apply delta depth bias to already deltified objects
[git] / builtin-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 "cache.h"
10 #include "cache-tree.h"
11 #include "quote.h"
12 #include "blob.h"
13 #include "delta.h"
14 #include "builtin.h"
15
16 /*
17  *  --check turns on checking that the working tree matches the
18  *    files that are being modified, but doesn't apply the patch
19  *  --stat does just a diffstat, and doesn't actually apply
20  *  --numstat does numeric diffstat, and doesn't actually apply
21  *  --index-info shows the old and new index info for paths if available.
22  *  --index updates the cache as well.
23  *  --cached updates only the cache without ever touching the working tree.
24  */
25 static const char *prefix;
26 static int prefix_length = -1;
27 static int newfd = -1;
28
29 static int unidiff_zero;
30 static int p_value = 1;
31 static int p_value_known;
32 static int check_index;
33 static int update_index;
34 static int cached;
35 static int diffstat;
36 static int numstat;
37 static int summary;
38 static int check;
39 static int apply = 1;
40 static int apply_in_reverse;
41 static int apply_with_reject;
42 static int apply_verbosely;
43 static int no_add;
44 static int show_index_info;
45 static int line_termination = '\n';
46 static unsigned long p_context = ULONG_MAX;
47 static const char apply_usage[] =
48 "git-apply [--stat] [--numstat] [--summary] [--check] [--index] [--cached] [--apply] [--no-add] [--index-info] [--allow-binary-replacement] [--reverse] [--reject] [--verbose] [-z] [-pNUM] [-CNUM] [--whitespace=<nowarn|warn|error|error-all|strip>] <patch>...";
49
50 static enum whitespace_eol {
51         nowarn_whitespace,
52         warn_on_whitespace,
53         error_on_whitespace,
54         strip_whitespace,
55 } new_whitespace = warn_on_whitespace;
56 static int whitespace_error;
57 static int squelch_whitespace_errors = 5;
58 static int applied_after_fixing_ws;
59 static const char *patch_input_file;
60
61 static void parse_whitespace_option(const char *option)
62 {
63         if (!option) {
64                 new_whitespace = warn_on_whitespace;
65                 return;
66         }
67         if (!strcmp(option, "warn")) {
68                 new_whitespace = warn_on_whitespace;
69                 return;
70         }
71         if (!strcmp(option, "nowarn")) {
72                 new_whitespace = nowarn_whitespace;
73                 return;
74         }
75         if (!strcmp(option, "error")) {
76                 new_whitespace = error_on_whitespace;
77                 return;
78         }
79         if (!strcmp(option, "error-all")) {
80                 new_whitespace = error_on_whitespace;
81                 squelch_whitespace_errors = 0;
82                 return;
83         }
84         if (!strcmp(option, "strip")) {
85                 new_whitespace = strip_whitespace;
86                 return;
87         }
88         die("unrecognized whitespace option '%s'", option);
89 }
90
91 static void set_default_whitespace_mode(const char *whitespace_option)
92 {
93         if (!whitespace_option && !apply_default_whitespace) {
94                 new_whitespace = (apply
95                                   ? warn_on_whitespace
96                                   : nowarn_whitespace);
97         }
98 }
99
100 /*
101  * For "diff-stat" like behaviour, we keep track of the biggest change
102  * we've seen, and the longest filename. That allows us to do simple
103  * scaling.
104  */
105 static int max_change, max_len;
106
107 /*
108  * Various "current state", notably line numbers and what
109  * file (and how) we're patching right now.. The "is_xxxx"
110  * things are flags, where -1 means "don't know yet".
111  */
112 static int linenr = 1;
113
114 /*
115  * This represents one "hunk" from a patch, starting with
116  * "@@ -oldpos,oldlines +newpos,newlines @@" marker.  The
117  * patch text is pointed at by patch, and its byte length
118  * is stored in size.  leading and trailing are the number
119  * of context lines.
120  */
121 struct fragment {
122         unsigned long leading, trailing;
123         unsigned long oldpos, oldlines;
124         unsigned long newpos, newlines;
125         const char *patch;
126         int size;
127         int rejected;
128         struct fragment *next;
129 };
130
131 /*
132  * When dealing with a binary patch, we reuse "leading" field
133  * to store the type of the binary hunk, either deflated "delta"
134  * or deflated "literal".
135  */
136 #define binary_patch_method leading
137 #define BINARY_DELTA_DEFLATED   1
138 #define BINARY_LITERAL_DEFLATED 2
139
140 struct patch {
141         char *new_name, *old_name, *def_name;
142         unsigned int old_mode, new_mode;
143         int is_new, is_delete;  /* -1 = unknown, 0 = false, 1 = true */
144         int rejected;
145         unsigned long deflate_origlen;
146         int lines_added, lines_deleted;
147         int score;
148         unsigned int is_toplevel_relative:1;
149         unsigned int inaccurate_eof:1;
150         unsigned int is_binary:1;
151         unsigned int is_copy:1;
152         unsigned int is_rename:1;
153         struct fragment *fragments;
154         char *result;
155         unsigned long resultsize;
156         char old_sha1_prefix[41];
157         char new_sha1_prefix[41];
158         struct patch *next;
159 };
160
161 static void say_patch_name(FILE *output, const char *pre, struct patch *patch, const char *post)
162 {
163         fputs(pre, output);
164         if (patch->old_name && patch->new_name &&
165             strcmp(patch->old_name, patch->new_name)) {
166                 write_name_quoted(NULL, 0, patch->old_name, 1, output);
167                 fputs(" => ", output);
168                 write_name_quoted(NULL, 0, patch->new_name, 1, output);
169         }
170         else {
171                 const char *n = patch->new_name;
172                 if (!n)
173                         n = patch->old_name;
174                 write_name_quoted(NULL, 0, n, 1, output);
175         }
176         fputs(post, output);
177 }
178
179 #define CHUNKSIZE (8192)
180 #define SLOP (16)
181
182 static void *read_patch_file(int fd, unsigned long *sizep)
183 {
184         unsigned long size = 0, alloc = CHUNKSIZE;
185         void *buffer = xmalloc(alloc);
186
187         for (;;) {
188                 ssize_t nr = alloc - size;
189                 if (nr < 1024) {
190                         alloc += CHUNKSIZE;
191                         buffer = xrealloc(buffer, alloc);
192                         nr = alloc - size;
193                 }
194                 nr = xread(fd, (char *) buffer + size, nr);
195                 if (!nr)
196                         break;
197                 if (nr < 0)
198                         die("git-apply: read returned %s", strerror(errno));
199                 size += nr;
200         }
201         *sizep = size;
202
203         /*
204          * Make sure that we have some slop in the buffer
205          * so that we can do speculative "memcmp" etc, and
206          * see to it that it is NUL-filled.
207          */
208         if (alloc < size + SLOP)
209                 buffer = xrealloc(buffer, size + SLOP);
210         memset((char *) buffer + size, 0, SLOP);
211         return buffer;
212 }
213
214 static unsigned long linelen(const char *buffer, unsigned long size)
215 {
216         unsigned long len = 0;
217         while (size--) {
218                 len++;
219                 if (*buffer++ == '\n')
220                         break;
221         }
222         return len;
223 }
224
225 static int is_dev_null(const char *str)
226 {
227         return !memcmp("/dev/null", str, 9) && isspace(str[9]);
228 }
229
230 #define TERM_SPACE      1
231 #define TERM_TAB        2
232
233 static int name_terminate(const char *name, int namelen, int c, int terminate)
234 {
235         if (c == ' ' && !(terminate & TERM_SPACE))
236                 return 0;
237         if (c == '\t' && !(terminate & TERM_TAB))
238                 return 0;
239
240         return 1;
241 }
242
243 static char *find_name(const char *line, char *def, int p_value, int terminate)
244 {
245         int len;
246         const char *start = line;
247         char *name;
248
249         if (*line == '"') {
250                 /* Proposed "new-style" GNU patch/diff format; see
251                  * http://marc.theaimsgroup.com/?l=git&m=112927316408690&w=2
252                  */
253                 name = unquote_c_style(line, NULL);
254                 if (name) {
255                         char *cp = name;
256                         while (p_value) {
257                                 cp = strchr(name, '/');
258                                 if (!cp)
259                                         break;
260                                 cp++;
261                                 p_value--;
262                         }
263                         if (cp) {
264                                 /* name can later be freed, so we need
265                                  * to memmove, not just return cp
266                                  */
267                                 memmove(name, cp, strlen(cp) + 1);
268                                 free(def);
269                                 return name;
270                         }
271                         else {
272                                 free(name);
273                                 name = NULL;
274                         }
275                 }
276         }
277
278         for (;;) {
279                 char c = *line;
280
281                 if (isspace(c)) {
282                         if (c == '\n')
283                                 break;
284                         if (name_terminate(start, line-start, c, terminate))
285                                 break;
286                 }
287                 line++;
288                 if (c == '/' && !--p_value)
289                         start = line;
290         }
291         if (!start)
292                 return def;
293         len = line - start;
294         if (!len)
295                 return def;
296
297         /*
298          * Generally we prefer the shorter name, especially
299          * if the other one is just a variation of that with
300          * something else tacked on to the end (ie "file.orig"
301          * or "file~").
302          */
303         if (def) {
304                 int deflen = strlen(def);
305                 if (deflen < len && !strncmp(start, def, deflen))
306                         return def;
307         }
308
309         name = xmalloc(len + 1);
310         memcpy(name, start, len);
311         name[len] = 0;
312         free(def);
313         return name;
314 }
315
316 static int count_slashes(const char *cp)
317 {
318         int cnt = 0;
319         char ch;
320
321         while ((ch = *cp++))
322                 if (ch == '/')
323                         cnt++;
324         return cnt;
325 }
326
327 /*
328  * Given the string after "--- " or "+++ ", guess the appropriate
329  * p_value for the given patch.
330  */
331 static int guess_p_value(const char *nameline)
332 {
333         char *name, *cp;
334         int val = -1;
335
336         if (is_dev_null(nameline))
337                 return -1;
338         name = find_name(nameline, NULL, 0, TERM_SPACE | TERM_TAB);
339         if (!name)
340                 return -1;
341         cp = strchr(name, '/');
342         if (!cp)
343                 val = 0;
344         else if (prefix) {
345                 /*
346                  * Does it begin with "a/$our-prefix" and such?  Then this is
347                  * very likely to apply to our directory.
348                  */
349                 if (!strncmp(name, prefix, prefix_length))
350                         val = count_slashes(prefix);
351                 else {
352                         cp++;
353                         if (!strncmp(cp, prefix, prefix_length))
354                                 val = count_slashes(prefix) + 1;
355                 }
356         }
357         free(name);
358         return val;
359 }
360
361 /*
362  * Get the name etc info from the --/+++ lines of a traditional patch header
363  *
364  * FIXME! The end-of-filename heuristics are kind of screwy. For existing
365  * files, we can happily check the index for a match, but for creating a
366  * new file we should try to match whatever "patch" does. I have no idea.
367  */
368 static void parse_traditional_patch(const char *first, const char *second, struct patch *patch)
369 {
370         char *name;
371
372         first += 4;     /* skip "--- " */
373         second += 4;    /* skip "+++ " */
374         if (!p_value_known) {
375                 int p, q;
376                 p = guess_p_value(first);
377                 q = guess_p_value(second);
378                 if (p < 0) p = q;
379                 if (0 <= p && p == q) {
380                         p_value = p;
381                         p_value_known = 1;
382                 }
383         }
384         if (is_dev_null(first)) {
385                 patch->is_new = 1;
386                 patch->is_delete = 0;
387                 name = find_name(second, NULL, p_value, TERM_SPACE | TERM_TAB);
388                 patch->new_name = name;
389         } else if (is_dev_null(second)) {
390                 patch->is_new = 0;
391                 patch->is_delete = 1;
392                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
393                 patch->old_name = name;
394         } else {
395                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
396                 name = find_name(second, name, p_value, TERM_SPACE | TERM_TAB);
397                 patch->old_name = patch->new_name = name;
398         }
399         if (!name)
400                 die("unable to find filename in patch at line %d", linenr);
401 }
402
403 static int gitdiff_hdrend(const char *line, struct patch *patch)
404 {
405         return -1;
406 }
407
408 /*
409  * We're anal about diff header consistency, to make
410  * sure that we don't end up having strange ambiguous
411  * patches floating around.
412  *
413  * As a result, gitdiff_{old|new}name() will check
414  * their names against any previous information, just
415  * to make sure..
416  */
417 static char *gitdiff_verify_name(const char *line, int isnull, char *orig_name, const char *oldnew)
418 {
419         if (!orig_name && !isnull)
420                 return find_name(line, NULL, p_value, TERM_TAB);
421
422         if (orig_name) {
423                 int len;
424                 const char *name;
425                 char *another;
426                 name = orig_name;
427                 len = strlen(name);
428                 if (isnull)
429                         die("git-apply: bad git-diff - expected /dev/null, got %s on line %d", name, linenr);
430                 another = find_name(line, NULL, p_value, TERM_TAB);
431                 if (!another || memcmp(another, name, len))
432                         die("git-apply: bad git-diff - inconsistent %s filename on line %d", oldnew, linenr);
433                 free(another);
434                 return orig_name;
435         }
436         else {
437                 /* expect "/dev/null" */
438                 if (memcmp("/dev/null", line, 9) || line[9] != '\n')
439                         die("git-apply: bad git-diff - expected /dev/null on line %d", linenr);
440                 return NULL;
441         }
442 }
443
444 static int gitdiff_oldname(const char *line, struct patch *patch)
445 {
446         patch->old_name = gitdiff_verify_name(line, patch->is_new, patch->old_name, "old");
447         return 0;
448 }
449
450 static int gitdiff_newname(const char *line, struct patch *patch)
451 {
452         patch->new_name = gitdiff_verify_name(line, patch->is_delete, patch->new_name, "new");
453         return 0;
454 }
455
456 static int gitdiff_oldmode(const char *line, struct patch *patch)
457 {
458         patch->old_mode = strtoul(line, NULL, 8);
459         return 0;
460 }
461
462 static int gitdiff_newmode(const char *line, struct patch *patch)
463 {
464         patch->new_mode = strtoul(line, NULL, 8);
465         return 0;
466 }
467
468 static int gitdiff_delete(const char *line, struct patch *patch)
469 {
470         patch->is_delete = 1;
471         patch->old_name = patch->def_name;
472         return gitdiff_oldmode(line, patch);
473 }
474
475 static int gitdiff_newfile(const char *line, struct patch *patch)
476 {
477         patch->is_new = 1;
478         patch->new_name = patch->def_name;
479         return gitdiff_newmode(line, patch);
480 }
481
482 static int gitdiff_copysrc(const char *line, struct patch *patch)
483 {
484         patch->is_copy = 1;
485         patch->old_name = find_name(line, NULL, 0, 0);
486         return 0;
487 }
488
489 static int gitdiff_copydst(const char *line, struct patch *patch)
490 {
491         patch->is_copy = 1;
492         patch->new_name = find_name(line, NULL, 0, 0);
493         return 0;
494 }
495
496 static int gitdiff_renamesrc(const char *line, struct patch *patch)
497 {
498         patch->is_rename = 1;
499         patch->old_name = find_name(line, NULL, 0, 0);
500         return 0;
501 }
502
503 static int gitdiff_renamedst(const char *line, struct patch *patch)
504 {
505         patch->is_rename = 1;
506         patch->new_name = find_name(line, NULL, 0, 0);
507         return 0;
508 }
509
510 static int gitdiff_similarity(const char *line, struct patch *patch)
511 {
512         if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
513                 patch->score = 0;
514         return 0;
515 }
516
517 static int gitdiff_dissimilarity(const char *line, struct patch *patch)
518 {
519         if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
520                 patch->score = 0;
521         return 0;
522 }
523
524 static int gitdiff_index(const char *line, struct patch *patch)
525 {
526         /* index line is N hexadecimal, "..", N hexadecimal,
527          * and optional space with octal mode.
528          */
529         const char *ptr, *eol;
530         int len;
531
532         ptr = strchr(line, '.');
533         if (!ptr || ptr[1] != '.' || 40 < ptr - line)
534                 return 0;
535         len = ptr - line;
536         memcpy(patch->old_sha1_prefix, line, len);
537         patch->old_sha1_prefix[len] = 0;
538
539         line = ptr + 2;
540         ptr = strchr(line, ' ');
541         eol = strchr(line, '\n');
542
543         if (!ptr || eol < ptr)
544                 ptr = eol;
545         len = ptr - line;
546
547         if (40 < len)
548                 return 0;
549         memcpy(patch->new_sha1_prefix, line, len);
550         patch->new_sha1_prefix[len] = 0;
551         if (*ptr == ' ')
552                 patch->new_mode = patch->old_mode = strtoul(ptr+1, NULL, 8);
553         return 0;
554 }
555
556 /*
557  * This is normal for a diff that doesn't change anything: we'll fall through
558  * into the next diff. Tell the parser to break out.
559  */
560 static int gitdiff_unrecognized(const char *line, struct patch *patch)
561 {
562         return -1;
563 }
564
565 static const char *stop_at_slash(const char *line, int llen)
566 {
567         int i;
568
569         for (i = 0; i < llen; i++) {
570                 int ch = line[i];
571                 if (ch == '/')
572                         return line + i;
573         }
574         return NULL;
575 }
576
577 /* This is to extract the same name that appears on "diff --git"
578  * line.  We do not find and return anything if it is a rename
579  * patch, and it is OK because we will find the name elsewhere.
580  * We need to reliably find name only when it is mode-change only,
581  * creation or deletion of an empty file.  In any of these cases,
582  * both sides are the same name under a/ and b/ respectively.
583  */
584 static char *git_header_name(char *line, int llen)
585 {
586         int len;
587         const char *name;
588         const char *second = NULL;
589
590         line += strlen("diff --git ");
591         llen -= strlen("diff --git ");
592
593         if (*line == '"') {
594                 const char *cp;
595                 char *first = unquote_c_style(line, &second);
596                 if (!first)
597                         return NULL;
598
599                 /* advance to the first slash */
600                 cp = stop_at_slash(first, strlen(first));
601                 if (!cp || cp == first) {
602                         /* we do not accept absolute paths */
603                 free_first_and_fail:
604                         free(first);
605                         return NULL;
606                 }
607                 len = strlen(cp+1);
608                 memmove(first, cp+1, len+1); /* including NUL */
609
610                 /* second points at one past closing dq of name.
611                  * find the second name.
612                  */
613                 while ((second < line + llen) && isspace(*second))
614                         second++;
615
616                 if (line + llen <= second)
617                         goto free_first_and_fail;
618                 if (*second == '"') {
619                         char *sp = unquote_c_style(second, NULL);
620                         if (!sp)
621                                 goto free_first_and_fail;
622                         cp = stop_at_slash(sp, strlen(sp));
623                         if (!cp || cp == sp) {
624                         free_both_and_fail:
625                                 free(sp);
626                                 goto free_first_and_fail;
627                         }
628                         /* They must match, otherwise ignore */
629                         if (strcmp(cp+1, first))
630                                 goto free_both_and_fail;
631                         free(sp);
632                         return first;
633                 }
634
635                 /* unquoted second */
636                 cp = stop_at_slash(second, line + llen - second);
637                 if (!cp || cp == second)
638                         goto free_first_and_fail;
639                 cp++;
640                 if (line + llen - cp != len + 1 ||
641                     memcmp(first, cp, len))
642                         goto free_first_and_fail;
643                 return first;
644         }
645
646         /* unquoted first name */
647         name = stop_at_slash(line, llen);
648         if (!name || name == line)
649                 return NULL;
650
651         name++;
652
653         /* since the first name is unquoted, a dq if exists must be
654          * the beginning of the second name.
655          */
656         for (second = name; second < line + llen; second++) {
657                 if (*second == '"') {
658                         const char *cp = second;
659                         const char *np;
660                         char *sp = unquote_c_style(second, NULL);
661
662                         if (!sp)
663                                 return NULL;
664                         np = stop_at_slash(sp, strlen(sp));
665                         if (!np || np == sp) {
666                         free_second_and_fail:
667                                 free(sp);
668                                 return NULL;
669                         }
670                         np++;
671                         len = strlen(np);
672                         if (len < cp - name &&
673                             !strncmp(np, name, len) &&
674                             isspace(name[len])) {
675                                 /* Good */
676                                 memmove(sp, np, len + 1);
677                                 return sp;
678                         }
679                         goto free_second_and_fail;
680                 }
681         }
682
683         /*
684          * Accept a name only if it shows up twice, exactly the same
685          * form.
686          */
687         for (len = 0 ; ; len++) {
688                 switch (name[len]) {
689                 default:
690                         continue;
691                 case '\n':
692                         return NULL;
693                 case '\t': case ' ':
694                         second = name+len;
695                         for (;;) {
696                                 char c = *second++;
697                                 if (c == '\n')
698                                         return NULL;
699                                 if (c == '/')
700                                         break;
701                         }
702                         if (second[len] == '\n' && !memcmp(name, second, len)) {
703                                 char *ret = xmalloc(len + 1);
704                                 memcpy(ret, name, len);
705                                 ret[len] = 0;
706                                 return ret;
707                         }
708                 }
709         }
710         return NULL;
711 }
712
713 /* Verify that we recognize the lines following a git header */
714 static int parse_git_header(char *line, int len, unsigned int size, struct patch *patch)
715 {
716         unsigned long offset;
717
718         /* A git diff has explicit new/delete information, so we don't guess */
719         patch->is_new = 0;
720         patch->is_delete = 0;
721
722         /*
723          * Some things may not have the old name in the
724          * rest of the headers anywhere (pure mode changes,
725          * or removing or adding empty files), so we get
726          * the default name from the header.
727          */
728         patch->def_name = git_header_name(line, len);
729
730         line += len;
731         size -= len;
732         linenr++;
733         for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) {
734                 static const struct opentry {
735                         const char *str;
736                         int (*fn)(const char *, struct patch *);
737                 } optable[] = {
738                         { "@@ -", gitdiff_hdrend },
739                         { "--- ", gitdiff_oldname },
740                         { "+++ ", gitdiff_newname },
741                         { "old mode ", gitdiff_oldmode },
742                         { "new mode ", gitdiff_newmode },
743                         { "deleted file mode ", gitdiff_delete },
744                         { "new file mode ", gitdiff_newfile },
745                         { "copy from ", gitdiff_copysrc },
746                         { "copy to ", gitdiff_copydst },
747                         { "rename old ", gitdiff_renamesrc },
748                         { "rename new ", gitdiff_renamedst },
749                         { "rename from ", gitdiff_renamesrc },
750                         { "rename to ", gitdiff_renamedst },
751                         { "similarity index ", gitdiff_similarity },
752                         { "dissimilarity index ", gitdiff_dissimilarity },
753                         { "index ", gitdiff_index },
754                         { "", gitdiff_unrecognized },
755                 };
756                 int i;
757
758                 len = linelen(line, size);
759                 if (!len || line[len-1] != '\n')
760                         break;
761                 for (i = 0; i < ARRAY_SIZE(optable); i++) {
762                         const struct opentry *p = optable + i;
763                         int oplen = strlen(p->str);
764                         if (len < oplen || memcmp(p->str, line, oplen))
765                                 continue;
766                         if (p->fn(line + oplen, patch) < 0)
767                                 return offset;
768                         break;
769                 }
770         }
771
772         return offset;
773 }
774
775 static int parse_num(const char *line, unsigned long *p)
776 {
777         char *ptr;
778
779         if (!isdigit(*line))
780                 return 0;
781         *p = strtoul(line, &ptr, 10);
782         return ptr - line;
783 }
784
785 static int parse_range(const char *line, int len, int offset, const char *expect,
786                         unsigned long *p1, unsigned long *p2)
787 {
788         int digits, ex;
789
790         if (offset < 0 || offset >= len)
791                 return -1;
792         line += offset;
793         len -= offset;
794
795         digits = parse_num(line, p1);
796         if (!digits)
797                 return -1;
798
799         offset += digits;
800         line += digits;
801         len -= digits;
802
803         *p2 = 1;
804         if (*line == ',') {
805                 digits = parse_num(line+1, p2);
806                 if (!digits)
807                         return -1;
808
809                 offset += digits+1;
810                 line += digits+1;
811                 len -= digits+1;
812         }
813
814         ex = strlen(expect);
815         if (ex > len)
816                 return -1;
817         if (memcmp(line, expect, ex))
818                 return -1;
819
820         return offset + ex;
821 }
822
823 /*
824  * Parse a unified diff fragment header of the
825  * form "@@ -a,b +c,d @@"
826  */
827 static int parse_fragment_header(char *line, int len, struct fragment *fragment)
828 {
829         int offset;
830
831         if (!len || line[len-1] != '\n')
832                 return -1;
833
834         /* Figure out the number of lines in a fragment */
835         offset = parse_range(line, len, 4, " +", &fragment->oldpos, &fragment->oldlines);
836         offset = parse_range(line, len, offset, " @@", &fragment->newpos, &fragment->newlines);
837
838         return offset;
839 }
840
841 static int find_header(char *line, unsigned long size, int *hdrsize, struct patch *patch)
842 {
843         unsigned long offset, len;
844
845         patch->is_toplevel_relative = 0;
846         patch->is_rename = patch->is_copy = 0;
847         patch->is_new = patch->is_delete = -1;
848         patch->old_mode = patch->new_mode = 0;
849         patch->old_name = patch->new_name = NULL;
850         for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) {
851                 unsigned long nextlen;
852
853                 len = linelen(line, size);
854                 if (!len)
855                         break;
856
857                 /* Testing this early allows us to take a few shortcuts.. */
858                 if (len < 6)
859                         continue;
860
861                 /*
862                  * Make sure we don't find any unconnected patch fragments.
863                  * That's a sign that we didn't find a header, and that a
864                  * patch has become corrupted/broken up.
865                  */
866                 if (!memcmp("@@ -", line, 4)) {
867                         struct fragment dummy;
868                         if (parse_fragment_header(line, len, &dummy) < 0)
869                                 continue;
870                         die("patch fragment without header at line %d: %.*s",
871                             linenr, (int)len-1, line);
872                 }
873
874                 if (size < len + 6)
875                         break;
876
877                 /*
878                  * Git patch? It might not have a real patch, just a rename
879                  * or mode change, so we handle that specially
880                  */
881                 if (!memcmp("diff --git ", line, 11)) {
882                         int git_hdr_len = parse_git_header(line, len, size, patch);
883                         if (git_hdr_len <= len)
884                                 continue;
885                         if (!patch->old_name && !patch->new_name) {
886                                 if (!patch->def_name)
887                                         die("git diff header lacks filename information (line %d)", linenr);
888                                 patch->old_name = patch->new_name = patch->def_name;
889                         }
890                         patch->is_toplevel_relative = 1;
891                         *hdrsize = git_hdr_len;
892                         return offset;
893                 }
894
895                 /** --- followed by +++ ? */
896                 if (memcmp("--- ", line,  4) || memcmp("+++ ", line + len, 4))
897                         continue;
898
899                 /*
900                  * We only accept unified patches, so we want it to
901                  * at least have "@@ -a,b +c,d @@\n", which is 14 chars
902                  * minimum
903                  */
904                 nextlen = linelen(line + len, size - len);
905                 if (size < nextlen + 14 || memcmp("@@ -", line + len + nextlen, 4))
906                         continue;
907
908                 /* Ok, we'll consider it a patch */
909                 parse_traditional_patch(line, line+len, patch);
910                 *hdrsize = len + nextlen;
911                 linenr += 2;
912                 return offset;
913         }
914         return -1;
915 }
916
917 static void check_whitespace(const char *line, int len)
918 {
919         const char *err = "Adds trailing whitespace";
920         int seen_space = 0;
921         int i;
922
923         /*
924          * We know len is at least two, since we have a '+' and we
925          * checked that the last character was a '\n' before calling
926          * this function.  That is, an addition of an empty line would
927          * check the '+' here.  Sneaky...
928          */
929         if (isspace(line[len-2]))
930                 goto error;
931
932         /*
933          * Make sure that there is no space followed by a tab in
934          * indentation.
935          */
936         err = "Space in indent is followed by a tab";
937         for (i = 1; i < len; i++) {
938                 if (line[i] == '\t') {
939                         if (seen_space)
940                                 goto error;
941                 }
942                 else if (line[i] == ' ')
943                         seen_space = 1;
944                 else
945                         break;
946         }
947         return;
948
949  error:
950         whitespace_error++;
951         if (squelch_whitespace_errors &&
952             squelch_whitespace_errors < whitespace_error)
953                 ;
954         else
955                 fprintf(stderr, "%s.\n%s:%d:%.*s\n",
956                         err, patch_input_file, linenr, len-2, line+1);
957 }
958
959
960 /*
961  * Parse a unified diff. Note that this really needs to parse each
962  * fragment separately, since the only way to know the difference
963  * between a "---" that is part of a patch, and a "---" that starts
964  * the next patch is to look at the line counts..
965  */
966 static int parse_fragment(char *line, unsigned long size, struct patch *patch, struct fragment *fragment)
967 {
968         int added, deleted;
969         int len = linelen(line, size), offset;
970         unsigned long oldlines, newlines;
971         unsigned long leading, trailing;
972
973         offset = parse_fragment_header(line, len, fragment);
974         if (offset < 0)
975                 return -1;
976         oldlines = fragment->oldlines;
977         newlines = fragment->newlines;
978         leading = 0;
979         trailing = 0;
980
981         /* Parse the thing.. */
982         line += len;
983         size -= len;
984         linenr++;
985         added = deleted = 0;
986         for (offset = len;
987              0 < size;
988              offset += len, size -= len, line += len, linenr++) {
989                 if (!oldlines && !newlines)
990                         break;
991                 len = linelen(line, size);
992                 if (!len || line[len-1] != '\n')
993                         return -1;
994                 switch (*line) {
995                 default:
996                         return -1;
997                 case '\n': /* newer GNU diff, an empty context line */
998                 case ' ':
999                         oldlines--;
1000                         newlines--;
1001                         if (!deleted && !added)
1002                                 leading++;
1003                         trailing++;
1004                         break;
1005                 case '-':
1006                         if (apply_in_reverse &&
1007                                         new_whitespace != nowarn_whitespace)
1008                                 check_whitespace(line, len);
1009                         deleted++;
1010                         oldlines--;
1011                         trailing = 0;
1012                         break;
1013                 case '+':
1014                         if (!apply_in_reverse &&
1015                                         new_whitespace != nowarn_whitespace)
1016                                 check_whitespace(line, len);
1017                         added++;
1018                         newlines--;
1019                         trailing = 0;
1020                         break;
1021
1022                 /* We allow "\ No newline at end of file". Depending
1023                  * on locale settings when the patch was produced we
1024                  * don't know what this line looks like. The only
1025                  * thing we do know is that it begins with "\ ".
1026                  * Checking for 12 is just for sanity check -- any
1027                  * l10n of "\ No newline..." is at least that long.
1028                  */
1029                 case '\\':
1030                         if (len < 12 || memcmp(line, "\\ ", 2))
1031                                 return -1;
1032                         break;
1033                 }
1034         }
1035         if (oldlines || newlines)
1036                 return -1;
1037         fragment->leading = leading;
1038         fragment->trailing = trailing;
1039
1040         /* If a fragment ends with an incomplete line, we failed to include
1041          * it in the above loop because we hit oldlines == newlines == 0
1042          * before seeing it.
1043          */
1044         if (12 < size && !memcmp(line, "\\ ", 2))
1045                 offset += linelen(line, size);
1046
1047         patch->lines_added += added;
1048         patch->lines_deleted += deleted;
1049
1050         if (0 < patch->is_new && oldlines)
1051                 return error("new file depends on old contents");
1052         if (0 < patch->is_delete && newlines)
1053                 return error("deleted file still has contents");
1054         return offset;
1055 }
1056
1057 static int parse_single_patch(char *line, unsigned long size, struct patch *patch)
1058 {
1059         unsigned long offset = 0;
1060         unsigned long oldlines = 0, newlines = 0, context = 0;
1061         struct fragment **fragp = &patch->fragments;
1062
1063         while (size > 4 && !memcmp(line, "@@ -", 4)) {
1064                 struct fragment *fragment;
1065                 int len;
1066
1067                 fragment = xcalloc(1, sizeof(*fragment));
1068                 len = parse_fragment(line, size, patch, fragment);
1069                 if (len <= 0)
1070                         die("corrupt patch at line %d", linenr);
1071                 fragment->patch = line;
1072                 fragment->size = len;
1073                 oldlines += fragment->oldlines;
1074                 newlines += fragment->newlines;
1075                 context += fragment->leading + fragment->trailing;
1076
1077                 *fragp = fragment;
1078                 fragp = &fragment->next;
1079
1080                 offset += len;
1081                 line += len;
1082                 size -= len;
1083         }
1084
1085         /*
1086          * If something was removed (i.e. we have old-lines) it cannot
1087          * be creation, and if something was added it cannot be
1088          * deletion.  However, the reverse is not true; --unified=0
1089          * patches that only add are not necessarily creation even
1090          * though they do not have any old lines, and ones that only
1091          * delete are not necessarily deletion.
1092          *
1093          * Unfortunately, a real creation/deletion patch do _not_ have
1094          * any context line by definition, so we cannot safely tell it
1095          * apart with --unified=0 insanity.  At least if the patch has
1096          * more than one hunk it is not creation or deletion.
1097          */
1098         if (patch->is_new < 0 &&
1099             (oldlines || (patch->fragments && patch->fragments->next)))
1100                 patch->is_new = 0;
1101         if (patch->is_delete < 0 &&
1102             (newlines || (patch->fragments && patch->fragments->next)))
1103                 patch->is_delete = 0;
1104         if (!unidiff_zero || context) {
1105                 /* If the user says the patch is not generated with
1106                  * --unified=0, or if we have seen context lines,
1107                  * then not having oldlines means the patch is creation,
1108                  * and not having newlines means the patch is deletion.
1109                  */
1110                 if (patch->is_new < 0 && !oldlines) {
1111                         patch->is_new = 1;
1112                         patch->old_name = NULL;
1113                 }
1114                 if (patch->is_delete < 0 && !newlines) {
1115                         patch->is_delete = 1;
1116                         patch->new_name = NULL;
1117                 }
1118         }
1119
1120         if (0 < patch->is_new && oldlines)
1121                 die("new file %s depends on old contents", patch->new_name);
1122         if (0 < patch->is_delete && newlines)
1123                 die("deleted file %s still has contents", patch->old_name);
1124         if (!patch->is_delete && !newlines && context)
1125                 fprintf(stderr, "** warning: file %s becomes empty but "
1126                         "is not deleted\n", patch->new_name);
1127
1128         return offset;
1129 }
1130
1131 static inline int metadata_changes(struct patch *patch)
1132 {
1133         return  patch->is_rename > 0 ||
1134                 patch->is_copy > 0 ||
1135                 patch->is_new > 0 ||
1136                 patch->is_delete ||
1137                 (patch->old_mode && patch->new_mode &&
1138                  patch->old_mode != patch->new_mode);
1139 }
1140
1141 static char *inflate_it(const void *data, unsigned long size,
1142                         unsigned long inflated_size)
1143 {
1144         z_stream stream;
1145         void *out;
1146         int st;
1147
1148         memset(&stream, 0, sizeof(stream));
1149
1150         stream.next_in = (unsigned char *)data;
1151         stream.avail_in = size;
1152         stream.next_out = out = xmalloc(inflated_size);
1153         stream.avail_out = inflated_size;
1154         inflateInit(&stream);
1155         st = inflate(&stream, Z_FINISH);
1156         if ((st != Z_STREAM_END) || stream.total_out != inflated_size) {
1157                 free(out);
1158                 return NULL;
1159         }
1160         return out;
1161 }
1162
1163 static struct fragment *parse_binary_hunk(char **buf_p,
1164                                           unsigned long *sz_p,
1165                                           int *status_p,
1166                                           int *used_p)
1167 {
1168         /* Expect a line that begins with binary patch method ("literal"
1169          * or "delta"), followed by the length of data before deflating.
1170          * a sequence of 'length-byte' followed by base-85 encoded data
1171          * should follow, terminated by a newline.
1172          *
1173          * Each 5-byte sequence of base-85 encodes up to 4 bytes,
1174          * and we would limit the patch line to 66 characters,
1175          * so one line can fit up to 13 groups that would decode
1176          * to 52 bytes max.  The length byte 'A'-'Z' corresponds
1177          * to 1-26 bytes, and 'a'-'z' corresponds to 27-52 bytes.
1178          */
1179         int llen, used;
1180         unsigned long size = *sz_p;
1181         char *buffer = *buf_p;
1182         int patch_method;
1183         unsigned long origlen;
1184         char *data = NULL;
1185         int hunk_size = 0;
1186         struct fragment *frag;
1187
1188         llen = linelen(buffer, size);
1189         used = llen;
1190
1191         *status_p = 0;
1192
1193         if (!prefixcmp(buffer, "delta ")) {
1194                 patch_method = BINARY_DELTA_DEFLATED;
1195                 origlen = strtoul(buffer + 6, NULL, 10);
1196         }
1197         else if (!prefixcmp(buffer, "literal ")) {
1198                 patch_method = BINARY_LITERAL_DEFLATED;
1199                 origlen = strtoul(buffer + 8, NULL, 10);
1200         }
1201         else
1202                 return NULL;
1203
1204         linenr++;
1205         buffer += llen;
1206         while (1) {
1207                 int byte_length, max_byte_length, newsize;
1208                 llen = linelen(buffer, size);
1209                 used += llen;
1210                 linenr++;
1211                 if (llen == 1) {
1212                         /* consume the blank line */
1213                         buffer++;
1214                         size--;
1215                         break;
1216                 }
1217                 /* Minimum line is "A00000\n" which is 7-byte long,
1218                  * and the line length must be multiple of 5 plus 2.
1219                  */
1220                 if ((llen < 7) || (llen-2) % 5)
1221                         goto corrupt;
1222                 max_byte_length = (llen - 2) / 5 * 4;
1223                 byte_length = *buffer;
1224                 if ('A' <= byte_length && byte_length <= 'Z')
1225                         byte_length = byte_length - 'A' + 1;
1226                 else if ('a' <= byte_length && byte_length <= 'z')
1227                         byte_length = byte_length - 'a' + 27;
1228                 else
1229                         goto corrupt;
1230                 /* if the input length was not multiple of 4, we would
1231                  * have filler at the end but the filler should never
1232                  * exceed 3 bytes
1233                  */
1234                 if (max_byte_length < byte_length ||
1235                     byte_length <= max_byte_length - 4)
1236                         goto corrupt;
1237                 newsize = hunk_size + byte_length;
1238                 data = xrealloc(data, newsize);
1239                 if (decode_85(data + hunk_size, buffer + 1, byte_length))
1240                         goto corrupt;
1241                 hunk_size = newsize;
1242                 buffer += llen;
1243                 size -= llen;
1244         }
1245
1246         frag = xcalloc(1, sizeof(*frag));
1247         frag->patch = inflate_it(data, hunk_size, origlen);
1248         if (!frag->patch)
1249                 goto corrupt;
1250         free(data);
1251         frag->size = origlen;
1252         *buf_p = buffer;
1253         *sz_p = size;
1254         *used_p = used;
1255         frag->binary_patch_method = patch_method;
1256         return frag;
1257
1258  corrupt:
1259         free(data);
1260         *status_p = -1;
1261         error("corrupt binary patch at line %d: %.*s",
1262               linenr-1, llen-1, buffer);
1263         return NULL;
1264 }
1265
1266 static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
1267 {
1268         /* We have read "GIT binary patch\n"; what follows is a line
1269          * that says the patch method (currently, either "literal" or
1270          * "delta") and the length of data before deflating; a
1271          * sequence of 'length-byte' followed by base-85 encoded data
1272          * follows.
1273          *
1274          * When a binary patch is reversible, there is another binary
1275          * hunk in the same format, starting with patch method (either
1276          * "literal" or "delta") with the length of data, and a sequence
1277          * of length-byte + base-85 encoded data, terminated with another
1278          * empty line.  This data, when applied to the postimage, produces
1279          * the preimage.
1280          */
1281         struct fragment *forward;
1282         struct fragment *reverse;
1283         int status;
1284         int used, used_1;
1285
1286         forward = parse_binary_hunk(&buffer, &size, &status, &used);
1287         if (!forward && !status)
1288                 /* there has to be one hunk (forward hunk) */
1289                 return error("unrecognized binary patch at line %d", linenr-1);
1290         if (status)
1291                 /* otherwise we already gave an error message */
1292                 return status;
1293
1294         reverse = parse_binary_hunk(&buffer, &size, &status, &used_1);
1295         if (reverse)
1296                 used += used_1;
1297         else if (status) {
1298                 /* not having reverse hunk is not an error, but having
1299                  * a corrupt reverse hunk is.
1300                  */
1301                 free((void*) forward->patch);
1302                 free(forward);
1303                 return status;
1304         }
1305         forward->next = reverse;
1306         patch->fragments = forward;
1307         patch->is_binary = 1;
1308         return used;
1309 }
1310
1311 static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
1312 {
1313         int hdrsize, patchsize;
1314         int offset = find_header(buffer, size, &hdrsize, patch);
1315
1316         if (offset < 0)
1317                 return offset;
1318
1319         patchsize = parse_single_patch(buffer + offset + hdrsize, size - offset - hdrsize, patch);
1320
1321         if (!patchsize) {
1322                 static const char *binhdr[] = {
1323                         "Binary files ",
1324                         "Files ",
1325                         NULL,
1326                 };
1327                 static const char git_binary[] = "GIT binary patch\n";
1328                 int i;
1329                 int hd = hdrsize + offset;
1330                 unsigned long llen = linelen(buffer + hd, size - hd);
1331
1332                 if (llen == sizeof(git_binary) - 1 &&
1333                     !memcmp(git_binary, buffer + hd, llen)) {
1334                         int used;
1335                         linenr++;
1336                         used = parse_binary(buffer + hd + llen,
1337                                             size - hd - llen, patch);
1338                         if (used)
1339                                 patchsize = used + llen;
1340                         else
1341                                 patchsize = 0;
1342                 }
1343                 else if (!memcmp(" differ\n", buffer + hd + llen - 8, 8)) {
1344                         for (i = 0; binhdr[i]; i++) {
1345                                 int len = strlen(binhdr[i]);
1346                                 if (len < size - hd &&
1347                                     !memcmp(binhdr[i], buffer + hd, len)) {
1348                                         linenr++;
1349                                         patch->is_binary = 1;
1350                                         patchsize = llen;
1351                                         break;
1352                                 }
1353                         }
1354                 }
1355
1356                 /* Empty patch cannot be applied if it is a text patch
1357                  * without metadata change.  A binary patch appears
1358                  * empty to us here.
1359                  */
1360                 if ((apply || check) &&
1361                     (!patch->is_binary && !metadata_changes(patch)))
1362                         die("patch with only garbage at line %d", linenr);
1363         }
1364
1365         return offset + hdrsize + patchsize;
1366 }
1367
1368 #define swap(a,b) myswap((a),(b),sizeof(a))
1369
1370 #define myswap(a, b, size) do {         \
1371         unsigned char mytmp[size];      \
1372         memcpy(mytmp, &a, size);                \
1373         memcpy(&a, &b, size);           \
1374         memcpy(&b, mytmp, size);                \
1375 } while (0)
1376
1377 static void reverse_patches(struct patch *p)
1378 {
1379         for (; p; p = p->next) {
1380                 struct fragment *frag = p->fragments;
1381
1382                 swap(p->new_name, p->old_name);
1383                 swap(p->new_mode, p->old_mode);
1384                 swap(p->is_new, p->is_delete);
1385                 swap(p->lines_added, p->lines_deleted);
1386                 swap(p->old_sha1_prefix, p->new_sha1_prefix);
1387
1388                 for (; frag; frag = frag->next) {
1389                         swap(frag->newpos, frag->oldpos);
1390                         swap(frag->newlines, frag->oldlines);
1391                 }
1392         }
1393 }
1394
1395 static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
1396 static const char minuses[]= "----------------------------------------------------------------------";
1397
1398 static void show_stats(struct patch *patch)
1399 {
1400         const char *prefix = "";
1401         char *name = patch->new_name;
1402         char *qname = NULL;
1403         int len, max, add, del, total;
1404
1405         if (!name)
1406                 name = patch->old_name;
1407
1408         if (0 < (len = quote_c_style(name, NULL, NULL, 0))) {
1409                 qname = xmalloc(len + 1);
1410                 quote_c_style(name, qname, NULL, 0);
1411                 name = qname;
1412         }
1413
1414         /*
1415          * "scale" the filename
1416          */
1417         len = strlen(name);
1418         max = max_len;
1419         if (max > 50)
1420                 max = 50;
1421         if (len > max) {
1422                 char *slash;
1423                 prefix = "...";
1424                 max -= 3;
1425                 name += len - max;
1426                 slash = strchr(name, '/');
1427                 if (slash)
1428                         name = slash;
1429         }
1430         len = max;
1431
1432         /*
1433          * scale the add/delete
1434          */
1435         max = max_change;
1436         if (max + len > 70)
1437                 max = 70 - len;
1438
1439         add = patch->lines_added;
1440         del = patch->lines_deleted;
1441         total = add + del;
1442
1443         if (max_change > 0) {
1444                 total = (total * max + max_change / 2) / max_change;
1445                 add = (add * max + max_change / 2) / max_change;
1446                 del = total - add;
1447         }
1448         if (patch->is_binary)
1449                 printf(" %s%-*s |  Bin\n", prefix, len, name);
1450         else
1451                 printf(" %s%-*s |%5d %.*s%.*s\n", prefix,
1452                        len, name, patch->lines_added + patch->lines_deleted,
1453                        add, pluses, del, minuses);
1454         free(qname);
1455 }
1456
1457 static int read_old_data(struct stat *st, const char *path, char **buf_p, unsigned long *alloc_p, unsigned long *size_p)
1458 {
1459         int fd;
1460         unsigned long got;
1461         unsigned long nsize;
1462         char *nbuf;
1463         unsigned long size = *size_p;
1464         char *buf = *buf_p;
1465
1466         switch (st->st_mode & S_IFMT) {
1467         case S_IFLNK:
1468                 return readlink(path, buf, size) != size;
1469         case S_IFREG:
1470                 fd = open(path, O_RDONLY);
1471                 if (fd < 0)
1472                         return error("unable to open %s", path);
1473                 got = 0;
1474                 for (;;) {
1475                         ssize_t ret = xread(fd, buf + got, size - got);
1476                         if (ret <= 0)
1477                                 break;
1478                         got += ret;
1479                 }
1480                 close(fd);
1481                 nsize = got;
1482                 nbuf = convert_to_git(path, buf, &nsize);
1483                 if (nbuf) {
1484                         free(buf);
1485                         *buf_p = nbuf;
1486                         *alloc_p = nsize;
1487                         *size_p = nsize;
1488                 }
1489                 return got != size;
1490         default:
1491                 return -1;
1492         }
1493 }
1494
1495 static int find_offset(const char *buf, unsigned long size, const char *fragment, unsigned long fragsize, int line, int *lines)
1496 {
1497         int i;
1498         unsigned long start, backwards, forwards;
1499
1500         if (fragsize > size)
1501                 return -1;
1502
1503         start = 0;
1504         if (line > 1) {
1505                 unsigned long offset = 0;
1506                 i = line-1;
1507                 while (offset + fragsize <= size) {
1508                         if (buf[offset++] == '\n') {
1509                                 start = offset;
1510                                 if (!--i)
1511                                         break;
1512                         }
1513                 }
1514         }
1515
1516         /* Exact line number? */
1517         if (!memcmp(buf + start, fragment, fragsize))
1518                 return start;
1519
1520         /*
1521          * There's probably some smart way to do this, but I'll leave
1522          * that to the smart and beautiful people. I'm simple and stupid.
1523          */
1524         backwards = start;
1525         forwards = start;
1526         for (i = 0; ; i++) {
1527                 unsigned long try;
1528                 int n;
1529
1530                 /* "backward" */
1531                 if (i & 1) {
1532                         if (!backwards) {
1533                                 if (forwards + fragsize > size)
1534                                         break;
1535                                 continue;
1536                         }
1537                         do {
1538                                 --backwards;
1539                         } while (backwards && buf[backwards-1] != '\n');
1540                         try = backwards;
1541                 } else {
1542                         while (forwards + fragsize <= size) {
1543                                 if (buf[forwards++] == '\n')
1544                                         break;
1545                         }
1546                         try = forwards;
1547                 }
1548
1549                 if (try + fragsize > size)
1550                         continue;
1551                 if (memcmp(buf + try, fragment, fragsize))
1552                         continue;
1553                 n = (i >> 1)+1;
1554                 if (i & 1)
1555                         n = -n;
1556                 *lines = n;
1557                 return try;
1558         }
1559
1560         /*
1561          * We should start searching forward and backward.
1562          */
1563         return -1;
1564 }
1565
1566 static void remove_first_line(const char **rbuf, int *rsize)
1567 {
1568         const char *buf = *rbuf;
1569         int size = *rsize;
1570         unsigned long offset;
1571         offset = 0;
1572         while (offset <= size) {
1573                 if (buf[offset++] == '\n')
1574                         break;
1575         }
1576         *rsize = size - offset;
1577         *rbuf = buf + offset;
1578 }
1579
1580 static void remove_last_line(const char **rbuf, int *rsize)
1581 {
1582         const char *buf = *rbuf;
1583         int size = *rsize;
1584         unsigned long offset;
1585         offset = size - 1;
1586         while (offset > 0) {
1587                 if (buf[--offset] == '\n')
1588                         break;
1589         }
1590         *rsize = offset + 1;
1591 }
1592
1593 struct buffer_desc {
1594         char *buffer;
1595         unsigned long size;
1596         unsigned long alloc;
1597 };
1598
1599 static int apply_line(char *output, const char *patch, int plen)
1600 {
1601         /* plen is number of bytes to be copied from patch,
1602          * starting at patch+1 (patch[0] is '+').  Typically
1603          * patch[plen] is '\n', unless this is the incomplete
1604          * last line.
1605          */
1606         int i;
1607         int add_nl_to_tail = 0;
1608         int fixed = 0;
1609         int last_tab_in_indent = -1;
1610         int last_space_in_indent = -1;
1611         int need_fix_leading_space = 0;
1612         char *buf;
1613
1614         if ((new_whitespace != strip_whitespace) || !whitespace_error ||
1615             *patch != '+') {
1616                 memcpy(output, patch + 1, plen);
1617                 return plen;
1618         }
1619
1620         if (1 < plen && isspace(patch[plen-1])) {
1621                 if (patch[plen] == '\n')
1622                         add_nl_to_tail = 1;
1623                 plen--;
1624                 while (0 < plen && isspace(patch[plen]))
1625                         plen--;
1626                 fixed = 1;
1627         }
1628
1629         for (i = 1; i < plen; i++) {
1630                 char ch = patch[i];
1631                 if (ch == '\t') {
1632                         last_tab_in_indent = i;
1633                         if (0 <= last_space_in_indent)
1634                                 need_fix_leading_space = 1;
1635                 }
1636                 else if (ch == ' ')
1637                         last_space_in_indent = i;
1638                 else
1639                         break;
1640         }
1641
1642         buf = output;
1643         if (need_fix_leading_space) {
1644                 /* between patch[1..last_tab_in_indent] strip the
1645                  * funny spaces, updating them to tab as needed.
1646                  */
1647                 for (i = 1; i < last_tab_in_indent; i++, plen--) {
1648                         char ch = patch[i];
1649                         if (ch != ' ')
1650                                 *output++ = ch;
1651                         else if ((i % 8) == 0)
1652                                 *output++ = '\t';
1653                 }
1654                 fixed = 1;
1655                 i = last_tab_in_indent;
1656         }
1657         else
1658                 i = 1;
1659
1660         memcpy(output, patch + i, plen);
1661         if (add_nl_to_tail)
1662                 output[plen++] = '\n';
1663         if (fixed)
1664                 applied_after_fixing_ws++;
1665         return output + plen - buf;
1666 }
1667
1668 static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag, int inaccurate_eof)
1669 {
1670         int match_beginning, match_end;
1671         char *buf = desc->buffer;
1672         const char *patch = frag->patch;
1673         int offset, size = frag->size;
1674         char *old = xmalloc(size);
1675         char *new = xmalloc(size);
1676         const char *oldlines, *newlines;
1677         int oldsize = 0, newsize = 0;
1678         int new_blank_lines_at_end = 0;
1679         unsigned long leading, trailing;
1680         int pos, lines;
1681
1682         while (size > 0) {
1683                 char first;
1684                 int len = linelen(patch, size);
1685                 int plen;
1686                 int added_blank_line = 0;
1687
1688                 if (!len)
1689                         break;
1690
1691                 /*
1692                  * "plen" is how much of the line we should use for
1693                  * the actual patch data. Normally we just remove the
1694                  * first character on the line, but if the line is
1695                  * followed by "\ No newline", then we also remove the
1696                  * last one (which is the newline, of course).
1697                  */
1698                 plen = len-1;
1699                 if (len < size && patch[len] == '\\')
1700                         plen--;
1701                 first = *patch;
1702                 if (apply_in_reverse) {
1703                         if (first == '-')
1704                                 first = '+';
1705                         else if (first == '+')
1706                                 first = '-';
1707                 }
1708
1709                 switch (first) {
1710                 case '\n':
1711                         /* Newer GNU diff, empty context line */
1712                         if (plen < 0)
1713                                 /* ... followed by '\No newline'; nothing */
1714                                 break;
1715                         old[oldsize++] = '\n';
1716                         new[newsize++] = '\n';
1717                         break;
1718                 case ' ':
1719                 case '-':
1720                         memcpy(old + oldsize, patch + 1, plen);
1721                         oldsize += plen;
1722                         if (first == '-')
1723                                 break;
1724                 /* Fall-through for ' ' */
1725                 case '+':
1726                         if (first != '+' || !no_add) {
1727                                 int added = apply_line(new + newsize, patch,
1728                                                        plen);
1729                                 newsize += added;
1730                                 if (first == '+' &&
1731                                     added == 1 && new[newsize-1] == '\n')
1732                                         added_blank_line = 1;
1733                         }
1734                         break;
1735                 case '@': case '\\':
1736                         /* Ignore it, we already handled it */
1737                         break;
1738                 default:
1739                         if (apply_verbosely)
1740                                 error("invalid start of line: '%c'", first);
1741                         return -1;
1742                 }
1743                 if (added_blank_line)
1744                         new_blank_lines_at_end++;
1745                 else
1746                         new_blank_lines_at_end = 0;
1747                 patch += len;
1748                 size -= len;
1749         }
1750
1751         if (inaccurate_eof && oldsize > 0 && old[oldsize - 1] == '\n' &&
1752                         newsize > 0 && new[newsize - 1] == '\n') {
1753                 oldsize--;
1754                 newsize--;
1755         }
1756
1757         oldlines = old;
1758         newlines = new;
1759         leading = frag->leading;
1760         trailing = frag->trailing;
1761
1762         /*
1763          * If we don't have any leading/trailing data in the patch,
1764          * we want it to match at the beginning/end of the file.
1765          *
1766          * But that would break if the patch is generated with
1767          * --unified=0; sane people wouldn't do that to cause us
1768          * trouble, but we try to please not so sane ones as well.
1769          */
1770         if (unidiff_zero) {
1771                 match_beginning = (!leading && !frag->oldpos);
1772                 match_end = 0;
1773         }
1774         else {
1775                 match_beginning = !leading && (frag->oldpos == 1);
1776                 match_end = !trailing;
1777         }
1778
1779         lines = 0;
1780         pos = frag->newpos;
1781         for (;;) {
1782                 offset = find_offset(buf, desc->size,
1783                                      oldlines, oldsize, pos, &lines);
1784                 if (match_end && offset + oldsize != desc->size)
1785                         offset = -1;
1786                 if (match_beginning && offset)
1787                         offset = -1;
1788                 if (offset >= 0) {
1789                         int diff;
1790                         unsigned long size, alloc;
1791
1792                         if (new_whitespace == strip_whitespace &&
1793                             (desc->size - oldsize - offset == 0)) /* end of file? */
1794                                 newsize -= new_blank_lines_at_end;
1795
1796                         diff = newsize - oldsize;
1797                         size = desc->size + diff;
1798                         alloc = desc->alloc;
1799
1800                         /* Warn if it was necessary to reduce the number
1801                          * of context lines.
1802                          */
1803                         if ((leading != frag->leading) ||
1804                             (trailing != frag->trailing))
1805                                 fprintf(stderr, "Context reduced to (%ld/%ld)"
1806                                         " to apply fragment at %d\n",
1807                                         leading, trailing, pos + lines);
1808
1809                         if (size > alloc) {
1810                                 alloc = size + 8192;
1811                                 desc->alloc = alloc;
1812                                 buf = xrealloc(buf, alloc);
1813                                 desc->buffer = buf;
1814                         }
1815                         desc->size = size;
1816                         memmove(buf + offset + newsize,
1817                                 buf + offset + oldsize,
1818                                 size - offset - newsize);
1819                         memcpy(buf + offset, newlines, newsize);
1820                         offset = 0;
1821
1822                         break;
1823                 }
1824
1825                 /* Am I at my context limits? */
1826                 if ((leading <= p_context) && (trailing <= p_context))
1827                         break;
1828                 if (match_beginning || match_end) {
1829                         match_beginning = match_end = 0;
1830                         continue;
1831                 }
1832                 /* Reduce the number of context lines
1833                  * Reduce both leading and trailing if they are equal
1834                  * otherwise just reduce the larger context.
1835                  */
1836                 if (leading >= trailing) {
1837                         remove_first_line(&oldlines, &oldsize);
1838                         remove_first_line(&newlines, &newsize);
1839                         pos--;
1840                         leading--;
1841                 }
1842                 if (trailing > leading) {
1843                         remove_last_line(&oldlines, &oldsize);
1844                         remove_last_line(&newlines, &newsize);
1845                         trailing--;
1846                 }
1847         }
1848
1849         if (offset && apply_verbosely)
1850                 error("while searching for:\n%.*s", oldsize, oldlines);
1851
1852         free(old);
1853         free(new);
1854         return offset;
1855 }
1856
1857 static int apply_binary_fragment(struct buffer_desc *desc, struct patch *patch)
1858 {
1859         unsigned long dst_size;
1860         struct fragment *fragment = patch->fragments;
1861         void *data;
1862         void *result;
1863
1864         /* Binary patch is irreversible without the optional second hunk */
1865         if (apply_in_reverse) {
1866                 if (!fragment->next)
1867                         return error("cannot reverse-apply a binary patch "
1868                                      "without the reverse hunk to '%s'",
1869                                      patch->new_name
1870                                      ? patch->new_name : patch->old_name);
1871                 fragment = fragment->next;
1872         }
1873         data = (void*) fragment->patch;
1874         switch (fragment->binary_patch_method) {
1875         case BINARY_DELTA_DEFLATED:
1876                 result = patch_delta(desc->buffer, desc->size,
1877                                      data,
1878                                      fragment->size,
1879                                      &dst_size);
1880                 free(desc->buffer);
1881                 desc->buffer = result;
1882                 break;
1883         case BINARY_LITERAL_DEFLATED:
1884                 free(desc->buffer);
1885                 desc->buffer = data;
1886                 dst_size = fragment->size;
1887                 break;
1888         }
1889         if (!desc->buffer)
1890                 return -1;
1891         desc->size = desc->alloc = dst_size;
1892         return 0;
1893 }
1894
1895 static int apply_binary(struct buffer_desc *desc, struct patch *patch)
1896 {
1897         const char *name = patch->old_name ? patch->old_name : patch->new_name;
1898         unsigned char sha1[20];
1899
1900         /* For safety, we require patch index line to contain
1901          * full 40-byte textual SHA1 for old and new, at least for now.
1902          */
1903         if (strlen(patch->old_sha1_prefix) != 40 ||
1904             strlen(patch->new_sha1_prefix) != 40 ||
1905             get_sha1_hex(patch->old_sha1_prefix, sha1) ||
1906             get_sha1_hex(patch->new_sha1_prefix, sha1))
1907                 return error("cannot apply binary patch to '%s' "
1908                              "without full index line", name);
1909
1910         if (patch->old_name) {
1911                 /* See if the old one matches what the patch
1912                  * applies to.
1913                  */
1914                 hash_sha1_file(desc->buffer, desc->size, blob_type, sha1);
1915                 if (strcmp(sha1_to_hex(sha1), patch->old_sha1_prefix))
1916                         return error("the patch applies to '%s' (%s), "
1917                                      "which does not match the "
1918                                      "current contents.",
1919                                      name, sha1_to_hex(sha1));
1920         }
1921         else {
1922                 /* Otherwise, the old one must be empty. */
1923                 if (desc->size)
1924                         return error("the patch applies to an empty "
1925                                      "'%s' but it is not empty", name);
1926         }
1927
1928         get_sha1_hex(patch->new_sha1_prefix, sha1);
1929         if (is_null_sha1(sha1)) {
1930                 free(desc->buffer);
1931                 desc->alloc = desc->size = 0;
1932                 desc->buffer = NULL;
1933                 return 0; /* deletion patch */
1934         }
1935
1936         if (has_sha1_file(sha1)) {
1937                 /* We already have the postimage */
1938                 enum object_type type;
1939                 unsigned long size;
1940
1941                 free(desc->buffer);
1942                 desc->buffer = read_sha1_file(sha1, &type, &size);
1943                 if (!desc->buffer)
1944                         return error("the necessary postimage %s for "
1945                                      "'%s' cannot be read",
1946                                      patch->new_sha1_prefix, name);
1947                 desc->alloc = desc->size = size;
1948         }
1949         else {
1950                 /* We have verified desc matches the preimage;
1951                  * apply the patch data to it, which is stored
1952                  * in the patch->fragments->{patch,size}.
1953                  */
1954                 if (apply_binary_fragment(desc, patch))
1955                         return error("binary patch does not apply to '%s'",
1956                                      name);
1957
1958                 /* verify that the result matches */
1959                 hash_sha1_file(desc->buffer, desc->size, blob_type, sha1);
1960                 if (strcmp(sha1_to_hex(sha1), patch->new_sha1_prefix))
1961                         return error("binary patch to '%s' creates incorrect result (expecting %s, got %s)", name, patch->new_sha1_prefix, sha1_to_hex(sha1));
1962         }
1963
1964         return 0;
1965 }
1966
1967 static int apply_fragments(struct buffer_desc *desc, struct patch *patch)
1968 {
1969         struct fragment *frag = patch->fragments;
1970         const char *name = patch->old_name ? patch->old_name : patch->new_name;
1971
1972         if (patch->is_binary)
1973                 return apply_binary(desc, patch);
1974
1975         while (frag) {
1976                 if (apply_one_fragment(desc, frag, patch->inaccurate_eof)) {
1977                         error("patch failed: %s:%ld", name, frag->oldpos);
1978                         if (!apply_with_reject)
1979                                 return -1;
1980                         frag->rejected = 1;
1981                 }
1982                 frag = frag->next;
1983         }
1984         return 0;
1985 }
1986
1987 static int apply_data(struct patch *patch, struct stat *st, struct cache_entry *ce)
1988 {
1989         char *buf;
1990         unsigned long size, alloc;
1991         struct buffer_desc desc;
1992
1993         size = 0;
1994         alloc = 0;
1995         buf = NULL;
1996         if (cached) {
1997                 if (ce) {
1998                         enum object_type type;
1999                         buf = read_sha1_file(ce->sha1, &type, &size);
2000                         if (!buf)
2001                                 return error("read of %s failed",
2002                                              patch->old_name);
2003                         alloc = size;
2004                 }
2005         }
2006         else if (patch->old_name) {
2007                 size = xsize_t(st->st_size);
2008                 alloc = size + 8192;
2009                 buf = xmalloc(alloc);
2010                 if (read_old_data(st, patch->old_name, &buf, &alloc, &size))
2011                         return error("read of %s failed", patch->old_name);
2012         }
2013
2014         desc.size = size;
2015         desc.alloc = alloc;
2016         desc.buffer = buf;
2017
2018         if (apply_fragments(&desc, patch) < 0)
2019                 return -1; /* note with --reject this succeeds. */
2020
2021         /* NUL terminate the result */
2022         if (desc.alloc <= desc.size)
2023                 desc.buffer = xrealloc(desc.buffer, desc.size + 1);
2024         desc.buffer[desc.size] = 0;
2025
2026         patch->result = desc.buffer;
2027         patch->resultsize = desc.size;
2028
2029         if (0 < patch->is_delete && patch->resultsize)
2030                 return error("removal patch leaves file contents");
2031
2032         return 0;
2033 }
2034
2035 static int check_to_create_blob(const char *new_name, int ok_if_exists)
2036 {
2037         struct stat nst;
2038         if (!lstat(new_name, &nst)) {
2039                 if (S_ISDIR(nst.st_mode) || ok_if_exists)
2040                         return 0;
2041                 /*
2042                  * A leading component of new_name might be a symlink
2043                  * that is going to be removed with this patch, but
2044                  * still pointing at somewhere that has the path.
2045                  * In such a case, path "new_name" does not exist as
2046                  * far as git is concerned.
2047                  */
2048                 if (has_symlink_leading_path(new_name, NULL))
2049                         return 0;
2050
2051                 return error("%s: already exists in working directory", new_name);
2052         }
2053         else if ((errno != ENOENT) && (errno != ENOTDIR))
2054                 return error("%s: %s", new_name, strerror(errno));
2055         return 0;
2056 }
2057
2058 static int check_patch(struct patch *patch, struct patch *prev_patch)
2059 {
2060         struct stat st;
2061         const char *old_name = patch->old_name;
2062         const char *new_name = patch->new_name;
2063         const char *name = old_name ? old_name : new_name;
2064         struct cache_entry *ce = NULL;
2065         int ok_if_exists;
2066
2067         patch->rejected = 1; /* we will drop this after we succeed */
2068         if (old_name) {
2069                 int changed = 0;
2070                 int stat_ret = 0;
2071                 unsigned st_mode = 0;
2072
2073                 if (!cached)
2074                         stat_ret = lstat(old_name, &st);
2075                 if (check_index) {
2076                         int pos = cache_name_pos(old_name, strlen(old_name));
2077                         if (pos < 0)
2078                                 return error("%s: does not exist in index",
2079                                              old_name);
2080                         ce = active_cache[pos];
2081                         if (stat_ret < 0) {
2082                                 struct checkout costate;
2083                                 if (errno != ENOENT)
2084                                         return error("%s: %s", old_name,
2085                                                      strerror(errno));
2086                                 /* checkout */
2087                                 costate.base_dir = "";
2088                                 costate.base_dir_len = 0;
2089                                 costate.force = 0;
2090                                 costate.quiet = 0;
2091                                 costate.not_new = 0;
2092                                 costate.refresh_cache = 1;
2093                                 if (checkout_entry(ce,
2094                                                    &costate,
2095                                                    NULL) ||
2096                                     lstat(old_name, &st))
2097                                         return -1;
2098                         }
2099                         if (!cached)
2100                                 changed = ce_match_stat(ce, &st, 1);
2101                         if (changed)
2102                                 return error("%s: does not match index",
2103                                              old_name);
2104                         if (cached)
2105                                 st_mode = ntohl(ce->ce_mode);
2106                 }
2107                 else if (stat_ret < 0)
2108                         return error("%s: %s", old_name, strerror(errno));
2109
2110                 if (!cached)
2111                         st_mode = ntohl(ce_mode_from_stat(ce, st.st_mode));
2112
2113                 if (patch->is_new < 0)
2114                         patch->is_new = 0;
2115                 if (!patch->old_mode)
2116                         patch->old_mode = st_mode;
2117                 if ((st_mode ^ patch->old_mode) & S_IFMT)
2118                         return error("%s: wrong type", old_name);
2119                 if (st_mode != patch->old_mode)
2120                         fprintf(stderr, "warning: %s has type %o, expected %o\n",
2121                                 old_name, st_mode, patch->old_mode);
2122         }
2123
2124         if (new_name && prev_patch && 0 < prev_patch->is_delete &&
2125             !strcmp(prev_patch->old_name, new_name))
2126                 /* A type-change diff is always split into a patch to
2127                  * delete old, immediately followed by a patch to
2128                  * create new (see diff.c::run_diff()); in such a case
2129                  * it is Ok that the entry to be deleted by the
2130                  * previous patch is still in the working tree and in
2131                  * the index.
2132                  */
2133                 ok_if_exists = 1;
2134         else
2135                 ok_if_exists = 0;
2136
2137         if (new_name &&
2138             ((0 < patch->is_new) | (0 < patch->is_rename) | patch->is_copy)) {
2139                 if (check_index &&
2140                     cache_name_pos(new_name, strlen(new_name)) >= 0 &&
2141                     !ok_if_exists)
2142                         return error("%s: already exists in index", new_name);
2143                 if (!cached) {
2144                         int err = check_to_create_blob(new_name, ok_if_exists);
2145                         if (err)
2146                                 return err;
2147                 }
2148                 if (!patch->new_mode) {
2149                         if (0 < patch->is_new)
2150                                 patch->new_mode = S_IFREG | 0644;
2151                         else
2152                                 patch->new_mode = patch->old_mode;
2153                 }
2154         }
2155
2156         if (new_name && old_name) {
2157                 int same = !strcmp(old_name, new_name);
2158                 if (!patch->new_mode)
2159                         patch->new_mode = patch->old_mode;
2160                 if ((patch->old_mode ^ patch->new_mode) & S_IFMT)
2161                         return error("new mode (%o) of %s does not match old mode (%o)%s%s",
2162                                 patch->new_mode, new_name, patch->old_mode,
2163                                 same ? "" : " of ", same ? "" : old_name);
2164         }
2165
2166         if (apply_data(patch, &st, ce) < 0)
2167                 return error("%s: patch does not apply", name);
2168         patch->rejected = 0;
2169         return 0;
2170 }
2171
2172 static int check_patch_list(struct patch *patch)
2173 {
2174         struct patch *prev_patch = NULL;
2175         int err = 0;
2176
2177         for (prev_patch = NULL; patch ; patch = patch->next) {
2178                 if (apply_verbosely)
2179                         say_patch_name(stderr,
2180                                        "Checking patch ", patch, "...\n");
2181                 err |= check_patch(patch, prev_patch);
2182                 prev_patch = patch;
2183         }
2184         return err;
2185 }
2186
2187 static void show_index_list(struct patch *list)
2188 {
2189         struct patch *patch;
2190
2191         /* Once we start supporting the reverse patch, it may be
2192          * worth showing the new sha1 prefix, but until then...
2193          */
2194         for (patch = list; patch; patch = patch->next) {
2195                 const unsigned char *sha1_ptr;
2196                 unsigned char sha1[20];
2197                 const char *name;
2198
2199                 name = patch->old_name ? patch->old_name : patch->new_name;
2200                 if (0 < patch->is_new)
2201                         sha1_ptr = null_sha1;
2202                 else if (get_sha1(patch->old_sha1_prefix, sha1))
2203                         die("sha1 information is lacking or useless (%s).",
2204                             name);
2205                 else
2206                         sha1_ptr = sha1;
2207
2208                 printf("%06o %s ",patch->old_mode, sha1_to_hex(sha1_ptr));
2209                 if (line_termination && quote_c_style(name, NULL, NULL, 0))
2210                         quote_c_style(name, NULL, stdout, 0);
2211                 else
2212                         fputs(name, stdout);
2213                 putchar(line_termination);
2214         }
2215 }
2216
2217 static void stat_patch_list(struct patch *patch)
2218 {
2219         int files, adds, dels;
2220
2221         for (files = adds = dels = 0 ; patch ; patch = patch->next) {
2222                 files++;
2223                 adds += patch->lines_added;
2224                 dels += patch->lines_deleted;
2225                 show_stats(patch);
2226         }
2227
2228         printf(" %d files changed, %d insertions(+), %d deletions(-)\n", files, adds, dels);
2229 }
2230
2231 static void numstat_patch_list(struct patch *patch)
2232 {
2233         for ( ; patch; patch = patch->next) {
2234                 const char *name;
2235                 name = patch->new_name ? patch->new_name : patch->old_name;
2236                 if (patch->is_binary)
2237                         printf("-\t-\t");
2238                 else
2239                         printf("%d\t%d\t",
2240                                patch->lines_added, patch->lines_deleted);
2241                 if (line_termination && quote_c_style(name, NULL, NULL, 0))
2242                         quote_c_style(name, NULL, stdout, 0);
2243                 else
2244                         fputs(name, stdout);
2245                 putchar(line_termination);
2246         }
2247 }
2248
2249 static void show_file_mode_name(const char *newdelete, unsigned int mode, const char *name)
2250 {
2251         if (mode)
2252                 printf(" %s mode %06o %s\n", newdelete, mode, name);
2253         else
2254                 printf(" %s %s\n", newdelete, name);
2255 }
2256
2257 static void show_mode_change(struct patch *p, int show_name)
2258 {
2259         if (p->old_mode && p->new_mode && p->old_mode != p->new_mode) {
2260                 if (show_name)
2261                         printf(" mode change %06o => %06o %s\n",
2262                                p->old_mode, p->new_mode, p->new_name);
2263                 else
2264                         printf(" mode change %06o => %06o\n",
2265                                p->old_mode, p->new_mode);
2266         }
2267 }
2268
2269 static void show_rename_copy(struct patch *p)
2270 {
2271         const char *renamecopy = p->is_rename ? "rename" : "copy";
2272         const char *old, *new;
2273
2274         /* Find common prefix */
2275         old = p->old_name;
2276         new = p->new_name;
2277         while (1) {
2278                 const char *slash_old, *slash_new;
2279                 slash_old = strchr(old, '/');
2280                 slash_new = strchr(new, '/');
2281                 if (!slash_old ||
2282                     !slash_new ||
2283                     slash_old - old != slash_new - new ||
2284                     memcmp(old, new, slash_new - new))
2285                         break;
2286                 old = slash_old + 1;
2287                 new = slash_new + 1;
2288         }
2289         /* p->old_name thru old is the common prefix, and old and new
2290          * through the end of names are renames
2291          */
2292         if (old != p->old_name)
2293                 printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
2294                        (int)(old - p->old_name), p->old_name,
2295                        old, new, p->score);
2296         else
2297                 printf(" %s %s => %s (%d%%)\n", renamecopy,
2298                        p->old_name, p->new_name, p->score);
2299         show_mode_change(p, 0);
2300 }
2301
2302 static void summary_patch_list(struct patch *patch)
2303 {
2304         struct patch *p;
2305
2306         for (p = patch; p; p = p->next) {
2307                 if (p->is_new)
2308                         show_file_mode_name("create", p->new_mode, p->new_name);
2309                 else if (p->is_delete)
2310                         show_file_mode_name("delete", p->old_mode, p->old_name);
2311                 else {
2312                         if (p->is_rename || p->is_copy)
2313                                 show_rename_copy(p);
2314                         else {
2315                                 if (p->score) {
2316                                         printf(" rewrite %s (%d%%)\n",
2317                                                p->new_name, p->score);
2318                                         show_mode_change(p, 0);
2319                                 }
2320                                 else
2321                                         show_mode_change(p, 1);
2322                         }
2323                 }
2324         }
2325 }
2326
2327 static void patch_stats(struct patch *patch)
2328 {
2329         int lines = patch->lines_added + patch->lines_deleted;
2330
2331         if (lines > max_change)
2332                 max_change = lines;
2333         if (patch->old_name) {
2334                 int len = quote_c_style(patch->old_name, NULL, NULL, 0);
2335                 if (!len)
2336                         len = strlen(patch->old_name);
2337                 if (len > max_len)
2338                         max_len = len;
2339         }
2340         if (patch->new_name) {
2341                 int len = quote_c_style(patch->new_name, NULL, NULL, 0);
2342                 if (!len)
2343                         len = strlen(patch->new_name);
2344                 if (len > max_len)
2345                         max_len = len;
2346         }
2347 }
2348
2349 static void remove_file(struct patch *patch, int rmdir_empty)
2350 {
2351         if (update_index) {
2352                 if (remove_file_from_cache(patch->old_name) < 0)
2353                         die("unable to remove %s from index", patch->old_name);
2354                 cache_tree_invalidate_path(active_cache_tree, patch->old_name);
2355         }
2356         if (!cached) {
2357                 if (!unlink(patch->old_name) && rmdir_empty) {
2358                         char *name = xstrdup(patch->old_name);
2359                         char *end = strrchr(name, '/');
2360                         while (end) {
2361                                 *end = 0;
2362                                 if (rmdir(name))
2363                                         break;
2364                                 end = strrchr(name, '/');
2365                         }
2366                         free(name);
2367                 }
2368         }
2369 }
2370
2371 static void add_index_file(const char *path, unsigned mode, void *buf, unsigned long size)
2372 {
2373         struct stat st;
2374         struct cache_entry *ce;
2375         int namelen = strlen(path);
2376         unsigned ce_size = cache_entry_size(namelen);
2377
2378         if (!update_index)
2379                 return;
2380
2381         ce = xcalloc(1, ce_size);
2382         memcpy(ce->name, path, namelen);
2383         ce->ce_mode = create_ce_mode(mode);
2384         ce->ce_flags = htons(namelen);
2385         if (!cached) {
2386                 if (lstat(path, &st) < 0)
2387                         die("unable to stat newly created file %s", path);
2388                 fill_stat_cache_info(ce, &st);
2389         }
2390         if (write_sha1_file(buf, size, blob_type, ce->sha1) < 0)
2391                 die("unable to create backing store for newly created file %s", path);
2392         if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0)
2393                 die("unable to add cache entry for %s", path);
2394 }
2395
2396 static int try_create_file(const char *path, unsigned int mode, const char *buf, unsigned long size)
2397 {
2398         int fd;
2399         char *nbuf;
2400
2401         if (has_symlinks && S_ISLNK(mode))
2402                 /* Although buf:size is counted string, it also is NUL
2403                  * terminated.
2404                  */
2405                 return symlink(buf, path);
2406
2407         fd = open(path, O_CREAT | O_EXCL | O_WRONLY, (mode & 0100) ? 0777 : 0666);
2408         if (fd < 0)
2409                 return -1;
2410
2411         nbuf = convert_to_working_tree(path, buf, &size);
2412         if (nbuf)
2413                 buf = nbuf;
2414
2415         while (size) {
2416                 int written = xwrite(fd, buf, size);
2417                 if (written < 0)
2418                         die("writing file %s: %s", path, strerror(errno));
2419                 if (!written)
2420                         die("out of space writing file %s", path);
2421                 buf += written;
2422                 size -= written;
2423         }
2424         if (close(fd) < 0)
2425                 die("closing file %s: %s", path, strerror(errno));
2426         if (nbuf)
2427                 free(nbuf);
2428         return 0;
2429 }
2430
2431 /*
2432  * We optimistically assume that the directories exist,
2433  * which is true 99% of the time anyway. If they don't,
2434  * we create them and try again.
2435  */
2436 static void create_one_file(char *path, unsigned mode, const char *buf, unsigned long size)
2437 {
2438         if (cached)
2439                 return;
2440         if (!try_create_file(path, mode, buf, size))
2441                 return;
2442
2443         if (errno == ENOENT) {
2444                 if (safe_create_leading_directories(path))
2445                         return;
2446                 if (!try_create_file(path, mode, buf, size))
2447                         return;
2448         }
2449
2450         if (errno == EEXIST || errno == EACCES) {
2451                 /* We may be trying to create a file where a directory
2452                  * used to be.
2453                  */
2454                 struct stat st;
2455                 if (!lstat(path, &st) && (!S_ISDIR(st.st_mode) || !rmdir(path)))
2456                         errno = EEXIST;
2457         }
2458
2459         if (errno == EEXIST) {
2460                 unsigned int nr = getpid();
2461
2462                 for (;;) {
2463                         const char *newpath;
2464                         newpath = mkpath("%s~%u", path, nr);
2465                         if (!try_create_file(newpath, mode, buf, size)) {
2466                                 if (!rename(newpath, path))
2467                                         return;
2468                                 unlink(newpath);
2469                                 break;
2470                         }
2471                         if (errno != EEXIST)
2472                                 break;
2473                         ++nr;
2474                 }
2475         }
2476         die("unable to write file %s mode %o", path, mode);
2477 }
2478
2479 static void create_file(struct patch *patch)
2480 {
2481         char *path = patch->new_name;
2482         unsigned mode = patch->new_mode;
2483         unsigned long size = patch->resultsize;
2484         char *buf = patch->result;
2485
2486         if (!mode)
2487                 mode = S_IFREG | 0644;
2488         create_one_file(path, mode, buf, size);
2489         add_index_file(path, mode, buf, size);
2490         cache_tree_invalidate_path(active_cache_tree, path);
2491 }
2492
2493 /* phase zero is to remove, phase one is to create */
2494 static void write_out_one_result(struct patch *patch, int phase)
2495 {
2496         if (patch->is_delete > 0) {
2497                 if (phase == 0)
2498                         remove_file(patch, 1);
2499                 return;
2500         }
2501         if (patch->is_new > 0 || patch->is_copy) {
2502                 if (phase == 1)
2503                         create_file(patch);
2504                 return;
2505         }
2506         /*
2507          * Rename or modification boils down to the same
2508          * thing: remove the old, write the new
2509          */
2510         if (phase == 0)
2511                 remove_file(patch, 0);
2512         if (phase == 1)
2513                 create_file(patch);
2514 }
2515
2516 static int write_out_one_reject(struct patch *patch)
2517 {
2518         FILE *rej;
2519         char namebuf[PATH_MAX];
2520         struct fragment *frag;
2521         int cnt = 0;
2522
2523         for (cnt = 0, frag = patch->fragments; frag; frag = frag->next) {
2524                 if (!frag->rejected)
2525                         continue;
2526                 cnt++;
2527         }
2528
2529         if (!cnt) {
2530                 if (apply_verbosely)
2531                         say_patch_name(stderr,
2532                                        "Applied patch ", patch, " cleanly.\n");
2533                 return 0;
2534         }
2535
2536         /* This should not happen, because a removal patch that leaves
2537          * contents are marked "rejected" at the patch level.
2538          */
2539         if (!patch->new_name)
2540                 die("internal error");
2541
2542         /* Say this even without --verbose */
2543         say_patch_name(stderr, "Applying patch ", patch, " with");
2544         fprintf(stderr, " %d rejects...\n", cnt);
2545
2546         cnt = strlen(patch->new_name);
2547         if (ARRAY_SIZE(namebuf) <= cnt + 5) {
2548                 cnt = ARRAY_SIZE(namebuf) - 5;
2549                 fprintf(stderr,
2550                         "warning: truncating .rej filename to %.*s.rej",
2551                         cnt - 1, patch->new_name);
2552         }
2553         memcpy(namebuf, patch->new_name, cnt);
2554         memcpy(namebuf + cnt, ".rej", 5);
2555
2556         rej = fopen(namebuf, "w");
2557         if (!rej)
2558                 return error("cannot open %s: %s", namebuf, strerror(errno));
2559
2560         /* Normal git tools never deal with .rej, so do not pretend
2561          * this is a git patch by saying --git nor give extended
2562          * headers.  While at it, maybe please "kompare" that wants
2563          * the trailing TAB and some garbage at the end of line ;-).
2564          */
2565         fprintf(rej, "diff a/%s b/%s\t(rejected hunks)\n",
2566                 patch->new_name, patch->new_name);
2567         for (cnt = 1, frag = patch->fragments;
2568              frag;
2569              cnt++, frag = frag->next) {
2570                 if (!frag->rejected) {
2571                         fprintf(stderr, "Hunk #%d applied cleanly.\n", cnt);
2572                         continue;
2573                 }
2574                 fprintf(stderr, "Rejected hunk #%d.\n", cnt);
2575                 fprintf(rej, "%.*s", frag->size, frag->patch);
2576                 if (frag->patch[frag->size-1] != '\n')
2577                         fputc('\n', rej);
2578         }
2579         fclose(rej);
2580         return -1;
2581 }
2582
2583 static int write_out_results(struct patch *list, int skipped_patch)
2584 {
2585         int phase;
2586         int errs = 0;
2587         struct patch *l;
2588
2589         if (!list && !skipped_patch)
2590                 return error("No changes");
2591
2592         for (phase = 0; phase < 2; phase++) {
2593                 l = list;
2594                 while (l) {
2595                         if (l->rejected)
2596                                 errs = 1;
2597                         else {
2598                                 write_out_one_result(l, phase);
2599                                 if (phase == 1 && write_out_one_reject(l))
2600                                         errs = 1;
2601                         }
2602                         l = l->next;
2603                 }
2604         }
2605         return errs;
2606 }
2607
2608 static struct lock_file lock_file;
2609
2610 static struct excludes {
2611         struct excludes *next;
2612         const char *path;
2613 } *excludes;
2614
2615 static int use_patch(struct patch *p)
2616 {
2617         const char *pathname = p->new_name ? p->new_name : p->old_name;
2618         struct excludes *x = excludes;
2619         while (x) {
2620                 if (fnmatch(x->path, pathname, 0) == 0)
2621                         return 0;
2622                 x = x->next;
2623         }
2624         if (0 < prefix_length) {
2625                 int pathlen = strlen(pathname);
2626                 if (pathlen <= prefix_length ||
2627                     memcmp(prefix, pathname, prefix_length))
2628                         return 0;
2629         }
2630         return 1;
2631 }
2632
2633 static void prefix_one(char **name)
2634 {
2635         char *old_name = *name;
2636         if (!old_name)
2637                 return;
2638         *name = xstrdup(prefix_filename(prefix, prefix_length, *name));
2639         free(old_name);
2640 }
2641
2642 static void prefix_patches(struct patch *p)
2643 {
2644         if (!prefix || p->is_toplevel_relative)
2645                 return;
2646         for ( ; p; p = p->next) {
2647                 if (p->new_name == p->old_name) {
2648                         char *prefixed = p->new_name;
2649                         prefix_one(&prefixed);
2650                         p->new_name = p->old_name = prefixed;
2651                 }
2652                 else {
2653                         prefix_one(&p->new_name);
2654                         prefix_one(&p->old_name);
2655                 }
2656         }
2657 }
2658
2659 static int apply_patch(int fd, const char *filename, int inaccurate_eof)
2660 {
2661         unsigned long offset, size;
2662         char *buffer = read_patch_file(fd, &size);
2663         struct patch *list = NULL, **listp = &list;
2664         int skipped_patch = 0;
2665
2666         patch_input_file = filename;
2667         if (!buffer)
2668                 return -1;
2669         offset = 0;
2670         while (size > 0) {
2671                 struct patch *patch;
2672                 int nr;
2673
2674                 patch = xcalloc(1, sizeof(*patch));
2675                 patch->inaccurate_eof = inaccurate_eof;
2676                 nr = parse_chunk(buffer + offset, size, patch);
2677                 if (nr < 0)
2678                         break;
2679                 if (apply_in_reverse)
2680                         reverse_patches(patch);
2681                 if (prefix)
2682                         prefix_patches(patch);
2683                 if (use_patch(patch)) {
2684                         patch_stats(patch);
2685                         *listp = patch;
2686                         listp = &patch->next;
2687                 }
2688                 else {
2689                         /* perhaps free it a bit better? */
2690                         free(patch);
2691                         skipped_patch++;
2692                 }
2693                 offset += nr;
2694                 size -= nr;
2695         }
2696
2697         if (whitespace_error && (new_whitespace == error_on_whitespace))
2698                 apply = 0;
2699
2700         update_index = check_index && apply;
2701         if (update_index && newfd < 0)
2702                 newfd = hold_locked_index(&lock_file, 1);
2703
2704         if (check_index) {
2705                 if (read_cache() < 0)
2706                         die("unable to read index file");
2707         }
2708
2709         if ((check || apply) &&
2710             check_patch_list(list) < 0 &&
2711             !apply_with_reject)
2712                 exit(1);
2713
2714         if (apply && write_out_results(list, skipped_patch))
2715                 exit(1);
2716
2717         if (show_index_info)
2718                 show_index_list(list);
2719
2720         if (diffstat)
2721                 stat_patch_list(list);
2722
2723         if (numstat)
2724                 numstat_patch_list(list);
2725
2726         if (summary)
2727                 summary_patch_list(list);
2728
2729         free(buffer);
2730         return 0;
2731 }
2732
2733 static int git_apply_config(const char *var, const char *value)
2734 {
2735         if (!strcmp(var, "apply.whitespace")) {
2736                 apply_default_whitespace = xstrdup(value);
2737                 return 0;
2738         }
2739         return git_default_config(var, value);
2740 }
2741
2742
2743 int cmd_apply(int argc, const char **argv, const char *unused_prefix)
2744 {
2745         int i;
2746         int read_stdin = 1;
2747         int inaccurate_eof = 0;
2748         int errs = 0;
2749         int is_not_gitdir = 0;
2750
2751         const char *whitespace_option = NULL;
2752
2753         prefix = setup_git_directory_gently(&is_not_gitdir);
2754         prefix_length = prefix ? strlen(prefix) : 0;
2755         git_config(git_apply_config);
2756         if (apply_default_whitespace)
2757                 parse_whitespace_option(apply_default_whitespace);
2758
2759         for (i = 1; i < argc; i++) {
2760                 const char *arg = argv[i];
2761                 char *end;
2762                 int fd;
2763
2764                 if (!strcmp(arg, "-")) {
2765                         errs |= apply_patch(0, "<stdin>", inaccurate_eof);
2766                         read_stdin = 0;
2767                         continue;
2768                 }
2769                 if (!prefixcmp(arg, "--exclude=")) {
2770                         struct excludes *x = xmalloc(sizeof(*x));
2771                         x->path = arg + 10;
2772                         x->next = excludes;
2773                         excludes = x;
2774                         continue;
2775                 }
2776                 if (!prefixcmp(arg, "-p")) {
2777                         p_value = atoi(arg + 2);
2778                         p_value_known = 1;
2779                         continue;
2780                 }
2781                 if (!strcmp(arg, "--no-add")) {
2782                         no_add = 1;
2783                         continue;
2784                 }
2785                 if (!strcmp(arg, "--stat")) {
2786                         apply = 0;
2787                         diffstat = 1;
2788                         continue;
2789                 }
2790                 if (!strcmp(arg, "--allow-binary-replacement") ||
2791                     !strcmp(arg, "--binary")) {
2792                         continue; /* now no-op */
2793                 }
2794                 if (!strcmp(arg, "--numstat")) {
2795                         apply = 0;
2796                         numstat = 1;
2797                         continue;
2798                 }
2799                 if (!strcmp(arg, "--summary")) {
2800                         apply = 0;
2801                         summary = 1;
2802                         continue;
2803                 }
2804                 if (!strcmp(arg, "--check")) {
2805                         apply = 0;
2806                         check = 1;
2807                         continue;
2808                 }
2809                 if (!strcmp(arg, "--index")) {
2810                         if (is_not_gitdir)
2811                                 die("--index outside a repository");
2812                         check_index = 1;
2813                         continue;
2814                 }
2815                 if (!strcmp(arg, "--cached")) {
2816                         if (is_not_gitdir)
2817                                 die("--cached outside a repository");
2818                         check_index = 1;
2819                         cached = 1;
2820                         continue;
2821                 }
2822                 if (!strcmp(arg, "--apply")) {
2823                         apply = 1;
2824                         continue;
2825                 }
2826                 if (!strcmp(arg, "--index-info")) {
2827                         apply = 0;
2828                         show_index_info = 1;
2829                         continue;
2830                 }
2831                 if (!strcmp(arg, "-z")) {
2832                         line_termination = 0;
2833                         continue;
2834                 }
2835                 if (!prefixcmp(arg, "-C")) {
2836                         p_context = strtoul(arg + 2, &end, 0);
2837                         if (*end != '\0')
2838                                 die("unrecognized context count '%s'", arg + 2);
2839                         continue;
2840                 }
2841                 if (!prefixcmp(arg, "--whitespace=")) {
2842                         whitespace_option = arg + 13;
2843                         parse_whitespace_option(arg + 13);
2844                         continue;
2845                 }
2846                 if (!strcmp(arg, "-R") || !strcmp(arg, "--reverse")) {
2847                         apply_in_reverse = 1;
2848                         continue;
2849                 }
2850                 if (!strcmp(arg, "--unidiff-zero")) {
2851                         unidiff_zero = 1;
2852                         continue;
2853                 }
2854                 if (!strcmp(arg, "--reject")) {
2855                         apply = apply_with_reject = apply_verbosely = 1;
2856                         continue;
2857                 }
2858                 if (!strcmp(arg, "-v") || !strcmp(arg, "--verbose")) {
2859                         apply_verbosely = 1;
2860                         continue;
2861                 }
2862                 if (!strcmp(arg, "--inaccurate-eof")) {
2863                         inaccurate_eof = 1;
2864                         continue;
2865                 }
2866                 if (0 < prefix_length)
2867                         arg = prefix_filename(prefix, prefix_length, arg);
2868
2869                 fd = open(arg, O_RDONLY);
2870                 if (fd < 0)
2871                         usage(apply_usage);
2872                 read_stdin = 0;
2873                 set_default_whitespace_mode(whitespace_option);
2874                 errs |= apply_patch(fd, arg, inaccurate_eof);
2875                 close(fd);
2876         }
2877         set_default_whitespace_mode(whitespace_option);
2878         if (read_stdin)
2879                 errs |= apply_patch(0, "<stdin>", inaccurate_eof);
2880         if (whitespace_error) {
2881                 if (squelch_whitespace_errors &&
2882                     squelch_whitespace_errors < whitespace_error) {
2883                         int squelched =
2884                                 whitespace_error - squelch_whitespace_errors;
2885                         fprintf(stderr, "warning: squelched %d "
2886                                 "whitespace error%s\n",
2887                                 squelched,
2888                                 squelched == 1 ? "" : "s");
2889                 }
2890                 if (new_whitespace == error_on_whitespace)
2891                         die("%d line%s add%s whitespace errors.",
2892                             whitespace_error,
2893                             whitespace_error == 1 ? "" : "s",
2894                             whitespace_error == 1 ? "s" : "");
2895                 if (applied_after_fixing_ws)
2896                         fprintf(stderr, "warning: %d line%s applied after"
2897                                 " fixing whitespace errors.\n",
2898                                 applied_after_fixing_ws,
2899                                 applied_after_fixing_ws == 1 ? "" : "s");
2900                 else if (whitespace_error)
2901                         fprintf(stderr, "warning: %d line%s add%s whitespace errors.\n",
2902                                 whitespace_error,
2903                                 whitespace_error == 1 ? "" : "s",
2904                                 whitespace_error == 1 ? "s" : "");
2905         }
2906
2907         if (update_index) {
2908                 if (write_cache(newfd, active_cache, active_nr) ||
2909                     close(newfd) || commit_locked_index(&lock_file))
2910                         die("Unable to write new index file");
2911         }
2912
2913         return !!errs;
2914 }