 		fatal("out of memory\n");
166 	out_of_mem = true;	/* whatever is null will be allocated again */
167 				/* from within plan_a(), of all places */
168 }
169 
170 /* True if the remainder of the patch file contains a diff of some sort. */
171 
172 bool
173 there_is_another_patch(void)
174 {
175 	bool exists = false;
176 
177 	if (p_base != 0 && p_base >= p_filesize) {
178 		if (verbose)
179 			say("done\n");
180 		return false;
181 	}
182 	if (verbose)
183 		say("Hmm...");
184 	diff_type = intuit_diff_type();
185 	if (!diff_type) {
186 		if (p_base != 0) {
187 			if (verbose)
188 				say("  Ignoring the trailing garbage.\ndone\n");
189 		} else
190 			say("  I can't seem to find a patch in there anywhere.\n");
191 		return false;
192 	}
193 	if (verbose)
194 		say("  %sooks like %s to me...\n",
195 		    (p_base == 0 ? "L" : "The next patch l"),
196 		    diff_type == UNI_DIFF ? "a unified diff" :
197 		    diff_type == CONTEXT_DIFF ? "a context diff" :
198 		diff_type == NEW_CONTEXT_DIFF ? "a new-style context diff" :
199 		    diff_type == NORMAL_DIFF ? "a normal diff" :
200 		    "an ed script");
201 	if (p_indent && verbose)
202 		say("(Patch is indented %d space%s.)\n", p_indent,
203 		    p_indent == 1 ? "" : "s");
204 	skip_to(p_start, p_sline);
205 	while (filearg[0] == NULL) {
206 		if (force || batch) {
207 			say("No file to patch.  Skipping...\n");
208 			filearg[0] = xstrdup(bestguess);
209 			skip_rest_of_patch = true;
210 			return true;
211 		}
212 		ask("File to patch: ");
213 		if (*buf != '\n') {
214 			free(bestguess);
215 			bestguess = xstrdup(buf);
216 			filearg[0] = fetchname(buf, &exists, 0);
217 		}
218 		if (!exists) {
219 			int def_skip = *bestguess == '\0';
220 			ask("No file found--skip this patch? [%c] ",
221 			    def_skip  ? 'y' : 'n');
222 			if (*buf == 'n' || (!def_skip && *buf != 'y'))
223 				continue;
224 			if (verbose)
225 				say("Skipping patch...\n");
226 			free(filearg[0]);
227 			filearg[0] = fetchname(bestguess, &exists, 0);
228 			skip_rest_of_patch = true;
229 			return true;
230 		}
231 	}
232 	return true;
233 }
234 
235 static void
236 p4_fetchname(struct file_name *name, char *str)
237 {
238 	char *t, *h;
239 
240 	/* Skip leading whitespace. */
241 	while (isspace((unsigned char)*str))
242 		str++;
243 
244 	/* Remove the file revision number. */
245 	for (t = str, h = NULL; *t != '\0' && !isspace((unsigned char)*t); t++)
246 		if (*t == '#')
247 			h = t;
248 	if (h != NULL)
249 		*h = '\0';
250 
251 	name->path = fetchname(str, &name->exists, strippath);
252 }
253 
254 /* Determine what kind of diff is in the remaining part of the patch file. */
255 
256 static int
257 intuit_diff_type(void)
258 {
259 	off_t	this_line = 0, previous_line;
260 	off_t	first_command_line = -1;
261 	LINENUM	fcl_line = -1;
262 	bool	last_line_was_command = false, this_is_a_command = false;
263 	bool	stars_last_line = false, stars_this_line = false;
264 	char	*s, *t;
265 	int	indent, retval;
266 	struct file_name names[MAX_FILE];
267 
268 	memset(names, 0, sizeof(names));
269 	ok_to_create_file = false;
270 	fseeko(pfp, p_base, SEEK_SET);
271 	p_input_line = p_bline - 1;
272 	for (;;) {
273 		previous_line = this_line;
274 		last_line_was_command = this_is_a_command;
275 		stars_last_line = stars_this_line;
276 		this_line = ftello(pfp);
277 		indent = 0;
278 		p_input_line++;
279 		if (pgets(false) == 0) {
280 			if (first_command_line >= 0) {
281 				/* nothing but deletes!? */
282 				p_start = first_command_line;
283 				p_sline = fcl_line;
284 				retval = ED_DIFF;
285 				goto scan_exit;
286 			} else {
287 				p_start = this_line;
288 				p_sline = p_input_line;
289 				retval = 0;
290 				goto scan_exit;
291 			}
292 		}
293 		for (s = buf; *s == ' ' || *s == '\t' || *s == 'X'; s++) {
294 			if (*s == '\t')
295 				indent += 8 - (indent % 8);
296 			else
297 				indent++;
298 		}
299 		for (t = s; isdigit((unsigned char)*t) || *t == ','; t++)
300 			;
301 		this_is_a_command = (isdigit((unsigned char)*s) &&
302 		    (*t == 'd' || *t == 'c' || *t == 'a'));
303 		if (first_command_line < 0 && this_is_a_command) {
304 			first_command_line = this_line;
305 			fcl_line = p_input_line;
306 			p_indent = indent;	/* assume this for now */
307 		}
308 		if (!stars_last_line && strnEQ(s, "*** ", 4))
309 			names[OLD_FILE].path = fetchname(s + 4,
310 			    &names[OLD_FILE].exists, strippath);
311 		else if (strnEQ(s, "--- ", 4))
312 			names[NEW_FILE].path = fetchname(s + 4,
313 			    &names[NEW_FILE].exists, strippath);
314 		else if (strnEQ(s, "+++ ", 4))
315 			/* pretend it is the old name */
316 			names[OLD_FILE].path = fetchname(s + 4,
317 			    &names[OLD_FILE].exists, strippath);
318 		else if (strnEQ(s, "Index:", 6))
319 			names[INDEX_FILE].path = fetchname(s + 6,
320 			    &names[INDEX_FILE].exists, strippath);
321 		else if (strnEQ(s, "Prereq:", 7)) {
322 			for (t = s + 7; isspace((unsigned char)*t); t++)
323 				;
324 			revision = xstrdup(t);
325 			for (t = revision;
326 			     *t && !isspace((unsigned char)*t); t++)
327 				;
328 			*t = '\0';
329 			if (*revision == '\0') {
330 				free(revision);
331 				revision = NULL;
332 			}
333 		} else if (strnEQ(s, "==== ", 5)) {
334 			/* Perforce-style diffs. */
335 			if ((t = strstr(s + 5, " - ")) != NULL)
336 				p4_fetchname(&names[NEW_FILE], t + 3);
337 			p4_fetchname(&names[OLD_FILE], s + 5);
338 		}
339 		if ((!diff_type || diff_type == ED_DIFF) &&
340 		    first_command_line >= 0 &&
341 		    strEQ(s, ".\n")) {
342 			p_indent = indent;
343 			p_start = first_command_line;
344 			p_sline = fcl_line;
345 			retval = ED_DIFF;
346 			goto scan_exit;
347 		}
348 		if ((!diff_type || diff_type == UNI_DIFF) && strnEQ(s, "@@ -", 4)) {
349 			if (strnEQ(s + 4, "0,0", 3))
350 				ok_to_create_file = true;
351 			p_indent = indent;
352 			p_start = this_line;
353 			p_sline = p_input_line;
354 			retval = UNI_DIFF;
355 			goto scan_exit;
356 		}
357 		stars_this_line = strnEQ(s, "********", 8);
358 		if ((!diff_type || diff_type == CONTEXT_DIFF) && stars_last_line &&
359 		    strnEQ(s, "*** ", 4)) {
360 			if (strtolinenum(s + 4, &s) == 0)
361 				ok_to_create_file = true;
362 			/*
363 			 * If this is a new context diff the character just
364 			 * at the end of the line is a '*'.
365 			 */
366 			while (*s && *s != '\n')
367 				s++;
368 			p_indent = indent;
369 			p_start = previous_line;
370 			p_sline = p_input_line - 1;
371 			retval = (*(s - 1) == '*' ? NEW_CONTEXT_DIFF : CONTEXT_DIFF);
372 			goto scan_exit;
373 		}
374 		if ((!diff_type || diff_type == NORMAL_DIFF) &&
375 		    last_line_was_command &&
376 		    (strnEQ(s, "< ", 2) || strnEQ(s, "> ", 2))) {
377 			p_start = previous_line;
378 			p_sline = p_input_line - 1;
379 			p_indent = indent;
380 			retval = NORMAL_DIFF;
381 			goto scan_exit;
382 		}
383 	}
384 scan_exit:
385 	if (retval == UNI_DIFF) {
386 		/* unswap old and new */
387 		struct file_name tmp = names[OLD_FILE];
388 		names[OLD_FILE] = names[NEW_FILE];
389 		names[NEW_FILE] = tmp;
390 	}
391 	if (filearg[0] == NULL) {
392 		if (posix)
393 			filearg[0] = posix_name(names, ok_to_create_file);
394 		else {
395 			/* Ignore the Index: name for context diffs, like GNU */
396 			if (names[OLD_FILE].path != NULL ||
397 			    names[NEW_FILE].path != NULL) {
398 				free(names[INDEX_FILE].path);
399 				names[INDEX_FILE].path = NULL;
400 			}
401 			filearg[0] = best_name(names, ok_to_create_file);
402 		}
403 	}
404 
405 	free(bestguess);
406 	bestguess = NULL;
407 	if (filearg[0] != NULL)
408 		bestguess = xstrdup(filearg[0]);
409 	else if (!ok_to_create_file) {
410 		/*
411 		 * We don't want to create a new file but we need a
412 		 * filename to set bestguess.  Avoid setting filearg[0]
413 		 * so the file is not created automatically.
414 		 */
415 		if (posix)
416 			bestguess = posix_name(names, true);
417 		else
418 			bestguess = best_name(names, true);
419 	}
420 	free(names[OLD_FILE].path);
421 	free(names[NEW_FILE].path);
422 	free(names[INDEX_FILE].path);
423 	return retval;
424 }
425 
426 /*
427  * Remember where this patch ends so we know where to start up again.
428  */
429 static void
430 next_intuit_at(off_t file_pos, LINENUM file_line)
431 {
432 	p_base = file_pos;
433 	p_bline = file_line;
434 }
435 
436 /*
437  * Basically a verbose fseeko() to the actual diff listing.
438  */
439 static void
440 skip_to(off_t file_pos, LINENUM file_line)
441 {
442 	size_t	len;
443 
444 	if (p_base > file_pos)
445 		fatal("Internal error: seek %lld>%lld\n",
446 		   (long long)p_base, (long long)file_pos);
447 	if (verbose && p_base < file_pos) {
448 		fseeko(pfp, p_base, SEEK_SET);
449 		say("The text leading up to this was:\n--------------------------\n");
450 		while (ftello(pfp) < file_pos) {
451 			len = pgets(false);
452 			if (len == 0)
453 				fatal("Unexpected end of file\n");
454 			say("|%s", buf);
455 		}
456 		say("--------------------------\n");
457 	} else
458 		fseeko(pfp, file_pos, SEEK_SET);
459 	p_input_line = file_line - 1;
460 }
461 
462 /* Make this a function for better debugging.  */
463 static void
464 malformed(void)
465 {
466 	fatal("malformed patch at line %ld: %s", p_input_line, buf);
467 	/* about as informative as "Syntax error" in C */
468 }
469 
470 /*
471  * True if the line has been discarded (i.e. it is a line saying
472  *  "\ No newline at end of file".)
473  */
474 static bool
475 remove_special_line(void)
476 {
477 	int	c;
478 
479 	c = fgetc(pfp);
480 	if (c == '\\') {
481 		do {
482 			c = fgetc(pfp);
483 		} while (c != EOF && c != '\n');
484 
485 		return true;
486 	}
487 	if (c != EOF)
488 		fseeko(pfp, -1, SEEK_CUR);
489 
490 	return false;
491 }
492 
493 /*
494  * True if there is more of the current diff listing to process.
495  */
496 bool
497 another_hunk(void)
498 {
499 	off_t	line_beginning;			/* file pos of the current line */
500 	LINENUM	repl_beginning;			/* index of --- line */
501 	LINENUM	fillcnt;			/* #lines of missing ptrn or repl */
502 	LINENUM	fillsrc;			/* index of first line to copy */
503 	LINENUM	filldst;			/* index of first missing line */
504 	bool	ptrn_spaces_eaten;		/* ptrn was slightly malformed */
505 	bool	repl_could_be_missing;		/* no + or ! lines in this hunk */
506 	bool	repl_missing;			/* we are now backtracking */
507 	off_t	repl_backtrack_position;	/* file pos of first repl line */
508 	LINENUM	repl_patch_line;		/* input line number for same */
509 	LINENUM	ptrn_copiable;			/* # of copiable lines in ptrn */
510 	char	*s;
511 	size_t	len;
512 	int	context = 0;
513 
514 	while (p_end >= 0) {
515 		if (p_end == p_efake)
516 			p_end = p_bfake;	/* don't free twice */
517 		else
518 			free(p_line[p_end]);
519 		p_end--;
520 	}
521 	p_efake = -1;
522 
523 	p_max = hunkmax;	/* gets reduced when --- found */
524 	if (diff_type == CONTEXT_DIFF || diff_type == NEW_CONTEXT_DIFF) {
525 		line_beginning = ftello(pfp);
526 		repl_beginning = 0;
527 		fillcnt = 0;
528 		fillsrc = 0;
529 		filldst = 0;
530 		ptrn_spaces_eaten = false;
531 		repl_could_be_missing = true;
532 		repl_missing = false;
533 		repl_backtrack_position = 0;
534 		repl_patch_line = 0;
535 		ptrn_copiable = 0;
536 
537 		len = pgets(true);
538 		p_input_line++;
539 		if (len == 0 || strnNE(buf, "********", 8)) {
540 			next_intuit_at(line_beginning, p_input_line);
541 			return false;
542 		}
543 		p_context = 100;
544 		p_hunk_beg = p_input_line + 1;
545 		while (p_end < p_max) {
546 			line_beginning = ftello(pfp);
547 			len = pgets(true);
548 			p_input_line++;
549 			if (len == 0) {
550 				if (p_max - p_end < 4) {
551 					/* assume blank lines got chopped */
552 					strlcpy(buf, "  \n", buf_size);
553 				} else {
554 					if (repl_beginning && repl_could_be_missing) {
555 						repl_missing = true;
556 						goto hunk_done;
557 					}
558 					fatal("unexpected end of file in patch\n");
559 				}
560 			}
561 			p_end++;
562 			if (p_end >= hunkmax)
563 				fatal("Internal error: hunk larger than hunk "
564 				    "buffer size");
565 			p_char[p_end] = *buf;
566 			p_line[p_end] = NULL;
567 			switch (*buf) {
568 			case '*':
569 				if (strnEQ(buf, "********", 8)) {
570 					if (repl_beginning && repl_could_be_missing) {
571 						repl_missing = true;
572 						goto hunk_done;
573 					} else
574 						fatal("unexpected end of hunk "
575 						    "at line %ld\n",
576 						    p_input_line);
577 				}
578 				if (p_end != 0) {
579 					if (repl_beginning && repl_could_be_missing) {
580 						repl_missing = true;
581 						goto hunk_done;
582 					}
583 					fatal("unexpected *** at line %ld: %s",
584 					    p_input_line, buf);
585 				}
586 				context = 0;
587 				p_line[p_end] = savestr(buf);
588 				if (out_of_mem) {
589 					p_end--;
590 					return false;
591 				}
592 				for (s = buf;
593 				     *s && !isdigit((unsigned char)*s); s++)
594 					;
595 				if (!*s)
596 					malformed();
597 				if (strnEQ(s, "0,0", 3))
598 					memmove(s, s + 2, strlen(s + 2) + 1);
599 				p_first = strtolinenum(s, &s);
600 				if (*s == ',') {
601 					for (;
602 					     *s && !isdigit((unsigned char)*s); s++)
603 						;
604 					if (!*s)
605 						malformed();
606 					p_ptrn_lines = strtolinenum(s, &s) - p_first + 1;
607 					if (p_ptrn_lines < 0)
608 						malformed();
609 				} else if (p_first)
610 					p_ptrn_lines = 1;
611 				else {
612 					p_ptrn_lines = 0;
613 					p_first = 1;
614 				}
615 				if (p_first >= LINENUM_MAX - p_ptrn_lines ||
616 				    p_ptrn_lines >= LINENUM_MAX - 6)
617 					malformed();
618 
619 				/* we need this much at least */
620 				p_max = p_ptrn_lines + 6;
621 				while (p_max >= hunkmax)
622 					grow_hunkmax();
623 				p_max = hunkmax;
624 				break;
625 			case '-':
626 				if (buf[1] == '-') {
627 					if (repl_beginning ||
628 					    (p_end != p_ptrn_lines + 1 +
629 					    (p_char[p_end - 1] == '\n'))) {
630 						if (p_end == 1) {
631 							/*
632 							 * `old' lines were omitted;
633 							 * set up to fill them in
634 							 * from 'new' context lines.
635 							 */
636 							p_end = p_ptrn_lines + 1;
637 							fillsrc = p_end + 1;
638 							filldst = 1;
639 							fillcnt = p_ptrn_lines;
640 						} else {
641 							if (repl_beginning) {
642 								if (repl_could_be_missing) {
643 									repl_missing = true;
644 									goto hunk_done;
645 								}
646 								fatal("duplicate \"---\" at line %ld--check line numbers at line %ld\n",
647 								    p_input_line, p_hunk_beg + repl_beginning);
648 							} else {
649 								fatal("%s \"---\" at line %ld--check line numbers at line %ld\n",
650 								    (p_end <= p_ptrn_lines
651 								    ? "Premature"
652 								    : "Overdue"),
653 								    p_input_line, p_hunk_beg);
654 							}
655 						}
656 					}
657 					repl_beginning = p_end;
658 					repl_backtrack_position = ftello(pfp);
659 					repl_patch_line = p_input_line;
660 					p_line[p_end] = savestr(buf);
661 					if (out_of_mem) {
662 						p_end--;
663 						return false;
664 					}
665 					p_char[p_end] = '=';
666 					for (s = buf; *s && !isdigit((unsigned char)*s); s++)
667 						;
668 					if (!*s)
669 						malformed();
670 					p_newfirst = strtolinenum(s, &s);
671 					if (*s == ',') {
672 						for (; *s && !isdigit((unsigned char)*s); s++)
673 							;
674 						if (!*s)
675 							malformed();
676 						p_repl_lines = strtolinenum(s, &s) -
677 						    p_newfirst + 1;
678 						if (p_repl_lines < 0)
679 							malformed();
680 					} else if (p_newfirst)
681 						p_repl_lines = 1;
682 					else {
683 						p_repl_lines = 0;
684 						p_newfirst = 1;
685 					}
686 					if (p_newfirst >= LINENUM_MAX - p_repl_lines ||
687 					    p_repl_lines >= LINENUM_MAX - p_end)
688 						malformed();
689 					p_max = p_repl_lines + p_end;
690 					if (p_max > MAXHUNKSIZE)
691 						fatal("hunk too large (%ld lines) at line %ld: %s",
692 						    p_max, p_input_line, buf);
693 					while (p_max >= hunkmax)
694 						grow_hunkmax();
695 					if (p_repl_lines != ptrn_copiable &&
696 					    (p_context != 0 || p_repl_lines != 1))
697 						repl_could_be_missing = false;
698 					break;
699 				}
700 				goto change_line;
701 			case '+':
702 			case '!':
703 				repl_could_be_missing = false;
704 		change_line:
705 				if (buf[1] == '\n' && canonicalize)
706 					strlcpy(buf + 1, " \n", buf_size - 1);
707 				if (!isspace((unsigned char)buf[1]) &&
708 				    buf[1] != '>' && buf[1] != '<' &&
709 				    repl_beginning && repl_could_be_missing) {
710 					repl_missing = true;
711 					goto hunk_done;
712 				}
713 				if (context >= 0) {
714 					if (context < p_context)
715 						p_context = context;
716 					context = -1000;
717 				}
718 				p_line[p_end] = savestr(buf + 2);
719 				if (out_of_mem) {
720 					p_end--;
721 					return false;
722 				}
723 				if (p_end == p_ptrn_lines) {
724 					if (remove_special_line()) {
725 						int	l;
726 
727 						l = strlen(p_line[p_end]) - 1;
728 						(p_line[p_end])[l] = 0;
729 					}
730 				}
731 				break;
732 			case '\t':
733 			case '\n':	/* assume the 2 spaces got eaten */
734 				if (repl_beginning && repl_could_be_missing &&
735 				    (!ptrn_spaces_eaten ||
736 				    diff_type == NEW_CONTEXT_DIFF)) {
737 					repl_missing = true;
738 					goto hunk_done;
739 				}
740 				p_line[p_end] = savestr(buf);
741 				if (out_of_mem) {
742 					p_end--;
743 					return false;
744 				}
745 				if (p_end != p_ptrn_lines + 1) {
746 					ptrn_spaces_eaten |= (repl_beginning != 0);
747 					context++;
748 					if (!repl_beginning)
749 						ptrn_copiable++;
750 					p_char[p_end] = ' ';
751 				}
752 				break;
753 			case ' ':
754 				if (!isspace((unsigned char)buf[1]) &&
755 				    repl_beginning && repl_could_be_missing) {
756 					repl_missing = true;
757 					goto hunk_done;
758 				}
759 				context++;
760 				if (!repl_beginning)
761 					ptrn_copiable++;
762 				p_line[p_end] = savestr(buf + 2);
763 				if (out_of_mem) {
764 					p_end--;
765 					return false;
766 				}
767 				break;
768 			default:
769 				if (repl_beginning && repl_could_be_missing) {
770 					repl_missing = true;
771 					goto hunk_done;
772 				}
773 				malformed();
774 			}
775 			/* set up p_len for strncmp() so we don't have to */
776 			/* assume null termination */
777 			if (p_line[p_end])
778 				p_len[p_end] = strlen(p_line[p_end]);
779 			else
780 				p_len[p_end] = 0;
781 		}
782 
783 hunk_done:
784 		if (p_end >= 0 && !repl_beginning)
785 			fatal("no --- found in patch at line %ld\n", pch_hunk_beg());
786 
787 		if (repl_missing) {
788 
789 			/* reset state back to just after --- */
790 			p_input_line = repl_patch_line;
791 			for (p_end--; p_end > repl_beginning; p_end--)
792 				free(p_line[p_end]);
793 			fseeko(pfp, repl_backtrack_position, SEEK_SET);
794 
795 			/* redundant 'new' context lines were omitted - set */
796 			/* up to fill them in from the old file context */
797 			if (!p_context && p_repl_lines == 1) {
798 				p_repl_lines = 0;
799 				p_max--;
800 			}
801 			fillsrc = 1;
802 			filldst = repl_beginning + 1;
803 			fillcnt = p_repl_lines;
804 			p_end = p_max;
805 		} else if (!p_context && fillcnt == 1) {
806 			/* the first hunk was a null hunk with no context */
807 			/* and we were expecting one line -- fix it up. */
808 			while (filldst < p_end) {
809 				p_line[filldst] = p_line[filldst + 1];
810 				p_char[filldst] = p_char[filldst + 1];
811 				p_len[filldst] = p_len[filldst + 1];
812 				filldst++;
813 			}
814 #if 0
815 			repl_beginning--;	/* this doesn't need to be fixed */
816 #endif
817 			p_end--;
818 			p_first++;	/* do append rather than insert */
819 			fillcnt = 0;
820 			p_ptrn_lines = 0;
821 		}
822 		if (diff_type == CONTEXT_DIFF &&
823 		    (fillcnt || (p_first > 1 && ptrn_copiable > 2 * p_context))) {
824 			if (verbose)
825 				say("%s\n%s\n%s\n",
826 				    "(Fascinating--this is really a new-style context diff but without",
827 				    "the telltale extra asterisks on the *** line that usually indicate",
828 				    "the new style...)");
829 			diff_type = NEW_CONTEXT_DIFF;
830 		}
831 		/* if there were omitted context lines, fill them in now */
832 		if (fillcnt) {
833 			p_bfake = filldst;	/* remember where not to free() */
834 			p_efake = filldst + fillcnt - 1;
835 			while (fillcnt-- > 0) {
836 				while (fillsrc <= p_end && p_char[fillsrc] != ' ')
837 					fillsrc++;
838 				if (fillsrc > p_end)
839 					fatal("replacement text or line numbers mangled in hunk at line %ld\n",
840 					    p_hunk_beg);
841 				p_line[filldst] = p_line[fillsrc];
842 				p_char[filldst] = p_char[fillsrc];
843 				p_len[filldst] = p_len[fillsrc];
844 				fillsrc++;
845 				filldst++;
846 			}
847 			while (fillsrc <= p_end && fillsrc != repl_beginning &&
848 			    p_char[fillsrc] != ' ')
849 				fillsrc++;
850 #ifdef DEBUGGING
851 			if (debug & 64)
852 				printf("fillsrc %ld, filldst %ld, rb %ld, e+1 %ld\n",
853 				fillsrc, filldst, repl_beginning, p_end + 1);
854 #endif
855 			if (fillsrc != p_end + 1 && fillsrc != repl_beginning)
856 				malformed();
857 			if (filldst != p_end + 1 && filldst != repl_beginning)
858 				malformed();
859 		}
860 		if (p_line[p_end] != NULL) {
861 			if (remove_special_line()) {
862 				p_len[p_end] -= 1;
863 				(p_line[p_end])[p_len[p_end]] = 0;
864 			}
865 		}
866 	} else if (diff_type == UNI_DIFF) {
867 		LINENUM	fillold;	/* index of old lines */
868 		LINENUM	fillnew;	/* index of new lines */
869 		char	ch;
870 
871 		line_beginning = ftello(pfp); /* file pos of the current line */
872 		len = pgets(true);
873 		p_input_line++;
874 		if (len == 0 || strnNE(buf, "@@ -", 4)) {
875 			next_intuit_at(line_beginning, p_input_line);
876 			return false;
877 		}
878 		s = buf + 4;
879 		if (!*s)
880 			malformed();
881 		p_first = strtolinenum(s, &s);
882 		if (*s == ',') {
883 			p_ptrn_lines = strtolinenum(s + 1, &s);
884 		} else
885 			p_ptrn_lines = 1;
886 		if (*s == ' ')
887 			s++;
888 		if (*s != '+' || !*++s)
889 			malformed();
890 		p_newfirst = strtolinenum(s, &s);
891 		if (*s == ',') {
892 			p_repl_lines = strtolinenum(s + 1, &s);
893 		} else
894 			p_repl_lines = 1;
895 		if (*s == ' ')
896 			s++;
897 		if (*s != '@')
898 			malformed();
899 		if (p_first >= LINENUM_MAX - p_ptrn_lines ||
900 		    p_newfirst > LINENUM_MAX - p_repl_lines ||
901 		    p_ptrn_lines >= LINENUM_MAX - p_repl_lines - 1)
902 			malformed();
903 		if (!p_ptrn_lines)
904 			p_first++;	/* do append rather than insert */
905 		p_max = p_ptrn_lines + p_repl_lines + 1;
906 		while (p_max >= hunkmax)
907 			grow_hunkmax();
908 		fillold = 1;
909 		fillnew = fillold + p_ptrn_lines;
910 		p_end = fillnew + p_repl_lines;
911 		snprintf(buf, buf_size, "*** %ld,%ld ****\n", p_first,
912 		    p_first + p_ptrn_lines - 1);
913 		p_line[0] = savestr(buf);
914 		if (out_of_mem) {
915 			p_end = -1;
916 			return false;
917 		}
918 		p_char[0] = '*';
919 		snprintf(buf, buf_size, "--- %ld,%ld ----\n", p_newfirst,
920 		    p_newfirst + p_repl_lines - 1);
921 		p_line[fillnew] = savestr(buf);
922 		if (out_of_mem) {
923 			p_end = 0;
924 			return false;
925 		}
926 		p_char[fillnew++] = '=';
927 		p_context = 100;
928 		context = 0;
929 		p_hunk_beg = p_input_line + 1;
930 		while (fillold <= p_ptrn_lines || fillnew <= p_end) {
931 			line_beginning = ftello(pfp);
932 			len = pgets(true);
933 			p_input_line++;
934 			if (len == 0) {
935 				if (p_max - fillnew < 3) {
936 					/* assume blank lines got chopped */
937 					strlcpy(buf, " \n", buf_size);
938 				} else {
939 					fatal("unexpected end of file in patch\n");
940 				}
941 			}
942 			if (*buf == '\t' || *buf == '\n') {
943 				ch = ' ';	/* assume the space got eaten */
944 				s = savestr(buf);
945 			} else {
946 				ch = *buf;
947 				s = savestr(buf + 1);
948 			}
949 			if (out_of_mem) {
950 				while (--fillnew > p_ptrn_lines)
951 					free(p_line[fillnew]);
952 				p_end = fillold - 1;
953 				return false;
954 			}
955 			switch (ch) {
956 			case '-':
957 				if (fillold > p_ptrn_lines) {
958 					free(s);
959 					p_end = fillnew - 1;
960 					malformed();
961 				}
962 				p_char[fillold] = ch;
963 				p_line[fillold] = s;
964 				p_len[fillold++] = strlen(s);
965 				if (fillold > p_ptrn_lines) {
966 					if (remove_special_line()) {
967 						p_len[fillold - 1] -= 1;
968 						s[p_len[fillold - 1]] = 0;
969 					}
970 				}
971 				break;
972 			case '=':
973 				ch = ' ';
974 				/* FALL THROUGH */
975 			case ' ':
976 				if (fillold > p_ptrn_lines) {
977 					free(s);
978 					while (--fillnew > p_ptrn_lines)
979 						free(p_line[fillnew]);
980 					p_end = fillold - 1;
981 					malformed();
982 				}
983 				context++;
984 				p_char[fillold] = ch;
985 				p_line[fillold] = s;
986 				p_len[fillold++] = strlen(s);
987 				s = savestr(s);
988 				if (out_of_mem) {
989 					while (--fillnew > p_ptrn_lines)
990 						free(p_line[fillnew]);
991 					p_end = fillold - 1;
992 					return false;
993 				}
994 				if (fillold > p_ptrn_lines) {
995 					if (remove_special_line()) {
996 						p_len[fillold - 1] -= 1;
997 						s[p_len[fillold - 1]] = 0;
998 					}
999 				}
1000 				/* FALL THROUGH */
1001 			case '+':
1002 				if (fillnew > p_end) {
1003 					free(s);
1004 					while (--fillnew > p_ptrn_lines)
1005 						free(p_line[fillnew]);
1006 					p_end = fillold - 1;
1007 					malformed();
1008 				}
1009 				p_char[fillnew] = ch;
1010 				p_line[fillnew] = s;
1011 				p_len[fillnew++] = strlen(s);
1012 				if (fillold > p_ptrn_lines) {
1013 					if (remove_special_line()) {
1014 						p_len[fillnew - 1] -= 1;
1015 						s[p_len[fillnew - 1]] = 0;
1016 					}
1017 				}
1018 				break;
1019 			default:
1020 				p_end = fillnew;
1021 				malformed();
1022 			}
1023 			if (ch != ' ' && context > 0) {
1024 				if (context < p_context)
1025 					p_context = context;
1026 				context = -1000;
1027 			}
1028 		}		/* while */
1029 	} else {		/* normal diff--fake it up */
1030 		char	hunk_type;
1031 		int	i;
1032 		LINENUM	min, max;
1033 
1034 		line_beginning = ftello(pfp);
1035 		p_context = 0;
1036 		len = pgets(true);
1037 		p_input_line++;
1038 		if (len == 0 || !isdigit((unsigned char)*buf)) {
1039 			next_intuit_at(line_beginning, p_input_line);
1040 			return false;
1041 		}
1042 		p_first = strtolinenum(buf, &s);
1043 		if (*s == ',') {
1044 			p_ptrn_lines = strtolinenum(s + 1, &s) - p_first + 1;
1045 			if (p_ptrn_lines < 0)
1046 				malformed();
1047 		} else
1048 			p_ptrn_lines = (*s != 'a');
1049 		hunk_type = *s;
1050 		if (hunk_type == 'a')
1051 			p_first++;	/* do append rather than insert */
1052 		min = strtolinenum(s + 1, &s);
1053 		if (*s == ',')
1054 			max = strtolinenum(s + 1, &s);
1055 		else
1056 			max = min;
1057 		if (min < 0 || min > max || max - min == LINENUM_MAX)
1058 			malformed();
1059 		if (hunk_type == 'd')
1060 			min++;
1061 		p_newfirst = min;
1062 		p_repl_lines = max - min + 1;
1063 		if (p_newfirst > LINENUM_MAX - p_repl_lines ||
1064 		    p_ptrn_lines >= LINENUM_MAX - p_repl_lines - 1)
1065 			malformed();
1066 		p_end = p_ptrn_lines + p_repl_lines + 1;
1067 		if (p_end > MAXHUNKSIZE)
1068 			fatal("hunk too large (%ld lines) at line %ld: %s",
1069 			    p_end, p_input_line, buf);
1070 		while (p_end >= hunkmax)
1071 			grow_hunkmax();
1072 		snprintf(buf, buf_size, "*** %ld,%ld\n", p_first,
1073 		    p_first + p_ptrn_lines - 1);
1074 		p_line[0] = savestr(buf);
1075 		if (out_of_mem) {
1076 			p_end = -1;
1077 			return false;
1078 		}
1079 		p_char[0] = '*';
1080 		for (i = 1; i <= p_ptrn_lines; i++) {
1081 			len = pgets(true);
1082 			p_input_line++;
1083 			if (len == 0)
1084 				fatal("unexpected end of file in patch at line %ld\n",
1085 				    p_input_line);
1086 			if (*buf != '<')
1087 				fatal("< expected at line %ld of patch\n",
1088 				    p_input_line);
1089 			p_line[i] = savestr(buf + 2);
1090 			if (out_of_mem) {
1091 				p_end = i - 1;
1092 				return false;
1093 			}
1094 			p_len[i] = strlen(p_line[i]);
1095 			p_char[i] = '-';
1096 		}
1097 
1098 		if (remove_special_line()) {
1099 			p_len[i - 1] -= 1;
1100 			(p_line[i - 1])[p_len[i - 1]] = 0;
1101 		}
1102 		if (hunk_type == 'c') {
1103 			len = pgets(true);
1104 			p_input_line++;
1105 			if (len == 0)
1106 				fatal("unexpected end of file in patch at line %ld\n",
1107 				    p_input_line);
1108 			if (*buf != '-')
1109 				fatal("--- expected at line %ld of patch\n",
1110 				    p_input_line);
1111 		}
1112 		snprintf(buf, buf_size, "--- %ld,%ld\n", min, max);
1113 		p_line[i] = savestr(buf);
1114 		if (out_of_mem) {
1115 			p_end = i - 1;
1116 			return false;
1117 		}
1118 		p_char[i] = '=';
1119 		for (i++; i <= p_end; i++) {
1120 			len = pgets(true);
1121 			p_input_line++;
1122 			if (len == 0)
1123 				fatal("unexpected end of file in patch at line %ld\n",
1124 				    p_input_line);
1125 			if (*buf != '>')
1126 				fatal("> expected at line %ld of patch\n",
1127 				    p_input_line);
1128 			p_line[i] = savestr(buf + 2);
1129 			if (out_of_mem) {
1130 				p_end = i - 1;
1131 				return false;
1132 			}
1133 			p_len[i] = strlen(p_line[i]);
1134 			p_char[i] = '+';
1135 		}
1136 
1137 		if (remove_special_line()) {
1138 			p_len[i - 1] -= 1;
1139 			(p_line[i - 1])[p_len[i - 1]] = 0;
1140 		}
1141 	}
1142 	if (reverse)		/* backwards patch? */
1143 		if (!pch_swap())
1144 			say("Not enough memory to swap next hunk!\n");
1145 #ifdef DEBUGGING
1146 	if (debug & 2) {
1147 		LINENUM	i;
1148 		char	special;
1149 
1150 		for (i = 0; i <= p_end; i++) {
1151 			if (i == p_ptrn_lines)
1152 				special = '^';
1153 			else
1154 				special = ' ';
1155 			fprintf(stderr, "%3ld %c %c %s", i, p_char[i],
1156 			    special, p_line[i]);
1157 			fflush(stderr);
1158 		}
1159 	}
1160 #endif
1161 	if (p_end + 1 < hunkmax)/* paranoia reigns supreme... */
1162 		p_char[p_end + 1] = '^';	/* add a stopper for apply_hunk */
1163 	return true;
1164 }
1165 
1166 /*
1167  * Input a line from the patch file.
1168  * Worry about indentation if do_indent is true.
1169  * The line is read directly into the buf global variable which
1170  * is resized if necessary in order to hold the complete line.
1171  * Returns the number of characters read including the terminating
1172  * '\n', if any.
1173  */
1174 size_t
1175 pgets(bool do_indent)
1176 {
1177 	char *line;
1178 	size_t len;
1179 	int indent = 0, skipped = 0;
1180 
1181 	line = fgetln(pfp, &len);
1182 	if (line != NULL) {
1183 		if (len + 1 > buf_size) {
1184 			while (len + 1 > buf_size)
1185 				buf_size *= 2;
1186 			free(buf);
1187 			buf = malloc(buf_size);
1188 			if (buf == NULL)
1189 				fatal("out of memory\n");
1190 		}
1191 		if (do_indent == 1 && p_indent) {
1192 			for (;
1193 			    indent < p_indent && (*line == ' ' || *line == '\t' || *line == 'X');
1194 			    line++, skipped++) {
1195 				if (*line == '\t')
1196 					indent += 8 - (indent %7);
1197 				else
1198 					indent++;
1199 			}
1200 		}
1201 		memcpy(buf, line, len - skipped);
1202 		buf[len - skipped] = '\0';
1203 	}
1204 	return len;
1205 }
1206 
1207 
1208 /*
1209  * Reverse the old and new portions of the current hunk.
1210  */
1211 bool
1212 pch_swap(void)
1213 {
1214 	char	**tp_line;	/* the text of the hunk */
1215 	unsigned short	*tp_len;/* length of each line */
1216 	char	*tp_char;	/* +, -, and ! */
1217 	LINENUM	i;
1218 	LINENUM	n;
1219 	bool	blankline = false;
1220 	char	*s;
1221 
1222 	i = p_first;
1223 	p_first = p_newfirst;
1224 	p_newfirst = i;
1225 
1226 	/* make a scratch copy */
1227 
1228 	tp_line = p_line;
1229 	tp_len = p_len;
1230 	tp_char = p_char;
1231 	p_line = NULL;	/* force set_hunkmax to allocate again */
1232 	p_len = NULL;
1233 	p_char = NULL;
1234 	set_hunkmax();
1235 	if (p_line == NULL || p_len == NULL || p_char == NULL) {
1236 
1237 		free(p_line);
1238 		p_line = tp_line;
1239 		free(p_len);
1240 		p_len = tp_len;
1241 		free(p_char);
1242 		p_char = tp_char;
1243 		return false;	/* not enough memory to swap hunk! */
1244 	}
1245 	/* now turn the new into the old */
1246 
1247 	i = p_ptrn_lines + 1;
1248 	if (tp_char[i] == '\n') {	/* account for possible blank line */
1249 		blankline = true;
1250 		i++;
1251 	}
1252 	if (p_efake >= 0) {	/* fix non-freeable ptr range */
1253 		if (p_efake <= i)
1254 			n = p_end - i + 1;
1255 		else
1256 			n = -i;
1257 		p_efake += n;
1258 		p_bfake += n;
1259 	}
1260 	for (n = 0; i <= p_end; i++, n++) {
1261 		p_line[n] = tp_line[i];
1262 		p_char[n] = tp_char[i];
1263 		if (p_char[n] == '+')
1264 			p_char[n] = '-';
1265 		p_len[n] = tp_len[i];
1266 	}
1267 	if (blankline) {
1268 		i = p_ptrn_lines + 1;
1269 		p_line[n] = tp_line[i];
1270 		p_char[n] = tp_char[i];
1271 		p_len[n] = tp_len[i];
1272 		n++;
1273 	}
1274 	if (p_char[0] != '=')
1275 		fatal("Malformed patch at line %ld: expected '=' found '%c'\n",
1276 		    p_input_line, p_char[0]);
1277 	p_char[0] = '*';
1278 	for (s = p_line[0]; *s; s++)
1279 		if (*s == '-')
1280 			*s = '*';
1281 
1282 	/* now turn the old into the new */
1283 
1284 	if (p_char[0] != '*')
1285 		fatal("Malformed patch at line %ld: expected '*' found '%c'\n",
1286 		    p_input_line, p_char[0]);
1287 	tp_char[0] = '=';
1288 	for (s = tp_line[0]; *s; s++)
1289 		if (*s == '*')
1290 			*s = '-';
1291 	for (i = 0; n <= p_end; i++, n++) {
1292 		p_line[n] = tp_line[i];
1293 		p_char[n] = tp_char[i];
1294 		if (p_char[n] == '-')
1295 			p_char[n] = '+';
1296 		p_len[n] = tp_len[i];
1297 	}
1298 
1299 	if (i != p_ptrn_lines + 1)
1300 		fatal("Malformed patch at line %ld: expected %ld lines, "
1301 		    "got %ld\n",
1302 		    p_input_line, p_ptrn_lines + 1, i);
1303 
1304 	i = p_ptrn_lines;
1305 	p_ptrn_lines = p_repl_lines;
1306 	p_repl_lines = i;
1307 
1308 	free(tp_line);
1309 	free(tp_len);
1310 	free(tp_char);
1311 
1312 	return true;
1313 }
1314 
1315 /*
1316  * Return the specified line position in the old file of the old context.
1317  */
1318 LINENUM
1319 pch_first(void)
1320 {
1321 	return p_first;
1322 }
1323 
1324 /*
1325  * Return the number of lines of old context.
1326  */
1327 LINENUM
1328 pch_ptrn_lines(void)
1329 {
1330 	return p_ptrn_lines;
1331 }
1332 
1333 /*
1334  * Return the probable line position in the new file of the first line.
1335  */
1336 LINENUM
1337 pch_newfirst(void)
1338 {
1339 	return p_newfirst;
1340 }
1341 
1342 /*
1343  * Return the number of lines in the replacement text including context.
1344  */
1345 LINENUM
1346 pch_repl_lines(void)
1347 {
1348 	return p_repl_lines;
1349 }
1350 
1351 /*
1352  * Return the number of lines in the whole hunk.
1353  */
1354 LINENUM
1355 pch_end(void)
1356 {
1357 	return p_end;
1358 }
1359 
1360 /*
1361  * Return the number of context lines before the first changed line.
1362  */
1363 LINENUM
1364 pch_context(void)
1365 {
1366 	return p_context;
1367 }
1368 
1369 /*
1370  * Return the length of a particular patch line.
1371  */
1372 unsigned short
1373 pch_line_len(LINENUM line)
1374 {
1375 	return p_len[line];
1376 }
1377 
1378 /*
1379  * Return the control character (+, -, *, !, etc) for a patch line.
1380  */
1381 char
1382 pch_char(LINENUM line)
1383 {
1384 	return p_char[line];
1385 }
1386 
1387 /*
1388  * Return a pointer to a particular patch line.
1389  */
1390 char *
1391 pfetch(LINENUM line)
1392 {
1393 	return p_line[line];
1394 }
1395 
1396 /*
1397  * Return where in the patch file this hunk began, for error messages.
1398  */
1399 LINENUM
1400 pch_hunk_beg(void)
1401 {
1402 	return p_hunk_beg;
1403 }
1404 
1405 /*
1406  * Apply an ed script by feeding ed itself.
1407  */
1408 void
1409 do_ed_script(void)
1410 {
1411 	char	*t;
1412 	off_t	beginning_of_this_line;
1413 	FILE	*pipefp = NULL;
1414 	int	continuation;
1415 
1416 	if (!skip_rest_of_patch) {
1417 		if (copy_file(filearg[0], TMPOUTNAME) < 0) {
1418 			unlink(TMPOUTNAME);
1419 			fatal("can't create temp file %s", TMPOUTNAME);
1420 		}
1421 		snprintf(buf, buf_size, "%s%s%s", _PATH_RED,
1422 		    verbose ? " " : " -s ", TMPOUTNAME);
1423 		pipefp = popen(buf, "w");
1424 	}
1425 	for (;;) {
1426 		beginning_of_this_line = ftello(pfp);
1427 		if (pgets(true) == 0) {
1428 			next_intuit_at(beginning_of_this_line, p_input_line);
1429 			break;
1430 		}
1431 		p_input_line++;
1432 		for (t = buf; isdigit((unsigned char)*t) || *t == ','; t++)
1433 			;
1434 		/* POSIX defines allowed commands as {a,c,d,i,s} */
1435 		if (isdigit((unsigned char)*buf) &&
1436 		    (*t == 'a' || *t == 'c' || *t == 'd' || *t == 'i' || *t == 's')) {
1437 			if (pipefp != NULL)
1438 				fputs(buf, pipefp);
1439 			if (*t == 's') {
1440 				for (;;) {
1441 					continuation = 0;
1442 					t = strchr(buf, '\0') - 1;
1443 					while (--t >= buf && *t == '\\')
1444 						continuation = !continuation;
1445 					if (!continuation ||
1446 					    pgets(true) == 0)
1447 						break;
1448 					if (pipefp != NULL)
1449 						fputs(buf, pipefp);
1450 				}
1451 			} else if (*t != 'd') {
1452 				while (pgets(true)) {
1453 					p_input_line++;
1454 					if (pipefp != NULL)
1455 						fputs(buf, pipefp);
1456 					if (strEQ(buf, ".\n"))
1457 						break;
1458 				}
1459 			}
1460 		} else {
1461 			next_intuit_at(beginning_of_this_line, p_input_line);
1462 			break;
1463 		}
1464 	}
1465 	if (pipefp == NULL)
1466 		return;
1467 	fprintf(pipefp, "w\n");
1468 	fprintf(pipefp, "q\n");
1469 	fflush(pipefp);
1470 	pclose(pipefp);
1471 	ignore_signals();
1472 	if (!check_only) {
1473 		if (move_file(TMPOUTNAME, outname) < 0) {
1474 			toutkeep = true;
1475 			chmod(TMPOUTNAME, filemode);
1476 		} else
1477 			chmod(outname, filemode);
1478 	}
1479 	set_signals(1);
1480 }
1481 
1482 /*
1483  * Choose the name of the file to be patched based on POSIX rules.
1484  * NOTE: the POSIX rules are amazingly stupid and we only follow them
1485  *       if the user specified --posix or set POSIXLY_CORRECT.
1486  */
1487 static char *
1488 posix_name(const struct file_name *names, bool assume_exists)
1489 {
1490 	char *path = NULL;
1491 	int i;
1492 
1493 	/*
1494 	 * POSIX states that the filename will be chosen from one
1495 	 * of the old, new and index names (in that order) if
1496 	 * the file exists relative to CWD after -p stripping.
1497 	 */
1498 	for (i = 0; i < MAX_FILE; i++) {
1499 		if (names[i].path != NULL && names[i].exists) {
1500 			path = names[i].path;
1501 			break;
1502 		}
1503 	}
1504 	if (path == NULL && !assume_exists) {
1505 		/*
1506 		 * No files found, check to see if the diff could be
1507 		 * creating a new file.
1508 		 */
1509 		if (path == NULL && ok_to_create_file &&
1510 		    names[NEW_FILE].path != NULL)
1511 			path = names[NEW_FILE].path;
1512 	}
1513 
1514 	return path ? xstrdup(path) : NULL;
1515 }
1516 
1517 static char *
1518 compare_names(const struct file_name *names, bool assume_exists)
1519 {
1520 	size_t min_components, min_baselen, min_len, tmp;
1521 	char *best = NULL;
1522 	char *path;
1523 	int i;
1524 
1525 	/*
1526 	 * The "best" name is the one with the fewest number of path
1527 	 * components, the shortest basename length, and the shortest
1528 	 * overall length (in that order).  We only use the Index: file
1529 	 * if neither of the old or new files could be intuited from
1530 	 * the diff header.
1531 	 */
1532 	min_components = min_baselen = min_len = SIZE_MAX;
1533 	for (i = INDEX_FILE; i >= OLD_FILE; i--) {
1534 		path = names[i].path;
1535 		if (path == NULL || (!names[i].exists && !assume_exists))
1536 			continue;
1537 		if ((tmp = num_components(path)) > min_components)
1538 			continue;
1539 		if (tmp < min_components) {
1540 			min_components = tmp;
1541 			best = path;
1542 		}
1543 		if ((tmp = strlen(basename(path))) > min_baselen)
1544 			continue;
1545 		if (tmp < min_baselen) {
1546 			min_baselen = tmp;
1547 			best = path;
1548 		}
1549 		if ((tmp = strlen(path)) > min_len)
1550 			continue;
1551 		min_len = tmp;
1552 		best = path;
1553 	}
1554 	return best;
1555 }
1556 
1557 /*
1558  * Choose the name of the file to be patched based the "best" one
1559  * available.
1560  */
1561 static char *
1562 best_name(const struct file_name *names, bool assume_exists)
1563 {
1564 	char *best;
1565 
1566 	best = compare_names(names, assume_exists);
1567 
1568 	/* No match?  Check to see if the diff could be creating a new file. */
1569 	if (best == NULL && ok_to_create_file)
1570 		best = names[NEW_FILE].path;
1571 
1572 	return best ? xstrdup(best) : NULL;
1573 }
1574 
1575 static size_t
1576 num_components(const char *path)
1577 {
1578 	size_t n;
1579 	const char *cp;
1580 
1581 	for (n = 0, cp = path; (cp = strchr(cp, '/')) != NULL; n++, cp++) {
1582 		while (*cp == '/')
1583 			cp++;		/* skip consecutive slashes */
1584 	}
1585 	return n;
1586 }
1587 
1588 /*
1589  * Convert number at NPTR into LINENUM and save address of first
1590  * character that is not a digit in ENDPTR.  If conversion is not
1591  * possible, call fatal.
1592  */
1593 static LINENUM
1594 strtolinenum(char *nptr, char **endptr)
1595 {
1596 	LINENUM rv;
1597 	char c;
1598 	char *p;
1599 	const char *errstr;
1600 
1601 	for (p = nptr; isdigit((unsigned char)*p); p++)
1602 		;
1603 
1604 	if (p == nptr)
1605 		malformed();
1606 
1607 	c = *p;
1608 	*p = '\0';
1609 
1610 	rv = strtonum(nptr, 0, LINENUM_MAX, &errstr);
1611 	if (errstr != NULL)
1612 		fatal("invalid line number at line %ld: `%s' is %s\n",
1613 		    p_input_line, nptr, errstr);
1614 
1615 	*p = c;
1616 	*endptr = p;
1617 
1618 	return rv;
1619 }
1620