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