Merge branch 'maint'
[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 #include "string-list.h"
16 #include "dir.h"
17 #include "parse-options.h"
18
19 /*
20  *  --check turns on checking that the working tree matches the
21  *    files that are being modified, but doesn't apply the patch
22  *  --stat does just a diffstat, and doesn't actually apply
23  *  --numstat does numeric diffstat, and doesn't actually apply
24  *  --index-info shows the old and new index info for paths if available.
25  *  --index updates the cache as well.
26  *  --cached updates only the cache without ever touching the working tree.
27  */
28 static const char *prefix;
29 static int prefix_length = -1;
30 static int newfd = -1;
31
32 static int unidiff_zero;
33 static int p_value = 1;
34 static int p_value_known;
35 static int check_index;
36 static int update_index;
37 static int cached;
38 static int diffstat;
39 static int numstat;
40 static int summary;
41 static int check;
42 static int apply = 1;
43 static int apply_in_reverse;
44 static int apply_with_reject;
45 static int apply_verbosely;
46 static int no_add;
47 static const char *fake_ancestor;
48 static int line_termination = '\n';
49 static unsigned int p_context = UINT_MAX;
50 static const char * const apply_usage[] = {
51         "git apply [options] [<patch>...]",
52         NULL
53 };
54
55 static enum ws_error_action {
56         nowarn_ws_error,
57         warn_on_ws_error,
58         die_on_ws_error,
59         correct_ws_error,
60 } ws_error_action = warn_on_ws_error;
61 static int whitespace_error;
62 static int squelch_whitespace_errors = 5;
63 static int applied_after_fixing_ws;
64 static const char *patch_input_file;
65 static const char *root;
66 static int root_len;
67 static int read_stdin = 1;
68 static int options;
69
70 static void parse_whitespace_option(const char *option)
71 {
72         if (!option) {
73                 ws_error_action = warn_on_ws_error;
74                 return;
75         }
76         if (!strcmp(option, "warn")) {
77                 ws_error_action = warn_on_ws_error;
78                 return;
79         }
80         if (!strcmp(option, "nowarn")) {
81                 ws_error_action = nowarn_ws_error;
82                 return;
83         }
84         if (!strcmp(option, "error")) {
85                 ws_error_action = die_on_ws_error;
86                 return;
87         }
88         if (!strcmp(option, "error-all")) {
89                 ws_error_action = die_on_ws_error;
90                 squelch_whitespace_errors = 0;
91                 return;
92         }
93         if (!strcmp(option, "strip") || !strcmp(option, "fix")) {
94                 ws_error_action = correct_ws_error;
95                 return;
96         }
97         die("unrecognized whitespace option '%s'", option);
98 }
99
100 static void set_default_whitespace_mode(const char *whitespace_option)
101 {
102         if (!whitespace_option && !apply_default_whitespace)
103                 ws_error_action = (apply ? warn_on_ws_error : nowarn_ws_error);
104 }
105
106 /*
107  * For "diff-stat" like behaviour, we keep track of the biggest change
108  * we've seen, and the longest filename. That allows us to do simple
109  * scaling.
110  */
111 static int max_change, max_len;
112
113 /*
114  * Various "current state", notably line numbers and what
115  * file (and how) we're patching right now.. The "is_xxxx"
116  * things are flags, where -1 means "don't know yet".
117  */
118 static int linenr = 1;
119
120 /*
121  * This represents one "hunk" from a patch, starting with
122  * "@@ -oldpos,oldlines +newpos,newlines @@" marker.  The
123  * patch text is pointed at by patch, and its byte length
124  * is stored in size.  leading and trailing are the number
125  * of context lines.
126  */
127 struct fragment {
128         unsigned long leading, trailing;
129         unsigned long oldpos, oldlines;
130         unsigned long newpos, newlines;
131         const char *patch;
132         int size;
133         int rejected;
134         struct fragment *next;
135 };
136
137 /*
138  * When dealing with a binary patch, we reuse "leading" field
139  * to store the type of the binary hunk, either deflated "delta"
140  * or deflated "literal".
141  */
142 #define binary_patch_method leading
143 #define BINARY_DELTA_DEFLATED   1
144 #define BINARY_LITERAL_DEFLATED 2
145
146 /*
147  * This represents a "patch" to a file, both metainfo changes
148  * such as creation/deletion, filemode and content changes represented
149  * as a series of fragments.
150  */
151 struct patch {
152         char *new_name, *old_name, *def_name;
153         unsigned int old_mode, new_mode;
154         int is_new, is_delete;  /* -1 = unknown, 0 = false, 1 = true */
155         int rejected;
156         unsigned ws_rule;
157         unsigned long deflate_origlen;
158         int lines_added, lines_deleted;
159         int score;
160         unsigned int is_toplevel_relative:1;
161         unsigned int inaccurate_eof:1;
162         unsigned int is_binary:1;
163         unsigned int is_copy:1;
164         unsigned int is_rename:1;
165         unsigned int recount:1;
166         struct fragment *fragments;
167         char *result;
168         size_t resultsize;
169         char old_sha1_prefix[41];
170         char new_sha1_prefix[41];
171         struct patch *next;
172 };
173
174 /*
175  * A line in a file, len-bytes long (includes the terminating LF,
176  * except for an incomplete line at the end if the file ends with
177  * one), and its contents hashes to 'hash'.
178  */
179 struct line {
180         size_t len;
181         unsigned hash : 24;
182         unsigned flag : 8;
183 #define LINE_COMMON     1
184 };
185
186 /*
187  * This represents a "file", which is an array of "lines".
188  */
189 struct image {
190         char *buf;
191         size_t len;
192         size_t nr;
193         size_t alloc;
194         struct line *line_allocated;
195         struct line *line;
196 };
197
198 /*
199  * Records filenames that have been touched, in order to handle
200  * the case where more than one patches touch the same file.
201  */
202
203 static struct string_list fn_table;
204
205 static uint32_t hash_line(const char *cp, size_t len)
206 {
207         size_t i;
208         uint32_t h;
209         for (i = 0, h = 0; i < len; i++) {
210                 if (!isspace(cp[i])) {
211                         h = h * 3 + (cp[i] & 0xff);
212                 }
213         }
214         return h;
215 }
216
217 static void add_line_info(struct image *img, const char *bol, size_t len, unsigned flag)
218 {
219         ALLOC_GROW(img->line_allocated, img->nr + 1, img->alloc);
220         img->line_allocated[img->nr].len = len;
221         img->line_allocated[img->nr].hash = hash_line(bol, len);
222         img->line_allocated[img->nr].flag = flag;
223         img->nr++;
224 }
225
226 static void prepare_image(struct image *image, char *buf, size_t len,
227                           int prepare_linetable)
228 {
229         const char *cp, *ep;
230
231         memset(image, 0, sizeof(*image));
232         image->buf = buf;
233         image->len = len;
234
235         if (!prepare_linetable)
236                 return;
237
238         ep = image->buf + image->len;
239         cp = image->buf;
240         while (cp < ep) {
241                 const char *next;
242                 for (next = cp; next < ep && *next != '\n'; next++)
243                         ;
244                 if (next < ep)
245                         next++;
246                 add_line_info(image, cp, next - cp, 0);
247                 cp = next;
248         }
249         image->line = image->line_allocated;
250 }
251
252 static void clear_image(struct image *image)
253 {
254         free(image->buf);
255         image->buf = NULL;
256         image->len = 0;
257 }
258
259 static void say_patch_name(FILE *output, const char *pre,
260                            struct patch *patch, const char *post)
261 {
262         fputs(pre, output);
263         if (patch->old_name && patch->new_name &&
264             strcmp(patch->old_name, patch->new_name)) {
265                 quote_c_style(patch->old_name, NULL, output, 0);
266                 fputs(" => ", output);
267                 quote_c_style(patch->new_name, NULL, output, 0);
268         } else {
269                 const char *n = patch->new_name;
270                 if (!n)
271                         n = patch->old_name;
272                 quote_c_style(n, NULL, output, 0);
273         }
274         fputs(post, output);
275 }
276
277 #define CHUNKSIZE (8192)
278 #define SLOP (16)
279
280 static void read_patch_file(struct strbuf *sb, int fd)
281 {
282         if (strbuf_read(sb, fd, 0) < 0)
283                 die_errno("git apply: failed to read");
284
285         /*
286          * Make sure that we have some slop in the buffer
287          * so that we can do speculative "memcmp" etc, and
288          * see to it that it is NUL-filled.
289          */
290         strbuf_grow(sb, SLOP);
291         memset(sb->buf + sb->len, 0, SLOP);
292 }
293
294 static unsigned long linelen(const char *buffer, unsigned long size)
295 {
296         unsigned long len = 0;
297         while (size--) {
298                 len++;
299                 if (*buffer++ == '\n')
300                         break;
301         }
302         return len;
303 }
304
305 static int is_dev_null(const char *str)
306 {
307         return !memcmp("/dev/null", str, 9) && isspace(str[9]);
308 }
309
310 #define TERM_SPACE      1
311 #define TERM_TAB        2
312
313 static int name_terminate(const char *name, int namelen, int c, int terminate)
314 {
315         if (c == ' ' && !(terminate & TERM_SPACE))
316                 return 0;
317         if (c == '\t' && !(terminate & TERM_TAB))
318                 return 0;
319
320         return 1;
321 }
322
323 /* remove double slashes to make --index work with such filenames */
324 static char *squash_slash(char *name)
325 {
326         int i = 0, j = 0;
327
328         while (name[i]) {
329                 if ((name[j++] = name[i++]) == '/')
330                         while (name[i] == '/')
331                                 i++;
332         }
333         name[j] = '\0';
334         return name;
335 }
336
337 static char *find_name(const char *line, char *def, int p_value, int terminate)
338 {
339         int len;
340         const char *start = line;
341
342         if (*line == '"') {
343                 struct strbuf name = STRBUF_INIT;
344
345                 /*
346                  * Proposed "new-style" GNU patch/diff format; see
347                  * http://marc.theaimsgroup.com/?l=git&m=112927316408690&w=2
348                  */
349                 if (!unquote_c_style(&name, line, NULL)) {
350                         char *cp;
351
352                         for (cp = name.buf; p_value; p_value--) {
353                                 cp = strchr(cp, '/');
354                                 if (!cp)
355                                         break;
356                                 cp++;
357                         }
358                         if (cp) {
359                                 /* name can later be freed, so we need
360                                  * to memmove, not just return cp
361                                  */
362                                 strbuf_remove(&name, 0, cp - name.buf);
363                                 free(def);
364                                 if (root)
365                                         strbuf_insert(&name, 0, root, root_len);
366                                 return squash_slash(strbuf_detach(&name, NULL));
367                         }
368                 }
369                 strbuf_release(&name);
370         }
371
372         for (;;) {
373                 char c = *line;
374
375                 if (isspace(c)) {
376                         if (c == '\n')
377                                 break;
378                         if (name_terminate(start, line-start, c, terminate))
379                                 break;
380                 }
381                 line++;
382                 if (c == '/' && !--p_value)
383                         start = line;
384         }
385         if (!start)
386                 return squash_slash(def);
387         len = line - start;
388         if (!len)
389                 return squash_slash(def);
390
391         /*
392          * Generally we prefer the shorter name, especially
393          * if the other one is just a variation of that with
394          * something else tacked on to the end (ie "file.orig"
395          * or "file~").
396          */
397         if (def) {
398                 int deflen = strlen(def);
399                 if (deflen < len && !strncmp(start, def, deflen))
400                         return squash_slash(def);
401                 free(def);
402         }
403
404         if (root) {
405                 char *ret = xmalloc(root_len + len + 1);
406                 strcpy(ret, root);
407                 memcpy(ret + root_len, start, len);
408                 ret[root_len + len] = '\0';
409                 return squash_slash(ret);
410         }
411
412         return squash_slash(xmemdupz(start, len));
413 }
414
415 static int count_slashes(const char *cp)
416 {
417         int cnt = 0;
418         char ch;
419
420         while ((ch = *cp++))
421                 if (ch == '/')
422                         cnt++;
423         return cnt;
424 }
425
426 /*
427  * Given the string after "--- " or "+++ ", guess the appropriate
428  * p_value for the given patch.
429  */
430 static int guess_p_value(const char *nameline)
431 {
432         char *name, *cp;
433         int val = -1;
434
435         if (is_dev_null(nameline))
436                 return -1;
437         name = find_name(nameline, NULL, 0, TERM_SPACE | TERM_TAB);
438         if (!name)
439                 return -1;
440         cp = strchr(name, '/');
441         if (!cp)
442                 val = 0;
443         else if (prefix) {
444                 /*
445                  * Does it begin with "a/$our-prefix" and such?  Then this is
446                  * very likely to apply to our directory.
447                  */
448                 if (!strncmp(name, prefix, prefix_length))
449                         val = count_slashes(prefix);
450                 else {
451                         cp++;
452                         if (!strncmp(cp, prefix, prefix_length))
453                                 val = count_slashes(prefix) + 1;
454                 }
455         }
456         free(name);
457         return val;
458 }
459
460 /*
461  * Does the ---/+++ line has the POSIX timestamp after the last HT?
462  * GNU diff puts epoch there to signal a creation/deletion event.  Is
463  * this such a timestamp?
464  */
465 static int has_epoch_timestamp(const char *nameline)
466 {
467         /*
468          * We are only interested in epoch timestamp; any non-zero
469          * fraction cannot be one, hence "(\.0+)?" in the regexp below.
470          * For the same reason, the date must be either 1969-12-31 or
471          * 1970-01-01, and the seconds part must be "00".
472          */
473         const char stamp_regexp[] =
474                 "^(1969-12-31|1970-01-01)"
475                 " "
476                 "[0-2][0-9]:[0-5][0-9]:00(\\.0+)?"
477                 " "
478                 "([-+][0-2][0-9][0-5][0-9])\n";
479         const char *timestamp = NULL, *cp;
480         static regex_t *stamp;
481         regmatch_t m[10];
482         int zoneoffset;
483         int hourminute;
484         int status;
485
486         for (cp = nameline; *cp != '\n'; cp++) {
487                 if (*cp == '\t')
488                         timestamp = cp + 1;
489         }
490         if (!timestamp)
491                 return 0;
492         if (!stamp) {
493                 stamp = xmalloc(sizeof(*stamp));
494                 if (regcomp(stamp, stamp_regexp, REG_EXTENDED)) {
495                         warning("Cannot prepare timestamp regexp %s",
496                                 stamp_regexp);
497                         return 0;
498                 }
499         }
500
501         status = regexec(stamp, timestamp, ARRAY_SIZE(m), m, 0);
502         if (status) {
503                 if (status != REG_NOMATCH)
504                         warning("regexec returned %d for input: %s",
505                                 status, timestamp);
506                 return 0;
507         }
508
509         zoneoffset = strtol(timestamp + m[3].rm_so + 1, NULL, 10);
510         zoneoffset = (zoneoffset / 100) * 60 + (zoneoffset % 100);
511         if (timestamp[m[3].rm_so] == '-')
512                 zoneoffset = -zoneoffset;
513
514         /*
515          * YYYY-MM-DD hh:mm:ss must be from either 1969-12-31
516          * (west of GMT) or 1970-01-01 (east of GMT)
517          */
518         if ((zoneoffset < 0 && memcmp(timestamp, "1969-12-31", 10)) ||
519             (0 <= zoneoffset && memcmp(timestamp, "1970-01-01", 10)))
520                 return 0;
521
522         hourminute = (strtol(timestamp + 11, NULL, 10) * 60 +
523                       strtol(timestamp + 14, NULL, 10) -
524                       zoneoffset);
525
526         return ((zoneoffset < 0 && hourminute == 1440) ||
527                 (0 <= zoneoffset && !hourminute));
528 }
529
530 /*
531  * Get the name etc info from the ---/+++ lines of a traditional patch header
532  *
533  * FIXME! The end-of-filename heuristics are kind of screwy. For existing
534  * files, we can happily check the index for a match, but for creating a
535  * new file we should try to match whatever "patch" does. I have no idea.
536  */
537 static void parse_traditional_patch(const char *first, const char *second, struct patch *patch)
538 {
539         char *name;
540
541         first += 4;     /* skip "--- " */
542         second += 4;    /* skip "+++ " */
543         if (!p_value_known) {
544                 int p, q;
545                 p = guess_p_value(first);
546                 q = guess_p_value(second);
547                 if (p < 0) p = q;
548                 if (0 <= p && p == q) {
549                         p_value = p;
550                         p_value_known = 1;
551                 }
552         }
553         if (is_dev_null(first)) {
554                 patch->is_new = 1;
555                 patch->is_delete = 0;
556                 name = find_name(second, NULL, p_value, TERM_SPACE | TERM_TAB);
557                 patch->new_name = name;
558         } else if (is_dev_null(second)) {
559                 patch->is_new = 0;
560                 patch->is_delete = 1;
561                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
562                 patch->old_name = name;
563         } else {
564                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
565                 name = find_name(second, name, p_value, TERM_SPACE | TERM_TAB);
566                 if (has_epoch_timestamp(first)) {
567                         patch->is_new = 1;
568                         patch->is_delete = 0;
569                         patch->new_name = name;
570                 } else if (has_epoch_timestamp(second)) {
571                         patch->is_new = 0;
572                         patch->is_delete = 1;
573                         patch->old_name = name;
574                 } else {
575                         patch->old_name = patch->new_name = name;
576                 }
577         }
578         if (!name)
579                 die("unable to find filename in patch at line %d", linenr);
580 }
581
582 static int gitdiff_hdrend(const char *line, struct patch *patch)
583 {
584         return -1;
585 }
586
587 /*
588  * We're anal about diff header consistency, to make
589  * sure that we don't end up having strange ambiguous
590  * patches floating around.
591  *
592  * As a result, gitdiff_{old|new}name() will check
593  * their names against any previous information, just
594  * to make sure..
595  */
596 static char *gitdiff_verify_name(const char *line, int isnull, char *orig_name, const char *oldnew)
597 {
598         if (!orig_name && !isnull)
599                 return find_name(line, NULL, p_value, TERM_TAB);
600
601         if (orig_name) {
602                 int len;
603                 const char *name;
604                 char *another;
605                 name = orig_name;
606                 len = strlen(name);
607                 if (isnull)
608                         die("git apply: bad git-diff - expected /dev/null, got %s on line %d", name, linenr);
609                 another = find_name(line, NULL, p_value, TERM_TAB);
610                 if (!another || memcmp(another, name, len))
611                         die("git apply: bad git-diff - inconsistent %s filename on line %d", oldnew, linenr);
612                 free(another);
613                 return orig_name;
614         }
615         else {
616                 /* expect "/dev/null" */
617                 if (memcmp("/dev/null", line, 9) || line[9] != '\n')
618                         die("git apply: bad git-diff - expected /dev/null on line %d", linenr);
619                 return NULL;
620         }
621 }
622
623 static int gitdiff_oldname(const char *line, struct patch *patch)
624 {
625         patch->old_name = gitdiff_verify_name(line, patch->is_new, patch->old_name, "old");
626         return 0;
627 }
628
629 static int gitdiff_newname(const char *line, struct patch *patch)
630 {
631         patch->new_name = gitdiff_verify_name(line, patch->is_delete, patch->new_name, "new");
632         return 0;
633 }
634
635 static int gitdiff_oldmode(const char *line, struct patch *patch)
636 {
637         patch->old_mode = strtoul(line, NULL, 8);
638         return 0;
639 }
640
641 static int gitdiff_newmode(const char *line, struct patch *patch)
642 {
643         patch->new_mode = strtoul(line, NULL, 8);
644         return 0;
645 }
646
647 static int gitdiff_delete(const char *line, struct patch *patch)
648 {
649         patch->is_delete = 1;
650         patch->old_name = patch->def_name;
651         return gitdiff_oldmode(line, patch);
652 }
653
654 static int gitdiff_newfile(const char *line, struct patch *patch)
655 {
656         patch->is_new = 1;
657         patch->new_name = patch->def_name;
658         return gitdiff_newmode(line, patch);
659 }
660
661 static int gitdiff_copysrc(const char *line, struct patch *patch)
662 {
663         patch->is_copy = 1;
664         patch->old_name = find_name(line, NULL, 0, 0);
665         return 0;
666 }
667
668 static int gitdiff_copydst(const char *line, struct patch *patch)
669 {
670         patch->is_copy = 1;
671         patch->new_name = find_name(line, NULL, 0, 0);
672         return 0;
673 }
674
675 static int gitdiff_renamesrc(const char *line, struct patch *patch)
676 {
677         patch->is_rename = 1;
678         patch->old_name = find_name(line, NULL, 0, 0);
679         return 0;
680 }
681
682 static int gitdiff_renamedst(const char *line, struct patch *patch)
683 {
684         patch->is_rename = 1;
685         patch->new_name = find_name(line, NULL, 0, 0);
686         return 0;
687 }
688
689 static int gitdiff_similarity(const char *line, struct patch *patch)
690 {
691         if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
692                 patch->score = 0;
693         return 0;
694 }
695
696 static int gitdiff_dissimilarity(const char *line, struct patch *patch)
697 {
698         if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
699                 patch->score = 0;
700         return 0;
701 }
702
703 static int gitdiff_index(const char *line, struct patch *patch)
704 {
705         /*
706          * index line is N hexadecimal, "..", N hexadecimal,
707          * and optional space with octal mode.
708          */
709         const char *ptr, *eol;
710         int len;
711
712         ptr = strchr(line, '.');
713         if (!ptr || ptr[1] != '.' || 40 < ptr - line)
714                 return 0;
715         len = ptr - line;
716         memcpy(patch->old_sha1_prefix, line, len);
717         patch->old_sha1_prefix[len] = 0;
718
719         line = ptr + 2;
720         ptr = strchr(line, ' ');
721         eol = strchr(line, '\n');
722
723         if (!ptr || eol < ptr)
724                 ptr = eol;
725         len = ptr - line;
726
727         if (40 < len)
728                 return 0;
729         memcpy(patch->new_sha1_prefix, line, len);
730         patch->new_sha1_prefix[len] = 0;
731         if (*ptr == ' ')
732                 patch->old_mode = strtoul(ptr+1, NULL, 8);
733         return 0;
734 }
735
736 /*
737  * This is normal for a diff that doesn't change anything: we'll fall through
738  * into the next diff. Tell the parser to break out.
739  */
740 static int gitdiff_unrecognized(const char *line, struct patch *patch)
741 {
742         return -1;
743 }
744
745 static const char *stop_at_slash(const char *line, int llen)
746 {
747         int i;
748
749         for (i = 0; i < llen; i++) {
750                 int ch = line[i];
751                 if (ch == '/')
752                         return line + i;
753         }
754         return NULL;
755 }
756
757 /*
758  * This is to extract the same name that appears on "diff --git"
759  * line.  We do not find and return anything if it is a rename
760  * patch, and it is OK because we will find the name elsewhere.
761  * We need to reliably find name only when it is mode-change only,
762  * creation or deletion of an empty file.  In any of these cases,
763  * both sides are the same name under a/ and b/ respectively.
764  */
765 static char *git_header_name(char *line, int llen)
766 {
767         const char *name;
768         const char *second = NULL;
769         size_t len;
770
771         line += strlen("diff --git ");
772         llen -= strlen("diff --git ");
773
774         if (*line == '"') {
775                 const char *cp;
776                 struct strbuf first = STRBUF_INIT;
777                 struct strbuf sp = STRBUF_INIT;
778
779                 if (unquote_c_style(&first, line, &second))
780                         goto free_and_fail1;
781
782                 /* advance to the first slash */
783                 cp = stop_at_slash(first.buf, first.len);
784                 /* we do not accept absolute paths */
785                 if (!cp || cp == first.buf)
786                         goto free_and_fail1;
787                 strbuf_remove(&first, 0, cp + 1 - first.buf);
788
789                 /*
790                  * second points at one past closing dq of name.
791                  * find the second name.
792                  */
793                 while ((second < line + llen) && isspace(*second))
794                         second++;
795
796                 if (line + llen <= second)
797                         goto free_and_fail1;
798                 if (*second == '"') {
799                         if (unquote_c_style(&sp, second, NULL))
800                                 goto free_and_fail1;
801                         cp = stop_at_slash(sp.buf, sp.len);
802                         if (!cp || cp == sp.buf)
803                                 goto free_and_fail1;
804                         /* They must match, otherwise ignore */
805                         if (strcmp(cp + 1, first.buf))
806                                 goto free_and_fail1;
807                         strbuf_release(&sp);
808                         return strbuf_detach(&first, NULL);
809                 }
810
811                 /* unquoted second */
812                 cp = stop_at_slash(second, line + llen - second);
813                 if (!cp || cp == second)
814                         goto free_and_fail1;
815                 cp++;
816                 if (line + llen - cp != first.len + 1 ||
817                     memcmp(first.buf, cp, first.len))
818                         goto free_and_fail1;
819                 return strbuf_detach(&first, NULL);
820
821         free_and_fail1:
822                 strbuf_release(&first);
823                 strbuf_release(&sp);
824                 return NULL;
825         }
826
827         /* unquoted first name */
828         name = stop_at_slash(line, llen);
829         if (!name || name == line)
830                 return NULL;
831         name++;
832
833         /*
834          * since the first name is unquoted, a dq if exists must be
835          * the beginning of the second name.
836          */
837         for (second = name; second < line + llen; second++) {
838                 if (*second == '"') {
839                         struct strbuf sp = STRBUF_INIT;
840                         const char *np;
841
842                         if (unquote_c_style(&sp, second, NULL))
843                                 goto free_and_fail2;
844
845                         np = stop_at_slash(sp.buf, sp.len);
846                         if (!np || np == sp.buf)
847                                 goto free_and_fail2;
848                         np++;
849
850                         len = sp.buf + sp.len - np;
851                         if (len < second - name &&
852                             !strncmp(np, name, len) &&
853                             isspace(name[len])) {
854                                 /* Good */
855                                 strbuf_remove(&sp, 0, np - sp.buf);
856                                 return strbuf_detach(&sp, NULL);
857                         }
858
859                 free_and_fail2:
860                         strbuf_release(&sp);
861                         return NULL;
862                 }
863         }
864
865         /*
866          * Accept a name only if it shows up twice, exactly the same
867          * form.
868          */
869         for (len = 0 ; ; len++) {
870                 switch (name[len]) {
871                 default:
872                         continue;
873                 case '\n':
874                         return NULL;
875                 case '\t': case ' ':
876                         second = name+len;
877                         for (;;) {
878                                 char c = *second++;
879                                 if (c == '\n')
880                                         return NULL;
881                                 if (c == '/')
882                                         break;
883                         }
884                         if (second[len] == '\n' && !memcmp(name, second, len)) {
885                                 return xmemdupz(name, len);
886                         }
887                 }
888         }
889 }
890
891 /* Verify that we recognize the lines following a git header */
892 static int parse_git_header(char *line, int len, unsigned int size, struct patch *patch)
893 {
894         unsigned long offset;
895
896         /* A git diff has explicit new/delete information, so we don't guess */
897         patch->is_new = 0;
898         patch->is_delete = 0;
899
900         /*
901          * Some things may not have the old name in the
902          * rest of the headers anywhere (pure mode changes,
903          * or removing or adding empty files), so we get
904          * the default name from the header.
905          */
906         patch->def_name = git_header_name(line, len);
907         if (patch->def_name && root) {
908                 char *s = xmalloc(root_len + strlen(patch->def_name) + 1);
909                 strcpy(s, root);
910                 strcpy(s + root_len, patch->def_name);
911                 free(patch->def_name);
912                 patch->def_name = s;
913         }
914
915         line += len;
916         size -= len;
917         linenr++;
918         for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) {
919                 static const struct opentry {
920                         const char *str;
921                         int (*fn)(const char *, struct patch *);
922                 } optable[] = {
923                         { "@@ -", gitdiff_hdrend },
924                         { "--- ", gitdiff_oldname },
925                         { "+++ ", gitdiff_newname },
926                         { "old mode ", gitdiff_oldmode },
927                         { "new mode ", gitdiff_newmode },
928                         { "deleted file mode ", gitdiff_delete },
929                         { "new file mode ", gitdiff_newfile },
930                         { "copy from ", gitdiff_copysrc },
931                         { "copy to ", gitdiff_copydst },
932                         { "rename old ", gitdiff_renamesrc },
933                         { "rename new ", gitdiff_renamedst },
934                         { "rename from ", gitdiff_renamesrc },
935                         { "rename to ", gitdiff_renamedst },
936                         { "similarity index ", gitdiff_similarity },
937                         { "dissimilarity index ", gitdiff_dissimilarity },
938                         { "index ", gitdiff_index },
939                         { "", gitdiff_unrecognized },
940                 };
941                 int i;
942
943                 len = linelen(line, size);
944                 if (!len || line[len-1] != '\n')
945                         break;
946                 for (i = 0; i < ARRAY_SIZE(optable); i++) {
947                         const struct opentry *p = optable + i;
948                         int oplen = strlen(p->str);
949                         if (len < oplen || memcmp(p->str, line, oplen))
950                                 continue;
951                         if (p->fn(line + oplen, patch) < 0)
952                                 return offset;
953                         break;
954                 }
955         }
956
957         return offset;
958 }
959
960 static int parse_num(const char *line, unsigned long *p)
961 {
962         char *ptr;
963
964         if (!isdigit(*line))
965                 return 0;
966         *p = strtoul(line, &ptr, 10);
967         return ptr - line;
968 }
969
970 static int parse_range(const char *line, int len, int offset, const char *expect,
971                        unsigned long *p1, unsigned long *p2)
972 {
973         int digits, ex;
974
975         if (offset < 0 || offset >= len)
976                 return -1;
977         line += offset;
978         len -= offset;
979
980         digits = parse_num(line, p1);
981         if (!digits)
982                 return -1;
983
984         offset += digits;
985         line += digits;
986         len -= digits;
987
988         *p2 = 1;
989         if (*line == ',') {
990                 digits = parse_num(line+1, p2);
991                 if (!digits)
992                         return -1;
993
994                 offset += digits+1;
995                 line += digits+1;
996                 len -= digits+1;
997         }
998
999         ex = strlen(expect);
1000         if (ex > len)
1001                 return -1;
1002         if (memcmp(line, expect, ex))
1003                 return -1;
1004
1005         return offset + ex;
1006 }
1007
1008 static void recount_diff(char *line, int size, struct fragment *fragment)
1009 {
1010         int oldlines = 0, newlines = 0, ret = 0;
1011
1012         if (size < 1) {
1013                 warning("recount: ignore empty hunk");
1014                 return;
1015         }
1016
1017         for (;;) {
1018                 int len = linelen(line, size);
1019                 size -= len;
1020                 line += len;
1021
1022                 if (size < 1)
1023                         break;
1024
1025                 switch (*line) {
1026                 case ' ': case '\n':
1027                         newlines++;
1028                         /* fall through */
1029                 case '-':
1030                         oldlines++;
1031                         continue;
1032                 case '+':
1033                         newlines++;
1034                         continue;
1035                 case '\\':
1036                         continue;
1037                 case '@':
1038                         ret = size < 3 || prefixcmp(line, "@@ ");
1039                         break;
1040                 case 'd':
1041                         ret = size < 5 || prefixcmp(line, "diff ");
1042                         break;
1043                 default:
1044                         ret = -1;
1045                         break;
1046                 }
1047                 if (ret) {
1048                         warning("recount: unexpected line: %.*s",
1049                                 (int)linelen(line, size), line);
1050                         return;
1051                 }
1052                 break;
1053         }
1054         fragment->oldlines = oldlines;
1055         fragment->newlines = newlines;
1056 }
1057
1058 /*
1059  * Parse a unified diff fragment header of the
1060  * form "@@ -a,b +c,d @@"
1061  */
1062 static int parse_fragment_header(char *line, int len, struct fragment *fragment)
1063 {
1064         int offset;
1065
1066         if (!len || line[len-1] != '\n')
1067                 return -1;
1068
1069         /* Figure out the number of lines in a fragment */
1070         offset = parse_range(line, len, 4, " +", &fragment->oldpos, &fragment->oldlines);
1071         offset = parse_range(line, len, offset, " @@", &fragment->newpos, &fragment->newlines);
1072
1073         return offset;
1074 }
1075
1076 static int find_header(char *line, unsigned long size, int *hdrsize, struct patch *patch)
1077 {
1078         unsigned long offset, len;
1079
1080         patch->is_toplevel_relative = 0;
1081         patch->is_rename = patch->is_copy = 0;
1082         patch->is_new = patch->is_delete = -1;
1083         patch->old_mode = patch->new_mode = 0;
1084         patch->old_name = patch->new_name = NULL;
1085         for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) {
1086                 unsigned long nextlen;
1087
1088                 len = linelen(line, size);
1089                 if (!len)
1090                         break;
1091
1092                 /* Testing this early allows us to take a few shortcuts.. */
1093                 if (len < 6)
1094                         continue;
1095
1096                 /*
1097                  * Make sure we don't find any unconnected patch fragments.
1098                  * That's a sign that we didn't find a header, and that a
1099                  * patch has become corrupted/broken up.
1100                  */
1101                 if (!memcmp("@@ -", line, 4)) {
1102                         struct fragment dummy;
1103                         if (parse_fragment_header(line, len, &dummy) < 0)
1104                                 continue;
1105                         die("patch fragment without header at line %d: %.*s",
1106                             linenr, (int)len-1, line);
1107                 }
1108
1109                 if (size < len + 6)
1110                         break;
1111
1112                 /*
1113                  * Git patch? It might not have a real patch, just a rename
1114                  * or mode change, so we handle that specially
1115                  */
1116                 if (!memcmp("diff --git ", line, 11)) {
1117                         int git_hdr_len = parse_git_header(line, len, size, patch);
1118                         if (git_hdr_len <= len)
1119                                 continue;
1120                         if (!patch->old_name && !patch->new_name) {
1121                                 if (!patch->def_name)
1122                                         die("git diff header lacks filename information (line %d)", linenr);
1123                                 patch->old_name = patch->new_name = patch->def_name;
1124                         }
1125                         patch->is_toplevel_relative = 1;
1126                         *hdrsize = git_hdr_len;
1127                         return offset;
1128                 }
1129
1130                 /* --- followed by +++ ? */
1131                 if (memcmp("--- ", line,  4) || memcmp("+++ ", line + len, 4))
1132                         continue;
1133
1134                 /*
1135                  * We only accept unified patches, so we want it to
1136                  * at least have "@@ -a,b +c,d @@\n", which is 14 chars
1137                  * minimum ("@@ -0,0 +1 @@\n" is the shortest).
1138                  */
1139                 nextlen = linelen(line + len, size - len);
1140                 if (size < nextlen + 14 || memcmp("@@ -", line + len + nextlen, 4))
1141                         continue;
1142
1143                 /* Ok, we'll consider it a patch */
1144                 parse_traditional_patch(line, line+len, patch);
1145                 *hdrsize = len + nextlen;
1146                 linenr += 2;
1147                 return offset;
1148         }
1149         return -1;
1150 }
1151
1152 static void check_whitespace(const char *line, int len, unsigned ws_rule)
1153 {
1154         char *err;
1155         unsigned result = ws_check(line + 1, len - 1, ws_rule);
1156         if (!result)
1157                 return;
1158
1159         whitespace_error++;
1160         if (squelch_whitespace_errors &&
1161             squelch_whitespace_errors < whitespace_error)
1162                 ;
1163         else {
1164                 err = whitespace_error_string(result);
1165                 fprintf(stderr, "%s:%d: %s.\n%.*s\n",
1166                         patch_input_file, linenr, err, len - 2, line + 1);
1167                 free(err);
1168         }
1169 }
1170
1171 /*
1172  * Parse a unified diff. Note that this really needs to parse each
1173  * fragment separately, since the only way to know the difference
1174  * between a "---" that is part of a patch, and a "---" that starts
1175  * the next patch is to look at the line counts..
1176  */
1177 static int parse_fragment(char *line, unsigned long size,
1178                           struct patch *patch, struct fragment *fragment)
1179 {
1180         int added, deleted;
1181         int len = linelen(line, size), offset;
1182         unsigned long oldlines, newlines;
1183         unsigned long leading, trailing;
1184
1185         offset = parse_fragment_header(line, len, fragment);
1186         if (offset < 0)
1187                 return -1;
1188         if (offset > 0 && patch->recount)
1189                 recount_diff(line + offset, size - offset, fragment);
1190         oldlines = fragment->oldlines;
1191         newlines = fragment->newlines;
1192         leading = 0;
1193         trailing = 0;
1194
1195         /* Parse the thing.. */
1196         line += len;
1197         size -= len;
1198         linenr++;
1199         added = deleted = 0;
1200         for (offset = len;
1201              0 < size;
1202              offset += len, size -= len, line += len, linenr++) {
1203                 if (!oldlines && !newlines)
1204                         break;
1205                 len = linelen(line, size);
1206                 if (!len || line[len-1] != '\n')
1207                         return -1;
1208                 switch (*line) {
1209                 default:
1210                         return -1;
1211                 case '\n': /* newer GNU diff, an empty context line */
1212                 case ' ':
1213                         oldlines--;
1214                         newlines--;
1215                         if (!deleted && !added)
1216                                 leading++;
1217                         trailing++;
1218                         break;
1219                 case '-':
1220                         if (apply_in_reverse &&
1221                             ws_error_action != nowarn_ws_error)
1222                                 check_whitespace(line, len, patch->ws_rule);
1223                         deleted++;
1224                         oldlines--;
1225                         trailing = 0;
1226                         break;
1227                 case '+':
1228                         if (!apply_in_reverse &&
1229                             ws_error_action != nowarn_ws_error)
1230                                 check_whitespace(line, len, patch->ws_rule);
1231                         added++;
1232                         newlines--;
1233                         trailing = 0;
1234                         break;
1235
1236                 /*
1237                  * We allow "\ No newline at end of file". Depending
1238                  * on locale settings when the patch was produced we
1239                  * don't know what this line looks like. The only
1240                  * thing we do know is that it begins with "\ ".
1241                  * Checking for 12 is just for sanity check -- any
1242                  * l10n of "\ No newline..." is at least that long.
1243                  */
1244                 case '\\':
1245                         if (len < 12 || memcmp(line, "\\ ", 2))
1246                                 return -1;
1247                         break;
1248                 }
1249         }
1250         if (oldlines || newlines)
1251                 return -1;
1252         fragment->leading = leading;
1253         fragment->trailing = trailing;
1254
1255         /*
1256          * If a fragment ends with an incomplete line, we failed to include
1257          * it in the above loop because we hit oldlines == newlines == 0
1258          * before seeing it.
1259          */
1260         if (12 < size && !memcmp(line, "\\ ", 2))
1261                 offset += linelen(line, size);
1262
1263         patch->lines_added += added;
1264         patch->lines_deleted += deleted;
1265
1266         if (0 < patch->is_new && oldlines)
1267                 return error("new file depends on old contents");
1268         if (0 < patch->is_delete && newlines)
1269                 return error("deleted file still has contents");
1270         return offset;
1271 }
1272
1273 static int parse_single_patch(char *line, unsigned long size, struct patch *patch)
1274 {
1275         unsigned long offset = 0;
1276         unsigned long oldlines = 0, newlines = 0, context = 0;
1277         struct fragment **fragp = &patch->fragments;
1278
1279         while (size > 4 && !memcmp(line, "@@ -", 4)) {
1280                 struct fragment *fragment;
1281                 int len;
1282
1283                 fragment = xcalloc(1, sizeof(*fragment));
1284                 len = parse_fragment(line, size, patch, fragment);
1285                 if (len <= 0)
1286                         die("corrupt patch at line %d", linenr);
1287                 fragment->patch = line;
1288                 fragment->size = len;
1289                 oldlines += fragment->oldlines;
1290                 newlines += fragment->newlines;
1291                 context += fragment->leading + fragment->trailing;
1292
1293                 *fragp = fragment;
1294                 fragp = &fragment->next;
1295
1296                 offset += len;
1297                 line += len;
1298                 size -= len;
1299         }
1300
1301         /*
1302          * If something was removed (i.e. we have old-lines) it cannot
1303          * be creation, and if something was added it cannot be
1304          * deletion.  However, the reverse is not true; --unified=0
1305          * patches that only add are not necessarily creation even
1306          * though they do not have any old lines, and ones that only
1307          * delete are not necessarily deletion.
1308          *
1309          * Unfortunately, a real creation/deletion patch do _not_ have
1310          * any context line by definition, so we cannot safely tell it
1311          * apart with --unified=0 insanity.  At least if the patch has
1312          * more than one hunk it is not creation or deletion.
1313          */
1314         if (patch->is_new < 0 &&
1315             (oldlines || (patch->fragments && patch->fragments->next)))
1316                 patch->is_new = 0;
1317         if (patch->is_delete < 0 &&
1318             (newlines || (patch->fragments && patch->fragments->next)))
1319                 patch->is_delete = 0;
1320
1321         if (0 < patch->is_new && oldlines)
1322                 die("new file %s depends on old contents", patch->new_name);
1323         if (0 < patch->is_delete && newlines)
1324                 die("deleted file %s still has contents", patch->old_name);
1325         if (!patch->is_delete && !newlines && context)
1326                 fprintf(stderr, "** warning: file %s becomes empty but "
1327                         "is not deleted\n", patch->new_name);
1328
1329         return offset;
1330 }
1331
1332 static inline int metadata_changes(struct patch *patch)
1333 {
1334         return  patch->is_rename > 0 ||
1335                 patch->is_copy > 0 ||
1336                 patch->is_new > 0 ||
1337                 patch->is_delete ||
1338                 (patch->old_mode && patch->new_mode &&
1339                  patch->old_mode != patch->new_mode);
1340 }
1341
1342 static char *inflate_it(const void *data, unsigned long size,
1343                         unsigned long inflated_size)
1344 {
1345         z_stream stream;
1346         void *out;
1347         int st;
1348
1349         memset(&stream, 0, sizeof(stream));
1350
1351         stream.next_in = (unsigned char *)data;
1352         stream.avail_in = size;
1353         stream.next_out = out = xmalloc(inflated_size);
1354         stream.avail_out = inflated_size;
1355         git_inflate_init(&stream);
1356         st = git_inflate(&stream, Z_FINISH);
1357         git_inflate_end(&stream);
1358         if ((st != Z_STREAM_END) || stream.total_out != inflated_size) {
1359                 free(out);
1360                 return NULL;
1361         }
1362         return out;
1363 }
1364
1365 static struct fragment *parse_binary_hunk(char **buf_p,
1366                                           unsigned long *sz_p,
1367                                           int *status_p,
1368                                           int *used_p)
1369 {
1370         /*
1371          * Expect a line that begins with binary patch method ("literal"
1372          * or "delta"), followed by the length of data before deflating.
1373          * a sequence of 'length-byte' followed by base-85 encoded data
1374          * should follow, terminated by a newline.
1375          *
1376          * Each 5-byte sequence of base-85 encodes up to 4 bytes,
1377          * and we would limit the patch line to 66 characters,
1378          * so one line can fit up to 13 groups that would decode
1379          * to 52 bytes max.  The length byte 'A'-'Z' corresponds
1380          * to 1-26 bytes, and 'a'-'z' corresponds to 27-52 bytes.
1381          */
1382         int llen, used;
1383         unsigned long size = *sz_p;
1384         char *buffer = *buf_p;
1385         int patch_method;
1386         unsigned long origlen;
1387         char *data = NULL;
1388         int hunk_size = 0;
1389         struct fragment *frag;
1390
1391         llen = linelen(buffer, size);
1392         used = llen;
1393
1394         *status_p = 0;
1395
1396         if (!prefixcmp(buffer, "delta ")) {
1397                 patch_method = BINARY_DELTA_DEFLATED;
1398                 origlen = strtoul(buffer + 6, NULL, 10);
1399         }
1400         else if (!prefixcmp(buffer, "literal ")) {
1401                 patch_method = BINARY_LITERAL_DEFLATED;
1402                 origlen = strtoul(buffer + 8, NULL, 10);
1403         }
1404         else
1405                 return NULL;
1406
1407         linenr++;
1408         buffer += llen;
1409         while (1) {
1410                 int byte_length, max_byte_length, newsize;
1411                 llen = linelen(buffer, size);
1412                 used += llen;
1413                 linenr++;
1414                 if (llen == 1) {
1415                         /* consume the blank line */
1416                         buffer++;
1417                         size--;
1418                         break;
1419                 }
1420                 /*
1421                  * Minimum line is "A00000\n" which is 7-byte long,
1422                  * and the line length must be multiple of 5 plus 2.
1423                  */
1424                 if ((llen < 7) || (llen-2) % 5)
1425                         goto corrupt;
1426                 max_byte_length = (llen - 2) / 5 * 4;
1427                 byte_length = *buffer;
1428                 if ('A' <= byte_length && byte_length <= 'Z')
1429                         byte_length = byte_length - 'A' + 1;
1430                 else if ('a' <= byte_length && byte_length <= 'z')
1431                         byte_length = byte_length - 'a' + 27;
1432                 else
1433                         goto corrupt;
1434                 /* if the input length was not multiple of 4, we would
1435                  * have filler at the end but the filler should never
1436                  * exceed 3 bytes
1437                  */
1438                 if (max_byte_length < byte_length ||
1439                     byte_length <= max_byte_length - 4)
1440                         goto corrupt;
1441                 newsize = hunk_size + byte_length;
1442                 data = xrealloc(data, newsize);
1443                 if (decode_85(data + hunk_size, buffer + 1, byte_length))
1444                         goto corrupt;
1445                 hunk_size = newsize;
1446                 buffer += llen;
1447                 size -= llen;
1448         }
1449
1450         frag = xcalloc(1, sizeof(*frag));
1451         frag->patch = inflate_it(data, hunk_size, origlen);
1452         if (!frag->patch)
1453                 goto corrupt;
1454         free(data);
1455         frag->size = origlen;
1456         *buf_p = buffer;
1457         *sz_p = size;
1458         *used_p = used;
1459         frag->binary_patch_method = patch_method;
1460         return frag;
1461
1462  corrupt:
1463         free(data);
1464         *status_p = -1;
1465         error("corrupt binary patch at line %d: %.*s",
1466               linenr-1, llen-1, buffer);
1467         return NULL;
1468 }
1469
1470 static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
1471 {
1472         /*
1473          * We have read "GIT binary patch\n"; what follows is a line
1474          * that says the patch method (currently, either "literal" or
1475          * "delta") and the length of data before deflating; a
1476          * sequence of 'length-byte' followed by base-85 encoded data
1477          * follows.
1478          *
1479          * When a binary patch is reversible, there is another binary
1480          * hunk in the same format, starting with patch method (either
1481          * "literal" or "delta") with the length of data, and a sequence
1482          * of length-byte + base-85 encoded data, terminated with another
1483          * empty line.  This data, when applied to the postimage, produces
1484          * the preimage.
1485          */
1486         struct fragment *forward;
1487         struct fragment *reverse;
1488         int status;
1489         int used, used_1;
1490
1491         forward = parse_binary_hunk(&buffer, &size, &status, &used);
1492         if (!forward && !status)
1493                 /* there has to be one hunk (forward hunk) */
1494                 return error("unrecognized binary patch at line %d", linenr-1);
1495         if (status)
1496                 /* otherwise we already gave an error message */
1497                 return status;
1498
1499         reverse = parse_binary_hunk(&buffer, &size, &status, &used_1);
1500         if (reverse)
1501                 used += used_1;
1502         else if (status) {
1503                 /*
1504                  * Not having reverse hunk is not an error, but having
1505                  * a corrupt reverse hunk is.
1506                  */
1507                 free((void*) forward->patch);
1508                 free(forward);
1509                 return status;
1510         }
1511         forward->next = reverse;
1512         patch->fragments = forward;
1513         patch->is_binary = 1;
1514         return used;
1515 }
1516
1517 static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
1518 {
1519         int hdrsize, patchsize;
1520         int offset = find_header(buffer, size, &hdrsize, patch);
1521
1522         if (offset < 0)
1523                 return offset;
1524
1525         patch->ws_rule = whitespace_rule(patch->new_name
1526                                          ? patch->new_name
1527                                          : patch->old_name);
1528
1529         patchsize = parse_single_patch(buffer + offset + hdrsize,
1530                                        size - offset - hdrsize, patch);
1531
1532         if (!patchsize) {
1533                 static const char *binhdr[] = {
1534                         "Binary files ",
1535                         "Files ",
1536                         NULL,
1537                 };
1538                 static const char git_binary[] = "GIT binary patch\n";
1539                 int i;
1540                 int hd = hdrsize + offset;
1541                 unsigned long llen = linelen(buffer + hd, size - hd);
1542
1543                 if (llen == sizeof(git_binary) - 1 &&
1544                     !memcmp(git_binary, buffer + hd, llen)) {
1545                         int used;
1546                         linenr++;
1547                         used = parse_binary(buffer + hd + llen,
1548                                             size - hd - llen, patch);
1549                         if (used)
1550                                 patchsize = used + llen;
1551                         else
1552                                 patchsize = 0;
1553                 }
1554                 else if (!memcmp(" differ\n", buffer + hd + llen - 8, 8)) {
1555                         for (i = 0; binhdr[i]; i++) {
1556                                 int len = strlen(binhdr[i]);
1557                                 if (len < size - hd &&
1558                                     !memcmp(binhdr[i], buffer + hd, len)) {
1559                                         linenr++;
1560                                         patch->is_binary = 1;
1561                                         patchsize = llen;
1562                                         break;
1563                                 }
1564                         }
1565                 }
1566
1567                 /* Empty patch cannot be applied if it is a text patch
1568                  * without metadata change.  A binary patch appears
1569                  * empty to us here.
1570                  */
1571                 if ((apply || check) &&
1572                     (!patch->is_binary && !metadata_changes(patch)))
1573                         die("patch with only garbage at line %d", linenr);
1574         }
1575
1576         return offset + hdrsize + patchsize;
1577 }
1578
1579 #define swap(a,b) myswap((a),(b),sizeof(a))
1580
1581 #define myswap(a, b, size) do {         \
1582         unsigned char mytmp[size];      \
1583         memcpy(mytmp, &a, size);                \
1584         memcpy(&a, &b, size);           \
1585         memcpy(&b, mytmp, size);                \
1586 } while (0)
1587
1588 static void reverse_patches(struct patch *p)
1589 {
1590         for (; p; p = p->next) {
1591                 struct fragment *frag = p->fragments;
1592
1593                 swap(p->new_name, p->old_name);
1594                 swap(p->new_mode, p->old_mode);
1595                 swap(p->is_new, p->is_delete);
1596                 swap(p->lines_added, p->lines_deleted);
1597                 swap(p->old_sha1_prefix, p->new_sha1_prefix);
1598
1599                 for (; frag; frag = frag->next) {
1600                         swap(frag->newpos, frag->oldpos);
1601                         swap(frag->newlines, frag->oldlines);
1602                 }
1603         }
1604 }
1605
1606 static const char pluses[] =
1607 "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
1608 static const char minuses[]=
1609 "----------------------------------------------------------------------";
1610
1611 static void show_stats(struct patch *patch)
1612 {
1613         struct strbuf qname = STRBUF_INIT;
1614         char *cp = patch->new_name ? patch->new_name : patch->old_name;
1615         int max, add, del;
1616
1617         quote_c_style(cp, &qname, NULL, 0);
1618
1619         /*
1620          * "scale" the filename
1621          */
1622         max = max_len;
1623         if (max > 50)
1624                 max = 50;
1625
1626         if (qname.len > max) {
1627                 cp = strchr(qname.buf + qname.len + 3 - max, '/');
1628                 if (!cp)
1629                         cp = qname.buf + qname.len + 3 - max;
1630                 strbuf_splice(&qname, 0, cp - qname.buf, "...", 3);
1631         }
1632
1633         if (patch->is_binary) {
1634                 printf(" %-*s |  Bin\n", max, qname.buf);
1635                 strbuf_release(&qname);
1636                 return;
1637         }
1638
1639         printf(" %-*s |", max, qname.buf);
1640         strbuf_release(&qname);
1641
1642         /*
1643          * scale the add/delete
1644          */
1645         max = max + max_change > 70 ? 70 - max : max_change;
1646         add = patch->lines_added;
1647         del = patch->lines_deleted;
1648
1649         if (max_change > 0) {
1650                 int total = ((add + del) * max + max_change / 2) / max_change;
1651                 add = (add * max + max_change / 2) / max_change;
1652                 del = total - add;
1653         }
1654         printf("%5d %.*s%.*s\n", patch->lines_added + patch->lines_deleted,
1655                 add, pluses, del, minuses);
1656 }
1657
1658 static int read_old_data(struct stat *st, const char *path, struct strbuf *buf)
1659 {
1660         switch (st->st_mode & S_IFMT) {
1661         case S_IFLNK:
1662                 if (strbuf_readlink(buf, path, st->st_size) < 0)
1663                         return error("unable to read symlink %s", path);
1664                 return 0;
1665         case S_IFREG:
1666                 if (strbuf_read_file(buf, path, st->st_size) != st->st_size)
1667                         return error("unable to open or read %s", path);
1668                 convert_to_git(path, buf->buf, buf->len, buf, 0);
1669                 return 0;
1670         default:
1671                 return -1;
1672         }
1673 }
1674
1675 static void update_pre_post_images(struct image *preimage,
1676                                    struct image *postimage,
1677                                    char *buf,
1678                                    size_t len)
1679 {
1680         int i, ctx;
1681         char *new, *old, *fixed;
1682         struct image fixed_preimage;
1683
1684         /*
1685          * Update the preimage with whitespace fixes.  Note that we
1686          * are not losing preimage->buf -- apply_one_fragment() will
1687          * free "oldlines".
1688          */
1689         prepare_image(&fixed_preimage, buf, len, 1);
1690         assert(fixed_preimage.nr == preimage->nr);
1691         for (i = 0; i < preimage->nr; i++)
1692                 fixed_preimage.line[i].flag = preimage->line[i].flag;
1693         free(preimage->line_allocated);
1694         *preimage = fixed_preimage;
1695
1696         /*
1697          * Adjust the common context lines in postimage, in place.
1698          * This is possible because whitespace fixing does not make
1699          * the string grow.
1700          */
1701         new = old = postimage->buf;
1702         fixed = preimage->buf;
1703         for (i = ctx = 0; i < postimage->nr; i++) {
1704                 size_t len = postimage->line[i].len;
1705                 if (!(postimage->line[i].flag & LINE_COMMON)) {
1706                         /* an added line -- no counterparts in preimage */
1707                         memmove(new, old, len);
1708                         old += len;
1709                         new += len;
1710                         continue;
1711                 }
1712
1713                 /* a common context -- skip it in the original postimage */
1714                 old += len;
1715
1716                 /* and find the corresponding one in the fixed preimage */
1717                 while (ctx < preimage->nr &&
1718                        !(preimage->line[ctx].flag & LINE_COMMON)) {
1719                         fixed += preimage->line[ctx].len;
1720                         ctx++;
1721                 }
1722                 if (preimage->nr <= ctx)
1723                         die("oops");
1724
1725                 /* and copy it in, while fixing the line length */
1726                 len = preimage->line[ctx].len;
1727                 memcpy(new, fixed, len);
1728                 new += len;
1729                 fixed += len;
1730                 postimage->line[i].len = len;
1731                 ctx++;
1732         }
1733
1734         /* Fix the length of the whole thing */
1735         postimage->len = new - postimage->buf;
1736 }
1737
1738 static int match_fragment(struct image *img,
1739                           struct image *preimage,
1740                           struct image *postimage,
1741                           unsigned long try,
1742                           int try_lno,
1743                           unsigned ws_rule,
1744                           int match_beginning, int match_end)
1745 {
1746         int i;
1747         char *fixed_buf, *buf, *orig, *target;
1748
1749         if (preimage->nr + try_lno > img->nr)
1750                 return 0;
1751
1752         if (match_beginning && try_lno)
1753                 return 0;
1754
1755         if (match_end && preimage->nr + try_lno != img->nr)
1756                 return 0;
1757
1758         /* Quick hash check */
1759         for (i = 0; i < preimage->nr; i++)
1760                 if (preimage->line[i].hash != img->line[try_lno + i].hash)
1761                         return 0;
1762
1763         /*
1764          * Do we have an exact match?  If we were told to match
1765          * at the end, size must be exactly at try+fragsize,
1766          * otherwise try+fragsize must be still within the preimage,
1767          * and either case, the old piece should match the preimage
1768          * exactly.
1769          */
1770         if ((match_end
1771              ? (try + preimage->len == img->len)
1772              : (try + preimage->len <= img->len)) &&
1773             !memcmp(img->buf + try, preimage->buf, preimage->len))
1774                 return 1;
1775
1776         if (ws_error_action != correct_ws_error)
1777                 return 0;
1778
1779         /*
1780          * The hunk does not apply byte-by-byte, but the hash says
1781          * it might with whitespace fuzz.
1782          */
1783         fixed_buf = xmalloc(preimage->len + 1);
1784         buf = fixed_buf;
1785         orig = preimage->buf;
1786         target = img->buf + try;
1787         for (i = 0; i < preimage->nr; i++) {
1788                 size_t fixlen; /* length after fixing the preimage */
1789                 size_t oldlen = preimage->line[i].len;
1790                 size_t tgtlen = img->line[try_lno + i].len;
1791                 size_t tgtfixlen; /* length after fixing the target line */
1792                 char tgtfixbuf[1024], *tgtfix;
1793                 int match;
1794
1795                 /* Try fixing the line in the preimage */
1796                 fixlen = ws_fix_copy(buf, orig, oldlen, ws_rule, NULL);
1797
1798                 /* Try fixing the line in the target */
1799                 if (sizeof(tgtfixbuf) > tgtlen)
1800                         tgtfix = tgtfixbuf;
1801                 else
1802                         tgtfix = xmalloc(tgtlen);
1803                 tgtfixlen = ws_fix_copy(tgtfix, target, tgtlen, ws_rule, NULL);
1804
1805                 /*
1806                  * If they match, either the preimage was based on
1807                  * a version before our tree fixed whitespace breakage,
1808                  * or we are lacking a whitespace-fix patch the tree
1809                  * the preimage was based on already had (i.e. target
1810                  * has whitespace breakage, the preimage doesn't).
1811                  * In either case, we are fixing the whitespace breakages
1812                  * so we might as well take the fix together with their
1813                  * real change.
1814                  */
1815                 match = (tgtfixlen == fixlen && !memcmp(tgtfix, buf, fixlen));
1816
1817                 if (tgtfix != tgtfixbuf)
1818                         free(tgtfix);
1819                 if (!match)
1820                         goto unmatch_exit;
1821
1822                 orig += oldlen;
1823                 buf += fixlen;
1824                 target += tgtlen;
1825         }
1826
1827         /*
1828          * Yes, the preimage is based on an older version that still
1829          * has whitespace breakages unfixed, and fixing them makes the
1830          * hunk match.  Update the context lines in the postimage.
1831          */
1832         update_pre_post_images(preimage, postimage,
1833                                fixed_buf, buf - fixed_buf);
1834         return 1;
1835
1836  unmatch_exit:
1837         free(fixed_buf);
1838         return 0;
1839 }
1840
1841 static int find_pos(struct image *img,
1842                     struct image *preimage,
1843                     struct image *postimage,
1844                     int line,
1845                     unsigned ws_rule,
1846                     int match_beginning, int match_end)
1847 {
1848         int i;
1849         unsigned long backwards, forwards, try;
1850         int backwards_lno, forwards_lno, try_lno;
1851
1852         if (preimage->nr > img->nr)
1853                 return -1;
1854
1855         /*
1856          * If match_begining or match_end is specified, there is no
1857          * point starting from a wrong line that will never match and
1858          * wander around and wait for a match at the specified end.
1859          */
1860         if (match_beginning)
1861                 line = 0;
1862         else if (match_end)
1863                 line = img->nr - preimage->nr;
1864
1865         if (line > img->nr)
1866                 line = img->nr;
1867
1868         try = 0;
1869         for (i = 0; i < line; i++)
1870                 try += img->line[i].len;
1871
1872         /*
1873          * There's probably some smart way to do this, but I'll leave
1874          * that to the smart and beautiful people. I'm simple and stupid.
1875          */
1876         backwards = try;
1877         backwards_lno = line;
1878         forwards = try;
1879         forwards_lno = line;
1880         try_lno = line;
1881
1882         for (i = 0; ; i++) {
1883                 if (match_fragment(img, preimage, postimage,
1884                                    try, try_lno, ws_rule,
1885                                    match_beginning, match_end))
1886                         return try_lno;
1887
1888         again:
1889                 if (backwards_lno == 0 && forwards_lno == img->nr)
1890                         break;
1891
1892                 if (i & 1) {
1893                         if (backwards_lno == 0) {
1894                                 i++;
1895                                 goto again;
1896                         }
1897                         backwards_lno--;
1898                         backwards -= img->line[backwards_lno].len;
1899                         try = backwards;
1900                         try_lno = backwards_lno;
1901                 } else {
1902                         if (forwards_lno == img->nr) {
1903                                 i++;
1904                                 goto again;
1905                         }
1906                         forwards += img->line[forwards_lno].len;
1907                         forwards_lno++;
1908                         try = forwards;
1909                         try_lno = forwards_lno;
1910                 }
1911
1912         }
1913         return -1;
1914 }
1915
1916 static void remove_first_line(struct image *img)
1917 {
1918         img->buf += img->line[0].len;
1919         img->len -= img->line[0].len;
1920         img->line++;
1921         img->nr--;
1922 }
1923
1924 static void remove_last_line(struct image *img)
1925 {
1926         img->len -= img->line[--img->nr].len;
1927 }
1928
1929 static void update_image(struct image *img,
1930                          int applied_pos,
1931                          struct image *preimage,
1932                          struct image *postimage)
1933 {
1934         /*
1935          * remove the copy of preimage at offset in img
1936          * and replace it with postimage
1937          */
1938         int i, nr;
1939         size_t remove_count, insert_count, applied_at = 0;
1940         char *result;
1941
1942         for (i = 0; i < applied_pos; i++)
1943                 applied_at += img->line[i].len;
1944
1945         remove_count = 0;
1946         for (i = 0; i < preimage->nr; i++)
1947                 remove_count += img->line[applied_pos + i].len;
1948         insert_count = postimage->len;
1949
1950         /* Adjust the contents */
1951         result = xmalloc(img->len + insert_count - remove_count + 1);
1952         memcpy(result, img->buf, applied_at);
1953         memcpy(result + applied_at, postimage->buf, postimage->len);
1954         memcpy(result + applied_at + postimage->len,
1955                img->buf + (applied_at + remove_count),
1956                img->len - (applied_at + remove_count));
1957         free(img->buf);
1958         img->buf = result;
1959         img->len += insert_count - remove_count;
1960         result[img->len] = '\0';
1961
1962         /* Adjust the line table */
1963         nr = img->nr + postimage->nr - preimage->nr;
1964         if (preimage->nr < postimage->nr) {
1965                 /*
1966                  * NOTE: this knows that we never call remove_first_line()
1967                  * on anything other than pre/post image.
1968                  */
1969                 img->line = xrealloc(img->line, nr * sizeof(*img->line));
1970                 img->line_allocated = img->line;
1971         }
1972         if (preimage->nr != postimage->nr)
1973                 memmove(img->line + applied_pos + postimage->nr,
1974                         img->line + applied_pos + preimage->nr,
1975                         (img->nr - (applied_pos + preimage->nr)) *
1976                         sizeof(*img->line));
1977         memcpy(img->line + applied_pos,
1978                postimage->line,
1979                postimage->nr * sizeof(*img->line));
1980         img->nr = nr;
1981 }
1982
1983 static int apply_one_fragment(struct image *img, struct fragment *frag,
1984                               int inaccurate_eof, unsigned ws_rule)
1985 {
1986         int match_beginning, match_end;
1987         const char *patch = frag->patch;
1988         int size = frag->size;
1989         char *old, *new, *oldlines, *newlines;
1990         int new_blank_lines_at_end = 0;
1991         unsigned long leading, trailing;
1992         int pos, applied_pos;
1993         struct image preimage;
1994         struct image postimage;
1995
1996         memset(&preimage, 0, sizeof(preimage));
1997         memset(&postimage, 0, sizeof(postimage));
1998         oldlines = xmalloc(size);
1999         newlines = xmalloc(size);
2000
2001         old = oldlines;
2002         new = newlines;
2003         while (size > 0) {
2004                 char first;
2005                 int len = linelen(patch, size);
2006                 int plen, added;
2007                 int added_blank_line = 0;
2008
2009                 if (!len)
2010                         break;
2011
2012                 /*
2013                  * "plen" is how much of the line we should use for
2014                  * the actual patch data. Normally we just remove the
2015                  * first character on the line, but if the line is
2016                  * followed by "\ No newline", then we also remove the
2017                  * last one (which is the newline, of course).
2018                  */
2019                 plen = len - 1;
2020                 if (len < size && patch[len] == '\\')
2021                         plen--;
2022                 first = *patch;
2023                 if (apply_in_reverse) {
2024                         if (first == '-')
2025                                 first = '+';
2026                         else if (first == '+')
2027                                 first = '-';
2028                 }
2029
2030                 switch (first) {
2031                 case '\n':
2032                         /* Newer GNU diff, empty context line */
2033                         if (plen < 0)
2034                                 /* ... followed by '\No newline'; nothing */
2035                                 break;
2036                         *old++ = '\n';
2037                         *new++ = '\n';
2038                         add_line_info(&preimage, "\n", 1, LINE_COMMON);
2039                         add_line_info(&postimage, "\n", 1, LINE_COMMON);
2040                         break;
2041                 case ' ':
2042                 case '-':
2043                         memcpy(old, patch + 1, plen);
2044                         add_line_info(&preimage, old, plen,
2045                                       (first == ' ' ? LINE_COMMON : 0));
2046                         old += plen;
2047                         if (first == '-')
2048                                 break;
2049                 /* Fall-through for ' ' */
2050                 case '+':
2051                         /* --no-add does not add new lines */
2052                         if (first == '+' && no_add)
2053                                 break;
2054
2055                         if (first != '+' ||
2056                             !whitespace_error ||
2057                             ws_error_action != correct_ws_error) {
2058                                 memcpy(new, patch + 1, plen);
2059                                 added = plen;
2060                         }
2061                         else {
2062                                 added = ws_fix_copy(new, patch + 1, plen, ws_rule, &applied_after_fixing_ws);
2063                         }
2064                         add_line_info(&postimage, new, added,
2065                                       (first == '+' ? 0 : LINE_COMMON));
2066                         new += added;
2067                         if (first == '+' &&
2068                             added == 1 && new[-1] == '\n')
2069                                 added_blank_line = 1;
2070                         break;
2071                 case '@': case '\\':
2072                         /* Ignore it, we already handled it */
2073                         break;
2074                 default:
2075                         if (apply_verbosely)
2076                                 error("invalid start of line: '%c'", first);
2077                         return -1;
2078                 }
2079                 if (added_blank_line)
2080                         new_blank_lines_at_end++;
2081                 else
2082                         new_blank_lines_at_end = 0;
2083                 patch += len;
2084                 size -= len;
2085         }
2086         if (inaccurate_eof &&
2087             old > oldlines && old[-1] == '\n' &&
2088             new > newlines && new[-1] == '\n') {
2089                 old--;
2090                 new--;
2091         }
2092
2093         leading = frag->leading;
2094         trailing = frag->trailing;
2095
2096         /*
2097          * A hunk to change lines at the beginning would begin with
2098          * @@ -1,L +N,M @@
2099          * but we need to be careful.  -U0 that inserts before the second
2100          * line also has this pattern.
2101          *
2102          * And a hunk to add to an empty file would begin with
2103          * @@ -0,0 +N,M @@
2104          *
2105          * In other words, a hunk that is (frag->oldpos <= 1) with or
2106          * without leading context must match at the beginning.
2107          */
2108         match_beginning = (!frag->oldpos ||
2109                            (frag->oldpos == 1 && !unidiff_zero));
2110
2111         /*
2112          * A hunk without trailing lines must match at the end.
2113          * However, we simply cannot tell if a hunk must match end
2114          * from the lack of trailing lines if the patch was generated
2115          * with unidiff without any context.
2116          */
2117         match_end = !unidiff_zero && !trailing;
2118
2119         pos = frag->newpos ? (frag->newpos - 1) : 0;
2120         preimage.buf = oldlines;
2121         preimage.len = old - oldlines;
2122         postimage.buf = newlines;
2123         postimage.len = new - newlines;
2124         preimage.line = preimage.line_allocated;
2125         postimage.line = postimage.line_allocated;
2126
2127         for (;;) {
2128
2129                 applied_pos = find_pos(img, &preimage, &postimage, pos,
2130                                        ws_rule, match_beginning, match_end);
2131
2132                 if (applied_pos >= 0)
2133                         break;
2134
2135                 /* Am I at my context limits? */
2136                 if ((leading <= p_context) && (trailing <= p_context))
2137                         break;
2138                 if (match_beginning || match_end) {
2139                         match_beginning = match_end = 0;
2140                         continue;
2141                 }
2142
2143                 /*
2144                  * Reduce the number of context lines; reduce both
2145                  * leading and trailing if they are equal otherwise
2146                  * just reduce the larger context.
2147                  */
2148                 if (leading >= trailing) {
2149                         remove_first_line(&preimage);
2150                         remove_first_line(&postimage);
2151                         pos--;
2152                         leading--;
2153                 }
2154                 if (trailing > leading) {
2155                         remove_last_line(&preimage);
2156                         remove_last_line(&postimage);
2157                         trailing--;
2158                 }
2159         }
2160
2161         if (applied_pos >= 0) {
2162                 if (ws_error_action == correct_ws_error &&
2163                     new_blank_lines_at_end &&
2164                     postimage.nr + applied_pos == img->nr) {
2165                         /*
2166                          * If the patch application adds blank lines
2167                          * at the end, and if the patch applies at the
2168                          * end of the image, remove those added blank
2169                          * lines.
2170                          */
2171                         while (new_blank_lines_at_end--)
2172                                 remove_last_line(&postimage);
2173                 }
2174
2175                 /*
2176                  * Warn if it was necessary to reduce the number
2177                  * of context lines.
2178                  */
2179                 if ((leading != frag->leading) ||
2180                     (trailing != frag->trailing))
2181                         fprintf(stderr, "Context reduced to (%ld/%ld)"
2182                                 " to apply fragment at %d\n",
2183                                 leading, trailing, applied_pos+1);
2184                 update_image(img, applied_pos, &preimage, &postimage);
2185         } else {
2186                 if (apply_verbosely)
2187                         error("while searching for:\n%.*s",
2188                               (int)(old - oldlines), oldlines);
2189         }
2190
2191         free(oldlines);
2192         free(newlines);
2193         free(preimage.line_allocated);
2194         free(postimage.line_allocated);
2195
2196         return (applied_pos < 0);
2197 }
2198
2199 static int apply_binary_fragment(struct image *img, struct patch *patch)
2200 {
2201         struct fragment *fragment = patch->fragments;
2202         unsigned long len;
2203         void *dst;
2204
2205         /* Binary patch is irreversible without the optional second hunk */
2206         if (apply_in_reverse) {
2207                 if (!fragment->next)
2208                         return error("cannot reverse-apply a binary patch "
2209                                      "without the reverse hunk to '%s'",
2210                                      patch->new_name
2211                                      ? patch->new_name : patch->old_name);
2212                 fragment = fragment->next;
2213         }
2214         switch (fragment->binary_patch_method) {
2215         case BINARY_DELTA_DEFLATED:
2216                 dst = patch_delta(img->buf, img->len, fragment->patch,
2217                                   fragment->size, &len);
2218                 if (!dst)
2219                         return -1;
2220                 clear_image(img);
2221                 img->buf = dst;
2222                 img->len = len;
2223                 return 0;
2224         case BINARY_LITERAL_DEFLATED:
2225                 clear_image(img);
2226                 img->len = fragment->size;
2227                 img->buf = xmalloc(img->len+1);
2228                 memcpy(img->buf, fragment->patch, img->len);
2229                 img->buf[img->len] = '\0';
2230                 return 0;
2231         }
2232         return -1;
2233 }
2234
2235 static int apply_binary(struct image *img, struct patch *patch)
2236 {
2237         const char *name = patch->old_name ? patch->old_name : patch->new_name;
2238         unsigned char sha1[20];
2239
2240         /*
2241          * For safety, we require patch index line to contain
2242          * full 40-byte textual SHA1 for old and new, at least for now.
2243          */
2244         if (strlen(patch->old_sha1_prefix) != 40 ||
2245             strlen(patch->new_sha1_prefix) != 40 ||
2246             get_sha1_hex(patch->old_sha1_prefix, sha1) ||
2247             get_sha1_hex(patch->new_sha1_prefix, sha1))
2248                 return error("cannot apply binary patch to '%s' "
2249                              "without full index line", name);
2250
2251         if (patch->old_name) {
2252                 /*
2253                  * See if the old one matches what the patch
2254                  * applies to.
2255                  */
2256                 hash_sha1_file(img->buf, img->len, blob_type, sha1);
2257                 if (strcmp(sha1_to_hex(sha1), patch->old_sha1_prefix))
2258                         return error("the patch applies to '%s' (%s), "
2259                                      "which does not match the "
2260                                      "current contents.",
2261                                      name, sha1_to_hex(sha1));
2262         }
2263         else {
2264                 /* Otherwise, the old one must be empty. */
2265                 if (img->len)
2266                         return error("the patch applies to an empty "
2267                                      "'%s' but it is not empty", name);
2268         }
2269
2270         get_sha1_hex(patch->new_sha1_prefix, sha1);
2271         if (is_null_sha1(sha1)) {
2272                 clear_image(img);
2273                 return 0; /* deletion patch */
2274         }
2275
2276         if (has_sha1_file(sha1)) {
2277                 /* We already have the postimage */
2278                 enum object_type type;
2279                 unsigned long size;
2280                 char *result;
2281
2282                 result = read_sha1_file(sha1, &type, &size);
2283                 if (!result)
2284                         return error("the necessary postimage %s for "
2285                                      "'%s' cannot be read",
2286                                      patch->new_sha1_prefix, name);
2287                 clear_image(img);
2288                 img->buf = result;
2289                 img->len = size;
2290         } else {
2291                 /*
2292                  * We have verified buf matches the preimage;
2293                  * apply the patch data to it, which is stored
2294                  * in the patch->fragments->{patch,size}.
2295                  */
2296                 if (apply_binary_fragment(img, patch))
2297                         return error("binary patch does not apply to '%s'",
2298                                      name);
2299
2300                 /* verify that the result matches */
2301                 hash_sha1_file(img->buf, img->len, blob_type, sha1);
2302                 if (strcmp(sha1_to_hex(sha1), patch->new_sha1_prefix))
2303                         return error("binary patch to '%s' creates incorrect result (expecting %s, got %s)",
2304                                 name, patch->new_sha1_prefix, sha1_to_hex(sha1));
2305         }
2306
2307         return 0;
2308 }
2309
2310 static int apply_fragments(struct image *img, struct patch *patch)
2311 {
2312         struct fragment *frag = patch->fragments;
2313         const char *name = patch->old_name ? patch->old_name : patch->new_name;
2314         unsigned ws_rule = patch->ws_rule;
2315         unsigned inaccurate_eof = patch->inaccurate_eof;
2316
2317         if (patch->is_binary)
2318                 return apply_binary(img, patch);
2319
2320         while (frag) {
2321                 if (apply_one_fragment(img, frag, inaccurate_eof, ws_rule)) {
2322                         error("patch failed: %s:%ld", name, frag->oldpos);
2323                         if (!apply_with_reject)
2324                                 return -1;
2325                         frag->rejected = 1;
2326                 }
2327                 frag = frag->next;
2328         }
2329         return 0;
2330 }
2331
2332 static int read_file_or_gitlink(struct cache_entry *ce, struct strbuf *buf)
2333 {
2334         if (!ce)
2335                 return 0;
2336
2337         if (S_ISGITLINK(ce->ce_mode)) {
2338                 strbuf_grow(buf, 100);
2339                 strbuf_addf(buf, "Subproject commit %s\n", sha1_to_hex(ce->sha1));
2340         } else {
2341                 enum object_type type;
2342                 unsigned long sz;
2343                 char *result;
2344
2345                 result = read_sha1_file(ce->sha1, &type, &sz);
2346                 if (!result)
2347                         return -1;
2348                 /* XXX read_sha1_file NUL-terminates */
2349                 strbuf_attach(buf, result, sz, sz + 1);
2350         }
2351         return 0;
2352 }
2353
2354 static struct patch *in_fn_table(const char *name)
2355 {
2356         struct string_list_item *item;
2357
2358         if (name == NULL)
2359                 return NULL;
2360
2361         item = string_list_lookup(name, &fn_table);
2362         if (item != NULL)
2363                 return (struct patch *)item->util;
2364
2365         return NULL;
2366 }
2367
2368 /*
2369  * item->util in the filename table records the status of the path.
2370  * Usually it points at a patch (whose result records the contents
2371  * of it after applying it), but it could be PATH_WAS_DELETED for a
2372  * path that a previously applied patch has already removed.
2373  */
2374  #define PATH_TO_BE_DELETED ((struct patch *) -2)
2375 #define PATH_WAS_DELETED ((struct patch *) -1)
2376
2377 static int to_be_deleted(struct patch *patch)
2378 {
2379         return patch == PATH_TO_BE_DELETED;
2380 }
2381
2382 static int was_deleted(struct patch *patch)
2383 {
2384         return patch == PATH_WAS_DELETED;
2385 }
2386
2387 static void add_to_fn_table(struct patch *patch)
2388 {
2389         struct string_list_item *item;
2390
2391         /*
2392          * Always add new_name unless patch is a deletion
2393          * This should cover the cases for normal diffs,
2394          * file creations and copies
2395          */
2396         if (patch->new_name != NULL) {
2397                 item = string_list_insert(patch->new_name, &fn_table);
2398                 item->util = patch;
2399         }
2400
2401         /*
2402          * store a failure on rename/deletion cases because
2403          * later chunks shouldn't patch old names
2404          */
2405         if ((patch->new_name == NULL) || (patch->is_rename)) {
2406                 item = string_list_insert(patch->old_name, &fn_table);
2407                 item->util = PATH_WAS_DELETED;
2408         }
2409 }
2410
2411 static void prepare_fn_table(struct patch *patch)
2412 {
2413         /*
2414          * store information about incoming file deletion
2415          */
2416         while (patch) {
2417                 if ((patch->new_name == NULL) || (patch->is_rename)) {
2418                         struct string_list_item *item;
2419                         item = string_list_insert(patch->old_name, &fn_table);
2420                         item->util = PATH_TO_BE_DELETED;
2421                 }
2422                 patch = patch->next;
2423         }
2424 }
2425
2426 static int apply_data(struct patch *patch, struct stat *st, struct cache_entry *ce)
2427 {
2428         struct strbuf buf = STRBUF_INIT;
2429         struct image image;
2430         size_t len;
2431         char *img;
2432         struct patch *tpatch;
2433
2434         if (!(patch->is_copy || patch->is_rename) &&
2435             (tpatch = in_fn_table(patch->old_name)) != NULL && !to_be_deleted(tpatch)) {
2436                 if (was_deleted(tpatch)) {
2437                         return error("patch %s has been renamed/deleted",
2438                                 patch->old_name);
2439                 }
2440                 /* We have a patched copy in memory use that */
2441                 strbuf_add(&buf, tpatch->result, tpatch->resultsize);
2442         } else if (cached) {
2443                 if (read_file_or_gitlink(ce, &buf))
2444                         return error("read of %s failed", patch->old_name);
2445         } else if (patch->old_name) {
2446                 if (S_ISGITLINK(patch->old_mode)) {
2447                         if (ce) {
2448                                 read_file_or_gitlink(ce, &buf);
2449                         } else {
2450                                 /*
2451                                  * There is no way to apply subproject
2452                                  * patch without looking at the index.
2453                                  */
2454                                 patch->fragments = NULL;
2455                         }
2456                 } else {
2457                         if (read_old_data(st, patch->old_name, &buf))
2458                                 return error("read of %s failed", patch->old_name);
2459                 }
2460         }
2461
2462         img = strbuf_detach(&buf, &len);
2463         prepare_image(&image, img, len, !patch->is_binary);
2464
2465         if (apply_fragments(&image, patch) < 0)
2466                 return -1; /* note with --reject this succeeds. */
2467         patch->result = image.buf;
2468         patch->resultsize = image.len;
2469         add_to_fn_table(patch);
2470         free(image.line_allocated);
2471
2472         if (0 < patch->is_delete && patch->resultsize)
2473                 return error("removal patch leaves file contents");
2474
2475         return 0;
2476 }
2477
2478 static int check_to_create_blob(const char *new_name, int ok_if_exists)
2479 {
2480         struct stat nst;
2481         if (!lstat(new_name, &nst)) {
2482                 if (S_ISDIR(nst.st_mode) || ok_if_exists)
2483                         return 0;
2484                 /*
2485                  * A leading component of new_name might be a symlink
2486                  * that is going to be removed with this patch, but
2487                  * still pointing at somewhere that has the path.
2488                  * In such a case, path "new_name" does not exist as
2489                  * far as git is concerned.
2490                  */
2491                 if (has_symlink_leading_path(new_name, strlen(new_name)))
2492                         return 0;
2493
2494                 return error("%s: already exists in working directory", new_name);
2495         }
2496         else if ((errno != ENOENT) && (errno != ENOTDIR))
2497                 return error("%s: %s", new_name, strerror(errno));
2498         return 0;
2499 }
2500
2501 static int verify_index_match(struct cache_entry *ce, struct stat *st)
2502 {
2503         if (S_ISGITLINK(ce->ce_mode)) {
2504                 if (!S_ISDIR(st->st_mode))
2505                         return -1;
2506                 return 0;
2507         }
2508         return ce_match_stat(ce, st, CE_MATCH_IGNORE_VALID);
2509 }
2510
2511 static int check_preimage(struct patch *patch, struct cache_entry **ce, struct stat *st)
2512 {
2513         const char *old_name = patch->old_name;
2514         struct patch *tpatch = NULL;
2515         int stat_ret = 0;
2516         unsigned st_mode = 0;
2517
2518         /*
2519          * Make sure that we do not have local modifications from the
2520          * index when we are looking at the index.  Also make sure
2521          * we have the preimage file to be patched in the work tree,
2522          * unless --cached, which tells git to apply only in the index.
2523          */
2524         if (!old_name)
2525                 return 0;
2526
2527         assert(patch->is_new <= 0);
2528
2529         if (!(patch->is_copy || patch->is_rename) &&
2530             (tpatch = in_fn_table(old_name)) != NULL && !to_be_deleted(tpatch)) {
2531                 if (was_deleted(tpatch))
2532                         return error("%s: has been deleted/renamed", old_name);
2533                 st_mode = tpatch->new_mode;
2534         } else if (!cached) {
2535                 stat_ret = lstat(old_name, st);
2536                 if (stat_ret && errno != ENOENT)
2537                         return error("%s: %s", old_name, strerror(errno));
2538         }
2539
2540         if (to_be_deleted(tpatch))
2541                 tpatch = NULL;
2542
2543         if (check_index && !tpatch) {
2544                 int pos = cache_name_pos(old_name, strlen(old_name));
2545                 if (pos < 0) {
2546                         if (patch->is_new < 0)
2547                                 goto is_new;
2548                         return error("%s: does not exist in index", old_name);
2549                 }
2550                 *ce = active_cache[pos];
2551                 if (stat_ret < 0) {
2552                         struct checkout costate;
2553                         /* checkout */
2554                         costate.base_dir = "";
2555                         costate.base_dir_len = 0;
2556                         costate.force = 0;
2557                         costate.quiet = 0;
2558                         costate.not_new = 0;
2559                         costate.refresh_cache = 1;
2560                         if (checkout_entry(*ce, &costate, NULL) ||
2561                             lstat(old_name, st))
2562                                 return -1;
2563                 }
2564                 if (!cached && verify_index_match(*ce, st))
2565                         return error("%s: does not match index", old_name);
2566                 if (cached)
2567                         st_mode = (*ce)->ce_mode;
2568         } else if (stat_ret < 0) {
2569                 if (patch->is_new < 0)
2570                         goto is_new;
2571                 return error("%s: %s", old_name, strerror(errno));
2572         }
2573
2574         if (!cached && !tpatch)
2575                 st_mode = ce_mode_from_stat(*ce, st->st_mode);
2576
2577         if (patch->is_new < 0)
2578                 patch->is_new = 0;
2579         if (!patch->old_mode)
2580                 patch->old_mode = st_mode;
2581         if ((st_mode ^ patch->old_mode) & S_IFMT)
2582                 return error("%s: wrong type", old_name);
2583         if (st_mode != patch->old_mode)
2584                 warning("%s has type %o, expected %o",
2585                         old_name, st_mode, patch->old_mode);
2586         if (!patch->new_mode && !patch->is_delete)
2587                 patch->new_mode = st_mode;
2588         return 0;
2589
2590  is_new:
2591         patch->is_new = 1;
2592         patch->is_delete = 0;
2593         patch->old_name = NULL;
2594         return 0;
2595 }
2596
2597 static int check_patch(struct patch *patch)
2598 {
2599         struct stat st;
2600         const char *old_name = patch->old_name;
2601         const char *new_name = patch->new_name;
2602         const char *name = old_name ? old_name : new_name;
2603         struct cache_entry *ce = NULL;
2604         struct patch *tpatch;
2605         int ok_if_exists;
2606         int status;
2607
2608         patch->rejected = 1; /* we will drop this after we succeed */
2609
2610         status = check_preimage(patch, &ce, &st);
2611         if (status)
2612                 return status;
2613         old_name = patch->old_name;
2614
2615         if ((tpatch = in_fn_table(new_name)) &&
2616                         (was_deleted(tpatch) || to_be_deleted(tpatch)))
2617                 /*
2618                  * A type-change diff is always split into a patch to
2619                  * delete old, immediately followed by a patch to
2620                  * create new (see diff.c::run_diff()); in such a case
2621                  * it is Ok that the entry to be deleted by the
2622                  * previous patch is still in the working tree and in
2623                  * the index.
2624                  */
2625                 ok_if_exists = 1;
2626         else
2627                 ok_if_exists = 0;
2628
2629         if (new_name &&
2630             ((0 < patch->is_new) | (0 < patch->is_rename) | patch->is_copy)) {
2631                 if (check_index &&
2632                     cache_name_pos(new_name, strlen(new_name)) >= 0 &&
2633                     !ok_if_exists)
2634                         return error("%s: already exists in index", new_name);
2635                 if (!cached) {
2636                         int err = check_to_create_blob(new_name, ok_if_exists);
2637                         if (err)
2638                                 return err;
2639                 }
2640                 if (!patch->new_mode) {
2641                         if (0 < patch->is_new)
2642                                 patch->new_mode = S_IFREG | 0644;
2643                         else
2644                                 patch->new_mode = patch->old_mode;
2645                 }
2646         }
2647
2648         if (new_name && old_name) {
2649                 int same = !strcmp(old_name, new_name);
2650                 if (!patch->new_mode)
2651                         patch->new_mode = patch->old_mode;
2652                 if ((patch->old_mode ^ patch->new_mode) & S_IFMT)
2653                         return error("new mode (%o) of %s does not match old mode (%o)%s%s",
2654                                 patch->new_mode, new_name, patch->old_mode,
2655                                 same ? "" : " of ", same ? "" : old_name);
2656         }
2657
2658         if (apply_data(patch, &st, ce) < 0)
2659                 return error("%s: patch does not apply", name);
2660         patch->rejected = 0;
2661         return 0;
2662 }
2663
2664 static int check_patch_list(struct patch *patch)
2665 {
2666         int err = 0;
2667
2668         prepare_fn_table(patch);
2669         while (patch) {
2670                 if (apply_verbosely)
2671                         say_patch_name(stderr,
2672                                        "Checking patch ", patch, "...\n");
2673                 err |= check_patch(patch);
2674                 patch = patch->next;
2675         }
2676         return err;
2677 }
2678
2679 /* This function tries to read the sha1 from the current index */
2680 static int get_current_sha1(const char *path, unsigned char *sha1)
2681 {
2682         int pos;
2683
2684         if (read_cache() < 0)
2685                 return -1;
2686         pos = cache_name_pos(path, strlen(path));
2687         if (pos < 0)
2688                 return -1;
2689         hashcpy(sha1, active_cache[pos]->sha1);
2690         return 0;
2691 }
2692
2693 /* Build an index that contains the just the files needed for a 3way merge */
2694 static void build_fake_ancestor(struct patch *list, const char *filename)
2695 {
2696         struct patch *patch;
2697         struct index_state result = { NULL };
2698         int fd;
2699
2700         /* Once we start supporting the reverse patch, it may be
2701          * worth showing the new sha1 prefix, but until then...
2702          */
2703         for (patch = list; patch; patch = patch->next) {
2704                 const unsigned char *sha1_ptr;
2705                 unsigned char sha1[20];
2706                 struct cache_entry *ce;
2707                 const char *name;
2708
2709                 name = patch->old_name ? patch->old_name : patch->new_name;
2710                 if (0 < patch->is_new)
2711                         continue;
2712                 else if (get_sha1(patch->old_sha1_prefix, sha1))
2713                         /* git diff has no index line for mode/type changes */
2714                         if (!patch->lines_added && !patch->lines_deleted) {
2715                                 if (get_current_sha1(patch->new_name, sha1) ||
2716                                     get_current_sha1(patch->old_name, sha1))
2717                                         die("mode change for %s, which is not "
2718                                                 "in current HEAD", name);
2719                                 sha1_ptr = sha1;
2720                         } else
2721                                 die("sha1 information is lacking or useless "
2722                                         "(%s).", name);
2723                 else
2724                         sha1_ptr = sha1;
2725
2726                 ce = make_cache_entry(patch->old_mode, sha1_ptr, name, 0, 0);
2727                 if (!ce)
2728                         die("make_cache_entry failed for path '%s'", name);
2729                 if (add_index_entry(&result, ce, ADD_CACHE_OK_TO_ADD))
2730                         die ("Could not add %s to temporary index", name);
2731         }
2732
2733         fd = open(filename, O_WRONLY | O_CREAT, 0666);
2734         if (fd < 0 || write_index(&result, fd) || close(fd))
2735                 die ("Could not write temporary index to %s", filename);
2736
2737         discard_index(&result);
2738 }
2739
2740 static void stat_patch_list(struct patch *patch)
2741 {
2742         int files, adds, dels;
2743
2744         for (files = adds = dels = 0 ; patch ; patch = patch->next) {
2745                 files++;
2746                 adds += patch->lines_added;
2747                 dels += patch->lines_deleted;
2748                 show_stats(patch);
2749         }
2750
2751         printf(" %d files changed, %d insertions(+), %d deletions(-)\n", files, adds, dels);
2752 }
2753
2754 static void numstat_patch_list(struct patch *patch)
2755 {
2756         for ( ; patch; patch = patch->next) {
2757                 const char *name;
2758                 name = patch->new_name ? patch->new_name : patch->old_name;
2759                 if (patch->is_binary)
2760                         printf("-\t-\t");
2761                 else
2762                         printf("%d\t%d\t", patch->lines_added, patch->lines_deleted);
2763                 write_name_quoted(name, stdout, line_termination);
2764         }
2765 }
2766
2767 static void show_file_mode_name(const char *newdelete, unsigned int mode, const char *name)
2768 {
2769         if (mode)
2770                 printf(" %s mode %06o %s\n", newdelete, mode, name);
2771         else
2772                 printf(" %s %s\n", newdelete, name);
2773 }
2774
2775 static void show_mode_change(struct patch *p, int show_name)
2776 {
2777         if (p->old_mode && p->new_mode && p->old_mode != p->new_mode) {
2778                 if (show_name)
2779                         printf(" mode change %06o => %06o %s\n",
2780                                p->old_mode, p->new_mode, p->new_name);
2781                 else
2782                         printf(" mode change %06o => %06o\n",
2783                                p->old_mode, p->new_mode);
2784         }
2785 }
2786
2787 static void show_rename_copy(struct patch *p)
2788 {
2789         const char *renamecopy = p->is_rename ? "rename" : "copy";
2790         const char *old, *new;
2791
2792         /* Find common prefix */
2793         old = p->old_name;
2794         new = p->new_name;
2795         while (1) {
2796                 const char *slash_old, *slash_new;
2797                 slash_old = strchr(old, '/');
2798                 slash_new = strchr(new, '/');
2799                 if (!slash_old ||
2800                     !slash_new ||
2801                     slash_old - old != slash_new - new ||
2802                     memcmp(old, new, slash_new - new))
2803                         break;
2804                 old = slash_old + 1;
2805                 new = slash_new + 1;
2806         }
2807         /* p->old_name thru old is the common prefix, and old and new
2808          * through the end of names are renames
2809          */
2810         if (old != p->old_name)
2811                 printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
2812                        (int)(old - p->old_name), p->old_name,
2813                        old, new, p->score);
2814         else
2815                 printf(" %s %s => %s (%d%%)\n", renamecopy,
2816                        p->old_name, p->new_name, p->score);
2817         show_mode_change(p, 0);
2818 }
2819
2820 static void summary_patch_list(struct patch *patch)
2821 {
2822         struct patch *p;
2823
2824         for (p = patch; p; p = p->next) {
2825                 if (p->is_new)
2826                         show_file_mode_name("create", p->new_mode, p->new_name);
2827                 else if (p->is_delete)
2828                         show_file_mode_name("delete", p->old_mode, p->old_name);
2829                 else {
2830                         if (p->is_rename || p->is_copy)
2831                                 show_rename_copy(p);
2832                         else {
2833                                 if (p->score) {
2834                                         printf(" rewrite %s (%d%%)\n",
2835                                                p->new_name, p->score);
2836                                         show_mode_change(p, 0);
2837                                 }
2838                                 else
2839                                         show_mode_change(p, 1);
2840                         }
2841                 }
2842         }
2843 }
2844
2845 static void patch_stats(struct patch *patch)
2846 {
2847         int lines = patch->lines_added + patch->lines_deleted;
2848
2849         if (lines > max_change)
2850                 max_change = lines;
2851         if (patch->old_name) {
2852                 int len = quote_c_style(patch->old_name, NULL, NULL, 0);
2853                 if (!len)
2854                         len = strlen(patch->old_name);
2855                 if (len > max_len)
2856                         max_len = len;
2857         }
2858         if (patch->new_name) {
2859                 int len = quote_c_style(patch->new_name, NULL, NULL, 0);
2860                 if (!len)
2861                         len = strlen(patch->new_name);
2862                 if (len > max_len)
2863                         max_len = len;
2864         }
2865 }
2866
2867 static void remove_file(struct patch *patch, int rmdir_empty)
2868 {
2869         if (update_index) {
2870                 if (remove_file_from_cache(patch->old_name) < 0)
2871                         die("unable to remove %s from index", patch->old_name);
2872         }
2873         if (!cached) {
2874                 if (S_ISGITLINK(patch->old_mode)) {
2875                         if (rmdir(patch->old_name))
2876                                 warning("unable to remove submodule %s",
2877                                         patch->old_name);
2878                 } else if (!unlink_or_warn(patch->old_name) && rmdir_empty) {
2879                         remove_path(patch->old_name);
2880                 }
2881         }
2882 }
2883
2884 static void add_index_file(const char *path, unsigned mode, void *buf, unsigned long size)
2885 {
2886         struct stat st;
2887         struct cache_entry *ce;
2888         int namelen = strlen(path);
2889         unsigned ce_size = cache_entry_size(namelen);
2890
2891         if (!update_index)
2892                 return;
2893
2894         ce = xcalloc(1, ce_size);
2895         memcpy(ce->name, path, namelen);
2896         ce->ce_mode = create_ce_mode(mode);
2897         ce->ce_flags = namelen;
2898         if (S_ISGITLINK(mode)) {
2899                 const char *s = buf;
2900
2901                 if (get_sha1_hex(s + strlen("Subproject commit "), ce->sha1))
2902                         die("corrupt patch for subproject %s", path);
2903         } else {
2904                 if (!cached) {
2905                         if (lstat(path, &st) < 0)
2906                                 die_errno("unable to stat newly created file '%s'",
2907                                           path);
2908                         fill_stat_cache_info(ce, &st);
2909                 }
2910                 if (write_sha1_file(buf, size, blob_type, ce->sha1) < 0)
2911                         die("unable to create backing store for newly created file %s", path);
2912         }
2913         if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0)
2914                 die("unable to add cache entry for %s", path);
2915 }
2916
2917 static int try_create_file(const char *path, unsigned int mode, const char *buf, unsigned long size)
2918 {
2919         int fd;
2920         struct strbuf nbuf = STRBUF_INIT;
2921
2922         if (S_ISGITLINK(mode)) {
2923                 struct stat st;
2924                 if (!lstat(path, &st) && S_ISDIR(st.st_mode))
2925                         return 0;
2926                 return mkdir(path, 0777);
2927         }
2928
2929         if (has_symlinks && S_ISLNK(mode))
2930                 /* Although buf:size is counted string, it also is NUL
2931                  * terminated.
2932                  */
2933                 return symlink(buf, path);
2934
2935         fd = open(path, O_CREAT | O_EXCL | O_WRONLY, (mode & 0100) ? 0777 : 0666);
2936         if (fd < 0)
2937                 return -1;
2938
2939         if (convert_to_working_tree(path, buf, size, &nbuf)) {
2940                 size = nbuf.len;
2941                 buf  = nbuf.buf;
2942         }
2943         write_or_die(fd, buf, size);
2944         strbuf_release(&nbuf);
2945
2946         if (close(fd) < 0)
2947                 die_errno("closing file '%s'", path);
2948         return 0;
2949 }
2950
2951 /*
2952  * We optimistically assume that the directories exist,
2953  * which is true 99% of the time anyway. If they don't,
2954  * we create them and try again.
2955  */
2956 static void create_one_file(char *path, unsigned mode, const char *buf, unsigned long size)
2957 {
2958         if (cached)
2959                 return;
2960         if (!try_create_file(path, mode, buf, size))
2961                 return;
2962
2963         if (errno == ENOENT) {
2964                 if (safe_create_leading_directories(path))
2965                         return;
2966                 if (!try_create_file(path, mode, buf, size))
2967                         return;
2968         }
2969
2970         if (errno == EEXIST || errno == EACCES) {
2971                 /* We may be trying to create a file where a directory
2972                  * used to be.
2973                  */
2974                 struct stat st;
2975                 if (!lstat(path, &st) && (!S_ISDIR(st.st_mode) || !rmdir(path)))
2976                         errno = EEXIST;
2977         }
2978
2979         if (errno == EEXIST) {
2980                 unsigned int nr = getpid();
2981
2982                 for (;;) {
2983                         char newpath[PATH_MAX];
2984                         mksnpath(newpath, sizeof(newpath), "%s~%u", path, nr);
2985                         if (!try_create_file(newpath, mode, buf, size)) {
2986                                 if (!rename(newpath, path))
2987                                         return;
2988                                 unlink_or_warn(newpath);
2989                                 break;
2990                         }
2991                         if (errno != EEXIST)
2992                                 break;
2993                         ++nr;
2994                 }
2995         }
2996         die_errno("unable to write file '%s' mode %o", path, mode);
2997 }
2998
2999 static void create_file(struct patch *patch)
3000 {
3001         char *path = patch->new_name;
3002         unsigned mode = patch->new_mode;
3003         unsigned long size = patch->resultsize;
3004         char *buf = patch->result;
3005
3006         if (!mode)
3007                 mode = S_IFREG | 0644;
3008         create_one_file(path, mode, buf, size);
3009         add_index_file(path, mode, buf, size);
3010 }
3011
3012 /* phase zero is to remove, phase one is to create */
3013 static void write_out_one_result(struct patch *patch, int phase)
3014 {
3015         if (patch->is_delete > 0) {
3016                 if (phase == 0)
3017                         remove_file(patch, 1);
3018                 return;
3019         }
3020         if (patch->is_new > 0 || patch->is_copy) {
3021                 if (phase == 1)
3022                         create_file(patch);
3023                 return;
3024         }
3025         /*
3026          * Rename or modification boils down to the same
3027          * thing: remove the old, write the new
3028          */
3029         if (phase == 0)
3030                 remove_file(patch, patch->is_rename);
3031         if (phase == 1)
3032                 create_file(patch);
3033 }
3034
3035 static int write_out_one_reject(struct patch *patch)
3036 {
3037         FILE *rej;
3038         char namebuf[PATH_MAX];
3039         struct fragment *frag;
3040         int cnt = 0;
3041
3042         for (cnt = 0, frag = patch->fragments; frag; frag = frag->next) {
3043                 if (!frag->rejected)
3044                         continue;
3045                 cnt++;
3046         }
3047
3048         if (!cnt) {
3049                 if (apply_verbosely)
3050                         say_patch_name(stderr,
3051                                        "Applied patch ", patch, " cleanly.\n");
3052                 return 0;
3053         }
3054
3055         /* This should not happen, because a removal patch that leaves
3056          * contents are marked "rejected" at the patch level.
3057          */
3058         if (!patch->new_name)
3059                 die("internal error");
3060
3061         /* Say this even without --verbose */
3062         say_patch_name(stderr, "Applying patch ", patch, " with");
3063         fprintf(stderr, " %d rejects...\n", cnt);
3064
3065         cnt = strlen(patch->new_name);
3066         if (ARRAY_SIZE(namebuf) <= cnt + 5) {
3067                 cnt = ARRAY_SIZE(namebuf) - 5;
3068                 warning("truncating .rej filename to %.*s.rej",
3069                         cnt - 1, patch->new_name);
3070         }
3071         memcpy(namebuf, patch->new_name, cnt);
3072         memcpy(namebuf + cnt, ".rej", 5);
3073
3074         rej = fopen(namebuf, "w");
3075         if (!rej)
3076                 return error("cannot open %s: %s", namebuf, strerror(errno));
3077
3078         /* Normal git tools never deal with .rej, so do not pretend
3079          * this is a git patch by saying --git nor give extended
3080          * headers.  While at it, maybe please "kompare" that wants
3081          * the trailing TAB and some garbage at the end of line ;-).
3082          */
3083         fprintf(rej, "diff a/%s b/%s\t(rejected hunks)\n",
3084                 patch->new_name, patch->new_name);
3085         for (cnt = 1, frag = patch->fragments;
3086              frag;
3087              cnt++, frag = frag->next) {
3088                 if (!frag->rejected) {
3089                         fprintf(stderr, "Hunk #%d applied cleanly.\n", cnt);
3090                         continue;
3091                 }
3092                 fprintf(stderr, "Rejected hunk #%d.\n", cnt);
3093                 fprintf(rej, "%.*s", frag->size, frag->patch);
3094                 if (frag->patch[frag->size-1] != '\n')
3095                         fputc('\n', rej);
3096         }
3097         fclose(rej);
3098         return -1;
3099 }
3100
3101 static int write_out_results(struct patch *list, int skipped_patch)
3102 {
3103         int phase;
3104         int errs = 0;
3105         struct patch *l;
3106
3107         if (!list && !skipped_patch)
3108                 return error("No changes");
3109
3110         for (phase = 0; phase < 2; phase++) {
3111                 l = list;
3112                 while (l) {
3113                         if (l->rejected)
3114                                 errs = 1;
3115                         else {
3116                                 write_out_one_result(l, phase);
3117                                 if (phase == 1 && write_out_one_reject(l))
3118                                         errs = 1;
3119                         }
3120                         l = l->next;
3121                 }
3122         }
3123         return errs;
3124 }
3125
3126 static struct lock_file lock_file;
3127
3128 static struct string_list limit_by_name;
3129 static int has_include;
3130 static void add_name_limit(const char *name, int exclude)
3131 {
3132         struct string_list_item *it;
3133
3134         it = string_list_append(name, &limit_by_name);
3135         it->util = exclude ? NULL : (void *) 1;
3136 }
3137
3138 static int use_patch(struct patch *p)
3139 {
3140         const char *pathname = p->new_name ? p->new_name : p->old_name;
3141         int i;
3142
3143         /* Paths outside are not touched regardless of "--include" */
3144         if (0 < prefix_length) {
3145                 int pathlen = strlen(pathname);
3146                 if (pathlen <= prefix_length ||
3147                     memcmp(prefix, pathname, prefix_length))
3148                         return 0;
3149         }
3150
3151         /* See if it matches any of exclude/include rule */
3152         for (i = 0; i < limit_by_name.nr; i++) {
3153                 struct string_list_item *it = &limit_by_name.items[i];
3154                 if (!fnmatch(it->string, pathname, 0))
3155                         return (it->util != NULL);
3156         }
3157
3158         /*
3159          * If we had any include, a path that does not match any rule is
3160          * not used.  Otherwise, we saw bunch of exclude rules (or none)
3161          * and such a path is used.
3162          */
3163         return !has_include;
3164 }
3165
3166
3167 static void prefix_one(char **name)
3168 {
3169         char *old_name = *name;
3170         if (!old_name)
3171                 return;
3172         *name = xstrdup(prefix_filename(prefix, prefix_length, *name));
3173         free(old_name);
3174 }
3175
3176 static void prefix_patches(struct patch *p)
3177 {
3178         if (!prefix || p->is_toplevel_relative)
3179                 return;
3180         for ( ; p; p = p->next) {
3181                 if (p->new_name == p->old_name) {
3182                         char *prefixed = p->new_name;
3183                         prefix_one(&prefixed);
3184                         p->new_name = p->old_name = prefixed;
3185                 }
3186                 else {
3187                         prefix_one(&p->new_name);
3188                         prefix_one(&p->old_name);
3189                 }
3190         }
3191 }
3192
3193 #define INACCURATE_EOF  (1<<0)
3194 #define RECOUNT         (1<<1)
3195
3196 static int apply_patch(int fd, const char *filename, int options)
3197 {
3198         size_t offset;
3199         struct strbuf buf = STRBUF_INIT;
3200         struct patch *list = NULL, **listp = &list;
3201         int skipped_patch = 0;
3202
3203         /* FIXME - memory leak when using multiple patch files as inputs */
3204         memset(&fn_table, 0, sizeof(struct string_list));
3205         patch_input_file = filename;
3206         read_patch_file(&buf, fd);
3207         offset = 0;
3208         while (offset < buf.len) {
3209                 struct patch *patch;
3210                 int nr;
3211
3212                 patch = xcalloc(1, sizeof(*patch));
3213                 patch->inaccurate_eof = !!(options & INACCURATE_EOF);
3214                 patch->recount =  !!(options & RECOUNT);
3215                 nr = parse_chunk(buf.buf + offset, buf.len - offset, patch);
3216                 if (nr < 0)
3217                         break;
3218                 if (apply_in_reverse)
3219                         reverse_patches(patch);
3220                 if (prefix)
3221                         prefix_patches(patch);
3222                 if (use_patch(patch)) {
3223                         patch_stats(patch);
3224                         *listp = patch;
3225                         listp = &patch->next;
3226                 }
3227                 else {
3228                         /* perhaps free it a bit better? */
3229                         free(patch);
3230                         skipped_patch++;
3231                 }
3232                 offset += nr;
3233         }
3234
3235         if (whitespace_error && (ws_error_action == die_on_ws_error))
3236                 apply = 0;
3237
3238         update_index = check_index && apply;
3239         if (update_index && newfd < 0)
3240                 newfd = hold_locked_index(&lock_file, 1);
3241
3242         if (check_index) {
3243                 if (read_cache() < 0)
3244                         die("unable to read index file");
3245         }
3246
3247         if ((check || apply) &&
3248             check_patch_list(list) < 0 &&
3249             !apply_with_reject)
3250                 exit(1);
3251
3252         if (apply && write_out_results(list, skipped_patch))
3253                 exit(1);
3254
3255         if (fake_ancestor)
3256                 build_fake_ancestor(list, fake_ancestor);
3257
3258         if (diffstat)
3259                 stat_patch_list(list);
3260
3261         if (numstat)
3262                 numstat_patch_list(list);
3263
3264         if (summary)
3265                 summary_patch_list(list);
3266
3267         strbuf_release(&buf);
3268         return 0;
3269 }
3270
3271 static int git_apply_config(const char *var, const char *value, void *cb)
3272 {
3273         if (!strcmp(var, "apply.whitespace"))
3274                 return git_config_string(&apply_default_whitespace, var, value);
3275         return git_default_config(var, value, cb);
3276 }
3277
3278 static int option_parse_exclude(const struct option *opt,
3279                                 const char *arg, int unset)
3280 {
3281         add_name_limit(arg, 1);
3282         return 0;
3283 }
3284
3285 static int option_parse_include(const struct option *opt,
3286                                 const char *arg, int unset)
3287 {
3288         add_name_limit(arg, 0);
3289         has_include = 1;
3290         return 0;
3291 }
3292
3293 static int option_parse_p(const struct option *opt,
3294                           const char *arg, int unset)
3295 {
3296         p_value = atoi(arg);
3297         p_value_known = 1;
3298         return 0;
3299 }
3300
3301 static int option_parse_z(const struct option *opt,
3302                           const char *arg, int unset)
3303 {
3304         if (unset)
3305                 line_termination = '\n';
3306         else
3307                 line_termination = 0;
3308         return 0;
3309 }
3310
3311 static int option_parse_whitespace(const struct option *opt,
3312                                    const char *arg, int unset)
3313 {
3314         const char **whitespace_option = opt->value;
3315
3316         *whitespace_option = arg;
3317         parse_whitespace_option(arg);
3318         return 0;
3319 }
3320
3321 static int option_parse_directory(const struct option *opt,
3322                                   const char *arg, int unset)
3323 {
3324         root_len = strlen(arg);
3325         if (root_len && arg[root_len - 1] != '/') {
3326                 char *new_root;
3327                 root = new_root = xmalloc(root_len + 2);
3328                 strcpy(new_root, arg);
3329                 strcpy(new_root + root_len++, "/");
3330         } else
3331                 root = arg;
3332         return 0;
3333 }
3334
3335 int cmd_apply(int argc, const char **argv, const char *unused_prefix)
3336 {
3337         int i;
3338         int errs = 0;
3339         int is_not_gitdir;
3340         int binary;
3341         int force_apply = 0;
3342
3343         const char *whitespace_option = NULL;
3344
3345         struct option builtin_apply_options[] = {
3346                 { OPTION_CALLBACK, 0, "exclude", NULL, "path",
3347                         "don't apply changes matching the given path",
3348                         0, option_parse_exclude },
3349                 { OPTION_CALLBACK, 0, "include", NULL, "path",
3350                         "apply changes matching the given path",
3351                         0, option_parse_include },
3352                 { OPTION_CALLBACK, 'p', NULL, NULL, "num",
3353                         "remove <num> leading slashes from traditional diff paths",
3354                         0, option_parse_p },
3355                 OPT_BOOLEAN(0, "no-add", &no_add,
3356                         "ignore additions made by the patch"),
3357                 OPT_BOOLEAN(0, "stat", &diffstat,
3358                         "instead of applying the patch, output diffstat for the input"),
3359                 { OPTION_BOOLEAN, 0, "allow-binary-replacement", &binary,
3360                   NULL, "old option, now no-op",
3361                   PARSE_OPT_HIDDEN | PARSE_OPT_NOARG },
3362                 { OPTION_BOOLEAN, 0, "binary", &binary,
3363                   NULL, "old option, now no-op",
3364                   PARSE_OPT_HIDDEN | PARSE_OPT_NOARG },
3365                 OPT_BOOLEAN(0, "numstat", &numstat,
3366                         "shows number of added and deleted lines in decimal notation"),
3367                 OPT_BOOLEAN(0, "summary", &summary,
3368                         "instead of applying the patch, output a summary for the input"),
3369                 OPT_BOOLEAN(0, "check", &check,
3370                         "instead of applying the patch, see if the patch is applicable"),
3371                 OPT_BOOLEAN(0, "index", &check_index,
3372                         "make sure the patch is applicable to the current index"),
3373                 OPT_BOOLEAN(0, "cached", &cached,
3374                         "apply a patch without touching the working tree"),
3375                 OPT_BOOLEAN(0, "apply", &force_apply,
3376                         "also apply the patch (use with --stat/--summary/--check)"),
3377                 OPT_FILENAME(0, "build-fake-ancestor", &fake_ancestor,
3378                         "build a temporary index based on embedded index information"),
3379                 { OPTION_CALLBACK, 'z', NULL, NULL, NULL,
3380                         "paths are separated with NUL character",
3381                         PARSE_OPT_NOARG, option_parse_z },
3382                 OPT_INTEGER('C', NULL, &p_context,
3383                                 "ensure at least <n> lines of context match"),
3384                 { OPTION_CALLBACK, 0, "whitespace", &whitespace_option, "action",
3385                         "detect new or modified lines that have whitespace errors",
3386                         0, option_parse_whitespace },
3387                 OPT_BOOLEAN('R', "reverse", &apply_in_reverse,
3388                         "apply the patch in reverse"),
3389                 OPT_BOOLEAN(0, "unidiff-zero", &unidiff_zero,
3390                         "don't expect at least one line of context"),
3391                 OPT_BOOLEAN(0, "reject", &apply_with_reject,
3392                         "leave the rejected hunks in corresponding *.rej files"),
3393                 OPT__VERBOSE(&apply_verbosely),
3394                 OPT_BIT(0, "inaccurate-eof", &options,
3395                         "tolerate incorrectly detected missing new-line at the end of file",
3396                         INACCURATE_EOF),
3397                 OPT_BIT(0, "recount", &options,
3398                         "do not trust the line counts in the hunk headers",
3399                         RECOUNT),
3400                 { OPTION_CALLBACK, 0, "directory", NULL, "root",
3401                         "prepend <root> to all filenames",
3402                         0, option_parse_directory },
3403                 OPT_END()
3404         };
3405
3406         prefix = setup_git_directory_gently(&is_not_gitdir);
3407         prefix_length = prefix ? strlen(prefix) : 0;
3408         git_config(git_apply_config, NULL);
3409         if (apply_default_whitespace)
3410                 parse_whitespace_option(apply_default_whitespace);
3411
3412         argc = parse_options(argc, argv, prefix, builtin_apply_options,
3413                         apply_usage, 0);
3414
3415         if (apply_with_reject)
3416                 apply = apply_verbosely = 1;
3417         if (!force_apply && (diffstat || numstat || summary || check || fake_ancestor))
3418                 apply = 0;
3419         if (check_index && is_not_gitdir)
3420                 die("--index outside a repository");
3421         if (cached) {
3422                 if (is_not_gitdir)
3423                         die("--cached outside a repository");
3424                 check_index = 1;
3425         }
3426         for (i = 0; i < argc; i++) {
3427                 const char *arg = argv[i];
3428                 int fd;
3429
3430                 if (!strcmp(arg, "-")) {
3431                         errs |= apply_patch(0, "<stdin>", options);
3432                         read_stdin = 0;
3433                         continue;
3434                 } else if (0 < prefix_length)
3435                         arg = prefix_filename(prefix, prefix_length, arg);
3436
3437                 fd = open(arg, O_RDONLY);
3438                 if (fd < 0)
3439                         die_errno("can't open patch '%s'", arg);
3440                 read_stdin = 0;
3441                 set_default_whitespace_mode(whitespace_option);
3442                 errs |= apply_patch(fd, arg, options);
3443                 close(fd);
3444         }
3445         set_default_whitespace_mode(whitespace_option);
3446         if (read_stdin)
3447                 errs |= apply_patch(0, "<stdin>", options);
3448         if (whitespace_error) {
3449                 if (squelch_whitespace_errors &&
3450                     squelch_whitespace_errors < whitespace_error) {
3451                         int squelched =
3452                                 whitespace_error - squelch_whitespace_errors;
3453                         warning("squelched %d "
3454                                 "whitespace error%s",
3455                                 squelched,
3456                                 squelched == 1 ? "" : "s");
3457                 }
3458                 if (ws_error_action == die_on_ws_error)
3459                         die("%d line%s add%s whitespace errors.",
3460                             whitespace_error,
3461                             whitespace_error == 1 ? "" : "s",
3462                             whitespace_error == 1 ? "s" : "");
3463                 if (applied_after_fixing_ws && apply)
3464                         warning("%d line%s applied after"
3465                                 " fixing whitespace errors.",
3466                                 applied_after_fixing_ws,
3467                                 applied_after_fixing_ws == 1 ? "" : "s");
3468                 else if (whitespace_error)
3469                         warning("%d line%s add%s whitespace errors.",
3470                                 whitespace_error,
3471                                 whitespace_error == 1 ? "" : "s",
3472                                 whitespace_error == 1 ? "s" : "");
3473         }
3474
3475         if (update_index) {
3476                 if (write_cache(newfd, active_cache, active_nr) ||
3477                     commit_locked_index(&lock_file))
3478                         die("Unable to write new index file");
3479         }
3480
3481         return !!errs;
3482 }