Merge master.kernel.org:/pub/scm/gitk/gitk
[git/git.git] / apply.c
1 /*
2 * apply.c
3 *
4 * Copyright (C) Linus Torvalds, 2005
5 *
6 * This applies patches on top of some (arbitrary) version of the SCM.
7 *
8 * NOTE! It does all its work in the index file, and only cares about
9 * the files in the working directory if you tell it to "merge" the
10 * patch apply.
11 *
12 * Even when merging it always takes the source from the index, and
13 * uses the working tree as a "branch" for a 3-way merge.
14 */
15 #include <ctype.h>
16
17 #include "cache.h"
18
19 // We default to the merge behaviour, since that's what most people would
20 // expect.
21 //
22 // --check turns on checking that the working tree matches the
23 // files that are being modified, but doesn't apply the patch
24 // --stat does just a diffstat, and doesn't actually apply
25 // --show-files shows the directory changes
26 //
27 static int merge_patch = 1;
28 static int check_index = 0;
29 static int write_index = 0;
30 static int diffstat = 0;
31 static int summary = 0;
32 static int check = 0;
33 static int apply = 1;
34 static int show_files = 0;
35 static const char apply_usage[] = "git-apply [--stat] [--summary] [--check] [--show-files] <patch>";
36
37 /*
38 * For "diff-stat" like behaviour, we keep track of the biggest change
39 * we've seen, and the longest filename. That allows us to do simple
40 * scaling.
41 */
42 static int max_change, max_len;
43
44 /*
45 * Various "current state", notably line numbers and what
46 * file (and how) we're patching right now.. The "is_xxxx"
47 * things are flags, where -1 means "don't know yet".
48 */
49 static int linenr = 1;
50
51 struct fragment {
52 unsigned long oldpos, oldlines;
53 unsigned long newpos, newlines;
54 const char *patch;
55 int size;
56 struct fragment *next;
57 };
58
59 struct patch {
60 char *new_name, *old_name, *def_name;
61 unsigned int old_mode, new_mode;
62 int is_rename, is_copy, is_new, is_delete;
63 int lines_added, lines_deleted;
64 int score;
65 struct fragment *fragments;
66 char *result;
67 unsigned long resultsize;
68 struct patch *next;
69 };
70
71 #define CHUNKSIZE (8192)
72 #define SLOP (16)
73
74 static void *read_patch_file(int fd, unsigned long *sizep)
75 {
76 unsigned long size = 0, alloc = CHUNKSIZE;
77 void *buffer = xmalloc(alloc);
78
79 for (;;) {
80 int nr = alloc - size;
81 if (nr < 1024) {
82 alloc += CHUNKSIZE;
83 buffer = xrealloc(buffer, alloc);
84 nr = alloc - size;
85 }
86 nr = read(fd, buffer + size, nr);
87 if (!nr)
88 break;
89 if (nr < 0) {
90 if (errno == EAGAIN)
91 continue;
92 die("git-apply: read returned %s", strerror(errno));
93 }
94 size += nr;
95 }
96 *sizep = size;
97
98 /*
99 * Make sure that we have some slop in the buffer
100 * so that we can do speculative "memcmp" etc, and
101 * see to it that it is NUL-filled.
102 */
103 if (alloc < size + SLOP)
104 buffer = xrealloc(buffer, size + SLOP);
105 memset(buffer + size, 0, SLOP);
106 return buffer;
107 }
108
109 static unsigned long linelen(const char *buffer, unsigned long size)
110 {
111 unsigned long len = 0;
112 while (size--) {
113 len++;
114 if (*buffer++ == '\n')
115 break;
116 }
117 return len;
118 }
119
120 static int is_dev_null(const char *str)
121 {
122 return !memcmp("/dev/null", str, 9) && isspace(str[9]);
123 }
124
125 #define TERM_SPACE 1
126 #define TERM_TAB 2
127
128 static int name_terminate(const char *name, int namelen, int c, int terminate)
129 {
130 if (c == ' ' && !(terminate & TERM_SPACE))
131 return 0;
132 if (c == '\t' && !(terminate & TERM_TAB))
133 return 0;
134
135 return 1;
136 }
137
138 static char * find_name(const char *line, char *def, int p_value, int terminate)
139 {
140 int len;
141 const char *start = line;
142 char *name;
143
144 for (;;) {
145 char c = *line;
146
147 if (isspace(c)) {
148 if (c == '\n')
149 break;
150 if (name_terminate(start, line-start, c, terminate))
151 break;
152 }
153 line++;
154 if (c == '/' && !--p_value)
155 start = line;
156 }
157 if (!start)
158 return def;
159 len = line - start;
160 if (!len)
161 return def;
162
163 /*
164 * Generally we prefer the shorter name, especially
165 * if the other one is just a variation of that with
166 * something else tacked on to the end (ie "file.orig"
167 * or "file~").
168 */
169 if (def) {
170 int deflen = strlen(def);
171 if (deflen < len && !strncmp(start, def, deflen))
172 return def;
173 }
174
175 name = xmalloc(len + 1);
176 memcpy(name, start, len);
177 name[len] = 0;
178 free(def);
179 return name;
180 }
181
182 /*
183 * Get the name etc info from the --/+++ lines of a traditional patch header
184 *
185 * NOTE! This hardcodes "-p1" behaviour in filename detection.
186 *
187 * FIXME! The end-of-filename heuristics are kind of screwy. For existing
188 * files, we can happily check the index for a match, but for creating a
189 * new file we should try to match whatever "patch" does. I have no idea.
190 */
191 static void parse_traditional_patch(const char *first, const char *second, struct patch *patch)
192 {
193 int p_value = 1;
194 char *name;
195
196 first += 4; // skip "--- "
197 second += 4; // skip "+++ "
198 if (is_dev_null(first)) {
199 patch->is_new = 1;
200 patch->is_delete = 0;
201 name = find_name(second, NULL, p_value, TERM_SPACE | TERM_TAB);
202 patch->new_name = name;
203 } else if (is_dev_null(second)) {
204 patch->is_new = 0;
205 patch->is_delete = 1;
206 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
207 patch->old_name = name;
208 } else {
209 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
210 name = find_name(second, name, p_value, TERM_SPACE | TERM_TAB);
211 patch->old_name = patch->new_name = name;
212 }
213 if (!name)
214 die("unable to find filename in patch at line %d", linenr);
215 }
216
217 static int gitdiff_hdrend(const char *line, struct patch *patch)
218 {
219 return -1;
220 }
221
222 /*
223 * We're anal about diff header consistency, to make
224 * sure that we don't end up having strange ambiguous
225 * patches floating around.
226 *
227 * As a result, gitdiff_{old|new}name() will check
228 * their names against any previous information, just
229 * to make sure..
230 */
231 static char *gitdiff_verify_name(const char *line, int isnull, char *orig_name, const char *oldnew)
232 {
233 int len;
234 const char *name;
235
236 if (!orig_name && !isnull)
237 return find_name(line, NULL, 1, 0);
238
239 name = "/dev/null";
240 len = 9;
241 if (orig_name) {
242 name = orig_name;
243 len = strlen(name);
244 if (isnull)
245 die("git-apply: bad git-diff - expected /dev/null, got %s on line %d", name, linenr);
246 }
247
248 if (*name == '/')
249 goto absolute_path;
250
251 for (;;) {
252 char c = *line++;
253 if (c == '\n')
254 break;
255 if (c != '/')
256 continue;
257 absolute_path:
258 if (memcmp(line, name, len) || line[len] != '\n')
259 break;
260 return orig_name;
261 }
262 die("git-apply: bad git-diff - inconsistent %s filename on line %d", oldnew, linenr);
263 return NULL;
264 }
265
266 static int gitdiff_oldname(const char *line, struct patch *patch)
267 {
268 patch->old_name = gitdiff_verify_name(line, patch->is_new, patch->old_name, "old");
269 return 0;
270 }
271
272 static int gitdiff_newname(const char *line, struct patch *patch)
273 {
274 patch->new_name = gitdiff_verify_name(line, patch->is_delete, patch->new_name, "new");
275 return 0;
276 }
277
278 static int gitdiff_oldmode(const char *line, struct patch *patch)
279 {
280 patch->old_mode = strtoul(line, NULL, 8);
281 return 0;
282 }
283
284 static int gitdiff_newmode(const char *line, struct patch *patch)
285 {
286 patch->new_mode = strtoul(line, NULL, 8);
287 return 0;
288 }
289
290 static int gitdiff_delete(const char *line, struct patch *patch)
291 {
292 patch->is_delete = 1;
293 patch->old_name = patch->def_name;
294 return gitdiff_oldmode(line, patch);
295 }
296
297 static int gitdiff_newfile(const char *line, struct patch *patch)
298 {
299 patch->is_new = 1;
300 patch->new_name = patch->def_name;
301 return gitdiff_newmode(line, patch);
302 }
303
304 static int gitdiff_copysrc(const char *line, struct patch *patch)
305 {
306 patch->is_copy = 1;
307 patch->old_name = find_name(line, NULL, 0, 0);
308 return 0;
309 }
310
311 static int gitdiff_copydst(const char *line, struct patch *patch)
312 {
313 patch->is_copy = 1;
314 patch->new_name = find_name(line, NULL, 0, 0);
315 return 0;
316 }
317
318 static int gitdiff_renamesrc(const char *line, struct patch *patch)
319 {
320 patch->is_rename = 1;
321 patch->old_name = find_name(line, NULL, 0, 0);
322 return 0;
323 }
324
325 static int gitdiff_renamedst(const char *line, struct patch *patch)
326 {
327 patch->is_rename = 1;
328 patch->new_name = find_name(line, NULL, 0, 0);
329 return 0;
330 }
331
332 static int gitdiff_similarity(const char *line, struct patch *patch)
333 {
334 if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
335 patch->score = 0;
336 return 0;
337 }
338
339 static int gitdiff_dissimilarity(const char *line, struct patch *patch)
340 {
341 if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
342 patch->score = 0;
343 return 0;
344 }
345
346 /*
347 * This is normal for a diff that doesn't change anything: we'll fall through
348 * into the next diff. Tell the parser to break out.
349 */
350 static int gitdiff_unrecognized(const char *line, struct patch *patch)
351 {
352 return -1;
353 }
354
355 static char *git_header_name(char *line)
356 {
357 int len;
358 char *name, *second;
359
360 /*
361 * Find the first '/'
362 */
363 name = line;
364 for (;;) {
365 char c = *name++;
366 if (c == '\n')
367 return NULL;
368 if (c == '/')
369 break;
370 }
371
372 /*
373 * We don't accept absolute paths (/dev/null) as possibly valid
374 */
375 if (name == line+1)
376 return NULL;
377
378 /*
379 * Accept a name only if it shows up twice, exactly the same
380 * form.
381 */
382 for (len = 0 ; ; len++) {
383 char c = name[len];
384
385 switch (c) {
386 default:
387 continue;
388 case '\n':
389 break;
390 case '\t': case ' ':
391 second = name+len;
392 for (;;) {
393 char c = *second++;
394 if (c == '\n')
395 return NULL;
396 if (c == '/')
397 break;
398 }
399 if (second[len] == '\n' && !memcmp(name, second, len)) {
400 char *ret = xmalloc(len + 1);
401 memcpy(ret, name, len);
402 ret[len] = 0;
403 return ret;
404 }
405 }
406 }
407 return NULL;
408 }
409
410 /* Verify that we recognize the lines following a git header */
411 static int parse_git_header(char *line, int len, unsigned int size, struct patch *patch)
412 {
413 unsigned long offset;
414
415 /* A git diff has explicit new/delete information, so we don't guess */
416 patch->is_new = 0;
417 patch->is_delete = 0;
418
419 /*
420 * Some things may not have the old name in the
421 * rest of the headers anywhere (pure mode changes,
422 * or removing or adding empty files), so we get
423 * the default name from the header.
424 */
425 patch->def_name = git_header_name(line + strlen("diff --git "));
426
427 line += len;
428 size -= len;
429 linenr++;
430 for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) {
431 static const struct opentry {
432 const char *str;
433 int (*fn)(const char *, struct patch *);
434 } optable[] = {
435 { "@@ -", gitdiff_hdrend },
436 { "--- ", gitdiff_oldname },
437 { "+++ ", gitdiff_newname },
438 { "old mode ", gitdiff_oldmode },
439 { "new mode ", gitdiff_newmode },
440 { "deleted file mode ", gitdiff_delete },
441 { "new file mode ", gitdiff_newfile },
442 { "copy from ", gitdiff_copysrc },
443 { "copy to ", gitdiff_copydst },
444 { "rename old ", gitdiff_renamesrc },
445 { "rename new ", gitdiff_renamedst },
446 { "rename from ", gitdiff_renamesrc },
447 { "rename to ", gitdiff_renamedst },
448 { "similarity index ", gitdiff_similarity },
449 { "dissimilarity index ", gitdiff_dissimilarity },
450 { "", gitdiff_unrecognized },
451 };
452 int i;
453
454 len = linelen(line, size);
455 if (!len || line[len-1] != '\n')
456 break;
457 for (i = 0; i < sizeof(optable) / sizeof(optable[0]); i++) {
458 const struct opentry *p = optable + i;
459 int oplen = strlen(p->str);
460 if (len < oplen || memcmp(p->str, line, oplen))
461 continue;
462 if (p->fn(line + oplen, patch) < 0)
463 return offset;
464 break;
465 }
466 }
467
468 return offset;
469 }
470
471 static int parse_num(const char *line, unsigned long *p)
472 {
473 char *ptr;
474
475 if (!isdigit(*line))
476 return 0;
477 *p = strtoul(line, &ptr, 10);
478 return ptr - line;
479 }
480
481 static int parse_range(const char *line, int len, int offset, const char *expect,
482 unsigned long *p1, unsigned long *p2)
483 {
484 int digits, ex;
485
486 if (offset < 0 || offset >= len)
487 return -1;
488 line += offset;
489 len -= offset;
490
491 digits = parse_num(line, p1);
492 if (!digits)
493 return -1;
494
495 offset += digits;
496 line += digits;
497 len -= digits;
498
499 *p2 = *p1;
500 if (*line == ',') {
501 digits = parse_num(line+1, p2);
502 if (!digits)
503 return -1;
504
505 offset += digits+1;
506 line += digits+1;
507 len -= digits+1;
508 }
509
510 ex = strlen(expect);
511 if (ex > len)
512 return -1;
513 if (memcmp(line, expect, ex))
514 return -1;
515
516 return offset + ex;
517 }
518
519 /*
520 * Parse a unified diff fragment header of the
521 * form "@@ -a,b +c,d @@"
522 */
523 static int parse_fragment_header(char *line, int len, struct fragment *fragment)
524 {
525 int offset;
526
527 if (!len || line[len-1] != '\n')
528 return -1;
529
530 /* Figure out the number of lines in a fragment */
531 offset = parse_range(line, len, 4, " +", &fragment->oldpos, &fragment->oldlines);
532 offset = parse_range(line, len, offset, " @@", &fragment->newpos, &fragment->newlines);
533
534 return offset;
535 }
536
537 static int find_header(char *line, unsigned long size, int *hdrsize, struct patch *patch)
538 {
539 unsigned long offset, len;
540
541 patch->is_rename = patch->is_copy = 0;
542 patch->is_new = patch->is_delete = -1;
543 patch->old_mode = patch->new_mode = 0;
544 patch->old_name = patch->new_name = NULL;
545 for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) {
546 unsigned long nextlen;
547
548 len = linelen(line, size);
549 if (!len)
550 break;
551
552 /* Testing this early allows us to take a few shortcuts.. */
553 if (len < 6)
554 continue;
555
556 /*
557 * Make sure we don't find any unconnected patch fragmants.
558 * That's a sign that we didn't find a header, and that a
559 * patch has become corrupted/broken up.
560 */
561 if (!memcmp("@@ -", line, 4)) {
562 struct fragment dummy;
563 if (parse_fragment_header(line, len, &dummy) < 0)
564 continue;
565 error("patch fragment without header at line %d: %.*s", linenr, len-1, line);
566 }
567
568 if (size < len + 6)
569 break;
570
571 /*
572 * Git patch? It might not have a real patch, just a rename
573 * or mode change, so we handle that specially
574 */
575 if (!memcmp("diff --git ", line, 11)) {
576 int git_hdr_len = parse_git_header(line, len, size, patch);
577 if (git_hdr_len <= len)
578 continue;
579 if (!patch->old_name && !patch->new_name) {
580 if (!patch->def_name)
581 die("git diff header lacks filename information (line %d)", linenr);
582 patch->old_name = patch->new_name = patch->def_name;
583 }
584 *hdrsize = git_hdr_len;
585 return offset;
586 }
587
588 /** --- followed by +++ ? */
589 if (memcmp("--- ", line, 4) || memcmp("+++ ", line + len, 4))
590 continue;
591
592 /*
593 * We only accept unified patches, so we want it to
594 * at least have "@@ -a,b +c,d @@\n", which is 14 chars
595 * minimum
596 */
597 nextlen = linelen(line + len, size - len);
598 if (size < nextlen + 14 || memcmp("@@ -", line + len + nextlen, 4))
599 continue;
600
601 /* Ok, we'll consider it a patch */
602 parse_traditional_patch(line, line+len, patch);
603 *hdrsize = len + nextlen;
604 linenr += 2;
605 return offset;
606 }
607 return -1;
608 }
609
610 /*
611 * Parse a unified diff. Note that this really needs
612 * to parse each fragment separately, since the only
613 * way to know the difference between a "---" that is
614 * part of a patch, and a "---" that starts the next
615 * patch is to look at the line counts..
616 */
617 static int parse_fragment(char *line, unsigned long size, struct patch *patch, struct fragment *fragment)
618 {
619 int added, deleted;
620 int len = linelen(line, size), offset;
621 unsigned long oldlines, newlines;
622
623 offset = parse_fragment_header(line, len, fragment);
624 if (offset < 0)
625 return -1;
626 oldlines = fragment->oldlines;
627 newlines = fragment->newlines;
628
629 if (patch->is_new < 0) {
630 patch->is_new = !oldlines;
631 if (!oldlines)
632 patch->old_name = NULL;
633 }
634 if (patch->is_delete < 0) {
635 patch->is_delete = !newlines;
636 if (!newlines)
637 patch->new_name = NULL;
638 }
639
640 if (patch->is_new != !oldlines)
641 return error("new file depends on old contents");
642 if (patch->is_delete != !newlines) {
643 if (newlines)
644 return error("deleted file still has contents");
645 fprintf(stderr, "** warning: file %s becomes empty but is not deleted\n", patch->new_name);
646 }
647
648 /* Parse the thing.. */
649 line += len;
650 size -= len;
651 linenr++;
652 added = deleted = 0;
653 for (offset = len; size > 0; offset += len, size -= len, line += len, linenr++) {
654 if (!oldlines && !newlines)
655 break;
656 len = linelen(line, size);
657 if (!len || line[len-1] != '\n')
658 return -1;
659 switch (*line) {
660 default:
661 return -1;
662 case ' ':
663 oldlines--;
664 newlines--;
665 break;
666 case '-':
667 deleted++;
668 oldlines--;
669 break;
670 case '+':
671 added++;
672 newlines--;
673 break;
674 /* We allow "\ No newline at end of file" */
675 case '\\':
676 if (len < 12 || memcmp(line, "\\ No newline", 12))
677 return -1;
678 break;
679 }
680 }
681 patch->lines_added += added;
682 patch->lines_deleted += deleted;
683 return offset;
684 }
685
686 static int parse_single_patch(char *line, unsigned long size, struct patch *patch)
687 {
688 unsigned long offset = 0;
689 struct fragment **fragp = &patch->fragments;
690
691 while (size > 4 && !memcmp(line, "@@ -", 4)) {
692 struct fragment *fragment;
693 int len;
694
695 fragment = xmalloc(sizeof(*fragment));
696 memset(fragment, 0, sizeof(*fragment));
697 len = parse_fragment(line, size, patch, fragment);
698 if (len <= 0)
699 die("corrupt patch at line %d", linenr);
700
701 fragment->patch = line;
702 fragment->size = len;
703
704 *fragp = fragment;
705 fragp = &fragment->next;
706
707 offset += len;
708 line += len;
709 size -= len;
710 }
711 return offset;
712 }
713
714 static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
715 {
716 int hdrsize, patchsize;
717 int offset = find_header(buffer, size, &hdrsize, patch);
718
719 if (offset < 0)
720 return offset;
721
722 patchsize = parse_single_patch(buffer + offset + hdrsize, size - offset - hdrsize, patch);
723
724 return offset + hdrsize + patchsize;
725 }
726
727 static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
728 static const char minuses[]= "----------------------------------------------------------------------";
729
730 static void show_stats(struct patch *patch)
731 {
732 char *name = patch->new_name;
733 int len, max, add, del, total;
734
735 if (!name)
736 name = patch->old_name;
737
738 /*
739 * "scale" the filename
740 */
741 len = strlen(name);
742 max = max_len;
743 if (max > 50)
744 max = 50;
745 if (len > max)
746 name += len - max;
747 len = max;
748
749 /*
750 * scale the add/delete
751 */
752 max = max_change;
753 if (max + len > 70)
754 max = 70 - len;
755
756 add = patch->lines_added;
757 del = patch->lines_deleted;
758 total = add + del;
759
760 if (max_change > 0) {
761 total = (total * max + max_change / 2) / max_change;
762 add = (add * max + max_change / 2) / max_change;
763 del = total - add;
764 }
765 printf(" %-*s |%5d %.*s%.*s\n",
766 len, name, patch->lines_added + patch->lines_deleted,
767 add, pluses, del, minuses);
768 }
769
770 static int read_old_data(struct stat *st, const char *path, void *buf, unsigned long size)
771 {
772 int fd;
773 unsigned long got;
774
775 switch (st->st_mode & S_IFMT) {
776 case S_IFLNK:
777 return readlink(path, buf, size);
778 case S_IFREG:
779 fd = open(path, O_RDONLY);
780 if (fd < 0)
781 return error("unable to open %s", path);
782 got = 0;
783 for (;;) {
784 int ret = read(fd, buf + got, size - got);
785 if (ret < 0) {
786 if (errno == EAGAIN)
787 continue;
788 break;
789 }
790 if (!ret)
791 break;
792 got += ret;
793 }
794 close(fd);
795 return got;
796
797 default:
798 return -1;
799 }
800 }
801
802 static int find_offset(const char *buf, unsigned long size, const char *fragment, unsigned long fragsize, int line)
803 {
804 int i;
805 unsigned long start, backwards, forwards;
806
807 if (fragsize > size)
808 return -1;
809
810 start = 0;
811 if (line > 1) {
812 unsigned long offset = 0;
813 i = line-1;
814 while (offset + fragsize <= size) {
815 if (buf[offset++] == '\n') {
816 start = offset;
817 if (!--i)
818 break;
819 }
820 }
821 }
822
823 /* Exact line number? */
824 if (!memcmp(buf + start, fragment, fragsize))
825 return start;
826
827 /*
828 * There's probably some smart way to do this, but I'll leave
829 * that to the smart and beautiful people. I'm simple and stupid.
830 */
831 backwards = start;
832 forwards = start;
833 for (i = 0; ; i++) {
834 unsigned long try;
835 int n;
836
837 /* "backward" */
838 if (i & 1) {
839 if (!backwards) {
840 if (forwards + fragsize > size)
841 break;
842 continue;
843 }
844 do {
845 --backwards;
846 } while (backwards && buf[backwards-1] != '\n');
847 try = backwards;
848 } else {
849 while (forwards + fragsize <= size) {
850 if (buf[forwards++] == '\n')
851 break;
852 }
853 try = forwards;
854 }
855
856 if (try + fragsize > size)
857 continue;
858 if (memcmp(buf + try, fragment, fragsize))
859 continue;
860 n = (i >> 1)+1;
861 if (i & 1)
862 n = -n;
863 return try;
864 }
865
866 /*
867 * We should start searching forward and backward.
868 */
869 return -1;
870 }
871
872 struct buffer_desc {
873 char *buffer;
874 unsigned long size;
875 unsigned long alloc;
876 };
877
878 static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag)
879 {
880 char *buf = desc->buffer;
881 const char *patch = frag->patch;
882 int offset, size = frag->size;
883 char *old = xmalloc(size);
884 char *new = xmalloc(size);
885 int oldsize = 0, newsize = 0;
886
887 while (size > 0) {
888 int len = linelen(patch, size);
889 int plen;
890
891 if (!len)
892 break;
893
894 /*
895 * "plen" is how much of the line we should use for
896 * the actual patch data. Normally we just remove the
897 * first character on the line, but if the line is
898 * followed by "\ No newline", then we also remove the
899 * last one (which is the newline, of course).
900 */
901 plen = len-1;
902 if (len > size && patch[len] == '\\')
903 plen--;
904 switch (*patch) {
905 case ' ':
906 case '-':
907 memcpy(old + oldsize, patch + 1, plen);
908 oldsize += plen;
909 if (*patch == '-')
910 break;
911 /* Fall-through for ' ' */
912 case '+':
913 memcpy(new + newsize, patch + 1, plen);
914 newsize += plen;
915 break;
916 case '@': case '\\':
917 /* Ignore it, we already handled it */
918 break;
919 default:
920 return -1;
921 }
922 patch += len;
923 size -= len;
924 }
925
926 offset = find_offset(buf, desc->size, old, oldsize, frag->newpos);
927 if (offset >= 0) {
928 int diff = newsize - oldsize;
929 unsigned long size = desc->size + diff;
930 unsigned long alloc = desc->alloc;
931
932 if (size > alloc) {
933 alloc = size + 8192;
934 desc->alloc = alloc;
935 buf = xrealloc(buf, alloc);
936 desc->buffer = buf;
937 }
938 desc->size = size;
939 memmove(buf + offset + newsize, buf + offset + oldsize, size - offset - newsize);
940 memcpy(buf + offset, new, newsize);
941 offset = 0;
942 }
943
944 free(old);
945 free(new);
946 return offset;
947 }
948
949 static int apply_fragments(struct buffer_desc *desc, struct patch *patch)
950 {
951 struct fragment *frag = patch->fragments;
952
953 while (frag) {
954 if (apply_one_fragment(desc, frag) < 0)
955 return error("patch failed: %s:%d", patch->old_name, frag->oldpos);
956 frag = frag->next;
957 }
958 return 0;
959 }
960
961 static int apply_data(struct patch *patch, struct stat *st)
962 {
963 char *buf;
964 unsigned long size, alloc;
965 struct buffer_desc desc;
966
967 size = 0;
968 alloc = 0;
969 buf = NULL;
970 if (patch->old_name) {
971 size = st->st_size;
972 alloc = size + 8192;
973 buf = xmalloc(alloc);
974 if (read_old_data(st, patch->old_name, buf, alloc) != size)
975 return error("read of %s failed", patch->old_name);
976 }
977
978 desc.size = size;
979 desc.alloc = alloc;
980 desc.buffer = buf;
981 if (apply_fragments(&desc, patch) < 0)
982 return -1;
983 patch->result = desc.buffer;
984 patch->resultsize = desc.size;
985
986 if (patch->is_delete && patch->resultsize)
987 return error("removal patch leaves file contents");
988
989 return 0;
990 }
991
992 static int check_patch(struct patch *patch)
993 {
994 struct stat st;
995 const char *old_name = patch->old_name;
996 const char *new_name = patch->new_name;
997
998 if (old_name) {
999 int changed;
1000
1001 if (lstat(old_name, &st) < 0)
1002 return error("%s: %s", old_name, strerror(errno));
1003 if (check_index) {
1004 int pos = cache_name_pos(old_name, strlen(old_name));
1005 if (pos < 0)
1006 return error("%s: does not exist in index", old_name);
1007 changed = ce_match_stat(active_cache[pos], &st);
1008 if (changed)
1009 return error("%s: does not match index", old_name);
1010 }
1011 if (patch->is_new < 0)
1012 patch->is_new = 0;
1013 st.st_mode = ntohl(create_ce_mode(st.st_mode));
1014 if (!patch->old_mode)
1015 patch->old_mode = st.st_mode;
1016 if ((st.st_mode ^ patch->old_mode) & S_IFMT)
1017 return error("%s: wrong type", old_name);
1018 if (st.st_mode != patch->old_mode)
1019 fprintf(stderr, "warning: %s has type %o, expected %o\n",
1020 old_name, st.st_mode, patch->old_mode);
1021 }
1022
1023 if (new_name && (patch->is_new | patch->is_rename | patch->is_copy)) {
1024 if (check_index && cache_name_pos(new_name, strlen(new_name)) >= 0)
1025 return error("%s: already exists in index", new_name);
1026 if (!lstat(new_name, &st))
1027 return error("%s: already exists in working directory", new_name);
1028 if (errno != ENOENT)
1029 return error("%s: %s", new_name, strerror(errno));
1030 if (!patch->new_mode)
1031 patch->new_mode = S_IFREG | 0644;
1032 }
1033
1034 if (new_name && old_name) {
1035 int same = !strcmp(old_name, new_name);
1036 if (!patch->new_mode)
1037 patch->new_mode = patch->old_mode;
1038 if ((patch->old_mode ^ patch->new_mode) & S_IFMT)
1039 return error("new mode (%o) of %s does not match old mode (%o)%s%s",
1040 patch->new_mode, new_name, patch->old_mode,
1041 same ? "" : " of ", same ? "" : old_name);
1042 }
1043
1044 if (apply_data(patch, &st) < 0)
1045 return error("%s: patch does not apply", old_name);
1046 return 0;
1047 }
1048
1049 static int check_patch_list(struct patch *patch)
1050 {
1051 int error = 0;
1052
1053 for (;patch ; patch = patch->next)
1054 error |= check_patch(patch);
1055 return error;
1056 }
1057
1058 static void show_file(int c, unsigned int mode, const char *name)
1059 {
1060 printf("%c %o %s\n", c, mode, name);
1061 }
1062
1063 static void show_file_list(struct patch *patch)
1064 {
1065 for (;patch ; patch = patch->next) {
1066 if (patch->is_rename) {
1067 show_file('-', patch->old_mode, patch->old_name);
1068 show_file('+', patch->new_mode, patch->new_name);
1069 continue;
1070 }
1071 if (patch->is_copy || patch->is_new) {
1072 show_file('+', patch->new_mode, patch->new_name);
1073 continue;
1074 }
1075 if (patch->is_delete) {
1076 show_file('-', patch->old_mode, patch->old_name);
1077 continue;
1078 }
1079 if (patch->old_mode && patch->new_mode && patch->old_mode != patch->new_mode) {
1080 printf("M %o:%o %s\n", patch->old_mode, patch->new_mode, patch->old_name);
1081 continue;
1082 }
1083 printf("M %o %s\n", patch->old_mode, patch->old_name);
1084 }
1085 }
1086
1087 static void stat_patch_list(struct patch *patch)
1088 {
1089 int files, adds, dels;
1090
1091 for (files = adds = dels = 0 ; patch ; patch = patch->next) {
1092 files++;
1093 adds += patch->lines_added;
1094 dels += patch->lines_deleted;
1095 show_stats(patch);
1096 }
1097
1098 printf(" %d files changed, %d insertions(+), %d deletions(-)\n", files, adds, dels);
1099 }
1100
1101 static void show_file_mode_name(const char *newdelete, unsigned int mode, const char *name)
1102 {
1103 if (mode)
1104 printf(" %s mode %06o %s\n", newdelete, mode, name);
1105 else
1106 printf(" %s %s\n", newdelete, name);
1107 }
1108
1109 static void show_mode_change(struct patch *p, int show_name)
1110 {
1111 if (p->old_mode && p->new_mode && p->old_mode != p->new_mode) {
1112 if (show_name)
1113 printf(" mode change %06o => %06o %s\n",
1114 p->old_mode, p->new_mode, p->new_name);
1115 else
1116 printf(" mode change %06o => %06o\n",
1117 p->old_mode, p->new_mode);
1118 }
1119 }
1120
1121 static void show_rename_copy(struct patch *p)
1122 {
1123 const char *renamecopy = p->is_rename ? "rename" : "copy";
1124 const char *old, *new;
1125
1126 /* Find common prefix */
1127 old = p->old_name;
1128 new = p->new_name;
1129 while (1) {
1130 const char *slash_old, *slash_new;
1131 slash_old = strchr(old, '/');
1132 slash_new = strchr(new, '/');
1133 if (!slash_old ||
1134 !slash_new ||
1135 slash_old - old != slash_new - new ||
1136 memcmp(old, new, slash_new - new))
1137 break;
1138 old = slash_old + 1;
1139 new = slash_new + 1;
1140 }
1141 /* p->old_name thru old is the common prefix, and old and new
1142 * through the end of names are renames
1143 */
1144 if (old != p->old_name)
1145 printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
1146 old - p->old_name, p->old_name,
1147 old, new, p->score);
1148 else
1149 printf(" %s %s => %s (%d%%)\n", renamecopy,
1150 p->old_name, p->new_name, p->score);
1151 show_mode_change(p, 0);
1152 }
1153
1154 static void summary_patch_list(struct patch *patch)
1155 {
1156 struct patch *p;
1157
1158 for (p = patch; p; p = p->next) {
1159 if (p->is_new)
1160 show_file_mode_name("create", p->new_mode, p->new_name);
1161 else if (p->is_delete)
1162 show_file_mode_name("delete", p->old_mode, p->old_name);
1163 else {
1164 if (p->is_rename || p->is_copy)
1165 show_rename_copy(p);
1166 else {
1167 if (p->score) {
1168 printf(" rewrite %s (%d%%)\n",
1169 p->new_name, p->score);
1170 show_mode_change(p, 0);
1171 }
1172 else
1173 show_mode_change(p, 1);
1174 }
1175 }
1176 }
1177 }
1178
1179 static void patch_stats(struct patch *patch)
1180 {
1181 int lines = patch->lines_added + patch->lines_deleted;
1182
1183 if (lines > max_change)
1184 max_change = lines;
1185 if (patch->old_name) {
1186 int len = strlen(patch->old_name);
1187 if (len > max_len)
1188 max_len = len;
1189 }
1190 if (patch->new_name) {
1191 int len = strlen(patch->new_name);
1192 if (len > max_len)
1193 max_len = len;
1194 }
1195 }
1196
1197 static void remove_file(struct patch *patch)
1198 {
1199 if (write_index) {
1200 if (remove_file_from_cache(patch->old_name) < 0)
1201 die("unable to remove %s from index", patch->old_name);
1202 }
1203 unlink(patch->old_name);
1204 }
1205
1206 static void add_index_file(const char *path, unsigned mode, void *buf, unsigned long size)
1207 {
1208 struct stat st;
1209 struct cache_entry *ce;
1210 int namelen = strlen(path);
1211 unsigned ce_size = cache_entry_size(namelen);
1212
1213 if (!write_index)
1214 return;
1215
1216 ce = xmalloc(ce_size);
1217 memset(ce, 0, ce_size);
1218 memcpy(ce->name, path, namelen);
1219 ce->ce_mode = create_ce_mode(mode);
1220 ce->ce_flags = htons(namelen);
1221 if (lstat(path, &st) < 0)
1222 die("unable to stat newly created file %s", path);
1223 fill_stat_cache_info(ce, &st);
1224 if (write_sha1_file(buf, size, "blob", ce->sha1) < 0)
1225 die("unable to create backing store for newly created file %s", path);
1226 if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0)
1227 die("unable to add cache entry for %s", path);
1228 }
1229
1230 static void create_subdirectories(const char *path)
1231 {
1232 int len = strlen(path);
1233 char *buf = xmalloc(len + 1);
1234 const char *slash = path;
1235
1236 while ((slash = strchr(slash+1, '/')) != NULL) {
1237 len = slash - path;
1238 memcpy(buf, path, len);
1239 buf[len] = 0;
1240 if (mkdir(buf, 0755) < 0) {
1241 if (errno != EEXIST)
1242 break;
1243 }
1244 }
1245 free(buf);
1246 }
1247
1248 /*
1249 * We optimistically assume that the directories exist,
1250 * which is true 99% of the time anyway. If they don't,
1251 * we create them and try again.
1252 */
1253 static int create_regular_file(const char *path, unsigned int mode)
1254 {
1255 int ret = open(path, O_WRONLY | O_CREAT | O_TRUNC, mode);
1256
1257 if (ret < 0 && errno == ENOENT) {
1258 create_subdirectories(path);
1259 ret = open(path, O_WRONLY | O_CREAT | O_TRUNC, mode);
1260 }
1261 return ret;
1262 }
1263
1264 static int create_symlink(const char *buf, const char *path)
1265 {
1266 int ret = symlink(buf, path);
1267
1268 if (ret < 0 && errno == ENOENT) {
1269 create_subdirectories(path);
1270 ret = symlink(buf, path);
1271 }
1272 return ret;
1273 }
1274
1275 static void create_file(struct patch *patch)
1276 {
1277 const char *path = patch->new_name;
1278 unsigned mode = patch->new_mode;
1279 unsigned long size = patch->resultsize;
1280 char *buf = patch->result;
1281
1282 if (!mode)
1283 mode = S_IFREG | 0644;
1284 if (S_ISREG(mode)) {
1285 int fd;
1286 mode = (mode & 0100) ? 0777 : 0666;
1287 fd = create_regular_file(path, mode);
1288 if (fd < 0)
1289 die("unable to create file %s (%s)", path, strerror(errno));
1290 if (write(fd, buf, size) != size)
1291 die("unable to write file %s", path);
1292 close(fd);
1293 add_index_file(path, mode, buf, size);
1294 return;
1295 }
1296 if (S_ISLNK(mode)) {
1297 if (size && buf[size-1] == '\n')
1298 size--;
1299 buf[size] = 0;
1300 if (create_symlink(buf, path) < 0)
1301 die("unable to write symlink %s", path);
1302 add_index_file(path, mode, buf, size);
1303 return;
1304 }
1305 die("unable to write file mode %o", mode);
1306 }
1307
1308 static void write_out_one_result(struct patch *patch)
1309 {
1310 if (patch->is_delete > 0) {
1311 remove_file(patch);
1312 return;
1313 }
1314 if (patch->is_new > 0 || patch->is_copy) {
1315 create_file(patch);
1316 return;
1317 }
1318 /*
1319 * Rename or modification boils down to the same
1320 * thing: remove the old, write the new
1321 */
1322 remove_file(patch);
1323 create_file(patch);
1324 }
1325
1326 static void write_out_results(struct patch *list)
1327 {
1328 if (!list)
1329 die("No changes");
1330
1331 while (list) {
1332 write_out_one_result(list);
1333 list = list->next;
1334 }
1335 }
1336
1337 static struct cache_file cache_file;
1338
1339 static int apply_patch(int fd)
1340 {
1341 int newfd;
1342 unsigned long offset, size;
1343 char *buffer = read_patch_file(fd, &size);
1344 struct patch *list = NULL, **listp = &list;
1345
1346 if (!buffer)
1347 return -1;
1348 offset = 0;
1349 while (size > 0) {
1350 struct patch *patch;
1351 int nr;
1352
1353 patch = xmalloc(sizeof(*patch));
1354 memset(patch, 0, sizeof(*patch));
1355 nr = parse_chunk(buffer + offset, size, patch);
1356 if (nr < 0)
1357 break;
1358 patch_stats(patch);
1359 *listp = patch;
1360 listp = &patch->next;
1361 offset += nr;
1362 size -= nr;
1363 }
1364
1365 newfd = -1;
1366 write_index = check_index && apply;
1367 if (write_index)
1368 newfd = hold_index_file_for_update(&cache_file, get_index_file());
1369 if (check_index) {
1370 if (read_cache() < 0)
1371 die("unable to read index file");
1372 }
1373
1374 if ((check || apply) && check_patch_list(list) < 0)
1375 exit(1);
1376
1377 if (apply)
1378 write_out_results(list);
1379
1380 if (write_index) {
1381 if (write_cache(newfd, active_cache, active_nr) ||
1382 commit_index_file(&cache_file))
1383 die("Unable to write new cachefile");
1384 }
1385
1386 if (show_files)
1387 show_file_list(list);
1388
1389 if (diffstat)
1390 stat_patch_list(list);
1391
1392 if (summary)
1393 summary_patch_list(list);
1394
1395 free(buffer);
1396 return 0;
1397 }
1398
1399 int main(int argc, char **argv)
1400 {
1401 int i;
1402 int read_stdin = 1;
1403
1404 for (i = 1; i < argc; i++) {
1405 const char *arg = argv[i];
1406 int fd;
1407
1408 if (!strcmp(arg, "-")) {
1409 apply_patch(0);
1410 read_stdin = 0;
1411 continue;
1412 }
1413 if (!strcmp(arg, "--no-merge")) {
1414 merge_patch = 0;
1415 continue;
1416 }
1417 if (!strcmp(arg, "--stat")) {
1418 apply = 0;
1419 diffstat = 1;
1420 continue;
1421 }
1422 if (!strcmp(arg, "--summary")) {
1423 apply = 0;
1424 summary = 1;
1425 continue;
1426 }
1427 if (!strcmp(arg, "--check")) {
1428 apply = 0;
1429 check = 1;
1430 continue;
1431 }
1432 if (!strcmp(arg, "--index")) {
1433 check_index = 1;
1434 continue;
1435 }
1436 if (!strcmp(arg, "--apply")) {
1437 apply = 1;
1438 continue;
1439 }
1440 if (!strcmp(arg, "--show-files")) {
1441 show_files = 1;
1442 continue;
1443 }
1444 fd = open(arg, O_RDONLY);
1445 if (fd < 0)
1446 usage(apply_usage);
1447 read_stdin = 0;
1448 apply_patch(fd);
1449 close(fd);
1450 }
1451 if (read_stdin)
1452 apply_patch(0);
1453 return 0;
1454 }