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