Merge branch 'lt/apply' into next
[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 p_value = 1;
23 static int allow_binary_replacement = 0;
24 static int check_index = 0;
25 static int write_index = 0;
26 static int diffstat = 0;
27 static int numstat = 0;
28 static int summary = 0;
29 static int check = 0;
30 static int apply = 1;
31 static int no_add = 0;
32 static int show_index_info = 0;
33 static int line_termination = '\n';
34 static const char apply_usage[] =
35 "git-apply [--stat] [--numstat] [--summary] [--check] [--index] [--apply] [--no-add] [--index-info] [--allow-binary-replacement] [-z] [-pNUM] <patch>...";
36
37 static enum whitespace_eol {
38         nowarn_whitespace,
39         warn_on_whitespace,
40         error_on_whitespace,
41         strip_whitespace,
42 } new_whitespace = nowarn_whitespace;
43 static int whitespace_error = 0;
44 static int squelch_whitespace_errors = 5;
45 static int applied_after_stripping = 0;
46 static const char *patch_input_file = NULL;
47
48 static void parse_whitespace_option(const char *option)
49 {
50         if (!option) {
51                 new_whitespace = nowarn_whitespace;
52                 return;
53         }
54         if (!strcmp(option, "warn")) {
55                 new_whitespace = warn_on_whitespace;
56                 return;
57         }
58         if (!strcmp(option, "error")) {
59                 new_whitespace = error_on_whitespace;
60                 return;
61         }
62         if (!strcmp(option, "error-all")) {
63                 new_whitespace = error_on_whitespace;
64                 squelch_whitespace_errors = 0;
65                 return;
66         }
67         if (!strcmp(option, "strip")) {
68                 new_whitespace = strip_whitespace;
69                 return;
70         }
71         die("unrecognized whitespace option '%s'", option);
72 }
73
74 /*
75  * For "diff-stat" like behaviour, we keep track of the biggest change
76  * we've seen, and the longest filename. That allows us to do simple
77  * scaling.
78  */
79 static int max_change, max_len;
80
81 /*
82  * Various "current state", notably line numbers and what
83  * file (and how) we're patching right now.. The "is_xxxx"
84  * things are flags, where -1 means "don't know yet".
85  */
86 static int linenr = 1;
87
88 struct fragment {
89         unsigned long oldpos, oldlines;
90         unsigned long newpos, newlines;
91         const char *patch;
92         int size;
93         struct fragment *next;
94 };
95
96 struct patch {
97         char *new_name, *old_name, *def_name;
98         unsigned int old_mode, new_mode;
99         int is_rename, is_copy, is_new, is_delete, is_binary;
100         int lines_added, lines_deleted;
101         int score;
102         struct fragment *fragments;
103         char *result;
104         unsigned long resultsize;
105         char old_sha1_prefix[41];
106         char new_sha1_prefix[41];
107         struct patch *next;
108 };
109
110 #define CHUNKSIZE (8192)
111 #define SLOP (16)
112
113 static void *read_patch_file(int fd, unsigned long *sizep)
114 {
115         unsigned long size = 0, alloc = CHUNKSIZE;
116         void *buffer = xmalloc(alloc);
117
118         for (;;) {
119                 int nr = alloc - size;
120                 if (nr < 1024) {
121                         alloc += CHUNKSIZE;
122                         buffer = xrealloc(buffer, alloc);
123                         nr = alloc - size;
124                 }
125                 nr = xread(fd, buffer + size, nr);
126                 if (!nr)
127                         break;
128                 if (nr < 0)
129                         die("git-apply: read returned %s", strerror(errno));
130                 size += nr;
131         }
132         *sizep = size;
133
134         /*
135          * Make sure that we have some slop in the buffer
136          * so that we can do speculative "memcmp" etc, and
137          * see to it that it is NUL-filled.
138          */
139         if (alloc < size + SLOP)
140                 buffer = xrealloc(buffer, size + SLOP);
141         memset(buffer + size, 0, SLOP);
142         return buffer;
143 }
144
145 static unsigned long linelen(const char *buffer, unsigned long size)
146 {
147         unsigned long len = 0;
148         while (size--) {
149                 len++;
150                 if (*buffer++ == '\n')
151                         break;
152         }
153         return len;
154 }
155
156 static int is_dev_null(const char *str)
157 {
158         return !memcmp("/dev/null", str, 9) && isspace(str[9]);
159 }
160
161 #define TERM_SPACE      1
162 #define TERM_TAB        2
163
164 static int name_terminate(const char *name, int namelen, int c, int terminate)
165 {
166         if (c == ' ' && !(terminate & TERM_SPACE))
167                 return 0;
168         if (c == '\t' && !(terminate & TERM_TAB))
169                 return 0;
170
171         return 1;
172 }
173
174 static char * find_name(const char *line, char *def, int p_value, int terminate)
175 {
176         int len;
177         const char *start = line;
178         char *name;
179
180         if (*line == '"') {
181                 /* Proposed "new-style" GNU patch/diff format; see
182                  * http://marc.theaimsgroup.com/?l=git&m=112927316408690&w=2
183                  */
184                 name = unquote_c_style(line, NULL);
185                 if (name) {
186                         char *cp = name;
187                         while (p_value) {
188                                 cp = strchr(name, '/');
189                                 if (!cp)
190                                         break;
191                                 cp++;
192                                 p_value--;
193                         }
194                         if (cp) {
195                                 /* name can later be freed, so we need
196                                  * to memmove, not just return cp
197                                  */
198                                 memmove(name, cp, strlen(cp) + 1);
199                                 free(def);
200                                 return name;
201                         }
202                         else {
203                                 free(name);
204                                 name = NULL;
205                         }
206                 }
207         }
208
209         for (;;) {
210                 char c = *line;
211
212                 if (isspace(c)) {
213                         if (c == '\n')
214                                 break;
215                         if (name_terminate(start, line-start, c, terminate))
216                                 break;
217                 }
218                 line++;
219                 if (c == '/' && !--p_value)
220                         start = line;
221         }
222         if (!start)
223                 return def;
224         len = line - start;
225         if (!len)
226                 return def;
227
228         /*
229          * Generally we prefer the shorter name, especially
230          * if the other one is just a variation of that with
231          * something else tacked on to the end (ie "file.orig"
232          * or "file~").
233          */
234         if (def) {
235                 int deflen = strlen(def);
236                 if (deflen < len && !strncmp(start, def, deflen))
237                         return def;
238         }
239
240         name = xmalloc(len + 1);
241         memcpy(name, start, len);
242         name[len] = 0;
243         free(def);
244         return name;
245 }
246
247 /*
248  * Get the name etc info from the --/+++ lines of a traditional patch header
249  *
250  * NOTE! This hardcodes "-p1" behaviour in filename detection.
251  *
252  * FIXME! The end-of-filename heuristics are kind of screwy. For existing
253  * files, we can happily check the index for a match, but for creating a
254  * new file we should try to match whatever "patch" does. I have no idea.
255  */
256 static void parse_traditional_patch(const char *first, const char *second, struct patch *patch)
257 {
258         char *name;
259
260         first += 4;     // skip "--- "
261         second += 4;    // skip "+++ "
262         if (is_dev_null(first)) {
263                 patch->is_new = 1;
264                 patch->is_delete = 0;
265                 name = find_name(second, NULL, p_value, TERM_SPACE | TERM_TAB);
266                 patch->new_name = name;
267         } else if (is_dev_null(second)) {
268                 patch->is_new = 0;
269                 patch->is_delete = 1;
270                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
271                 patch->old_name = name;
272         } else {
273                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
274                 name = find_name(second, name, p_value, TERM_SPACE | TERM_TAB);
275                 patch->old_name = patch->new_name = name;
276         }
277         if (!name)
278                 die("unable to find filename in patch at line %d", linenr);
279 }
280
281 static int gitdiff_hdrend(const char *line, struct patch *patch)
282 {
283         return -1;
284 }
285
286 /*
287  * We're anal about diff header consistency, to make
288  * sure that we don't end up having strange ambiguous
289  * patches floating around.
290  *
291  * As a result, gitdiff_{old|new}name() will check
292  * their names against any previous information, just
293  * to make sure..
294  */
295 static char *gitdiff_verify_name(const char *line, int isnull, char *orig_name, const char *oldnew)
296 {
297         if (!orig_name && !isnull)
298                 return find_name(line, NULL, 1, 0);
299
300         if (orig_name) {
301                 int len;
302                 const char *name;
303                 char *another;
304                 name = orig_name;
305                 len = strlen(name);
306                 if (isnull)
307                         die("git-apply: bad git-diff - expected /dev/null, got %s on line %d", name, linenr);
308                 another = find_name(line, NULL, 1, 0);
309                 if (!another || memcmp(another, name, len))
310                         die("git-apply: bad git-diff - inconsistent %s filename on line %d", oldnew, linenr);
311                 free(another);
312                 return orig_name;
313         }
314         else {
315                 /* expect "/dev/null" */
316                 if (memcmp("/dev/null", line, 9) || line[9] != '\n')
317                         die("git-apply: bad git-diff - expected /dev/null on line %d", linenr);
318                 return NULL;
319         }
320 }
321
322 static int gitdiff_oldname(const char *line, struct patch *patch)
323 {
324         patch->old_name = gitdiff_verify_name(line, patch->is_new, patch->old_name, "old");
325         return 0;
326 }
327
328 static int gitdiff_newname(const char *line, struct patch *patch)
329 {
330         patch->new_name = gitdiff_verify_name(line, patch->is_delete, patch->new_name, "new");
331         return 0;
332 }
333
334 static int gitdiff_oldmode(const char *line, struct patch *patch)
335 {
336         patch->old_mode = strtoul(line, NULL, 8);
337         return 0;
338 }
339
340 static int gitdiff_newmode(const char *line, struct patch *patch)
341 {
342         patch->new_mode = strtoul(line, NULL, 8);
343         return 0;
344 }
345
346 static int gitdiff_delete(const char *line, struct patch *patch)
347 {
348         patch->is_delete = 1;
349         patch->old_name = patch->def_name;
350         return gitdiff_oldmode(line, patch);
351 }
352
353 static int gitdiff_newfile(const char *line, struct patch *patch)
354 {
355         patch->is_new = 1;
356         patch->new_name = patch->def_name;
357         return gitdiff_newmode(line, patch);
358 }
359
360 static int gitdiff_copysrc(const char *line, struct patch *patch)
361 {
362         patch->is_copy = 1;
363         patch->old_name = find_name(line, NULL, 0, 0);
364         return 0;
365 }
366
367 static int gitdiff_copydst(const char *line, struct patch *patch)
368 {
369         patch->is_copy = 1;
370         patch->new_name = find_name(line, NULL, 0, 0);
371         return 0;
372 }
373
374 static int gitdiff_renamesrc(const char *line, struct patch *patch)
375 {
376         patch->is_rename = 1;
377         patch->old_name = find_name(line, NULL, 0, 0);
378         return 0;
379 }
380
381 static int gitdiff_renamedst(const char *line, struct patch *patch)
382 {
383         patch->is_rename = 1;
384         patch->new_name = find_name(line, NULL, 0, 0);
385         return 0;
386 }
387
388 static int gitdiff_similarity(const char *line, struct patch *patch)
389 {
390         if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
391                 patch->score = 0;
392         return 0;
393 }
394
395 static int gitdiff_dissimilarity(const char *line, struct patch *patch)
396 {
397         if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
398                 patch->score = 0;
399         return 0;
400 }
401
402 static int gitdiff_index(const char *line, struct patch *patch)
403 {
404         /* index line is N hexadecimal, "..", N hexadecimal,
405          * and optional space with octal mode.
406          */
407         const char *ptr, *eol;
408         int len;
409
410         ptr = strchr(line, '.');
411         if (!ptr || ptr[1] != '.' || 40 < ptr - line)
412                 return 0;
413         len = ptr - line;
414         memcpy(patch->old_sha1_prefix, line, len);
415         patch->old_sha1_prefix[len] = 0;
416
417         line = ptr + 2;
418         ptr = strchr(line, ' ');
419         eol = strchr(line, '\n');
420
421         if (!ptr || eol < ptr)
422                 ptr = eol;
423         len = ptr - line;
424
425         if (40 < len)
426                 return 0;
427         memcpy(patch->new_sha1_prefix, line, len);
428         patch->new_sha1_prefix[len] = 0;
429         if (*ptr == ' ')
430                 patch->new_mode = patch->old_mode = strtoul(ptr+1, NULL, 8);
431         return 0;
432 }
433
434 /*
435  * This is normal for a diff that doesn't change anything: we'll fall through
436  * into the next diff. Tell the parser to break out.
437  */
438 static int gitdiff_unrecognized(const char *line, struct patch *patch)
439 {
440         return -1;
441 }
442
443 static const char *stop_at_slash(const char *line, int llen)
444 {
445         int i;
446
447         for (i = 0; i < llen; i++) {
448                 int ch = line[i];
449                 if (ch == '/')
450                         return line + i;
451         }
452         return NULL;
453 }
454
455 /* This is to extract the same name that appears on "diff --git"
456  * line.  We do not find and return anything if it is a rename
457  * patch, and it is OK because we will find the name elsewhere.
458  * We need to reliably find name only when it is mode-change only,
459  * creation or deletion of an empty file.  In any of these cases,
460  * both sides are the same name under a/ and b/ respectively.
461  */
462 static char *git_header_name(char *line, int llen)
463 {
464         int len;
465         const char *name;
466         const char *second = NULL;
467
468         line += strlen("diff --git ");
469         llen -= strlen("diff --git ");
470
471         if (*line == '"') {
472                 const char *cp;
473                 char *first = unquote_c_style(line, &second);
474                 if (!first)
475                         return NULL;
476
477                 /* advance to the first slash */
478                 cp = stop_at_slash(first, strlen(first));
479                 if (!cp || cp == first) {
480                         /* we do not accept absolute paths */
481                 free_first_and_fail:
482                         free(first);
483                         return NULL;
484                 }
485                 len = strlen(cp+1);
486                 memmove(first, cp+1, len+1); /* including NUL */
487
488                 /* second points at one past closing dq of name.
489                  * find the second name.
490                  */
491                 while ((second < line + llen) && isspace(*second))
492                         second++;
493
494                 if (line + llen <= second)
495                         goto free_first_and_fail;
496                 if (*second == '"') {
497                         char *sp = unquote_c_style(second, NULL);
498                         if (!sp)
499                                 goto free_first_and_fail;
500                         cp = stop_at_slash(sp, strlen(sp));
501                         if (!cp || cp == sp) {
502                         free_both_and_fail:
503                                 free(sp);
504                                 goto free_first_and_fail;
505                         }
506                         /* They must match, otherwise ignore */
507                         if (strcmp(cp+1, first))
508                                 goto free_both_and_fail;
509                         free(sp);
510                         return first;
511                 }
512
513                 /* unquoted second */
514                 cp = stop_at_slash(second, line + llen - second);
515                 if (!cp || cp == second)
516                         goto free_first_and_fail;
517                 cp++;
518                 if (line + llen - cp != len + 1 ||
519                     memcmp(first, cp, len))
520                         goto free_first_and_fail;
521                 return first;
522         }
523
524         /* unquoted first name */
525         name = stop_at_slash(line, llen);
526         if (!name || name == line)
527                 return NULL;
528
529         name++;
530
531         /* since the first name is unquoted, a dq if exists must be
532          * the beginning of the second name.
533          */
534         for (second = name; second < line + llen; second++) {
535                 if (*second == '"') {
536                         const char *cp = second;
537                         const char *np;
538                         char *sp = unquote_c_style(second, NULL);
539
540                         if (!sp)
541                                 return NULL;
542                         np = stop_at_slash(sp, strlen(sp));
543                         if (!np || np == sp) {
544                         free_second_and_fail:
545                                 free(sp);
546                                 return NULL;
547                         }
548                         np++;
549                         len = strlen(np);
550                         if (len < cp - name &&
551                             !strncmp(np, name, len) &&
552                             isspace(name[len])) {
553                                 /* Good */
554                                 memmove(sp, np, len + 1);
555                                 return sp;
556                         }
557                         goto free_second_and_fail;
558                 }
559         }
560
561         /*
562          * Accept a name only if it shows up twice, exactly the same
563          * form.
564          */
565         for (len = 0 ; ; len++) {
566                 char c = name[len];
567
568                 switch (c) {
569                 default:
570                         continue;
571                 case '\n':
572                         return NULL;
573                 case '\t': case ' ':
574                         second = name+len;
575                         for (;;) {
576                                 char c = *second++;
577                                 if (c == '\n')
578                                         return NULL;
579                                 if (c == '/')
580                                         break;
581                         }
582                         if (second[len] == '\n' && !memcmp(name, second, len)) {
583                                 char *ret = xmalloc(len + 1);
584                                 memcpy(ret, name, len);
585                                 ret[len] = 0;
586                                 return ret;
587                         }
588                 }
589         }
590         return NULL;
591 }
592
593 /* Verify that we recognize the lines following a git header */
594 static int parse_git_header(char *line, int len, unsigned int size, struct patch *patch)
595 {
596         unsigned long offset;
597
598         /* A git diff has explicit new/delete information, so we don't guess */
599         patch->is_new = 0;
600         patch->is_delete = 0;
601
602         /*
603          * Some things may not have the old name in the
604          * rest of the headers anywhere (pure mode changes,
605          * or removing or adding empty files), so we get
606          * the default name from the header.
607          */
608         patch->def_name = git_header_name(line, len);
609
610         line += len;
611         size -= len;
612         linenr++;
613         for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) {
614                 static const struct opentry {
615                         const char *str;
616                         int (*fn)(const char *, struct patch *);
617                 } optable[] = {
618                         { "@@ -", gitdiff_hdrend },
619                         { "--- ", gitdiff_oldname },
620                         { "+++ ", gitdiff_newname },
621                         { "old mode ", gitdiff_oldmode },
622                         { "new mode ", gitdiff_newmode },
623                         { "deleted file mode ", gitdiff_delete },
624                         { "new file mode ", gitdiff_newfile },
625                         { "copy from ", gitdiff_copysrc },
626                         { "copy to ", gitdiff_copydst },
627                         { "rename old ", gitdiff_renamesrc },
628                         { "rename new ", gitdiff_renamedst },
629                         { "rename from ", gitdiff_renamesrc },
630                         { "rename to ", gitdiff_renamedst },
631                         { "similarity index ", gitdiff_similarity },
632                         { "dissimilarity index ", gitdiff_dissimilarity },
633                         { "index ", gitdiff_index },
634                         { "", gitdiff_unrecognized },
635                 };
636                 int i;
637
638                 len = linelen(line, size);
639                 if (!len || line[len-1] != '\n')
640                         break;
641                 for (i = 0; i < sizeof(optable) / sizeof(optable[0]); i++) {
642                         const struct opentry *p = optable + i;
643                         int oplen = strlen(p->str);
644                         if (len < oplen || memcmp(p->str, line, oplen))
645                                 continue;
646                         if (p->fn(line + oplen, patch) < 0)
647                                 return offset;
648                         break;
649                 }
650         }
651
652         return offset;
653 }
654
655 static int parse_num(const char *line, unsigned long *p)
656 {
657         char *ptr;
658
659         if (!isdigit(*line))
660                 return 0;
661         *p = strtoul(line, &ptr, 10);
662         return ptr - line;
663 }
664
665 static int parse_range(const char *line, int len, int offset, const char *expect,
666                         unsigned long *p1, unsigned long *p2)
667 {
668         int digits, ex;
669
670         if (offset < 0 || offset >= len)
671                 return -1;
672         line += offset;
673         len -= offset;
674
675         digits = parse_num(line, p1);
676         if (!digits)
677                 return -1;
678
679         offset += digits;
680         line += digits;
681         len -= digits;
682
683         *p2 = *p1;
684         if (*line == ',') {
685                 digits = parse_num(line+1, p2);
686                 if (!digits)
687                         return -1;
688
689                 offset += digits+1;
690                 line += digits+1;
691                 len -= digits+1;
692         }
693
694         ex = strlen(expect);
695         if (ex > len)
696                 return -1;
697         if (memcmp(line, expect, ex))
698                 return -1;
699
700         return offset + ex;
701 }
702
703 /*
704  * Parse a unified diff fragment header of the
705  * form "@@ -a,b +c,d @@"
706  */
707 static int parse_fragment_header(char *line, int len, struct fragment *fragment)
708 {
709         int offset;
710
711         if (!len || line[len-1] != '\n')
712                 return -1;
713
714         /* Figure out the number of lines in a fragment */
715         offset = parse_range(line, len, 4, " +", &fragment->oldpos, &fragment->oldlines);
716         offset = parse_range(line, len, offset, " @@", &fragment->newpos, &fragment->newlines);
717
718         return offset;
719 }
720
721 static int find_header(char *line, unsigned long size, int *hdrsize, struct patch *patch)
722 {
723         unsigned long offset, len;
724
725         patch->is_rename = patch->is_copy = 0;
726         patch->is_new = patch->is_delete = -1;
727         patch->old_mode = patch->new_mode = 0;
728         patch->old_name = patch->new_name = NULL;
729         for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) {
730                 unsigned long nextlen;
731
732                 len = linelen(line, size);
733                 if (!len)
734                         break;
735
736                 /* Testing this early allows us to take a few shortcuts.. */
737                 if (len < 6)
738                         continue;
739
740                 /*
741                  * Make sure we don't find any unconnected patch fragmants.
742                  * That's a sign that we didn't find a header, and that a
743                  * patch has become corrupted/broken up.
744                  */
745                 if (!memcmp("@@ -", line, 4)) {
746                         struct fragment dummy;
747                         if (parse_fragment_header(line, len, &dummy) < 0)
748                                 continue;
749                         error("patch fragment without header at line %d: %.*s", linenr, (int)len-1, line);
750                 }
751
752                 if (size < len + 6)
753                         break;
754
755                 /*
756                  * Git patch? It might not have a real patch, just a rename
757                  * or mode change, so we handle that specially
758                  */
759                 if (!memcmp("diff --git ", line, 11)) {
760                         int git_hdr_len = parse_git_header(line, len, size, patch);
761                         if (git_hdr_len <= len)
762                                 continue;
763                         if (!patch->old_name && !patch->new_name) {
764                                 if (!patch->def_name)
765                                         die("git diff header lacks filename information (line %d)", linenr);
766                                 patch->old_name = patch->new_name = patch->def_name;
767                         }
768                         *hdrsize = git_hdr_len;
769                         return offset;
770                 }
771
772                 /** --- followed by +++ ? */
773                 if (memcmp("--- ", line,  4) || memcmp("+++ ", line + len, 4))
774                         continue;
775
776                 /*
777                  * We only accept unified patches, so we want it to
778                  * at least have "@@ -a,b +c,d @@\n", which is 14 chars
779                  * minimum
780                  */
781                 nextlen = linelen(line + len, size - len);
782                 if (size < nextlen + 14 || memcmp("@@ -", line + len + nextlen, 4))
783                         continue;
784
785                 /* Ok, we'll consider it a patch */
786                 parse_traditional_patch(line, line+len, patch);
787                 *hdrsize = len + nextlen;
788                 linenr += 2;
789                 return offset;
790         }
791         return -1;
792 }
793
794 /*
795  * Parse a unified diff. Note that this really needs
796  * to parse each fragment separately, since the only
797  * way to know the difference between a "---" that is
798  * part of a patch, and a "---" that starts the next
799  * patch is to look at the line counts..
800  */
801 static int parse_fragment(char *line, unsigned long size, struct patch *patch, struct fragment *fragment)
802 {
803         int added, deleted;
804         int len = linelen(line, size), offset;
805         unsigned long oldlines, newlines;
806
807         offset = parse_fragment_header(line, len, fragment);
808         if (offset < 0)
809                 return -1;
810         oldlines = fragment->oldlines;
811         newlines = fragment->newlines;
812
813         if (patch->is_new < 0) {
814                 patch->is_new =  !oldlines;
815                 if (!oldlines)
816                         patch->old_name = NULL;
817         }
818         if (patch->is_delete < 0) {
819                 patch->is_delete = !newlines;
820                 if (!newlines)
821                         patch->new_name = NULL;
822         }
823
824         if (patch->is_new != !oldlines)
825                 return error("new file depends on old contents");
826         if (patch->is_delete != !newlines) {
827                 if (newlines)
828                         return error("deleted file still has contents");
829                 fprintf(stderr, "** warning: file %s becomes empty but is not deleted\n", patch->new_name);
830         }
831
832         /* Parse the thing.. */
833         line += len;
834         size -= len;
835         linenr++;
836         added = deleted = 0;
837         for (offset = len; size > 0; offset += len, size -= len, line += len, linenr++) {
838                 if (!oldlines && !newlines)
839                         break;
840                 len = linelen(line, size);
841                 if (!len || line[len-1] != '\n')
842                         return -1;
843                 switch (*line) {
844                 default:
845                         return -1;
846                 case ' ':
847                         oldlines--;
848                         newlines--;
849                         break;
850                 case '-':
851                         deleted++;
852                         oldlines--;
853                         break;
854                 case '+':
855                         /*
856                          * We know len is at least two, since we have a '+' and
857                          * we checked that the last character was a '\n' above.
858                          * That is, an addition of an empty line would check
859                          * the '+' here.  Sneaky...
860                          */
861                         if ((new_whitespace != nowarn_whitespace) &&
862                             isspace(line[len-2])) {
863                                 whitespace_error++;
864                                 if (squelch_whitespace_errors &&
865                                     squelch_whitespace_errors <
866                                     whitespace_error)
867                                         ;
868                                 else {
869                                         fprintf(stderr, "Adds trailing whitespace.\n%s:%d:%.*s\n",
870                                                 patch_input_file,
871                                                 linenr, len-2, line+1);
872                                 }
873                         }
874                         added++;
875                         newlines--;
876                         break;
877
878                 /* We allow "\ No newline at end of file". Depending
879                  * on locale settings when the patch was produced we
880                  * don't know what this line looks like. The only
881                  * thing we do know is that it begins with "\ ".
882                  * Checking for 12 is just for sanity check -- any
883                  * l10n of "\ No newline..." is at least that long.
884                  */
885                 case '\\':
886                         if (len < 12 || memcmp(line, "\\ ", 2))
887                                 return -1;
888                         break;
889                 }
890         }
891         /* If a fragment ends with an incomplete line, we failed to include
892          * it in the above loop because we hit oldlines == newlines == 0
893          * before seeing it.
894          */
895         if (12 < size && !memcmp(line, "\\ ", 2))
896                 offset += linelen(line, size);
897
898         patch->lines_added += added;
899         patch->lines_deleted += deleted;
900         return offset;
901 }
902
903 static int parse_single_patch(char *line, unsigned long size, struct patch *patch)
904 {
905         unsigned long offset = 0;
906         struct fragment **fragp = &patch->fragments;
907
908         while (size > 4 && !memcmp(line, "@@ -", 4)) {
909                 struct fragment *fragment;
910                 int len;
911
912                 fragment = xmalloc(sizeof(*fragment));
913                 memset(fragment, 0, sizeof(*fragment));
914                 len = parse_fragment(line, size, patch, fragment);
915                 if (len <= 0)
916                         die("corrupt patch at line %d", linenr);
917
918                 fragment->patch = line;
919                 fragment->size = len;
920
921                 *fragp = fragment;
922                 fragp = &fragment->next;
923
924                 offset += len;
925                 line += len;
926                 size -= len;
927         }
928         return offset;
929 }
930
931 static inline int metadata_changes(struct patch *patch)
932 {
933         return  patch->is_rename > 0 ||
934                 patch->is_copy > 0 ||
935                 patch->is_new > 0 ||
936                 patch->is_delete ||
937                 (patch->old_mode && patch->new_mode &&
938                  patch->old_mode != patch->new_mode);
939 }
940
941 static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
942 {
943         int hdrsize, patchsize;
944         int offset = find_header(buffer, size, &hdrsize, patch);
945
946         if (offset < 0)
947                 return offset;
948
949         patchsize = parse_single_patch(buffer + offset + hdrsize, size - offset - hdrsize, patch);
950
951         if (!patchsize) {
952                 static const char *binhdr[] = {
953                         "Binary files ",
954                         "Files ",
955                         NULL,
956                 };
957                 int i;
958                 int hd = hdrsize + offset;
959                 unsigned long llen = linelen(buffer + hd, size - hd);
960
961                 if (!memcmp(" differ\n", buffer + hd + llen - 8, 8))
962                         for (i = 0; binhdr[i]; i++) {
963                                 int len = strlen(binhdr[i]);
964                                 if (len < size - hd &&
965                                     !memcmp(binhdr[i], buffer + hd, len)) {
966                                         patch->is_binary = 1;
967                                         break;
968                                 }
969                         }
970
971                 /* Empty patch cannot be applied if:
972                  * - it is a binary patch and we do not do binary_replace, or
973                  * - text patch without metadata change
974                  */
975                 if ((apply || check) &&
976                     (patch->is_binary
977                      ? !allow_binary_replacement
978                      : !metadata_changes(patch)))
979                         die("patch with only garbage at line %d", linenr);
980         }
981
982         return offset + hdrsize + patchsize;
983 }
984
985 static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
986 static const char minuses[]= "----------------------------------------------------------------------";
987
988 static void show_stats(struct patch *patch)
989 {
990         const char *prefix = "";
991         char *name = patch->new_name;
992         char *qname = NULL;
993         int len, max, add, del, total;
994
995         if (!name)
996                 name = patch->old_name;
997
998         if (0 < (len = quote_c_style(name, NULL, NULL, 0))) {
999                 qname = xmalloc(len + 1);
1000                 quote_c_style(name, qname, NULL, 0);
1001                 name = qname;
1002         }
1003
1004         /*
1005          * "scale" the filename
1006          */
1007         len = strlen(name);
1008         max = max_len;
1009         if (max > 50)
1010                 max = 50;
1011         if (len > max) {
1012                 char *slash;
1013                 prefix = "...";
1014                 max -= 3;
1015                 name += len - max;
1016                 slash = strchr(name, '/');
1017                 if (slash)
1018                         name = slash;
1019         }
1020         len = max;
1021
1022         /*
1023          * scale the add/delete
1024          */
1025         max = max_change;
1026         if (max + len > 70)
1027                 max = 70 - len;
1028
1029         add = patch->lines_added;
1030         del = patch->lines_deleted;
1031         total = add + del;
1032
1033         if (max_change > 0) {
1034                 total = (total * max + max_change / 2) / max_change;
1035                 add = (add * max + max_change / 2) / max_change;
1036                 del = total - add;
1037         }
1038         if (patch->is_binary)
1039                 printf(" %s%-*s |  Bin\n", prefix, len, name);
1040         else
1041                 printf(" %s%-*s |%5d %.*s%.*s\n", prefix,
1042                        len, name, patch->lines_added + patch->lines_deleted,
1043                        add, pluses, del, minuses);
1044         if (qname)
1045                 free(qname);
1046 }
1047
1048 static int read_old_data(struct stat *st, const char *path, void *buf, unsigned long size)
1049 {
1050         int fd;
1051         unsigned long got;
1052
1053         switch (st->st_mode & S_IFMT) {
1054         case S_IFLNK:
1055                 return readlink(path, buf, size);
1056         case S_IFREG:
1057                 fd = open(path, O_RDONLY);
1058                 if (fd < 0)
1059                         return error("unable to open %s", path);
1060                 got = 0;
1061                 for (;;) {
1062                         int ret = xread(fd, buf + got, size - got);
1063                         if (ret <= 0)
1064                                 break;
1065                         got += ret;
1066                 }
1067                 close(fd);
1068                 return got;
1069
1070         default:
1071                 return -1;
1072         }
1073 }
1074
1075 static int find_offset(const char *buf, unsigned long size, const char *fragment, unsigned long fragsize, int line)
1076 {
1077         int i;
1078         unsigned long start, backwards, forwards;
1079
1080         if (fragsize > size)
1081                 return -1;
1082
1083         start = 0;
1084         if (line > 1) {
1085                 unsigned long offset = 0;
1086                 i = line-1;
1087                 while (offset + fragsize <= size) {
1088                         if (buf[offset++] == '\n') {
1089                                 start = offset;
1090                                 if (!--i)
1091                                         break;
1092                         }
1093                 }
1094         }
1095
1096         /* Exact line number? */
1097         if (!memcmp(buf + start, fragment, fragsize))
1098                 return start;
1099
1100         /*
1101          * There's probably some smart way to do this, but I'll leave
1102          * that to the smart and beautiful people. I'm simple and stupid.
1103          */
1104         backwards = start;
1105         forwards = start;
1106         for (i = 0; ; i++) {
1107                 unsigned long try;
1108                 int n;
1109
1110                 /* "backward" */
1111                 if (i & 1) {
1112                         if (!backwards) {
1113                                 if (forwards + fragsize > size)
1114                                         break;
1115                                 continue;
1116                         }
1117                         do {
1118                                 --backwards;
1119                         } while (backwards && buf[backwards-1] != '\n');
1120                         try = backwards;
1121                 } else {
1122                         while (forwards + fragsize <= size) {
1123                                 if (buf[forwards++] == '\n')
1124                                         break;
1125                         }
1126                         try = forwards;
1127                 }
1128
1129                 if (try + fragsize > size)
1130                         continue;
1131                 if (memcmp(buf + try, fragment, fragsize))
1132                         continue;
1133                 n = (i >> 1)+1;
1134                 if (i & 1)
1135                         n = -n;
1136                 return try;
1137         }
1138
1139         /*
1140          * We should start searching forward and backward.
1141          */
1142         return -1;
1143 }
1144
1145 struct buffer_desc {
1146         char *buffer;
1147         unsigned long size;
1148         unsigned long alloc;
1149 };
1150
1151 static int apply_line(char *output, const char *patch, int plen)
1152 {
1153         /* plen is number of bytes to be copied from patch,
1154          * starting at patch+1 (patch[0] is '+').  Typically
1155          * patch[plen] is '\n'.
1156          */
1157         int add_nl_to_tail = 0;
1158         if ((new_whitespace == strip_whitespace) &&
1159             1 < plen && isspace(patch[plen-1])) {
1160                 if (patch[plen] == '\n')
1161                         add_nl_to_tail = 1;
1162                 plen--;
1163                 while (0 < plen && isspace(patch[plen]))
1164                         plen--;
1165                 applied_after_stripping++;
1166         }
1167         memcpy(output, patch + 1, plen);
1168         if (add_nl_to_tail)
1169                 output[plen++] = '\n';
1170         return plen;
1171 }
1172
1173 static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag)
1174 {
1175         char *buf = desc->buffer;
1176         const char *patch = frag->patch;
1177         int offset, size = frag->size;
1178         char *old = xmalloc(size);
1179         char *new = xmalloc(size);
1180         int oldsize = 0, newsize = 0;
1181
1182         while (size > 0) {
1183                 int len = linelen(patch, size);
1184                 int plen;
1185
1186                 if (!len)
1187                         break;
1188
1189                 /*
1190                  * "plen" is how much of the line we should use for
1191                  * the actual patch data. Normally we just remove the
1192                  * first character on the line, but if the line is
1193                  * followed by "\ No newline", then we also remove the
1194                  * last one (which is the newline, of course).
1195                  */
1196                 plen = len-1;
1197                 if (len < size && patch[len] == '\\')
1198                         plen--;
1199                 switch (*patch) {
1200                 case ' ':
1201                 case '-':
1202                         memcpy(old + oldsize, patch + 1, plen);
1203                         oldsize += plen;
1204                         if (*patch == '-')
1205                                 break;
1206                 /* Fall-through for ' ' */
1207                 case '+':
1208                         if (*patch != '+' || !no_add)
1209                                 newsize += apply_line(new + newsize, patch,
1210                                                       plen);
1211                         break;
1212                 case '@': case '\\':
1213                         /* Ignore it, we already handled it */
1214                         break;
1215                 default:
1216                         return -1;
1217                 }
1218                 patch += len;
1219                 size -= len;
1220         }
1221
1222 #ifdef NO_ACCURATE_DIFF
1223         if (oldsize > 0 && old[oldsize - 1] == '\n' &&
1224                         newsize > 0 && new[newsize - 1] == '\n') {
1225                 oldsize--;
1226                 newsize--;
1227         }
1228 #endif
1229                         
1230         offset = find_offset(buf, desc->size, old, oldsize, frag->newpos);
1231         if (offset >= 0) {
1232                 int diff = newsize - oldsize;
1233                 unsigned long size = desc->size + diff;
1234                 unsigned long alloc = desc->alloc;
1235
1236                 if (size > alloc) {
1237                         alloc = size + 8192;
1238                         desc->alloc = alloc;
1239                         buf = xrealloc(buf, alloc);
1240                         desc->buffer = buf;
1241                 }
1242                 desc->size = size;
1243                 memmove(buf + offset + newsize, buf + offset + oldsize, size - offset - newsize);
1244                 memcpy(buf + offset, new, newsize);
1245                 offset = 0;
1246         }
1247
1248         free(old);
1249         free(new);
1250         return offset;
1251 }
1252
1253 static int apply_fragments(struct buffer_desc *desc, struct patch *patch)
1254 {
1255         struct fragment *frag = patch->fragments;
1256         const char *name = patch->old_name ? patch->old_name : patch->new_name;
1257
1258         if (patch->is_binary) {
1259                 unsigned char sha1[20];
1260
1261                 if (!allow_binary_replacement)
1262                         return error("cannot apply binary patch to '%s' "
1263                                      "without --allow-binary-replacement",
1264                                      name);
1265
1266                 /* For safety, we require patch index line to contain
1267                  * full 40-byte textual SHA1 for old and new, at least for now.
1268                  */
1269                 if (strlen(patch->old_sha1_prefix) != 40 ||
1270                     strlen(patch->new_sha1_prefix) != 40 ||
1271                     get_sha1_hex(patch->old_sha1_prefix, sha1) ||
1272                     get_sha1_hex(patch->new_sha1_prefix, sha1))
1273                         return error("cannot apply binary patch to '%s' "
1274                                      "without full index line", name);
1275
1276                 if (patch->old_name) {
1277                         unsigned char hdr[50];
1278                         int hdrlen;
1279
1280                         /* See if the old one matches what the patch
1281                          * applies to.
1282                          */
1283                         write_sha1_file_prepare(desc->buffer, desc->size,
1284                                                 "blob", sha1, hdr, &hdrlen);
1285                         if (strcmp(sha1_to_hex(sha1), patch->old_sha1_prefix))
1286                                 return error("the patch applies to '%s' (%s), "
1287                                              "which does not match the "
1288                                              "current contents.",
1289                                              name, sha1_to_hex(sha1));
1290                 }
1291                 else {
1292                         /* Otherwise, the old one must be empty. */
1293                         if (desc->size)
1294                                 return error("the patch applies to an empty "
1295                                              "'%s' but it is not empty", name);
1296                 }
1297
1298                 /* For now, we do not record post-image data in the patch,
1299                  * and require the object already present in the recipient's
1300                  * object database.
1301                  */
1302                 if (desc->buffer) {
1303                         free(desc->buffer);
1304                         desc->alloc = desc->size = 0;
1305                 }
1306                 get_sha1_hex(patch->new_sha1_prefix, sha1);
1307
1308                 if (memcmp(sha1, null_sha1, 20)) {
1309                         char type[10];
1310                         unsigned long size;
1311
1312                         desc->buffer = read_sha1_file(sha1, type, &size);
1313                         if (!desc->buffer)
1314                                 return error("the necessary postimage %s for "
1315                                              "'%s' does not exist",
1316                                              patch->new_sha1_prefix, name);
1317                         desc->alloc = desc->size = size;
1318                 }
1319
1320                 return 0;
1321         }
1322
1323         while (frag) {
1324                 if (apply_one_fragment(desc, frag) < 0)
1325                         return error("patch failed: %s:%ld",
1326                                      name, frag->oldpos);
1327                 frag = frag->next;
1328         }
1329         return 0;
1330 }
1331
1332 static int apply_data(struct patch *patch, struct stat *st)
1333 {
1334         char *buf;
1335         unsigned long size, alloc;
1336         struct buffer_desc desc;
1337
1338         size = 0;
1339         alloc = 0;
1340         buf = NULL;
1341         if (patch->old_name) {
1342                 size = st->st_size;
1343                 alloc = size + 8192;
1344                 buf = xmalloc(alloc);
1345                 if (read_old_data(st, patch->old_name, buf, alloc) != size)
1346                         return error("read of %s failed", patch->old_name);
1347         }
1348
1349         desc.size = size;
1350         desc.alloc = alloc;
1351         desc.buffer = buf;
1352         if (apply_fragments(&desc, patch) < 0)
1353                 return -1;
1354         patch->result = desc.buffer;
1355         patch->resultsize = desc.size;
1356
1357         if (patch->is_delete && patch->resultsize)
1358                 return error("removal patch leaves file contents");
1359
1360         return 0;
1361 }
1362
1363 static int check_patch(struct patch *patch)
1364 {
1365         struct stat st;
1366         const char *old_name = patch->old_name;
1367         const char *new_name = patch->new_name;
1368         const char *name = old_name ? old_name : new_name;
1369
1370         if (old_name) {
1371                 int changed;
1372                 int stat_ret = lstat(old_name, &st);
1373
1374                 if (check_index) {
1375                         int pos = cache_name_pos(old_name, strlen(old_name));
1376                         if (pos < 0)
1377                                 return error("%s: does not exist in index",
1378                                              old_name);
1379                         if (stat_ret < 0) {
1380                                 struct checkout costate;
1381                                 if (errno != ENOENT)
1382                                         return error("%s: %s", old_name,
1383                                                      strerror(errno));
1384                                 /* checkout */
1385                                 costate.base_dir = "";
1386                                 costate.base_dir_len = 0;
1387                                 costate.force = 0;
1388                                 costate.quiet = 0;
1389                                 costate.not_new = 0;
1390                                 costate.refresh_cache = 1;
1391                                 if (checkout_entry(active_cache[pos],
1392                                                    &costate) ||
1393                                     lstat(old_name, &st))
1394                                         return -1;
1395                         }
1396
1397                         changed = ce_match_stat(active_cache[pos], &st, 1);
1398                         if (changed)
1399                                 return error("%s: does not match index",
1400                                              old_name);
1401                 }
1402                 else if (stat_ret < 0)
1403                         return error("%s: %s", old_name, strerror(errno));
1404
1405                 if (patch->is_new < 0)
1406                         patch->is_new = 0;
1407                 st.st_mode = ntohl(create_ce_mode(st.st_mode));
1408                 if (!patch->old_mode)
1409                         patch->old_mode = st.st_mode;
1410                 if ((st.st_mode ^ patch->old_mode) & S_IFMT)
1411                         return error("%s: wrong type", old_name);
1412                 if (st.st_mode != patch->old_mode)
1413                         fprintf(stderr, "warning: %s has type %o, expected %o\n",
1414                                 old_name, st.st_mode, patch->old_mode);
1415         }
1416
1417         if (new_name && (patch->is_new | patch->is_rename | patch->is_copy)) {
1418                 if (check_index && cache_name_pos(new_name, strlen(new_name)) >= 0)
1419                         return error("%s: already exists in index", new_name);
1420                 if (!lstat(new_name, &st))
1421                         return error("%s: already exists in working directory", new_name);
1422                 if (errno != ENOENT)
1423                         return error("%s: %s", new_name, strerror(errno));
1424                 if (!patch->new_mode) {
1425                         if (patch->is_new)
1426                                 patch->new_mode = S_IFREG | 0644;
1427                         else
1428                                 patch->new_mode = patch->old_mode;
1429                 }
1430         }
1431
1432         if (new_name && old_name) {
1433                 int same = !strcmp(old_name, new_name);
1434                 if (!patch->new_mode)
1435                         patch->new_mode = patch->old_mode;
1436                 if ((patch->old_mode ^ patch->new_mode) & S_IFMT)
1437                         return error("new mode (%o) of %s does not match old mode (%o)%s%s",
1438                                 patch->new_mode, new_name, patch->old_mode,
1439                                 same ? "" : " of ", same ? "" : old_name);
1440         }       
1441
1442         if (apply_data(patch, &st) < 0)
1443                 return error("%s: patch does not apply", name);
1444         return 0;
1445 }
1446
1447 static int check_patch_list(struct patch *patch)
1448 {
1449         int error = 0;
1450
1451         for (;patch ; patch = patch->next)
1452                 error |= check_patch(patch);
1453         return error;
1454 }
1455
1456 static inline int is_null_sha1(const unsigned char *sha1)
1457 {
1458         return !memcmp(sha1, null_sha1, 20);
1459 }
1460
1461 static void show_index_list(struct patch *list)
1462 {
1463         struct patch *patch;
1464
1465         /* Once we start supporting the reverse patch, it may be
1466          * worth showing the new sha1 prefix, but until then...
1467          */
1468         for (patch = list; patch; patch = patch->next) {
1469                 const unsigned char *sha1_ptr;
1470                 unsigned char sha1[20];
1471                 const char *name;
1472
1473                 name = patch->old_name ? patch->old_name : patch->new_name;
1474                 if (patch->is_new)
1475                         sha1_ptr = null_sha1;
1476                 else if (get_sha1(patch->old_sha1_prefix, sha1))
1477                         die("sha1 information is lacking or useless (%s).",
1478                             name);
1479                 else
1480                         sha1_ptr = sha1;
1481
1482                 printf("%06o %s ",patch->old_mode, sha1_to_hex(sha1_ptr));
1483                 if (line_termination && quote_c_style(name, NULL, NULL, 0))
1484                         quote_c_style(name, NULL, stdout, 0);
1485                 else
1486                         fputs(name, stdout);
1487                 putchar(line_termination);
1488         }
1489 }
1490
1491 static void stat_patch_list(struct patch *patch)
1492 {
1493         int files, adds, dels;
1494
1495         for (files = adds = dels = 0 ; patch ; patch = patch->next) {
1496                 files++;
1497                 adds += patch->lines_added;
1498                 dels += patch->lines_deleted;
1499                 show_stats(patch);
1500         }
1501
1502         printf(" %d files changed, %d insertions(+), %d deletions(-)\n", files, adds, dels);
1503 }
1504
1505 static void numstat_patch_list(struct patch *patch)
1506 {
1507         for ( ; patch; patch = patch->next) {
1508                 const char *name;
1509                 name = patch->old_name ? patch->old_name : patch->new_name;
1510                 printf("%d\t%d\t", patch->lines_added, patch->lines_deleted);
1511                 if (line_termination && quote_c_style(name, NULL, NULL, 0))
1512                         quote_c_style(name, NULL, stdout, 0);
1513                 else
1514                         fputs(name, stdout);
1515                 putchar('\n');
1516         }
1517 }
1518
1519 static void show_file_mode_name(const char *newdelete, unsigned int mode, const char *name)
1520 {
1521         if (mode)
1522                 printf(" %s mode %06o %s\n", newdelete, mode, name);
1523         else
1524                 printf(" %s %s\n", newdelete, name);
1525 }
1526
1527 static void show_mode_change(struct patch *p, int show_name)
1528 {
1529         if (p->old_mode && p->new_mode && p->old_mode != p->new_mode) {
1530                 if (show_name)
1531                         printf(" mode change %06o => %06o %s\n",
1532                                p->old_mode, p->new_mode, p->new_name);
1533                 else
1534                         printf(" mode change %06o => %06o\n",
1535                                p->old_mode, p->new_mode);
1536         }
1537 }
1538
1539 static void show_rename_copy(struct patch *p)
1540 {
1541         const char *renamecopy = p->is_rename ? "rename" : "copy";
1542         const char *old, *new;
1543
1544         /* Find common prefix */
1545         old = p->old_name;
1546         new = p->new_name;
1547         while (1) {
1548                 const char *slash_old, *slash_new;
1549                 slash_old = strchr(old, '/');
1550                 slash_new = strchr(new, '/');
1551                 if (!slash_old ||
1552                     !slash_new ||
1553                     slash_old - old != slash_new - new ||
1554                     memcmp(old, new, slash_new - new))
1555                         break;
1556                 old = slash_old + 1;
1557                 new = slash_new + 1;
1558         }
1559         /* p->old_name thru old is the common prefix, and old and new
1560          * through the end of names are renames
1561          */
1562         if (old != p->old_name)
1563                 printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
1564                        (int)(old - p->old_name), p->old_name,
1565                        old, new, p->score);
1566         else
1567                 printf(" %s %s => %s (%d%%)\n", renamecopy,
1568                        p->old_name, p->new_name, p->score);
1569         show_mode_change(p, 0);
1570 }
1571
1572 static void summary_patch_list(struct patch *patch)
1573 {
1574         struct patch *p;
1575
1576         for (p = patch; p; p = p->next) {
1577                 if (p->is_new)
1578                         show_file_mode_name("create", p->new_mode, p->new_name);
1579                 else if (p->is_delete)
1580                         show_file_mode_name("delete", p->old_mode, p->old_name);
1581                 else {
1582                         if (p->is_rename || p->is_copy)
1583                                 show_rename_copy(p);
1584                         else {
1585                                 if (p->score) {
1586                                         printf(" rewrite %s (%d%%)\n",
1587                                                p->new_name, p->score);
1588                                         show_mode_change(p, 0);
1589                                 }
1590                                 else
1591                                         show_mode_change(p, 1);
1592                         }
1593                 }
1594         }
1595 }
1596
1597 static void patch_stats(struct patch *patch)
1598 {
1599         int lines = patch->lines_added + patch->lines_deleted;
1600
1601         if (lines > max_change)
1602                 max_change = lines;
1603         if (patch->old_name) {
1604                 int len = quote_c_style(patch->old_name, NULL, NULL, 0);
1605                 if (!len)
1606                         len = strlen(patch->old_name);
1607                 if (len > max_len)
1608                         max_len = len;
1609         }
1610         if (patch->new_name) {
1611                 int len = quote_c_style(patch->new_name, NULL, NULL, 0);
1612                 if (!len)
1613                         len = strlen(patch->new_name);
1614                 if (len > max_len)
1615                         max_len = len;
1616         }
1617 }
1618
1619 static void remove_file(struct patch *patch)
1620 {
1621         if (write_index) {
1622                 if (remove_file_from_cache(patch->old_name) < 0)
1623                         die("unable to remove %s from index", patch->old_name);
1624         }
1625         unlink(patch->old_name);
1626 }
1627
1628 static void add_index_file(const char *path, unsigned mode, void *buf, unsigned long size)
1629 {
1630         struct stat st;
1631         struct cache_entry *ce;
1632         int namelen = strlen(path);
1633         unsigned ce_size = cache_entry_size(namelen);
1634
1635         if (!write_index)
1636                 return;
1637
1638         ce = xmalloc(ce_size);
1639         memset(ce, 0, ce_size);
1640         memcpy(ce->name, path, namelen);
1641         ce->ce_mode = create_ce_mode(mode);
1642         ce->ce_flags = htons(namelen);
1643         if (lstat(path, &st) < 0)
1644                 die("unable to stat newly created file %s", path);
1645         fill_stat_cache_info(ce, &st);
1646         if (write_sha1_file(buf, size, "blob", ce->sha1) < 0)
1647                 die("unable to create backing store for newly created file %s", path);
1648         if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0)
1649                 die("unable to add cache entry for %s", path);
1650 }
1651
1652 static int try_create_file(const char *path, unsigned int mode, const char *buf, unsigned long size)
1653 {
1654         int fd;
1655
1656         if (S_ISLNK(mode))
1657                 return symlink(buf, path);
1658         fd = open(path, O_CREAT | O_EXCL | O_WRONLY, (mode & 0100) ? 0777 : 0666);
1659         if (fd < 0)
1660                 return -1;
1661         while (size) {
1662                 int written = xwrite(fd, buf, size);
1663                 if (written < 0)
1664                         die("writing file %s: %s", path, strerror(errno));
1665                 if (!written)
1666                         die("out of space writing file %s", path);
1667                 buf += written;
1668                 size -= written;
1669         }
1670         if (close(fd) < 0)
1671                 die("closing file %s: %s", path, strerror(errno));
1672         return 0;
1673 }
1674
1675 /*
1676  * We optimistically assume that the directories exist,
1677  * which is true 99% of the time anyway. If they don't,
1678  * we create them and try again.
1679  */
1680 static void create_one_file(char *path, unsigned mode, const char *buf, unsigned long size)
1681 {
1682         if (!try_create_file(path, mode, buf, size))
1683                 return;
1684
1685         if (errno == ENOENT) {
1686                 if (safe_create_leading_directories(path))
1687                         return;
1688                 if (!try_create_file(path, mode, buf, size))
1689                         return;
1690         }
1691
1692         if (errno == EEXIST) {
1693                 unsigned int nr = getpid();
1694
1695                 for (;;) {
1696                         const char *newpath;
1697                         newpath = mkpath("%s~%u", path, nr);
1698                         if (!try_create_file(newpath, mode, buf, size)) {
1699                                 if (!rename(newpath, path))
1700                                         return;
1701                                 unlink(newpath);
1702                                 break;
1703                         }
1704                         if (errno != EEXIST)
1705                                 break;
1706                         ++nr;
1707                 }
1708         }
1709         die("unable to write file %s mode %o", path, mode);
1710 }
1711
1712 static void create_file(struct patch *patch)
1713 {
1714         char *path = patch->new_name;
1715         unsigned mode = patch->new_mode;
1716         unsigned long size = patch->resultsize;
1717         char *buf = patch->result;
1718
1719         if (!mode)
1720                 mode = S_IFREG | 0644;
1721         create_one_file(path, mode, buf, size); 
1722         add_index_file(path, mode, buf, size);
1723 }
1724
1725 static void write_out_one_result(struct patch *patch)
1726 {
1727         if (patch->is_delete > 0) {
1728                 remove_file(patch);
1729                 return;
1730         }
1731         if (patch->is_new > 0 || patch->is_copy) {
1732                 create_file(patch);
1733                 return;
1734         }
1735         /*
1736          * Rename or modification boils down to the same
1737          * thing: remove the old, write the new
1738          */
1739         remove_file(patch);
1740         create_file(patch);
1741 }
1742
1743 static void write_out_results(struct patch *list, int skipped_patch)
1744 {
1745         if (!list && !skipped_patch)
1746                 die("No changes");
1747
1748         while (list) {
1749                 write_out_one_result(list);
1750                 list = list->next;
1751         }
1752 }
1753
1754 static struct cache_file cache_file;
1755
1756 static struct excludes {
1757         struct excludes *next;
1758         const char *path;
1759 } *excludes;
1760
1761 static int use_patch(struct patch *p)
1762 {
1763         const char *pathname = p->new_name ? p->new_name : p->old_name;
1764         struct excludes *x = excludes;
1765         while (x) {
1766                 if (fnmatch(x->path, pathname, 0) == 0)
1767                         return 0;
1768                 x = x->next;
1769         }
1770         if (0 < prefix_length) {
1771                 int pathlen = strlen(pathname);
1772                 if (pathlen <= prefix_length ||
1773                     memcmp(prefix, pathname, prefix_length))
1774                         return 0;
1775         }
1776         return 1;
1777 }
1778
1779 static int apply_patch(int fd, const char *filename)
1780 {
1781         int newfd;
1782         unsigned long offset, size;
1783         char *buffer = read_patch_file(fd, &size);
1784         struct patch *list = NULL, **listp = &list;
1785         int skipped_patch = 0;
1786
1787         patch_input_file = filename;
1788         if (!buffer)
1789                 return -1;
1790         offset = 0;
1791         while (size > 0) {
1792                 struct patch *patch;
1793                 int nr;
1794
1795                 patch = xmalloc(sizeof(*patch));
1796                 memset(patch, 0, sizeof(*patch));
1797                 nr = parse_chunk(buffer + offset, size, patch);
1798                 if (nr < 0)
1799                         break;
1800                 if (use_patch(patch)) {
1801                         patch_stats(patch);
1802                         *listp = patch;
1803                         listp = &patch->next;
1804                 } else {
1805                         /* perhaps free it a bit better? */
1806                         free(patch);
1807                         skipped_patch++;
1808                 }
1809                 offset += nr;
1810                 size -= nr;
1811         }
1812
1813         newfd = -1;
1814         if (whitespace_error && (new_whitespace == error_on_whitespace))
1815                 apply = 0;
1816
1817         write_index = check_index && apply;
1818         if (write_index)
1819                 newfd = hold_index_file_for_update(&cache_file, get_index_file());
1820         if (check_index) {
1821                 if (read_cache() < 0)
1822                         die("unable to read index file");
1823         }
1824
1825         if ((check || apply) && check_patch_list(list) < 0)
1826                 exit(1);
1827
1828         if (apply)
1829                 write_out_results(list, skipped_patch);
1830
1831         if (write_index) {
1832                 if (write_cache(newfd, active_cache, active_nr) ||
1833                     commit_index_file(&cache_file))
1834                         die("Unable to write new cachefile");
1835         }
1836
1837         if (show_index_info)
1838                 show_index_list(list);
1839
1840         if (diffstat)
1841                 stat_patch_list(list);
1842
1843         if (numstat)
1844                 numstat_patch_list(list);
1845
1846         if (summary)
1847                 summary_patch_list(list);
1848
1849         free(buffer);
1850         return 0;
1851 }
1852
1853 static int git_apply_config(const char *var, const char *value)
1854 {
1855         if (!strcmp(var, "apply.whitespace")) {
1856                 apply_default_whitespace = strdup(value);
1857                 return 0;
1858         }
1859         return git_default_config(var, value);
1860 }
1861
1862
1863 int main(int argc, char **argv)
1864 {
1865         int i;
1866         int read_stdin = 1;
1867         const char *whitespace_option = NULL;
1868
1869         for (i = 1; i < argc; i++) {
1870                 const char *arg = argv[i];
1871                 int fd;
1872
1873                 if (!strcmp(arg, "-")) {
1874                         apply_patch(0, "<stdin>");
1875                         read_stdin = 0;
1876                         continue;
1877                 }
1878                 if (!strncmp(arg, "--exclude=", 10)) {
1879                         struct excludes *x = xmalloc(sizeof(*x));
1880                         x->path = arg + 10;
1881                         x->next = excludes;
1882                         excludes = x;
1883                         continue;
1884                 }
1885                 if (!strncmp(arg, "-p", 2)) {
1886                         p_value = atoi(arg + 2);
1887                         continue;
1888                 }
1889                 if (!strcmp(arg, "--no-add")) {
1890                         no_add = 1;
1891                         continue;
1892                 }
1893                 if (!strcmp(arg, "--stat")) {
1894                         apply = 0;
1895                         diffstat = 1;
1896                         continue;
1897                 }
1898                 if (!strcmp(arg, "--allow-binary-replacement")) {
1899                         allow_binary_replacement = 1;
1900                         continue;
1901                 }
1902                 if (!strcmp(arg, "--numstat")) {
1903                         apply = 0;
1904                         numstat = 1;
1905                         continue;
1906                 }
1907                 if (!strcmp(arg, "--summary")) {
1908                         apply = 0;
1909                         summary = 1;
1910                         continue;
1911                 }
1912                 if (!strcmp(arg, "--check")) {
1913                         apply = 0;
1914                         check = 1;
1915                         continue;
1916                 }
1917                 if (!strcmp(arg, "--index")) {
1918                         check_index = 1;
1919                         continue;
1920                 }
1921                 if (!strcmp(arg, "--apply")) {
1922                         apply = 1;
1923                         continue;
1924                 }
1925                 if (!strcmp(arg, "--index-info")) {
1926                         apply = 0;
1927                         show_index_info = 1;
1928                         continue;
1929                 }
1930                 if (!strcmp(arg, "-z")) {
1931                         line_termination = 0;
1932                         continue;
1933                 }
1934                 if (!strncmp(arg, "--whitespace=", 13)) {
1935                         whitespace_option = arg + 13;
1936                         parse_whitespace_option(arg + 13);
1937                         continue;
1938                 }
1939
1940                 if (check_index && prefix_length < 0) {
1941                         prefix = setup_git_directory();
1942                         prefix_length = prefix ? strlen(prefix) : 0;
1943                         git_config(git_apply_config);
1944                         if (!whitespace_option && apply_default_whitespace)
1945                                 parse_whitespace_option(apply_default_whitespace);
1946                 }
1947                 if (0 < prefix_length)
1948                         arg = prefix_filename(prefix, prefix_length, arg);
1949
1950                 fd = open(arg, O_RDONLY);
1951                 if (fd < 0)
1952                         usage(apply_usage);
1953                 read_stdin = 0;
1954                 apply_patch(fd, arg);
1955                 close(fd);
1956         }
1957         if (read_stdin)
1958                 apply_patch(0, "<stdin>");
1959         if (whitespace_error) {
1960                 if (squelch_whitespace_errors &&
1961                     squelch_whitespace_errors < whitespace_error) {
1962                         int squelched =
1963                                 whitespace_error - squelch_whitespace_errors;
1964                         fprintf(stderr, "warning: squelched %d whitespace error%s\n",
1965                                 squelched,
1966                                 squelched == 1 ? "" : "s");
1967                 }
1968                 if (new_whitespace == error_on_whitespace)
1969                         die("%d line%s add%s trailing whitespaces.",
1970                             whitespace_error,
1971                             whitespace_error == 1 ? "" : "s",
1972                             whitespace_error == 1 ? "s" : "");
1973                 if (applied_after_stripping)
1974                         fprintf(stderr, "warning: %d line%s applied after"
1975                                 " stripping trailing whitespaces.\n",
1976                                 applied_after_stripping,
1977                                 applied_after_stripping == 1 ? "" : "s");
1978                 else if (whitespace_error)
1979                         fprintf(stderr, "warning: %d line%s add%s trailing"
1980                                 " whitespaces.\n",
1981                                 whitespace_error,
1982                                 whitespace_error == 1 ? "" : "s",
1983                                 whitespace_error == 1 ? "s" : "");
1984         }
1985         return 0;
1986 }