Documentation: HTTP needs update-server-info.
[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  */
9 #include <fnmatch.h>
10 #include "cache.h"
11 #include "quote.h"
12
13 //  --check turns on checking that the working tree matches the
14 //    files that are being modified, but doesn't apply the patch
15 //  --stat does just a diffstat, and doesn't actually apply
16 //  --numstat does numeric diffstat, and doesn't actually apply
17 //  --index-info shows the old and new index info for paths if available.
18 //
19 static const char *prefix;
20 static int prefix_length = -1;
21
22 static int allow_binary_replacement = 0;
23 static int check_index = 0;
24 static int write_index = 0;
25 static int diffstat = 0;
26 static int numstat = 0;
27 static int summary = 0;
28 static int check = 0;
29 static int apply = 1;
30 static int no_add = 0;
31 static int show_index_info = 0;
32 static int line_termination = '\n';
33 static const char apply_usage[] =
34 "git-apply [--stat] [--numstat] [--summary] [--check] [--index] [--apply] [--no-add] [--index-info] [--allow-binary-replacement] [-z] <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, is_binary;
62         int lines_added, lines_deleted;
63         int score;
64         struct fragment *fragments;
65         char *result;
66         unsigned long resultsize;
67         char old_sha1_prefix[41];
68         char new_sha1_prefix[41];
69         struct patch *next;
70 };
71
72 #define CHUNKSIZE (8192)
73 #define SLOP (16)
74
75 static void *read_patch_file(int fd, unsigned long *sizep)
76 {
77         unsigned long size = 0, alloc = CHUNKSIZE;
78         void *buffer = xmalloc(alloc);
79
80         for (;;) {
81                 int nr = alloc - size;
82                 if (nr < 1024) {
83                         alloc += CHUNKSIZE;
84                         buffer = xrealloc(buffer, alloc);
85                         nr = alloc - size;
86                 }
87                 nr = read(fd, buffer + size, nr);
88                 if (!nr)
89                         break;
90                 if (nr < 0) {
91                         if (errno == EAGAIN)
92                                 continue;
93                         die("git-apply: read returned %s", strerror(errno));
94                 }
95                 size += nr;
96         }
97         *sizep = size;
98
99         /*
100          * Make sure that we have some slop in the buffer
101          * so that we can do speculative "memcmp" etc, and
102          * see to it that it is NUL-filled.
103          */
104         if (alloc < size + SLOP)
105                 buffer = xrealloc(buffer, size + SLOP);
106         memset(buffer + size, 0, SLOP);
107         return buffer;
108 }
109
110 static unsigned long linelen(const char *buffer, unsigned long size)
111 {
112         unsigned long len = 0;
113         while (size--) {
114                 len++;
115                 if (*buffer++ == '\n')
116                         break;
117         }
118         return len;
119 }
120
121 static int is_dev_null(const char *str)
122 {
123         return !memcmp("/dev/null", str, 9) && isspace(str[9]);
124 }
125
126 #define TERM_SPACE      1
127 #define TERM_TAB        2
128
129 static int name_terminate(const char *name, int namelen, int c, int terminate)
130 {
131         if (c == ' ' && !(terminate & TERM_SPACE))
132                 return 0;
133         if (c == '\t' && !(terminate & TERM_TAB))
134                 return 0;
135
136         return 1;
137 }
138
139 static char * find_name(const char *line, char *def, int p_value, int terminate)
140 {
141         int len;
142         const char *start = line;
143         char *name;
144
145         if (*line == '"') {
146                 /* Proposed "new-style" GNU patch/diff format; see
147                  * http://marc.theaimsgroup.com/?l=git&m=112927316408690&w=2
148                  */
149                 name = unquote_c_style(line, NULL);
150                 if (name) {
151                         char *cp = name;
152                         while (p_value) {
153                                 cp = strchr(name, '/');
154                                 if (!cp)
155                                         break;
156                                 cp++;
157                                 p_value--;
158                         }
159                         if (cp) {
160                                 /* name can later be freed, so we need
161                                  * to memmove, not just return cp
162                                  */
163                                 memmove(name, cp, strlen(cp) + 1);
164                                 free(def);
165                                 return name;
166                         }
167                         else {
168                                 free(name);
169                                 name = NULL;
170                         }
171                 }
172         }
173
174         for (;;) {
175                 char c = *line;
176
177                 if (isspace(c)) {
178                         if (c == '\n')
179                                 break;
180                         if (name_terminate(start, line-start, c, terminate))
181                                 break;
182                 }
183                 line++;
184                 if (c == '/' && !--p_value)
185                         start = line;
186         }
187         if (!start)
188                 return def;
189         len = line - start;
190         if (!len)
191                 return def;
192
193         /*
194          * Generally we prefer the shorter name, especially
195          * if the other one is just a variation of that with
196          * something else tacked on to the end (ie "file.orig"
197          * or "file~").
198          */
199         if (def) {
200                 int deflen = strlen(def);
201                 if (deflen < len && !strncmp(start, def, deflen))
202                         return def;
203         }
204
205         name = xmalloc(len + 1);
206         memcpy(name, start, len);
207         name[len] = 0;
208         free(def);
209         return name;
210 }
211
212 /*
213  * Get the name etc info from the --/+++ lines of a traditional patch header
214  *
215  * NOTE! This hardcodes "-p1" behaviour in filename detection.
216  *
217  * FIXME! The end-of-filename heuristics are kind of screwy. For existing
218  * files, we can happily check the index for a match, but for creating a
219  * new file we should try to match whatever "patch" does. I have no idea.
220  */
221 static void parse_traditional_patch(const char *first, const char *second, struct patch *patch)
222 {
223         int p_value = 1;
224         char *name;
225
226         first += 4;     // skip "--- "
227         second += 4;    // skip "+++ "
228         if (is_dev_null(first)) {
229                 patch->is_new = 1;
230                 patch->is_delete = 0;
231                 name = find_name(second, NULL, p_value, TERM_SPACE | TERM_TAB);
232                 patch->new_name = name;
233         } else if (is_dev_null(second)) {
234                 patch->is_new = 0;
235                 patch->is_delete = 1;
236                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
237                 patch->old_name = name;
238         } else {
239                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
240                 name = find_name(second, name, p_value, TERM_SPACE | TERM_TAB);
241                 patch->old_name = patch->new_name = name;
242         }
243         if (!name)
244                 die("unable to find filename in patch at line %d", linenr);
245 }
246
247 static int gitdiff_hdrend(const char *line, struct patch *patch)
248 {
249         return -1;
250 }
251
252 /*
253  * We're anal about diff header consistency, to make
254  * sure that we don't end up having strange ambiguous
255  * patches floating around.
256  *
257  * As a result, gitdiff_{old|new}name() will check
258  * their names against any previous information, just
259  * to make sure..
260  */
261 static char *gitdiff_verify_name(const char *line, int isnull, char *orig_name, const char *oldnew)
262 {
263         if (!orig_name && !isnull)
264                 return find_name(line, NULL, 1, 0);
265
266         if (orig_name) {
267                 int len;
268                 const char *name;
269                 char *another;
270                 name = orig_name;
271                 len = strlen(name);
272                 if (isnull)
273                         die("git-apply: bad git-diff - expected /dev/null, got %s on line %d", name, linenr);
274                 another = find_name(line, NULL, 1, 0);
275                 if (!another || memcmp(another, name, len))
276                         die("git-apply: bad git-diff - inconsistent %s filename on line %d", oldnew, linenr);
277                 free(another);
278                 return orig_name;
279         }
280         else {
281                 /* expect "/dev/null" */
282                 if (memcmp("/dev/null", line, 9) || line[9] != '\n')
283                         die("git-apply: bad git-diff - expected /dev/null on line %d", linenr);
284                 return NULL;
285         }
286 }
287
288 static int gitdiff_oldname(const char *line, struct patch *patch)
289 {
290         patch->old_name = gitdiff_verify_name(line, patch->is_new, patch->old_name, "old");
291         return 0;
292 }
293
294 static int gitdiff_newname(const char *line, struct patch *patch)
295 {
296         patch->new_name = gitdiff_verify_name(line, patch->is_delete, patch->new_name, "new");
297         return 0;
298 }
299
300 static int gitdiff_oldmode(const char *line, struct patch *patch)
301 {
302         patch->old_mode = strtoul(line, NULL, 8);
303         return 0;
304 }
305
306 static int gitdiff_newmode(const char *line, struct patch *patch)
307 {
308         patch->new_mode = strtoul(line, NULL, 8);
309         return 0;
310 }
311
312 static int gitdiff_delete(const char *line, struct patch *patch)
313 {
314         patch->is_delete = 1;
315         patch->old_name = patch->def_name;
316         return gitdiff_oldmode(line, patch);
317 }
318
319 static int gitdiff_newfile(const char *line, struct patch *patch)
320 {
321         patch->is_new = 1;
322         patch->new_name = patch->def_name;
323         return gitdiff_newmode(line, patch);
324 }
325
326 static int gitdiff_copysrc(const char *line, struct patch *patch)
327 {
328         patch->is_copy = 1;
329         patch->old_name = find_name(line, NULL, 0, 0);
330         return 0;
331 }
332
333 static int gitdiff_copydst(const char *line, struct patch *patch)
334 {
335         patch->is_copy = 1;
336         patch->new_name = find_name(line, NULL, 0, 0);
337         return 0;
338 }
339
340 static int gitdiff_renamesrc(const char *line, struct patch *patch)
341 {
342         patch->is_rename = 1;
343         patch->old_name = find_name(line, NULL, 0, 0);
344         return 0;
345 }
346
347 static int gitdiff_renamedst(const char *line, struct patch *patch)
348 {
349         patch->is_rename = 1;
350         patch->new_name = find_name(line, NULL, 0, 0);
351         return 0;
352 }
353
354 static int gitdiff_similarity(const char *line, struct patch *patch)
355 {
356         if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
357                 patch->score = 0;
358         return 0;
359 }
360
361 static int gitdiff_dissimilarity(const char *line, struct patch *patch)
362 {
363         if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
364                 patch->score = 0;
365         return 0;
366 }
367
368 static int gitdiff_index(const char *line, struct patch *patch)
369 {
370         /* index line is N hexadecimal, "..", N hexadecimal,
371          * and optional space with octal mode.
372          */
373         const char *ptr, *eol;
374         int len;
375
376         ptr = strchr(line, '.');
377         if (!ptr || ptr[1] != '.' || 40 < ptr - line)
378                 return 0;
379         len = ptr - line;
380         memcpy(patch->old_sha1_prefix, line, len);
381         patch->old_sha1_prefix[len] = 0;
382
383         line = ptr + 2;
384         ptr = strchr(line, ' ');
385         eol = strchr(line, '\n');
386
387         if (!ptr || eol < ptr)
388                 ptr = eol;
389         len = ptr - line;
390
391         if (40 < len)
392                 return 0;
393         memcpy(patch->new_sha1_prefix, line, len);
394         patch->new_sha1_prefix[len] = 0;
395         if (*ptr == ' ')
396                 patch->new_mode = patch->old_mode = strtoul(ptr+1, NULL, 8);
397         return 0;
398 }
399
400 /*
401  * This is normal for a diff that doesn't change anything: we'll fall through
402  * into the next diff. Tell the parser to break out.
403  */
404 static int gitdiff_unrecognized(const char *line, struct patch *patch)
405 {
406         return -1;
407 }
408
409 static const char *stop_at_slash(const char *line, int llen)
410 {
411         int i;
412
413         for (i = 0; i < llen; i++) {
414                 int ch = line[i];
415                 if (ch == '/')
416                         return line + i;
417         }
418         return NULL;
419 }
420
421 /* This is to extract the same name that appears on "diff --git"
422  * line.  We do not find and return anything if it is a rename
423  * patch, and it is OK because we will find the name elsewhere.
424  * We need to reliably find name only when it is mode-change only,
425  * creation or deletion of an empty file.  In any of these cases,
426  * both sides are the same name under a/ and b/ respectively.
427  */
428 static char *git_header_name(char *line, int llen)
429 {
430         int len;
431         const char *name;
432         const char *second = NULL;
433
434         line += strlen("diff --git ");
435         llen -= strlen("diff --git ");
436
437         if (*line == '"') {
438                 const char *cp;
439                 char *first = unquote_c_style(line, &second);
440                 if (!first)
441                         return NULL;
442
443                 /* advance to the first slash */
444                 cp = stop_at_slash(first, strlen(first));
445                 if (!cp || cp == first) {
446                         /* we do not accept absolute paths */
447                 free_first_and_fail:
448                         free(first);
449                         return NULL;
450                 }
451                 len = strlen(cp+1);
452                 memmove(first, cp+1, len+1); /* including NUL */
453
454                 /* second points at one past closing dq of name.
455                  * find the second name.
456                  */
457                 while ((second < line + llen) && isspace(*second))
458                         second++;
459
460                 if (line + llen <= second)
461                         goto free_first_and_fail;
462                 if (*second == '"') {
463                         char *sp = unquote_c_style(second, NULL);
464                         if (!sp)
465                                 goto free_first_and_fail;
466                         cp = stop_at_slash(sp, strlen(sp));
467                         if (!cp || cp == sp) {
468                         free_both_and_fail:
469                                 free(sp);
470                                 goto free_first_and_fail;
471                         }
472                         /* They must match, otherwise ignore */
473                         if (strcmp(cp+1, first))
474                                 goto free_both_and_fail;
475                         free(sp);
476                         return first;
477                 }
478
479                 /* unquoted second */
480                 cp = stop_at_slash(second, line + llen - second);
481                 if (!cp || cp == second)
482                         goto free_first_and_fail;
483                 cp++;
484                 if (line + llen - cp != len + 1 ||
485                     memcmp(first, cp, len))
486                         goto free_first_and_fail;
487                 return first;
488         }
489
490         /* unquoted first name */
491         name = stop_at_slash(line, llen);
492         if (!name || name == line)
493                 return NULL;
494
495         name++;
496
497         /* since the first name is unquoted, a dq if exists must be
498          * the beginning of the second name.
499          */
500         for (second = name; second < line + llen; second++) {
501                 if (*second == '"') {
502                         const char *cp = second;
503                         const char *np;
504                         char *sp = unquote_c_style(second, NULL);
505
506                         if (!sp)
507                                 return NULL;
508                         np = stop_at_slash(sp, strlen(sp));
509                         if (!np || np == sp) {
510                         free_second_and_fail:
511                                 free(sp);
512                                 return NULL;
513                         }
514                         np++;
515                         len = strlen(np);
516                         if (len < cp - name &&
517                             !strncmp(np, name, len) &&
518                             isspace(name[len])) {
519                                 /* Good */
520                                 memmove(sp, np, len + 1);
521                                 return sp;
522                         }
523                         goto free_second_and_fail;
524                 }
525         }
526
527         /*
528          * Accept a name only if it shows up twice, exactly the same
529          * form.
530          */
531         for (len = 0 ; ; len++) {
532                 char c = name[len];
533
534                 switch (c) {
535                 default:
536                         continue;
537                 case '\n':
538                         return NULL;
539                 case '\t': case ' ':
540                         second = name+len;
541                         for (;;) {
542                                 char c = *second++;
543                                 if (c == '\n')
544                                         return NULL;
545                                 if (c == '/')
546                                         break;
547                         }
548                         if (second[len] == '\n' && !memcmp(name, second, len)) {
549                                 char *ret = xmalloc(len + 1);
550                                 memcpy(ret, name, len);
551                                 ret[len] = 0;
552                                 return ret;
553                         }
554                 }
555         }
556         return NULL;
557 }
558
559 /* Verify that we recognize the lines following a git header */
560 static int parse_git_header(char *line, int len, unsigned int size, struct patch *patch)
561 {
562         unsigned long offset;
563
564         /* A git diff has explicit new/delete information, so we don't guess */
565         patch->is_new = 0;
566         patch->is_delete = 0;
567
568         /*
569          * Some things may not have the old name in the
570          * rest of the headers anywhere (pure mode changes,
571          * or removing or adding empty files), so we get
572          * the default name from the header.
573          */
574         patch->def_name = git_header_name(line, len);
575
576         line += len;
577         size -= len;
578         linenr++;
579         for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) {
580                 static const struct opentry {
581                         const char *str;
582                         int (*fn)(const char *, struct patch *);
583                 } optable[] = {
584                         { "@@ -", gitdiff_hdrend },
585                         { "--- ", gitdiff_oldname },
586                         { "+++ ", gitdiff_newname },
587                         { "old mode ", gitdiff_oldmode },
588                         { "new mode ", gitdiff_newmode },
589                         { "deleted file mode ", gitdiff_delete },
590                         { "new file mode ", gitdiff_newfile },
591                         { "copy from ", gitdiff_copysrc },
592                         { "copy to ", gitdiff_copydst },
593                         { "rename old ", gitdiff_renamesrc },
594                         { "rename new ", gitdiff_renamedst },
595                         { "rename from ", gitdiff_renamesrc },
596                         { "rename to ", gitdiff_renamedst },
597                         { "similarity index ", gitdiff_similarity },
598                         { "dissimilarity index ", gitdiff_dissimilarity },
599                         { "index ", gitdiff_index },
600                         { "", gitdiff_unrecognized },
601                 };
602                 int i;
603
604                 len = linelen(line, size);
605                 if (!len || line[len-1] != '\n')
606                         break;
607                 for (i = 0; i < sizeof(optable) / sizeof(optable[0]); i++) {
608                         const struct opentry *p = optable + i;
609                         int oplen = strlen(p->str);
610                         if (len < oplen || memcmp(p->str, line, oplen))
611                                 continue;
612                         if (p->fn(line + oplen, patch) < 0)
613                                 return offset;
614                         break;
615                 }
616         }
617
618         return offset;
619 }
620
621 static int parse_num(const char *line, unsigned long *p)
622 {
623         char *ptr;
624
625         if (!isdigit(*line))
626                 return 0;
627         *p = strtoul(line, &ptr, 10);
628         return ptr - line;
629 }
630
631 static int parse_range(const char *line, int len, int offset, const char *expect,
632                         unsigned long *p1, unsigned long *p2)
633 {
634         int digits, ex;
635
636         if (offset < 0 || offset >= len)
637                 return -1;
638         line += offset;
639         len -= offset;
640
641         digits = parse_num(line, p1);
642         if (!digits)
643                 return -1;
644
645         offset += digits;
646         line += digits;
647         len -= digits;
648
649         *p2 = *p1;
650         if (*line == ',') {
651                 digits = parse_num(line+1, p2);
652                 if (!digits)
653                         return -1;
654
655                 offset += digits+1;
656                 line += digits+1;
657                 len -= digits+1;
658         }
659
660         ex = strlen(expect);
661         if (ex > len)
662                 return -1;
663         if (memcmp(line, expect, ex))
664                 return -1;
665
666         return offset + ex;
667 }
668
669 /*
670  * Parse a unified diff fragment header of the
671  * form "@@ -a,b +c,d @@"
672  */
673 static int parse_fragment_header(char *line, int len, struct fragment *fragment)
674 {
675         int offset;
676
677         if (!len || line[len-1] != '\n')
678                 return -1;
679
680         /* Figure out the number of lines in a fragment */
681         offset = parse_range(line, len, 4, " +", &fragment->oldpos, &fragment->oldlines);
682         offset = parse_range(line, len, offset, " @@", &fragment->newpos, &fragment->newlines);
683
684         return offset;
685 }
686
687 static int find_header(char *line, unsigned long size, int *hdrsize, struct patch *patch)
688 {
689         unsigned long offset, len;
690
691         patch->is_rename = patch->is_copy = 0;
692         patch->is_new = patch->is_delete = -1;
693         patch->old_mode = patch->new_mode = 0;
694         patch->old_name = patch->new_name = NULL;
695         for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) {
696                 unsigned long nextlen;
697
698                 len = linelen(line, size);
699                 if (!len)
700                         break;
701
702                 /* Testing this early allows us to take a few shortcuts.. */
703                 if (len < 6)
704                         continue;
705
706                 /*
707                  * Make sure we don't find any unconnected patch fragmants.
708                  * That's a sign that we didn't find a header, and that a
709                  * patch has become corrupted/broken up.
710                  */
711                 if (!memcmp("@@ -", line, 4)) {
712                         struct fragment dummy;
713                         if (parse_fragment_header(line, len, &dummy) < 0)
714                                 continue;
715                         error("patch fragment without header at line %d: %.*s", linenr, (int)len-1, line);
716                 }
717
718                 if (size < len + 6)
719                         break;
720
721                 /*
722                  * Git patch? It might not have a real patch, just a rename
723                  * or mode change, so we handle that specially
724                  */
725                 if (!memcmp("diff --git ", line, 11)) {
726                         int git_hdr_len = parse_git_header(line, len, size, patch);
727                         if (git_hdr_len <= len)
728                                 continue;
729                         if (!patch->old_name && !patch->new_name) {
730                                 if (!patch->def_name)
731                                         die("git diff header lacks filename information (line %d)", linenr);
732                                 patch->old_name = patch->new_name = patch->def_name;
733                         }
734                         *hdrsize = git_hdr_len;
735                         return offset;
736                 }
737
738                 /** --- followed by +++ ? */
739                 if (memcmp("--- ", line,  4) || memcmp("+++ ", line + len, 4))
740                         continue;
741
742                 /*
743                  * We only accept unified patches, so we want it to
744                  * at least have "@@ -a,b +c,d @@\n", which is 14 chars
745                  * minimum
746                  */
747                 nextlen = linelen(line + len, size - len);
748                 if (size < nextlen + 14 || memcmp("@@ -", line + len + nextlen, 4))
749                         continue;
750
751                 /* Ok, we'll consider it a patch */
752                 parse_traditional_patch(line, line+len, patch);
753                 *hdrsize = len + nextlen;
754                 linenr += 2;
755                 return offset;
756         }
757         return -1;
758 }
759
760 /*
761  * Parse a unified diff. Note that this really needs
762  * to parse each fragment separately, since the only
763  * way to know the difference between a "---" that is
764  * part of a patch, and a "---" that starts the next
765  * patch is to look at the line counts..
766  */
767 static int parse_fragment(char *line, unsigned long size, struct patch *patch, struct fragment *fragment)
768 {
769         int added, deleted;
770         int len = linelen(line, size), offset;
771         unsigned long oldlines, newlines;
772
773         offset = parse_fragment_header(line, len, fragment);
774         if (offset < 0)
775                 return -1;
776         oldlines = fragment->oldlines;
777         newlines = fragment->newlines;
778
779         if (patch->is_new < 0) {
780                 patch->is_new =  !oldlines;
781                 if (!oldlines)
782                         patch->old_name = NULL;
783         }
784         if (patch->is_delete < 0) {
785                 patch->is_delete = !newlines;
786                 if (!newlines)
787                         patch->new_name = NULL;
788         }
789
790         if (patch->is_new != !oldlines)
791                 return error("new file depends on old contents");
792         if (patch->is_delete != !newlines) {
793                 if (newlines)
794                         return error("deleted file still has contents");
795                 fprintf(stderr, "** warning: file %s becomes empty but is not deleted\n", patch->new_name);
796         }
797
798         /* Parse the thing.. */
799         line += len;
800         size -= len;
801         linenr++;
802         added = deleted = 0;
803         for (offset = len; size > 0; offset += len, size -= len, line += len, linenr++) {
804                 if (!oldlines && !newlines)
805                         break;
806                 len = linelen(line, size);
807                 if (!len || line[len-1] != '\n')
808                         return -1;
809                 switch (*line) {
810                 default:
811                         return -1;
812                 case ' ':
813                         oldlines--;
814                         newlines--;
815                         break;
816                 case '-':
817                         deleted++;
818                         oldlines--;
819                         break;
820                 case '+':
821                         added++;
822                         newlines--;
823                         break;
824
825                 /* We allow "\ No newline at end of file". Depending
826                  * on locale settings when the patch was produced we
827                  * don't know what this line looks like. The only
828                  * thing we do know is that it begins with "\ ".
829                  * Checking for 12 is just for sanity check -- any
830                  * l10n of "\ No newline..." is at least that long.
831                  */
832                 case '\\':
833                         if (len < 12 || memcmp(line, "\\ ", 2))
834                                 return -1;
835                         break;
836                 }
837         }
838         /* If a fragment ends with an incomplete line, we failed to include
839          * it in the above loop because we hit oldlines == newlines == 0
840          * before seeing it.
841          */
842         if (12 < size && !memcmp(line, "\\ ", 2))
843                 offset += linelen(line, size);
844
845         patch->lines_added += added;
846         patch->lines_deleted += deleted;
847         return offset;
848 }
849
850 static int parse_single_patch(char *line, unsigned long size, struct patch *patch)
851 {
852         unsigned long offset = 0;
853         struct fragment **fragp = &patch->fragments;
854
855         while (size > 4 && !memcmp(line, "@@ -", 4)) {
856                 struct fragment *fragment;
857                 int len;
858
859                 fragment = xmalloc(sizeof(*fragment));
860                 memset(fragment, 0, sizeof(*fragment));
861                 len = parse_fragment(line, size, patch, fragment);
862                 if (len <= 0)
863                         die("corrupt patch at line %d", linenr);
864
865                 fragment->patch = line;
866                 fragment->size = len;
867
868                 *fragp = fragment;
869                 fragp = &fragment->next;
870
871                 offset += len;
872                 line += len;
873                 size -= len;
874         }
875         return offset;
876 }
877
878 static inline int metadata_changes(struct patch *patch)
879 {
880         return  patch->is_rename > 0 ||
881                 patch->is_copy > 0 ||
882                 patch->is_new > 0 ||
883                 patch->is_delete ||
884                 (patch->old_mode && patch->new_mode &&
885                  patch->old_mode != patch->new_mode);
886 }
887
888 static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
889 {
890         int hdrsize, patchsize;
891         int offset = find_header(buffer, size, &hdrsize, patch);
892
893         if (offset < 0)
894                 return offset;
895
896         patchsize = parse_single_patch(buffer + offset + hdrsize, size - offset - hdrsize, patch);
897
898         if (!patchsize) {
899                 static const char *binhdr[] = {
900                         "Binary files ",
901                         "Files ",
902                         NULL,
903                 };
904                 int i;
905                 int hd = hdrsize + offset;
906                 unsigned long llen = linelen(buffer + hd, size - hd);
907
908                 if (!memcmp(" differ\n", buffer + hd + llen - 8, 8))
909                         for (i = 0; binhdr[i]; i++) {
910                                 int len = strlen(binhdr[i]);
911                                 if (len < size - hd &&
912                                     !memcmp(binhdr[i], buffer + hd, len)) {
913                                         patch->is_binary = 1;
914                                         break;
915                                 }
916                         }
917
918                 /* Empty patch cannot be applied if:
919                  * - it is a binary patch and we do not do binary_replace, or
920                  * - text patch without metadata change
921                  */
922                 if ((apply || check) &&
923                     (patch->is_binary
924                      ? !allow_binary_replacement
925                      : !metadata_changes(patch)))
926                         die("patch with only garbage at line %d", linenr);
927         }
928
929         return offset + hdrsize + patchsize;
930 }
931
932 static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
933 static const char minuses[]= "----------------------------------------------------------------------";
934
935 static void show_stats(struct patch *patch)
936 {
937         const char *prefix = "";
938         char *name = patch->new_name;
939         char *qname = NULL;
940         int len, max, add, del, total;
941
942         if (!name)
943                 name = patch->old_name;
944
945         if (0 < (len = quote_c_style(name, NULL, NULL, 0))) {
946                 qname = xmalloc(len + 1);
947                 quote_c_style(name, qname, NULL, 0);
948                 name = qname;
949         }
950
951         /*
952          * "scale" the filename
953          */
954         len = strlen(name);
955         max = max_len;
956         if (max > 50)
957                 max = 50;
958         if (len > max) {
959                 char *slash;
960                 prefix = "...";
961                 max -= 3;
962                 name += len - max;
963                 slash = strchr(name, '/');
964                 if (slash)
965                         name = slash;
966         }
967         len = max;
968
969         /*
970          * scale the add/delete
971          */
972         max = max_change;
973         if (max + len > 70)
974                 max = 70 - len;
975
976         add = patch->lines_added;
977         del = patch->lines_deleted;
978         total = add + del;
979
980         if (max_change > 0) {
981                 total = (total * max + max_change / 2) / max_change;
982                 add = (add * max + max_change / 2) / max_change;
983                 del = total - add;
984         }
985         if (patch->is_binary)
986                 printf(" %s%-*s |  Bin\n", prefix, len, name);
987         else
988                 printf(" %s%-*s |%5d %.*s%.*s\n", prefix,
989                        len, name, patch->lines_added + patch->lines_deleted,
990                        add, pluses, del, minuses);
991         if (qname)
992                 free(qname);
993 }
994
995 static int read_old_data(struct stat *st, const char *path, void *buf, unsigned long size)
996 {
997         int fd;
998         unsigned long got;
999
1000         switch (st->st_mode & S_IFMT) {
1001         case S_IFLNK:
1002                 return readlink(path, buf, size);
1003         case S_IFREG:
1004                 fd = open(path, O_RDONLY);
1005                 if (fd < 0)
1006                         return error("unable to open %s", path);
1007                 got = 0;
1008                 for (;;) {
1009                         int ret = read(fd, buf + got, size - got);
1010                         if (ret < 0) {
1011                                 if (errno == EAGAIN)
1012                                         continue;
1013                                 break;
1014                         }
1015                         if (!ret)
1016                                 break;
1017                         got += ret;
1018                 }
1019                 close(fd);
1020                 return got;
1021
1022         default:
1023                 return -1;
1024         }
1025 }
1026
1027 static int find_offset(const char *buf, unsigned long size, const char *fragment, unsigned long fragsize, int line)
1028 {
1029         int i;
1030         unsigned long start, backwards, forwards;
1031
1032         if (fragsize > size)
1033                 return -1;
1034
1035         start = 0;
1036         if (line > 1) {
1037                 unsigned long offset = 0;
1038                 i = line-1;
1039                 while (offset + fragsize <= size) {
1040                         if (buf[offset++] == '\n') {
1041                                 start = offset;
1042                                 if (!--i)
1043                                         break;
1044                         }
1045                 }
1046         }
1047
1048         /* Exact line number? */
1049         if (!memcmp(buf + start, fragment, fragsize))
1050                 return start;
1051
1052         /*
1053          * There's probably some smart way to do this, but I'll leave
1054          * that to the smart and beautiful people. I'm simple and stupid.
1055          */
1056         backwards = start;
1057         forwards = start;
1058         for (i = 0; ; i++) {
1059                 unsigned long try;
1060                 int n;
1061
1062                 /* "backward" */
1063                 if (i & 1) {
1064                         if (!backwards) {
1065                                 if (forwards + fragsize > size)
1066                                         break;
1067                                 continue;
1068                         }
1069                         do {
1070                                 --backwards;
1071                         } while (backwards && buf[backwards-1] != '\n');
1072                         try = backwards;
1073                 } else {
1074                         while (forwards + fragsize <= size) {
1075                                 if (buf[forwards++] == '\n')
1076                                         break;
1077                         }
1078                         try = forwards;
1079                 }
1080
1081                 if (try + fragsize > size)
1082                         continue;
1083                 if (memcmp(buf + try, fragment, fragsize))
1084                         continue;
1085                 n = (i >> 1)+1;
1086                 if (i & 1)
1087                         n = -n;
1088                 return try;
1089         }
1090
1091         /*
1092          * We should start searching forward and backward.
1093          */
1094         return -1;
1095 }
1096
1097 struct buffer_desc {
1098         char *buffer;
1099         unsigned long size;
1100         unsigned long alloc;
1101 };
1102
1103 static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag)
1104 {
1105         char *buf = desc->buffer;
1106         const char *patch = frag->patch;
1107         int offset, size = frag->size;
1108         char *old = xmalloc(size);
1109         char *new = xmalloc(size);
1110         int oldsize = 0, newsize = 0;
1111
1112         while (size > 0) {
1113                 int len = linelen(patch, size);
1114                 int plen;
1115
1116                 if (!len)
1117                         break;
1118
1119                 /*
1120                  * "plen" is how much of the line we should use for
1121                  * the actual patch data. Normally we just remove the
1122                  * first character on the line, but if the line is
1123                  * followed by "\ No newline", then we also remove the
1124                  * last one (which is the newline, of course).
1125                  */
1126                 plen = len-1;
1127                 if (len < size && patch[len] == '\\')
1128                         plen--;
1129                 switch (*patch) {
1130                 case ' ':
1131                 case '-':
1132                         memcpy(old + oldsize, patch + 1, plen);
1133                         oldsize += plen;
1134                         if (*patch == '-')
1135                                 break;
1136                 /* Fall-through for ' ' */
1137                 case '+':
1138                         if (*patch != '+' || !no_add) {
1139                                 memcpy(new + newsize, patch + 1, plen);
1140                                 newsize += plen;
1141                         }
1142                         break;
1143                 case '@': case '\\':
1144                         /* Ignore it, we already handled it */
1145                         break;
1146                 default:
1147                         return -1;
1148                 }
1149                 patch += len;
1150                 size -= len;
1151         }
1152
1153         offset = find_offset(buf, desc->size, old, oldsize, frag->newpos);
1154         if (offset >= 0) {
1155                 int diff = newsize - oldsize;
1156                 unsigned long size = desc->size + diff;
1157                 unsigned long alloc = desc->alloc;
1158
1159                 if (size > alloc) {
1160                         alloc = size + 8192;
1161                         desc->alloc = alloc;
1162                         buf = xrealloc(buf, alloc);
1163                         desc->buffer = buf;
1164                 }
1165                 desc->size = size;
1166                 memmove(buf + offset + newsize, buf + offset + oldsize, size - offset - newsize);
1167                 memcpy(buf + offset, new, newsize);
1168                 offset = 0;
1169         }
1170
1171         free(old);
1172         free(new);
1173         return offset;
1174 }
1175
1176 static int apply_fragments(struct buffer_desc *desc, struct patch *patch)
1177 {
1178         struct fragment *frag = patch->fragments;
1179         const char *name = patch->old_name ? patch->old_name : patch->new_name;
1180
1181         if (patch->is_binary) {
1182                 unsigned char sha1[20];
1183
1184                 if (!allow_binary_replacement)
1185                         return error("cannot apply binary patch to '%s' "
1186                                      "without --allow-binary-replacement",
1187                                      name);
1188
1189                 /* For safety, we require patch index line to contain
1190                  * full 40-byte textual SHA1 for old and new, at least for now.
1191                  */
1192                 if (strlen(patch->old_sha1_prefix) != 40 ||
1193                     strlen(patch->new_sha1_prefix) != 40 ||
1194                     get_sha1_hex(patch->old_sha1_prefix, sha1) ||
1195                     get_sha1_hex(patch->new_sha1_prefix, sha1))
1196                         return error("cannot apply binary patch to '%s' "
1197                                      "without full index line", name);
1198
1199                 if (patch->old_name) {
1200                         unsigned char hdr[50];
1201                         int hdrlen;
1202
1203                         /* See if the old one matches what the patch
1204                          * applies to.
1205                          */
1206                         write_sha1_file_prepare(desc->buffer, desc->size,
1207                                                 "blob", sha1, hdr, &hdrlen);
1208                         if (strcmp(sha1_to_hex(sha1), patch->old_sha1_prefix))
1209                                 return error("the patch applies to '%s' (%s), "
1210                                              "which does not match the "
1211                                              "current contents.",
1212                                              name, sha1_to_hex(sha1));
1213                 }
1214                 else {
1215                         /* Otherwise, the old one must be empty. */
1216                         if (desc->size)
1217                                 return error("the patch applies to an empty "
1218                                              "'%s' but it is not empty", name);
1219                 }
1220
1221                 /* For now, we do not record post-image data in the patch,
1222                  * and require the object already present in the recipient's
1223                  * object database.
1224                  */
1225                 if (desc->buffer) {
1226                         free(desc->buffer);
1227                         desc->alloc = desc->size = 0;
1228                 }
1229                 get_sha1_hex(patch->new_sha1_prefix, sha1);
1230
1231                 if (memcmp(sha1, null_sha1, 20)) {
1232                         char type[10];
1233                         unsigned long size;
1234
1235                         desc->buffer = read_sha1_file(sha1, type, &size);
1236                         if (!desc->buffer)
1237                                 return error("the necessary postimage %s for "
1238                                              "'%s' does not exist",
1239                                              patch->new_sha1_prefix, name);
1240                         desc->alloc = desc->size = size;
1241                 }
1242
1243                 return 0;
1244         }
1245
1246         while (frag) {
1247                 if (apply_one_fragment(desc, frag) < 0)
1248                         return error("patch failed: %s:%ld",
1249                                      name, frag->oldpos);
1250                 frag = frag->next;
1251         }
1252         return 0;
1253 }
1254
1255 static int apply_data(struct patch *patch, struct stat *st)
1256 {
1257         char *buf;
1258         unsigned long size, alloc;
1259         struct buffer_desc desc;
1260
1261         size = 0;
1262         alloc = 0;
1263         buf = NULL;
1264         if (patch->old_name) {
1265                 size = st->st_size;
1266                 alloc = size + 8192;
1267                 buf = xmalloc(alloc);
1268                 if (read_old_data(st, patch->old_name, buf, alloc) != size)
1269                         return error("read of %s failed", patch->old_name);
1270         }
1271
1272         desc.size = size;
1273         desc.alloc = alloc;
1274         desc.buffer = buf;
1275         if (apply_fragments(&desc, patch) < 0)
1276                 return -1;
1277         patch->result = desc.buffer;
1278         patch->resultsize = desc.size;
1279
1280         if (patch->is_delete && patch->resultsize)
1281                 return error("removal patch leaves file contents");
1282
1283         return 0;
1284 }
1285
1286 static int check_patch(struct patch *patch)
1287 {
1288         struct stat st;
1289         const char *old_name = patch->old_name;
1290         const char *new_name = patch->new_name;
1291         const char *name = old_name ? old_name : new_name;
1292
1293         if (old_name) {
1294                 int changed;
1295                 int stat_ret = lstat(old_name, &st);
1296
1297                 if (check_index) {
1298                         int pos = cache_name_pos(old_name, strlen(old_name));
1299                         if (pos < 0)
1300                                 return error("%s: does not exist in index",
1301                                              old_name);
1302                         if (stat_ret < 0) {
1303                                 struct checkout costate;
1304                                 if (errno != ENOENT)
1305                                         return error("%s: %s", old_name,
1306                                                      strerror(errno));
1307                                 /* checkout */
1308                                 costate.base_dir = "";
1309                                 costate.base_dir_len = 0;
1310                                 costate.force = 0;
1311                                 costate.quiet = 0;
1312                                 costate.not_new = 0;
1313                                 costate.refresh_cache = 1;
1314                                 if (checkout_entry(active_cache[pos],
1315                                                    &costate) ||
1316                                     lstat(old_name, &st))
1317                                         return -1;
1318                         }
1319
1320                         changed = ce_match_stat(active_cache[pos], &st);
1321                         if (changed)
1322                                 return error("%s: does not match index",
1323                                              old_name);
1324                 }
1325                 else if (stat_ret < 0)
1326                         return error("%s: %s", old_name, strerror(errno));
1327
1328                 if (patch->is_new < 0)
1329                         patch->is_new = 0;
1330                 st.st_mode = ntohl(create_ce_mode(st.st_mode));
1331                 if (!patch->old_mode)
1332                         patch->old_mode = st.st_mode;
1333                 if ((st.st_mode ^ patch->old_mode) & S_IFMT)
1334                         return error("%s: wrong type", old_name);
1335                 if (st.st_mode != patch->old_mode)
1336                         fprintf(stderr, "warning: %s has type %o, expected %o\n",
1337                                 old_name, st.st_mode, patch->old_mode);
1338         }
1339
1340         if (new_name && (patch->is_new | patch->is_rename | patch->is_copy)) {
1341                 if (check_index && cache_name_pos(new_name, strlen(new_name)) >= 0)
1342                         return error("%s: already exists in index", new_name);
1343                 if (!lstat(new_name, &st))
1344                         return error("%s: already exists in working directory", new_name);
1345                 if (errno != ENOENT)
1346                         return error("%s: %s", new_name, strerror(errno));
1347                 if (!patch->new_mode) {
1348                         if (patch->is_new)
1349                                 patch->new_mode = S_IFREG | 0644;
1350                         else
1351                                 patch->new_mode = patch->old_mode;
1352                 }
1353         }
1354
1355         if (new_name && old_name) {
1356                 int same = !strcmp(old_name, new_name);
1357                 if (!patch->new_mode)
1358                         patch->new_mode = patch->old_mode;
1359                 if ((patch->old_mode ^ patch->new_mode) & S_IFMT)
1360                         return error("new mode (%o) of %s does not match old mode (%o)%s%s",
1361                                 patch->new_mode, new_name, patch->old_mode,
1362                                 same ? "" : " of ", same ? "" : old_name);
1363         }       
1364
1365         if (apply_data(patch, &st) < 0)
1366                 return error("%s: patch does not apply", name);
1367         return 0;
1368 }
1369
1370 static int check_patch_list(struct patch *patch)
1371 {
1372         int error = 0;
1373
1374         for (;patch ; patch = patch->next)
1375                 error |= check_patch(patch);
1376         return error;
1377 }
1378
1379 static inline int is_null_sha1(const unsigned char *sha1)
1380 {
1381         return !memcmp(sha1, null_sha1, 20);
1382 }
1383
1384 static void show_index_list(struct patch *list)
1385 {
1386         struct patch *patch;
1387
1388         /* Once we start supporting the reverse patch, it may be
1389          * worth showing the new sha1 prefix, but until then...
1390          */
1391         for (patch = list; patch; patch = patch->next) {
1392                 const unsigned char *sha1_ptr;
1393                 unsigned char sha1[20];
1394                 const char *name;
1395
1396                 name = patch->old_name ? patch->old_name : patch->new_name;
1397                 if (patch->is_new)
1398                         sha1_ptr = null_sha1;
1399                 else if (get_sha1(patch->old_sha1_prefix, sha1))
1400                         die("sha1 information is lacking or useless (%s).",
1401                             name);
1402                 else
1403                         sha1_ptr = sha1;
1404
1405                 printf("%06o %s ",patch->old_mode, sha1_to_hex(sha1_ptr));
1406                 if (line_termination && quote_c_style(name, NULL, NULL, 0))
1407                         quote_c_style(name, NULL, stdout, 0);
1408                 else
1409                         fputs(name, stdout);
1410                 putchar(line_termination);
1411         }
1412 }
1413
1414 static void stat_patch_list(struct patch *patch)
1415 {
1416         int files, adds, dels;
1417
1418         for (files = adds = dels = 0 ; patch ; patch = patch->next) {
1419                 files++;
1420                 adds += patch->lines_added;
1421                 dels += patch->lines_deleted;
1422                 show_stats(patch);
1423         }
1424
1425         printf(" %d files changed, %d insertions(+), %d deletions(-)\n", files, adds, dels);
1426 }
1427
1428 static void numstat_patch_list(struct patch *patch)
1429 {
1430         for ( ; patch; patch = patch->next) {
1431                 const char *name;
1432                 name = patch->old_name ? patch->old_name : patch->new_name;
1433                 printf("%d\t%d\t", patch->lines_added, patch->lines_deleted);
1434                 if (line_termination && quote_c_style(name, NULL, NULL, 0))
1435                         quote_c_style(name, NULL, stdout, 0);
1436                 else
1437                         fputs(name, stdout);
1438                 putchar('\n');
1439         }
1440 }
1441
1442 static void show_file_mode_name(const char *newdelete, unsigned int mode, const char *name)
1443 {
1444         if (mode)
1445                 printf(" %s mode %06o %s\n", newdelete, mode, name);
1446         else
1447                 printf(" %s %s\n", newdelete, name);
1448 }
1449
1450 static void show_mode_change(struct patch *p, int show_name)
1451 {
1452         if (p->old_mode && p->new_mode && p->old_mode != p->new_mode) {
1453                 if (show_name)
1454                         printf(" mode change %06o => %06o %s\n",
1455                                p->old_mode, p->new_mode, p->new_name);
1456                 else
1457                         printf(" mode change %06o => %06o\n",
1458                                p->old_mode, p->new_mode);
1459         }
1460 }
1461
1462 static void show_rename_copy(struct patch *p)
1463 {
1464         const char *renamecopy = p->is_rename ? "rename" : "copy";
1465         const char *old, *new;
1466
1467         /* Find common prefix */
1468         old = p->old_name;
1469         new = p->new_name;
1470         while (1) {
1471                 const char *slash_old, *slash_new;
1472                 slash_old = strchr(old, '/');
1473                 slash_new = strchr(new, '/');
1474                 if (!slash_old ||
1475                     !slash_new ||
1476                     slash_old - old != slash_new - new ||
1477                     memcmp(old, new, slash_new - new))
1478                         break;
1479                 old = slash_old + 1;
1480                 new = slash_new + 1;
1481         }
1482         /* p->old_name thru old is the common prefix, and old and new
1483          * through the end of names are renames
1484          */
1485         if (old != p->old_name)
1486                 printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
1487                        (int)(old - p->old_name), p->old_name,
1488                        old, new, p->score);
1489         else
1490                 printf(" %s %s => %s (%d%%)\n", renamecopy,
1491                        p->old_name, p->new_name, p->score);
1492         show_mode_change(p, 0);
1493 }
1494
1495 static void summary_patch_list(struct patch *patch)
1496 {
1497         struct patch *p;
1498
1499         for (p = patch; p; p = p->next) {
1500                 if (p->is_new)
1501                         show_file_mode_name("create", p->new_mode, p->new_name);
1502                 else if (p->is_delete)
1503                         show_file_mode_name("delete", p->old_mode, p->old_name);
1504                 else {
1505                         if (p->is_rename || p->is_copy)
1506                                 show_rename_copy(p);
1507                         else {
1508                                 if (p->score) {
1509                                         printf(" rewrite %s (%d%%)\n",
1510                                                p->new_name, p->score);
1511                                         show_mode_change(p, 0);
1512                                 }
1513                                 else
1514                                         show_mode_change(p, 1);
1515                         }
1516                 }
1517         }
1518 }
1519
1520 static void patch_stats(struct patch *patch)
1521 {
1522         int lines = patch->lines_added + patch->lines_deleted;
1523
1524         if (lines > max_change)
1525                 max_change = lines;
1526         if (patch->old_name) {
1527                 int len = quote_c_style(patch->old_name, NULL, NULL, 0);
1528                 if (!len)
1529                         len = strlen(patch->old_name);
1530                 if (len > max_len)
1531                         max_len = len;
1532         }
1533         if (patch->new_name) {
1534                 int len = quote_c_style(patch->new_name, NULL, NULL, 0);
1535                 if (!len)
1536                         len = strlen(patch->new_name);
1537                 if (len > max_len)
1538                         max_len = len;
1539         }
1540 }
1541
1542 static void remove_file(struct patch *patch)
1543 {
1544         if (write_index) {
1545                 if (remove_file_from_cache(patch->old_name) < 0)
1546                         die("unable to remove %s from index", patch->old_name);
1547         }
1548         unlink(patch->old_name);
1549 }
1550
1551 static void add_index_file(const char *path, unsigned mode, void *buf, unsigned long size)
1552 {
1553         struct stat st;
1554         struct cache_entry *ce;
1555         int namelen = strlen(path);
1556         unsigned ce_size = cache_entry_size(namelen);
1557
1558         if (!write_index)
1559                 return;
1560
1561         ce = xmalloc(ce_size);
1562         memset(ce, 0, ce_size);
1563         memcpy(ce->name, path, namelen);
1564         ce->ce_mode = create_ce_mode(mode);
1565         ce->ce_flags = htons(namelen);
1566         if (lstat(path, &st) < 0)
1567                 die("unable to stat newly created file %s", path);
1568         fill_stat_cache_info(ce, &st);
1569         if (write_sha1_file(buf, size, "blob", ce->sha1) < 0)
1570                 die("unable to create backing store for newly created file %s", path);
1571         if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0)
1572                 die("unable to add cache entry for %s", path);
1573 }
1574
1575 static void create_subdirectories(const char *path)
1576 {
1577         int len = strlen(path);
1578         char *buf = xmalloc(len + 1);
1579         const char *slash = path;
1580
1581         while ((slash = strchr(slash+1, '/')) != NULL) {
1582                 len = slash - path;
1583                 memcpy(buf, path, len);
1584                 buf[len] = 0;
1585                 if (mkdir(buf, 0777) < 0) {
1586                         if (errno != EEXIST)
1587                                 break;
1588                 }
1589         }
1590         free(buf);
1591 }
1592
1593 static int try_create_file(const char *path, unsigned int mode, const char *buf, unsigned long size)
1594 {
1595         int fd;
1596
1597         if (S_ISLNK(mode))
1598                 return symlink(buf, path);
1599         fd = open(path, O_CREAT | O_EXCL | O_WRONLY | O_TRUNC, (mode & 0100) ? 0777 : 0666);
1600         if (fd < 0)
1601                 return -1;
1602         while (size) {
1603                 int written = write(fd, buf, size);
1604                 if (written < 0) {
1605                         if (errno == EINTR || errno == EAGAIN)
1606                                 continue;
1607                         die("writing file %s: %s", path, strerror(errno));
1608                 }
1609                 if (!written)
1610                         die("out of space writing file %s", path);
1611                 buf += written;
1612                 size -= written;
1613         }
1614         if (close(fd) < 0)
1615                 die("closing file %s: %s", path, strerror(errno));
1616         return 0;
1617 }
1618
1619 /*
1620  * We optimistically assume that the directories exist,
1621  * which is true 99% of the time anyway. If they don't,
1622  * we create them and try again.
1623  */
1624 static void create_one_file(const char *path, unsigned mode, const char *buf, unsigned long size)
1625 {
1626         if (!try_create_file(path, mode, buf, size))
1627                 return;
1628
1629         if (errno == ENOENT) {
1630                 create_subdirectories(path);
1631                 if (!try_create_file(path, mode, buf, size))
1632                         return;
1633         }
1634
1635         if (errno == EEXIST) {
1636                 unsigned int nr = getpid();
1637
1638                 for (;;) {
1639                         const char *newpath;
1640                         newpath = mkpath("%s~%u", path, nr);
1641                         if (!try_create_file(newpath, mode, buf, size)) {
1642                                 if (!rename(newpath, path))
1643                                         return;
1644                                 unlink(newpath);
1645                                 break;
1646                         }
1647                         if (errno != EEXIST)
1648                                 break;
1649                 }                       
1650         }
1651         die("unable to write file %s mode %o", path, mode);
1652 }
1653
1654 static void create_file(struct patch *patch)
1655 {
1656         const char *path = patch->new_name;
1657         unsigned mode = patch->new_mode;
1658         unsigned long size = patch->resultsize;
1659         char *buf = patch->result;
1660
1661         if (!mode)
1662                 mode = S_IFREG | 0644;
1663         create_one_file(path, mode, buf, size); 
1664         add_index_file(path, mode, buf, size);
1665 }
1666
1667 static void write_out_one_result(struct patch *patch)
1668 {
1669         if (patch->is_delete > 0) {
1670                 remove_file(patch);
1671                 return;
1672         }
1673         if (patch->is_new > 0 || patch->is_copy) {
1674                 create_file(patch);
1675                 return;
1676         }
1677         /*
1678          * Rename or modification boils down to the same
1679          * thing: remove the old, write the new
1680          */
1681         remove_file(patch);
1682         create_file(patch);
1683 }
1684
1685 static void write_out_results(struct patch *list, int skipped_patch)
1686 {
1687         if (!list && !skipped_patch)
1688                 die("No changes");
1689
1690         while (list) {
1691                 write_out_one_result(list);
1692                 list = list->next;
1693         }
1694 }
1695
1696 static struct cache_file cache_file;
1697
1698 static struct excludes {
1699         struct excludes *next;
1700         const char *path;
1701 } *excludes;
1702
1703 static int use_patch(struct patch *p)
1704 {
1705         const char *pathname = p->new_name ? p->new_name : p->old_name;
1706         struct excludes *x = excludes;
1707         while (x) {
1708                 if (fnmatch(x->path, pathname, 0) == 0)
1709                         return 0;
1710                 x = x->next;
1711         }
1712         if (0 < prefix_length) {
1713                 int pathlen = strlen(pathname);
1714                 if (pathlen <= prefix_length ||
1715                     memcmp(prefix, pathname, prefix_length))
1716                         return 0;
1717         }
1718         return 1;
1719 }
1720
1721 static int apply_patch(int fd)
1722 {
1723         int newfd;
1724         unsigned long offset, size;
1725         char *buffer = read_patch_file(fd, &size);
1726         struct patch *list = NULL, **listp = &list;
1727         int skipped_patch = 0;
1728
1729         if (!buffer)
1730                 return -1;
1731         offset = 0;
1732         while (size > 0) {
1733                 struct patch *patch;
1734                 int nr;
1735
1736                 patch = xmalloc(sizeof(*patch));
1737                 memset(patch, 0, sizeof(*patch));
1738                 nr = parse_chunk(buffer + offset, size, patch);
1739                 if (nr < 0)
1740                         break;
1741                 if (use_patch(patch)) {
1742                         patch_stats(patch);
1743                         *listp = patch;
1744                         listp = &patch->next;
1745                 } else {
1746                         /* perhaps free it a bit better? */
1747                         free(patch);
1748                         skipped_patch++;
1749                 }
1750                 offset += nr;
1751                 size -= nr;
1752         }
1753
1754         newfd = -1;
1755         write_index = check_index && apply;
1756         if (write_index)
1757                 newfd = hold_index_file_for_update(&cache_file, get_index_file());
1758         if (check_index) {
1759                 if (read_cache() < 0)
1760                         die("unable to read index file");
1761         }
1762
1763         if ((check || apply) && check_patch_list(list) < 0)
1764                 exit(1);
1765
1766         if (apply)
1767                 write_out_results(list, skipped_patch);
1768
1769         if (write_index) {
1770                 if (write_cache(newfd, active_cache, active_nr) ||
1771                     commit_index_file(&cache_file))
1772                         die("Unable to write new cachefile");
1773         }
1774
1775         if (show_index_info)
1776                 show_index_list(list);
1777
1778         if (diffstat)
1779                 stat_patch_list(list);
1780
1781         if (numstat)
1782                 numstat_patch_list(list);
1783
1784         if (summary)
1785                 summary_patch_list(list);
1786
1787         free(buffer);
1788         return 0;
1789 }
1790
1791 int main(int argc, char **argv)
1792 {
1793         int i;
1794         int read_stdin = 1;
1795
1796         for (i = 1; i < argc; i++) {
1797                 const char *arg = argv[i];
1798                 int fd;
1799
1800                 if (!strcmp(arg, "-")) {
1801                         apply_patch(0);
1802                         read_stdin = 0;
1803                         continue;
1804                 }
1805                 if (!strncmp(arg, "--exclude=", 10)) {
1806                         struct excludes *x = xmalloc(sizeof(*x));
1807                         x->path = arg + 10;
1808                         x->next = excludes;
1809                         excludes = x;
1810                         continue;
1811                 }
1812                 if (!strcmp(arg, "--no-add")) {
1813                         no_add = 1;
1814                         continue;
1815                 }
1816                 if (!strcmp(arg, "--stat")) {
1817                         apply = 0;
1818                         diffstat = 1;
1819                         continue;
1820                 }
1821                 if (!strcmp(arg, "--allow-binary-replacement")) {
1822                         allow_binary_replacement = 1;
1823                         continue;
1824                 }
1825                 if (!strcmp(arg, "--numstat")) {
1826                         apply = 0;
1827                         numstat = 1;
1828                         continue;
1829                 }
1830                 if (!strcmp(arg, "--summary")) {
1831                         apply = 0;
1832                         summary = 1;
1833                         continue;
1834                 }
1835                 if (!strcmp(arg, "--check")) {
1836                         apply = 0;
1837                         check = 1;
1838                         continue;
1839                 }
1840                 if (!strcmp(arg, "--index")) {
1841                         check_index = 1;
1842                         continue;
1843                 }
1844                 if (!strcmp(arg, "--apply")) {
1845                         apply = 1;
1846                         continue;
1847                 }
1848                 if (!strcmp(arg, "--index-info")) {
1849                         apply = 0;
1850                         show_index_info = 1;
1851                         continue;
1852                 }
1853                 if (!strcmp(arg, "-z")) {
1854                         line_termination = 0;
1855                         continue;
1856                 }
1857
1858                 if (check_index && prefix_length < 0) {
1859                         prefix = setup_git_directory();
1860                         prefix_length = prefix ? strlen(prefix) : 0;
1861                         git_config(git_default_config);
1862                 }
1863                 if (0 < prefix_length)
1864                         arg = prefix_filename(prefix, prefix_length, arg);
1865
1866                 fd = open(arg, O_RDONLY);
1867                 if (fd < 0)
1868                         usage(apply_usage);
1869                 read_stdin = 0;
1870                 apply_patch(fd);
1871                 close(fd);
1872         }
1873         if (read_stdin)
1874                 apply_patch(0);
1875         return 0;
1876 }