blame: rename 'this' variables
[git] / apply.c
1 /*
2  * apply.c
3  *
4  * Copyright (C) Linus Torvalds, 2005
5  *
6  * This applies patches on top of some (arbitrary) version of the SCM.
7  *
8  */
9
10 #include "cache.h"
11 #include "config.h"
12 #include "blob.h"
13 #include "delta.h"
14 #include "diff.h"
15 #include "dir.h"
16 #include "xdiff-interface.h"
17 #include "ll-merge.h"
18 #include "lockfile.h"
19 #include "parse-options.h"
20 #include "quote.h"
21 #include "rerere.h"
22 #include "apply.h"
23
24 static void git_apply_config(void)
25 {
26         git_config_get_string_const("apply.whitespace", &apply_default_whitespace);
27         git_config_get_string_const("apply.ignorewhitespace", &apply_default_ignorewhitespace);
28         git_config(git_default_config, NULL);
29 }
30
31 static int parse_whitespace_option(struct apply_state *state, const char *option)
32 {
33         if (!option) {
34                 state->ws_error_action = warn_on_ws_error;
35                 return 0;
36         }
37         if (!strcmp(option, "warn")) {
38                 state->ws_error_action = warn_on_ws_error;
39                 return 0;
40         }
41         if (!strcmp(option, "nowarn")) {
42                 state->ws_error_action = nowarn_ws_error;
43                 return 0;
44         }
45         if (!strcmp(option, "error")) {
46                 state->ws_error_action = die_on_ws_error;
47                 return 0;
48         }
49         if (!strcmp(option, "error-all")) {
50                 state->ws_error_action = die_on_ws_error;
51                 state->squelch_whitespace_errors = 0;
52                 return 0;
53         }
54         if (!strcmp(option, "strip") || !strcmp(option, "fix")) {
55                 state->ws_error_action = correct_ws_error;
56                 return 0;
57         }
58         return error(_("unrecognized whitespace option '%s'"), option);
59 }
60
61 static int parse_ignorewhitespace_option(struct apply_state *state,
62                                                  const char *option)
63 {
64         if (!option || !strcmp(option, "no") ||
65             !strcmp(option, "false") || !strcmp(option, "never") ||
66             !strcmp(option, "none")) {
67                 state->ws_ignore_action = ignore_ws_none;
68                 return 0;
69         }
70         if (!strcmp(option, "change")) {
71                 state->ws_ignore_action = ignore_ws_change;
72                 return 0;
73         }
74         return error(_("unrecognized whitespace ignore option '%s'"), option);
75 }
76
77 int init_apply_state(struct apply_state *state,
78                      const char *prefix)
79 {
80         memset(state, 0, sizeof(*state));
81         state->prefix = prefix;
82         state->apply = 1;
83         state->line_termination = '\n';
84         state->p_value = 1;
85         state->p_context = UINT_MAX;
86         state->squelch_whitespace_errors = 5;
87         state->ws_error_action = warn_on_ws_error;
88         state->ws_ignore_action = ignore_ws_none;
89         state->linenr = 1;
90         string_list_init(&state->fn_table, 0);
91         string_list_init(&state->limit_by_name, 0);
92         string_list_init(&state->symlink_changes, 0);
93         strbuf_init(&state->root, 0);
94
95         git_apply_config();
96         if (apply_default_whitespace && parse_whitespace_option(state, apply_default_whitespace))
97                 return -1;
98         if (apply_default_ignorewhitespace && parse_ignorewhitespace_option(state, apply_default_ignorewhitespace))
99                 return -1;
100         return 0;
101 }
102
103 void clear_apply_state(struct apply_state *state)
104 {
105         string_list_clear(&state->limit_by_name, 0);
106         string_list_clear(&state->symlink_changes, 0);
107         strbuf_release(&state->root);
108
109         /* &state->fn_table is cleared at the end of apply_patch() */
110 }
111
112 static void mute_routine(const char *msg, va_list params)
113 {
114         /* do nothing */
115 }
116
117 int check_apply_state(struct apply_state *state, int force_apply)
118 {
119         int is_not_gitdir = !startup_info->have_repository;
120
121         if (state->apply_with_reject && state->threeway)
122                 return error(_("--reject and --3way cannot be used together."));
123         if (state->cached && state->threeway)
124                 return error(_("--cached and --3way cannot be used together."));
125         if (state->threeway) {
126                 if (is_not_gitdir)
127                         return error(_("--3way outside a repository"));
128                 state->check_index = 1;
129         }
130         if (state->apply_with_reject) {
131                 state->apply = 1;
132                 if (state->apply_verbosity == verbosity_normal)
133                         state->apply_verbosity = verbosity_verbose;
134         }
135         if (!force_apply && (state->diffstat || state->numstat || state->summary || state->check || state->fake_ancestor))
136                 state->apply = 0;
137         if (state->check_index && is_not_gitdir)
138                 return error(_("--index outside a repository"));
139         if (state->cached) {
140                 if (is_not_gitdir)
141                         return error(_("--cached outside a repository"));
142                 state->check_index = 1;
143         }
144         if (state->check_index)
145                 state->unsafe_paths = 0;
146
147         if (state->apply_verbosity <= verbosity_silent) {
148                 state->saved_error_routine = get_error_routine();
149                 state->saved_warn_routine = get_warn_routine();
150                 set_error_routine(mute_routine);
151                 set_warn_routine(mute_routine);
152         }
153
154         return 0;
155 }
156
157 static void set_default_whitespace_mode(struct apply_state *state)
158 {
159         if (!state->whitespace_option && !apply_default_whitespace)
160                 state->ws_error_action = (state->apply ? warn_on_ws_error : nowarn_ws_error);
161 }
162
163 /*
164  * This represents one "hunk" from a patch, starting with
165  * "@@ -oldpos,oldlines +newpos,newlines @@" marker.  The
166  * patch text is pointed at by patch, and its byte length
167  * is stored in size.  leading and trailing are the number
168  * of context lines.
169  */
170 struct fragment {
171         unsigned long leading, trailing;
172         unsigned long oldpos, oldlines;
173         unsigned long newpos, newlines;
174         /*
175          * 'patch' is usually borrowed from buf in apply_patch(),
176          * but some codepaths store an allocated buffer.
177          */
178         const char *patch;
179         unsigned free_patch:1,
180                 rejected:1;
181         int size;
182         int linenr;
183         struct fragment *next;
184 };
185
186 /*
187  * When dealing with a binary patch, we reuse "leading" field
188  * to store the type of the binary hunk, either deflated "delta"
189  * or deflated "literal".
190  */
191 #define binary_patch_method leading
192 #define BINARY_DELTA_DEFLATED   1
193 #define BINARY_LITERAL_DEFLATED 2
194
195 /*
196  * This represents a "patch" to a file, both metainfo changes
197  * such as creation/deletion, filemode and content changes represented
198  * as a series of fragments.
199  */
200 struct patch {
201         char *new_name, *old_name, *def_name;
202         unsigned int old_mode, new_mode;
203         int is_new, is_delete;  /* -1 = unknown, 0 = false, 1 = true */
204         int rejected;
205         unsigned ws_rule;
206         int lines_added, lines_deleted;
207         int score;
208         int extension_linenr; /* first line specifying delete/new/rename/copy */
209         unsigned int is_toplevel_relative:1;
210         unsigned int inaccurate_eof:1;
211         unsigned int is_binary:1;
212         unsigned int is_copy:1;
213         unsigned int is_rename:1;
214         unsigned int recount:1;
215         unsigned int conflicted_threeway:1;
216         unsigned int direct_to_threeway:1;
217         unsigned int crlf_in_old:1;
218         struct fragment *fragments;
219         char *result;
220         size_t resultsize;
221         char old_sha1_prefix[41];
222         char new_sha1_prefix[41];
223         struct patch *next;
224
225         /* three-way fallback result */
226         struct object_id threeway_stage[3];
227 };
228
229 static void free_fragment_list(struct fragment *list)
230 {
231         while (list) {
232                 struct fragment *next = list->next;
233                 if (list->free_patch)
234                         free((char *)list->patch);
235                 free(list);
236                 list = next;
237         }
238 }
239
240 static void free_patch(struct patch *patch)
241 {
242         free_fragment_list(patch->fragments);
243         free(patch->def_name);
244         free(patch->old_name);
245         free(patch->new_name);
246         free(patch->result);
247         free(patch);
248 }
249
250 static void free_patch_list(struct patch *list)
251 {
252         while (list) {
253                 struct patch *next = list->next;
254                 free_patch(list);
255                 list = next;
256         }
257 }
258
259 /*
260  * A line in a file, len-bytes long (includes the terminating LF,
261  * except for an incomplete line at the end if the file ends with
262  * one), and its contents hashes to 'hash'.
263  */
264 struct line {
265         size_t len;
266         unsigned hash : 24;
267         unsigned flag : 8;
268 #define LINE_COMMON     1
269 #define LINE_PATCHED    2
270 };
271
272 /*
273  * This represents a "file", which is an array of "lines".
274  */
275 struct image {
276         char *buf;
277         size_t len;
278         size_t nr;
279         size_t alloc;
280         struct line *line_allocated;
281         struct line *line;
282 };
283
284 static uint32_t hash_line(const char *cp, size_t len)
285 {
286         size_t i;
287         uint32_t h;
288         for (i = 0, h = 0; i < len; i++) {
289                 if (!isspace(cp[i])) {
290                         h = h * 3 + (cp[i] & 0xff);
291                 }
292         }
293         return h;
294 }
295
296 /*
297  * Compare lines s1 of length n1 and s2 of length n2, ignoring
298  * whitespace difference. Returns 1 if they match, 0 otherwise
299  */
300 static int fuzzy_matchlines(const char *s1, size_t n1,
301                             const char *s2, size_t n2)
302 {
303         const char *end1 = s1 + n1;
304         const char *end2 = s2 + n2;
305
306         /* ignore line endings */
307         while (s1 < end1 && (end1[-1] == '\r' || end1[-1] == '\n'))
308                 end1--;
309         while (s2 < end2 && (end2[-1] == '\r' || end2[-1] == '\n'))
310                 end2--;
311
312         while (s1 < end1 && s2 < end2) {
313                 if (isspace(*s1)) {
314                         /*
315                          * Skip whitespace. We check on both buffers
316                          * because we don't want "a b" to match "ab".
317                          */
318                         if (!isspace(*s2))
319                                 return 0;
320                         while (s1 < end1 && isspace(*s1))
321                                 s1++;
322                         while (s2 < end2 && isspace(*s2))
323                                 s2++;
324                 } else if (*s1++ != *s2++)
325                         return 0;
326         }
327
328         /* If we reached the end on one side only, lines don't match. */
329         return s1 == end1 && s2 == end2;
330 }
331
332 static void add_line_info(struct image *img, const char *bol, size_t len, unsigned flag)
333 {
334         ALLOC_GROW(img->line_allocated, img->nr + 1, img->alloc);
335         img->line_allocated[img->nr].len = len;
336         img->line_allocated[img->nr].hash = hash_line(bol, len);
337         img->line_allocated[img->nr].flag = flag;
338         img->nr++;
339 }
340
341 /*
342  * "buf" has the file contents to be patched (read from various sources).
343  * attach it to "image" and add line-based index to it.
344  * "image" now owns the "buf".
345  */
346 static void prepare_image(struct image *image, char *buf, size_t len,
347                           int prepare_linetable)
348 {
349         const char *cp, *ep;
350
351         memset(image, 0, sizeof(*image));
352         image->buf = buf;
353         image->len = len;
354
355         if (!prepare_linetable)
356                 return;
357
358         ep = image->buf + image->len;
359         cp = image->buf;
360         while (cp < ep) {
361                 const char *next;
362                 for (next = cp; next < ep && *next != '\n'; next++)
363                         ;
364                 if (next < ep)
365                         next++;
366                 add_line_info(image, cp, next - cp, 0);
367                 cp = next;
368         }
369         image->line = image->line_allocated;
370 }
371
372 static void clear_image(struct image *image)
373 {
374         free(image->buf);
375         free(image->line_allocated);
376         memset(image, 0, sizeof(*image));
377 }
378
379 /* fmt must contain _one_ %s and no other substitution */
380 static void say_patch_name(FILE *output, const char *fmt, struct patch *patch)
381 {
382         struct strbuf sb = STRBUF_INIT;
383
384         if (patch->old_name && patch->new_name &&
385             strcmp(patch->old_name, patch->new_name)) {
386                 quote_c_style(patch->old_name, &sb, NULL, 0);
387                 strbuf_addstr(&sb, " => ");
388                 quote_c_style(patch->new_name, &sb, NULL, 0);
389         } else {
390                 const char *n = patch->new_name;
391                 if (!n)
392                         n = patch->old_name;
393                 quote_c_style(n, &sb, NULL, 0);
394         }
395         fprintf(output, fmt, sb.buf);
396         fputc('\n', output);
397         strbuf_release(&sb);
398 }
399
400 #define SLOP (16)
401
402 static int read_patch_file(struct strbuf *sb, int fd)
403 {
404         if (strbuf_read(sb, fd, 0) < 0)
405                 return error_errno("git apply: failed to read");
406
407         /*
408          * Make sure that we have some slop in the buffer
409          * so that we can do speculative "memcmp" etc, and
410          * see to it that it is NUL-filled.
411          */
412         strbuf_grow(sb, SLOP);
413         memset(sb->buf + sb->len, 0, SLOP);
414         return 0;
415 }
416
417 static unsigned long linelen(const char *buffer, unsigned long size)
418 {
419         unsigned long len = 0;
420         while (size--) {
421                 len++;
422                 if (*buffer++ == '\n')
423                         break;
424         }
425         return len;
426 }
427
428 static int is_dev_null(const char *str)
429 {
430         return skip_prefix(str, "/dev/null", &str) && isspace(*str);
431 }
432
433 #define TERM_SPACE      1
434 #define TERM_TAB        2
435
436 static int name_terminate(int c, int terminate)
437 {
438         if (c == ' ' && !(terminate & TERM_SPACE))
439                 return 0;
440         if (c == '\t' && !(terminate & TERM_TAB))
441                 return 0;
442
443         return 1;
444 }
445
446 /* remove double slashes to make --index work with such filenames */
447 static char *squash_slash(char *name)
448 {
449         int i = 0, j = 0;
450
451         if (!name)
452                 return NULL;
453
454         while (name[i]) {
455                 if ((name[j++] = name[i++]) == '/')
456                         while (name[i] == '/')
457                                 i++;
458         }
459         name[j] = '\0';
460         return name;
461 }
462
463 static char *find_name_gnu(struct apply_state *state,
464                            const char *line,
465                            const char *def,
466                            int p_value)
467 {
468         struct strbuf name = STRBUF_INIT;
469         char *cp;
470
471         /*
472          * Proposed "new-style" GNU patch/diff format; see
473          * http://marc.info/?l=git&m=112927316408690&w=2
474          */
475         if (unquote_c_style(&name, line, NULL)) {
476                 strbuf_release(&name);
477                 return NULL;
478         }
479
480         for (cp = name.buf; p_value; p_value--) {
481                 cp = strchr(cp, '/');
482                 if (!cp) {
483                         strbuf_release(&name);
484                         return NULL;
485                 }
486                 cp++;
487         }
488
489         strbuf_remove(&name, 0, cp - name.buf);
490         if (state->root.len)
491                 strbuf_insert(&name, 0, state->root.buf, state->root.len);
492         return squash_slash(strbuf_detach(&name, NULL));
493 }
494
495 static size_t sane_tz_len(const char *line, size_t len)
496 {
497         const char *tz, *p;
498
499         if (len < strlen(" +0500") || line[len-strlen(" +0500")] != ' ')
500                 return 0;
501         tz = line + len - strlen(" +0500");
502
503         if (tz[1] != '+' && tz[1] != '-')
504                 return 0;
505
506         for (p = tz + 2; p != line + len; p++)
507                 if (!isdigit(*p))
508                         return 0;
509
510         return line + len - tz;
511 }
512
513 static size_t tz_with_colon_len(const char *line, size_t len)
514 {
515         const char *tz, *p;
516
517         if (len < strlen(" +08:00") || line[len - strlen(":00")] != ':')
518                 return 0;
519         tz = line + len - strlen(" +08:00");
520
521         if (tz[0] != ' ' || (tz[1] != '+' && tz[1] != '-'))
522                 return 0;
523         p = tz + 2;
524         if (!isdigit(*p++) || !isdigit(*p++) || *p++ != ':' ||
525             !isdigit(*p++) || !isdigit(*p++))
526                 return 0;
527
528         return line + len - tz;
529 }
530
531 static size_t date_len(const char *line, size_t len)
532 {
533         const char *date, *p;
534
535         if (len < strlen("72-02-05") || line[len-strlen("-05")] != '-')
536                 return 0;
537         p = date = line + len - strlen("72-02-05");
538
539         if (!isdigit(*p++) || !isdigit(*p++) || *p++ != '-' ||
540             !isdigit(*p++) || !isdigit(*p++) || *p++ != '-' ||
541             !isdigit(*p++) || !isdigit(*p++))   /* Not a date. */
542                 return 0;
543
544         if (date - line >= strlen("19") &&
545             isdigit(date[-1]) && isdigit(date[-2]))     /* 4-digit year */
546                 date -= strlen("19");
547
548         return line + len - date;
549 }
550
551 static size_t short_time_len(const char *line, size_t len)
552 {
553         const char *time, *p;
554
555         if (len < strlen(" 07:01:32") || line[len-strlen(":32")] != ':')
556                 return 0;
557         p = time = line + len - strlen(" 07:01:32");
558
559         /* Permit 1-digit hours? */
560         if (*p++ != ' ' ||
561             !isdigit(*p++) || !isdigit(*p++) || *p++ != ':' ||
562             !isdigit(*p++) || !isdigit(*p++) || *p++ != ':' ||
563             !isdigit(*p++) || !isdigit(*p++))   /* Not a time. */
564                 return 0;
565
566         return line + len - time;
567 }
568
569 static size_t fractional_time_len(const char *line, size_t len)
570 {
571         const char *p;
572         size_t n;
573
574         /* Expected format: 19:41:17.620000023 */
575         if (!len || !isdigit(line[len - 1]))
576                 return 0;
577         p = line + len - 1;
578
579         /* Fractional seconds. */
580         while (p > line && isdigit(*p))
581                 p--;
582         if (*p != '.')
583                 return 0;
584
585         /* Hours, minutes, and whole seconds. */
586         n = short_time_len(line, p - line);
587         if (!n)
588                 return 0;
589
590         return line + len - p + n;
591 }
592
593 static size_t trailing_spaces_len(const char *line, size_t len)
594 {
595         const char *p;
596
597         /* Expected format: ' ' x (1 or more)  */
598         if (!len || line[len - 1] != ' ')
599                 return 0;
600
601         p = line + len;
602         while (p != line) {
603                 p--;
604                 if (*p != ' ')
605                         return line + len - (p + 1);
606         }
607
608         /* All spaces! */
609         return len;
610 }
611
612 static size_t diff_timestamp_len(const char *line, size_t len)
613 {
614         const char *end = line + len;
615         size_t n;
616
617         /*
618          * Posix: 2010-07-05 19:41:17
619          * GNU: 2010-07-05 19:41:17.620000023 -0500
620          */
621
622         if (!isdigit(end[-1]))
623                 return 0;
624
625         n = sane_tz_len(line, end - line);
626         if (!n)
627                 n = tz_with_colon_len(line, end - line);
628         end -= n;
629
630         n = short_time_len(line, end - line);
631         if (!n)
632                 n = fractional_time_len(line, end - line);
633         end -= n;
634
635         n = date_len(line, end - line);
636         if (!n) /* No date.  Too bad. */
637                 return 0;
638         end -= n;
639
640         if (end == line)        /* No space before date. */
641                 return 0;
642         if (end[-1] == '\t') {  /* Success! */
643                 end--;
644                 return line + len - end;
645         }
646         if (end[-1] != ' ')     /* No space before date. */
647                 return 0;
648
649         /* Whitespace damage. */
650         end -= trailing_spaces_len(line, end - line);
651         return line + len - end;
652 }
653
654 static char *find_name_common(struct apply_state *state,
655                               const char *line,
656                               const char *def,
657                               int p_value,
658                               const char *end,
659                               int terminate)
660 {
661         int len;
662         const char *start = NULL;
663
664         if (p_value == 0)
665                 start = line;
666         while (line != end) {
667                 char c = *line;
668
669                 if (!end && isspace(c)) {
670                         if (c == '\n')
671                                 break;
672                         if (name_terminate(c, terminate))
673                                 break;
674                 }
675                 line++;
676                 if (c == '/' && !--p_value)
677                         start = line;
678         }
679         if (!start)
680                 return squash_slash(xstrdup_or_null(def));
681         len = line - start;
682         if (!len)
683                 return squash_slash(xstrdup_or_null(def));
684
685         /*
686          * Generally we prefer the shorter name, especially
687          * if the other one is just a variation of that with
688          * something else tacked on to the end (ie "file.orig"
689          * or "file~").
690          */
691         if (def) {
692                 int deflen = strlen(def);
693                 if (deflen < len && !strncmp(start, def, deflen))
694                         return squash_slash(xstrdup(def));
695         }
696
697         if (state->root.len) {
698                 char *ret = xstrfmt("%s%.*s", state->root.buf, len, start);
699                 return squash_slash(ret);
700         }
701
702         return squash_slash(xmemdupz(start, len));
703 }
704
705 static char *find_name(struct apply_state *state,
706                        const char *line,
707                        char *def,
708                        int p_value,
709                        int terminate)
710 {
711         if (*line == '"') {
712                 char *name = find_name_gnu(state, line, def, p_value);
713                 if (name)
714                         return name;
715         }
716
717         return find_name_common(state, line, def, p_value, NULL, terminate);
718 }
719
720 static char *find_name_traditional(struct apply_state *state,
721                                    const char *line,
722                                    char *def,
723                                    int p_value)
724 {
725         size_t len;
726         size_t date_len;
727
728         if (*line == '"') {
729                 char *name = find_name_gnu(state, line, def, p_value);
730                 if (name)
731                         return name;
732         }
733
734         len = strchrnul(line, '\n') - line;
735         date_len = diff_timestamp_len(line, len);
736         if (!date_len)
737                 return find_name_common(state, line, def, p_value, NULL, TERM_TAB);
738         len -= date_len;
739
740         return find_name_common(state, line, def, p_value, line + len, 0);
741 }
742
743 /*
744  * Given the string after "--- " or "+++ ", guess the appropriate
745  * p_value for the given patch.
746  */
747 static int guess_p_value(struct apply_state *state, const char *nameline)
748 {
749         char *name, *cp;
750         int val = -1;
751
752         if (is_dev_null(nameline))
753                 return -1;
754         name = find_name_traditional(state, nameline, NULL, 0);
755         if (!name)
756                 return -1;
757         cp = strchr(name, '/');
758         if (!cp)
759                 val = 0;
760         else if (state->prefix) {
761                 /*
762                  * Does it begin with "a/$our-prefix" and such?  Then this is
763                  * very likely to apply to our directory.
764                  */
765                 if (starts_with(name, state->prefix))
766                         val = count_slashes(state->prefix);
767                 else {
768                         cp++;
769                         if (starts_with(cp, state->prefix))
770                                 val = count_slashes(state->prefix) + 1;
771                 }
772         }
773         free(name);
774         return val;
775 }
776
777 /*
778  * Does the ---/+++ line have the POSIX timestamp after the last HT?
779  * GNU diff puts epoch there to signal a creation/deletion event.  Is
780  * this such a timestamp?
781  */
782 static int has_epoch_timestamp(const char *nameline)
783 {
784         /*
785          * We are only interested in epoch timestamp; any non-zero
786          * fraction cannot be one, hence "(\.0+)?" in the regexp below.
787          * For the same reason, the date must be either 1969-12-31 or
788          * 1970-01-01, and the seconds part must be "00".
789          */
790         const char stamp_regexp[] =
791                 "^[0-2][0-9]:([0-5][0-9]):00(\\.0+)?"
792                 " "
793                 "([-+][0-2][0-9]:?[0-5][0-9])\n";
794         const char *timestamp = NULL, *cp, *colon;
795         static regex_t *stamp;
796         regmatch_t m[10];
797         int zoneoffset, epoch_hour, hour, minute;
798         int status;
799
800         for (cp = nameline; *cp != '\n'; cp++) {
801                 if (*cp == '\t')
802                         timestamp = cp + 1;
803         }
804         if (!timestamp)
805                 return 0;
806
807         /*
808          * YYYY-MM-DD hh:mm:ss must be from either 1969-12-31
809          * (west of GMT) or 1970-01-01 (east of GMT)
810          */
811         if (skip_prefix(timestamp, "1969-12-31 ", &timestamp))
812                 epoch_hour = 24;
813         else if (skip_prefix(timestamp, "1970-01-01 ", &timestamp))
814                 epoch_hour = 0;
815         else
816                 return 0;
817
818         if (!stamp) {
819                 stamp = xmalloc(sizeof(*stamp));
820                 if (regcomp(stamp, stamp_regexp, REG_EXTENDED)) {
821                         warning(_("Cannot prepare timestamp regexp %s"),
822                                 stamp_regexp);
823                         return 0;
824                 }
825         }
826
827         status = regexec(stamp, timestamp, ARRAY_SIZE(m), m, 0);
828         if (status) {
829                 if (status != REG_NOMATCH)
830                         warning(_("regexec returned %d for input: %s"),
831                                 status, timestamp);
832                 return 0;
833         }
834
835         hour = strtol(timestamp, NULL, 10);
836         minute = strtol(timestamp + m[1].rm_so, NULL, 10);
837
838         zoneoffset = strtol(timestamp + m[3].rm_so + 1, (char **) &colon, 10);
839         if (*colon == ':')
840                 zoneoffset = zoneoffset * 60 + strtol(colon + 1, NULL, 10);
841         else
842                 zoneoffset = (zoneoffset / 100) * 60 + (zoneoffset % 100);
843         if (timestamp[m[3].rm_so] == '-')
844                 zoneoffset = -zoneoffset;
845
846         return hour * 60 + minute - zoneoffset == epoch_hour * 60;
847 }
848
849 /*
850  * Get the name etc info from the ---/+++ lines of a traditional patch header
851  *
852  * FIXME! The end-of-filename heuristics are kind of screwy. For existing
853  * files, we can happily check the index for a match, but for creating a
854  * new file we should try to match whatever "patch" does. I have no idea.
855  */
856 static int parse_traditional_patch(struct apply_state *state,
857                                    const char *first,
858                                    const char *second,
859                                    struct patch *patch)
860 {
861         char *name;
862
863         first += 4;     /* skip "--- " */
864         second += 4;    /* skip "+++ " */
865         if (!state->p_value_known) {
866                 int p, q;
867                 p = guess_p_value(state, first);
868                 q = guess_p_value(state, second);
869                 if (p < 0) p = q;
870                 if (0 <= p && p == q) {
871                         state->p_value = p;
872                         state->p_value_known = 1;
873                 }
874         }
875         if (is_dev_null(first)) {
876                 patch->is_new = 1;
877                 patch->is_delete = 0;
878                 name = find_name_traditional(state, second, NULL, state->p_value);
879                 patch->new_name = name;
880         } else if (is_dev_null(second)) {
881                 patch->is_new = 0;
882                 patch->is_delete = 1;
883                 name = find_name_traditional(state, first, NULL, state->p_value);
884                 patch->old_name = name;
885         } else {
886                 char *first_name;
887                 first_name = find_name_traditional(state, first, NULL, state->p_value);
888                 name = find_name_traditional(state, second, first_name, state->p_value);
889                 free(first_name);
890                 if (has_epoch_timestamp(first)) {
891                         patch->is_new = 1;
892                         patch->is_delete = 0;
893                         patch->new_name = name;
894                 } else if (has_epoch_timestamp(second)) {
895                         patch->is_new = 0;
896                         patch->is_delete = 1;
897                         patch->old_name = name;
898                 } else {
899                         patch->old_name = name;
900                         patch->new_name = xstrdup_or_null(name);
901                 }
902         }
903         if (!name)
904                 return error(_("unable to find filename in patch at line %d"), state->linenr);
905
906         return 0;
907 }
908
909 static int gitdiff_hdrend(struct apply_state *state,
910                           const char *line,
911                           struct patch *patch)
912 {
913         return 1;
914 }
915
916 /*
917  * We're anal about diff header consistency, to make
918  * sure that we don't end up having strange ambiguous
919  * patches floating around.
920  *
921  * As a result, gitdiff_{old|new}name() will check
922  * their names against any previous information, just
923  * to make sure..
924  */
925 #define DIFF_OLD_NAME 0
926 #define DIFF_NEW_NAME 1
927
928 static int gitdiff_verify_name(struct apply_state *state,
929                                const char *line,
930                                int isnull,
931                                char **name,
932                                int side)
933 {
934         if (!*name && !isnull) {
935                 *name = find_name(state, line, NULL, state->p_value, TERM_TAB);
936                 return 0;
937         }
938
939         if (*name) {
940                 char *another;
941                 if (isnull)
942                         return error(_("git apply: bad git-diff - expected /dev/null, got %s on line %d"),
943                                      *name, state->linenr);
944                 another = find_name(state, line, NULL, state->p_value, TERM_TAB);
945                 if (!another || strcmp(another, *name)) {
946                         free(another);
947                         return error((side == DIFF_NEW_NAME) ?
948                             _("git apply: bad git-diff - inconsistent new filename on line %d") :
949                             _("git apply: bad git-diff - inconsistent old filename on line %d"), state->linenr);
950                 }
951                 free(another);
952         } else {
953                 if (!starts_with(line, "/dev/null\n"))
954                         return error(_("git apply: bad git-diff - expected /dev/null on line %d"), state->linenr);
955         }
956
957         return 0;
958 }
959
960 static int gitdiff_oldname(struct apply_state *state,
961                            const char *line,
962                            struct patch *patch)
963 {
964         return gitdiff_verify_name(state, line,
965                                    patch->is_new, &patch->old_name,
966                                    DIFF_OLD_NAME);
967 }
968
969 static int gitdiff_newname(struct apply_state *state,
970                            const char *line,
971                            struct patch *patch)
972 {
973         return gitdiff_verify_name(state, line,
974                                    patch->is_delete, &patch->new_name,
975                                    DIFF_NEW_NAME);
976 }
977
978 static int parse_mode_line(const char *line, int linenr, unsigned int *mode)
979 {
980         char *end;
981         *mode = strtoul(line, &end, 8);
982         if (end == line || !isspace(*end))
983                 return error(_("invalid mode on line %d: %s"), linenr, line);
984         return 0;
985 }
986
987 static int gitdiff_oldmode(struct apply_state *state,
988                            const char *line,
989                            struct patch *patch)
990 {
991         return parse_mode_line(line, state->linenr, &patch->old_mode);
992 }
993
994 static int gitdiff_newmode(struct apply_state *state,
995                            const char *line,
996                            struct patch *patch)
997 {
998         return parse_mode_line(line, state->linenr, &patch->new_mode);
999 }
1000
1001 static int gitdiff_delete(struct apply_state *state,
1002                           const char *line,
1003                           struct patch *patch)
1004 {
1005         patch->is_delete = 1;
1006         free(patch->old_name);
1007         patch->old_name = xstrdup_or_null(patch->def_name);
1008         return gitdiff_oldmode(state, line, patch);
1009 }
1010
1011 static int gitdiff_newfile(struct apply_state *state,
1012                            const char *line,
1013                            struct patch *patch)
1014 {
1015         patch->is_new = 1;
1016         free(patch->new_name);
1017         patch->new_name = xstrdup_or_null(patch->def_name);
1018         return gitdiff_newmode(state, line, patch);
1019 }
1020
1021 static int gitdiff_copysrc(struct apply_state *state,
1022                            const char *line,
1023                            struct patch *patch)
1024 {
1025         patch->is_copy = 1;
1026         free(patch->old_name);
1027         patch->old_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
1028         return 0;
1029 }
1030
1031 static int gitdiff_copydst(struct apply_state *state,
1032                            const char *line,
1033                            struct patch *patch)
1034 {
1035         patch->is_copy = 1;
1036         free(patch->new_name);
1037         patch->new_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
1038         return 0;
1039 }
1040
1041 static int gitdiff_renamesrc(struct apply_state *state,
1042                              const char *line,
1043                              struct patch *patch)
1044 {
1045         patch->is_rename = 1;
1046         free(patch->old_name);
1047         patch->old_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
1048         return 0;
1049 }
1050
1051 static int gitdiff_renamedst(struct apply_state *state,
1052                              const char *line,
1053                              struct patch *patch)
1054 {
1055         patch->is_rename = 1;
1056         free(patch->new_name);
1057         patch->new_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
1058         return 0;
1059 }
1060
1061 static int gitdiff_similarity(struct apply_state *state,
1062                               const char *line,
1063                               struct patch *patch)
1064 {
1065         unsigned long val = strtoul(line, NULL, 10);
1066         if (val <= 100)
1067                 patch->score = val;
1068         return 0;
1069 }
1070
1071 static int gitdiff_dissimilarity(struct apply_state *state,
1072                                  const char *line,
1073                                  struct patch *patch)
1074 {
1075         unsigned long val = strtoul(line, NULL, 10);
1076         if (val <= 100)
1077                 patch->score = val;
1078         return 0;
1079 }
1080
1081 static int gitdiff_index(struct apply_state *state,
1082                          const char *line,
1083                          struct patch *patch)
1084 {
1085         /*
1086          * index line is N hexadecimal, "..", N hexadecimal,
1087          * and optional space with octal mode.
1088          */
1089         const char *ptr, *eol;
1090         int len;
1091
1092         ptr = strchr(line, '.');
1093         if (!ptr || ptr[1] != '.' || 40 < ptr - line)
1094                 return 0;
1095         len = ptr - line;
1096         memcpy(patch->old_sha1_prefix, line, len);
1097         patch->old_sha1_prefix[len] = 0;
1098
1099         line = ptr + 2;
1100         ptr = strchr(line, ' ');
1101         eol = strchrnul(line, '\n');
1102
1103         if (!ptr || eol < ptr)
1104                 ptr = eol;
1105         len = ptr - line;
1106
1107         if (40 < len)
1108                 return 0;
1109         memcpy(patch->new_sha1_prefix, line, len);
1110         patch->new_sha1_prefix[len] = 0;
1111         if (*ptr == ' ')
1112                 return gitdiff_oldmode(state, ptr + 1, patch);
1113         return 0;
1114 }
1115
1116 /*
1117  * This is normal for a diff that doesn't change anything: we'll fall through
1118  * into the next diff. Tell the parser to break out.
1119  */
1120 static int gitdiff_unrecognized(struct apply_state *state,
1121                                 const char *line,
1122                                 struct patch *patch)
1123 {
1124         return 1;
1125 }
1126
1127 /*
1128  * Skip p_value leading components from "line"; as we do not accept
1129  * absolute paths, return NULL in that case.
1130  */
1131 static const char *skip_tree_prefix(struct apply_state *state,
1132                                     const char *line,
1133                                     int llen)
1134 {
1135         int nslash;
1136         int i;
1137
1138         if (!state->p_value)
1139                 return (llen && line[0] == '/') ? NULL : line;
1140
1141         nslash = state->p_value;
1142         for (i = 0; i < llen; i++) {
1143                 int ch = line[i];
1144                 if (ch == '/' && --nslash <= 0)
1145                         return (i == 0) ? NULL : &line[i + 1];
1146         }
1147         return NULL;
1148 }
1149
1150 /*
1151  * This is to extract the same name that appears on "diff --git"
1152  * line.  We do not find and return anything if it is a rename
1153  * patch, and it is OK because we will find the name elsewhere.
1154  * We need to reliably find name only when it is mode-change only,
1155  * creation or deletion of an empty file.  In any of these cases,
1156  * both sides are the same name under a/ and b/ respectively.
1157  */
1158 static char *git_header_name(struct apply_state *state,
1159                              const char *line,
1160                              int llen)
1161 {
1162         const char *name;
1163         const char *second = NULL;
1164         size_t len, line_len;
1165
1166         line += strlen("diff --git ");
1167         llen -= strlen("diff --git ");
1168
1169         if (*line == '"') {
1170                 const char *cp;
1171                 struct strbuf first = STRBUF_INIT;
1172                 struct strbuf sp = STRBUF_INIT;
1173
1174                 if (unquote_c_style(&first, line, &second))
1175                         goto free_and_fail1;
1176
1177                 /* strip the a/b prefix including trailing slash */
1178                 cp = skip_tree_prefix(state, first.buf, first.len);
1179                 if (!cp)
1180                         goto free_and_fail1;
1181                 strbuf_remove(&first, 0, cp - first.buf);
1182
1183                 /*
1184                  * second points at one past closing dq of name.
1185                  * find the second name.
1186                  */
1187                 while ((second < line + llen) && isspace(*second))
1188                         second++;
1189
1190                 if (line + llen <= second)
1191                         goto free_and_fail1;
1192                 if (*second == '"') {
1193                         if (unquote_c_style(&sp, second, NULL))
1194                                 goto free_and_fail1;
1195                         cp = skip_tree_prefix(state, sp.buf, sp.len);
1196                         if (!cp)
1197                                 goto free_and_fail1;
1198                         /* They must match, otherwise ignore */
1199                         if (strcmp(cp, first.buf))
1200                                 goto free_and_fail1;
1201                         strbuf_release(&sp);
1202                         return strbuf_detach(&first, NULL);
1203                 }
1204
1205                 /* unquoted second */
1206                 cp = skip_tree_prefix(state, second, line + llen - second);
1207                 if (!cp)
1208                         goto free_and_fail1;
1209                 if (line + llen - cp != first.len ||
1210                     memcmp(first.buf, cp, first.len))
1211                         goto free_and_fail1;
1212                 return strbuf_detach(&first, NULL);
1213
1214         free_and_fail1:
1215                 strbuf_release(&first);
1216                 strbuf_release(&sp);
1217                 return NULL;
1218         }
1219
1220         /* unquoted first name */
1221         name = skip_tree_prefix(state, line, llen);
1222         if (!name)
1223                 return NULL;
1224
1225         /*
1226          * since the first name is unquoted, a dq if exists must be
1227          * the beginning of the second name.
1228          */
1229         for (second = name; second < line + llen; second++) {
1230                 if (*second == '"') {
1231                         struct strbuf sp = STRBUF_INIT;
1232                         const char *np;
1233
1234                         if (unquote_c_style(&sp, second, NULL))
1235                                 goto free_and_fail2;
1236
1237                         np = skip_tree_prefix(state, sp.buf, sp.len);
1238                         if (!np)
1239                                 goto free_and_fail2;
1240
1241                         len = sp.buf + sp.len - np;
1242                         if (len < second - name &&
1243                             !strncmp(np, name, len) &&
1244                             isspace(name[len])) {
1245                                 /* Good */
1246                                 strbuf_remove(&sp, 0, np - sp.buf);
1247                                 return strbuf_detach(&sp, NULL);
1248                         }
1249
1250                 free_and_fail2:
1251                         strbuf_release(&sp);
1252                         return NULL;
1253                 }
1254         }
1255
1256         /*
1257          * Accept a name only if it shows up twice, exactly the same
1258          * form.
1259          */
1260         second = strchr(name, '\n');
1261         if (!second)
1262                 return NULL;
1263         line_len = second - name;
1264         for (len = 0 ; ; len++) {
1265                 switch (name[len]) {
1266                 default:
1267                         continue;
1268                 case '\n':
1269                         return NULL;
1270                 case '\t': case ' ':
1271                         /*
1272                          * Is this the separator between the preimage
1273                          * and the postimage pathname?  Again, we are
1274                          * only interested in the case where there is
1275                          * no rename, as this is only to set def_name
1276                          * and a rename patch has the names elsewhere
1277                          * in an unambiguous form.
1278                          */
1279                         if (!name[len + 1])
1280                                 return NULL; /* no postimage name */
1281                         second = skip_tree_prefix(state, name + len + 1,
1282                                                   line_len - (len + 1));
1283                         if (!second)
1284                                 return NULL;
1285                         /*
1286                          * Does len bytes starting at "name" and "second"
1287                          * (that are separated by one HT or SP we just
1288                          * found) exactly match?
1289                          */
1290                         if (second[len] == '\n' && !strncmp(name, second, len))
1291                                 return xmemdupz(name, len);
1292                 }
1293         }
1294 }
1295
1296 static int check_header_line(struct apply_state *state, struct patch *patch)
1297 {
1298         int extensions = (patch->is_delete == 1) + (patch->is_new == 1) +
1299                          (patch->is_rename == 1) + (patch->is_copy == 1);
1300         if (extensions > 1)
1301                 return error(_("inconsistent header lines %d and %d"),
1302                              patch->extension_linenr, state->linenr);
1303         if (extensions && !patch->extension_linenr)
1304                 patch->extension_linenr = state->linenr;
1305         return 0;
1306 }
1307
1308 /* Verify that we recognize the lines following a git header */
1309 static int parse_git_header(struct apply_state *state,
1310                             const char *line,
1311                             int len,
1312                             unsigned int size,
1313                             struct patch *patch)
1314 {
1315         unsigned long offset;
1316
1317         /* A git diff has explicit new/delete information, so we don't guess */
1318         patch->is_new = 0;
1319         patch->is_delete = 0;
1320
1321         /*
1322          * Some things may not have the old name in the
1323          * rest of the headers anywhere (pure mode changes,
1324          * or removing or adding empty files), so we get
1325          * the default name from the header.
1326          */
1327         patch->def_name = git_header_name(state, line, len);
1328         if (patch->def_name && state->root.len) {
1329                 char *s = xstrfmt("%s%s", state->root.buf, patch->def_name);
1330                 free(patch->def_name);
1331                 patch->def_name = s;
1332         }
1333
1334         line += len;
1335         size -= len;
1336         state->linenr++;
1337         for (offset = len ; size > 0 ; offset += len, size -= len, line += len, state->linenr++) {
1338                 static const struct opentry {
1339                         const char *str;
1340                         int (*fn)(struct apply_state *, const char *, struct patch *);
1341                 } optable[] = {
1342                         { "@@ -", gitdiff_hdrend },
1343                         { "--- ", gitdiff_oldname },
1344                         { "+++ ", gitdiff_newname },
1345                         { "old mode ", gitdiff_oldmode },
1346                         { "new mode ", gitdiff_newmode },
1347                         { "deleted file mode ", gitdiff_delete },
1348                         { "new file mode ", gitdiff_newfile },
1349                         { "copy from ", gitdiff_copysrc },
1350                         { "copy to ", gitdiff_copydst },
1351                         { "rename old ", gitdiff_renamesrc },
1352                         { "rename new ", gitdiff_renamedst },
1353                         { "rename from ", gitdiff_renamesrc },
1354                         { "rename to ", gitdiff_renamedst },
1355                         { "similarity index ", gitdiff_similarity },
1356                         { "dissimilarity index ", gitdiff_dissimilarity },
1357                         { "index ", gitdiff_index },
1358                         { "", gitdiff_unrecognized },
1359                 };
1360                 int i;
1361
1362                 len = linelen(line, size);
1363                 if (!len || line[len-1] != '\n')
1364                         break;
1365                 for (i = 0; i < ARRAY_SIZE(optable); i++) {
1366                         const struct opentry *p = optable + i;
1367                         int oplen = strlen(p->str);
1368                         int res;
1369                         if (len < oplen || memcmp(p->str, line, oplen))
1370                                 continue;
1371                         res = p->fn(state, line + oplen, patch);
1372                         if (res < 0)
1373                                 return -1;
1374                         if (check_header_line(state, patch))
1375                                 return -1;
1376                         if (res > 0)
1377                                 return offset;
1378                         break;
1379                 }
1380         }
1381
1382         return offset;
1383 }
1384
1385 static int parse_num(const char *line, unsigned long *p)
1386 {
1387         char *ptr;
1388
1389         if (!isdigit(*line))
1390                 return 0;
1391         *p = strtoul(line, &ptr, 10);
1392         return ptr - line;
1393 }
1394
1395 static int parse_range(const char *line, int len, int offset, const char *expect,
1396                        unsigned long *p1, unsigned long *p2)
1397 {
1398         int digits, ex;
1399
1400         if (offset < 0 || offset >= len)
1401                 return -1;
1402         line += offset;
1403         len -= offset;
1404
1405         digits = parse_num(line, p1);
1406         if (!digits)
1407                 return -1;
1408
1409         offset += digits;
1410         line += digits;
1411         len -= digits;
1412
1413         *p2 = 1;
1414         if (*line == ',') {
1415                 digits = parse_num(line+1, p2);
1416                 if (!digits)
1417                         return -1;
1418
1419                 offset += digits+1;
1420                 line += digits+1;
1421                 len -= digits+1;
1422         }
1423
1424         ex = strlen(expect);
1425         if (ex > len)
1426                 return -1;
1427         if (memcmp(line, expect, ex))
1428                 return -1;
1429
1430         return offset + ex;
1431 }
1432
1433 static void recount_diff(const char *line, int size, struct fragment *fragment)
1434 {
1435         int oldlines = 0, newlines = 0, ret = 0;
1436
1437         if (size < 1) {
1438                 warning("recount: ignore empty hunk");
1439                 return;
1440         }
1441
1442         for (;;) {
1443                 int len = linelen(line, size);
1444                 size -= len;
1445                 line += len;
1446
1447                 if (size < 1)
1448                         break;
1449
1450                 switch (*line) {
1451                 case ' ': case '\n':
1452                         newlines++;
1453                         /* fall through */
1454                 case '-':
1455                         oldlines++;
1456                         continue;
1457                 case '+':
1458                         newlines++;
1459                         continue;
1460                 case '\\':
1461                         continue;
1462                 case '@':
1463                         ret = size < 3 || !starts_with(line, "@@ ");
1464                         break;
1465                 case 'd':
1466                         ret = size < 5 || !starts_with(line, "diff ");
1467                         break;
1468                 default:
1469                         ret = -1;
1470                         break;
1471                 }
1472                 if (ret) {
1473                         warning(_("recount: unexpected line: %.*s"),
1474                                 (int)linelen(line, size), line);
1475                         return;
1476                 }
1477                 break;
1478         }
1479         fragment->oldlines = oldlines;
1480         fragment->newlines = newlines;
1481 }
1482
1483 /*
1484  * Parse a unified diff fragment header of the
1485  * form "@@ -a,b +c,d @@"
1486  */
1487 static int parse_fragment_header(const char *line, int len, struct fragment *fragment)
1488 {
1489         int offset;
1490
1491         if (!len || line[len-1] != '\n')
1492                 return -1;
1493
1494         /* Figure out the number of lines in a fragment */
1495         offset = parse_range(line, len, 4, " +", &fragment->oldpos, &fragment->oldlines);
1496         offset = parse_range(line, len, offset, " @@", &fragment->newpos, &fragment->newlines);
1497
1498         return offset;
1499 }
1500
1501 /*
1502  * Find file diff header
1503  *
1504  * Returns:
1505  *  -1 if no header was found
1506  *  -128 in case of error
1507  *   the size of the header in bytes (called "offset") otherwise
1508  */
1509 static int find_header(struct apply_state *state,
1510                        const char *line,
1511                        unsigned long size,
1512                        int *hdrsize,
1513                        struct patch *patch)
1514 {
1515         unsigned long offset, len;
1516
1517         patch->is_toplevel_relative = 0;
1518         patch->is_rename = patch->is_copy = 0;
1519         patch->is_new = patch->is_delete = -1;
1520         patch->old_mode = patch->new_mode = 0;
1521         patch->old_name = patch->new_name = NULL;
1522         for (offset = 0; size > 0; offset += len, size -= len, line += len, state->linenr++) {
1523                 unsigned long nextlen;
1524
1525                 len = linelen(line, size);
1526                 if (!len)
1527                         break;
1528
1529                 /* Testing this early allows us to take a few shortcuts.. */
1530                 if (len < 6)
1531                         continue;
1532
1533                 /*
1534                  * Make sure we don't find any unconnected patch fragments.
1535                  * That's a sign that we didn't find a header, and that a
1536                  * patch has become corrupted/broken up.
1537                  */
1538                 if (!memcmp("@@ -", line, 4)) {
1539                         struct fragment dummy;
1540                         if (parse_fragment_header(line, len, &dummy) < 0)
1541                                 continue;
1542                         error(_("patch fragment without header at line %d: %.*s"),
1543                                      state->linenr, (int)len-1, line);
1544                         return -128;
1545                 }
1546
1547                 if (size < len + 6)
1548                         break;
1549
1550                 /*
1551                  * Git patch? It might not have a real patch, just a rename
1552                  * or mode change, so we handle that specially
1553                  */
1554                 if (!memcmp("diff --git ", line, 11)) {
1555                         int git_hdr_len = parse_git_header(state, line, len, size, patch);
1556                         if (git_hdr_len < 0)
1557                                 return -128;
1558                         if (git_hdr_len <= len)
1559                                 continue;
1560                         if (!patch->old_name && !patch->new_name) {
1561                                 if (!patch->def_name) {
1562                                         error(Q_("git diff header lacks filename information when removing "
1563                                                         "%d leading pathname component (line %d)",
1564                                                         "git diff header lacks filename information when removing "
1565                                                         "%d leading pathname components (line %d)",
1566                                                         state->p_value),
1567                                                      state->p_value, state->linenr);
1568                                         return -128;
1569                                 }
1570                                 patch->old_name = xstrdup(patch->def_name);
1571                                 patch->new_name = xstrdup(patch->def_name);
1572                         }
1573                         if ((!patch->new_name && !patch->is_delete) ||
1574                             (!patch->old_name && !patch->is_new)) {
1575                                 error(_("git diff header lacks filename information "
1576                                              "(line %d)"), state->linenr);
1577                                 return -128;
1578                         }
1579                         patch->is_toplevel_relative = 1;
1580                         *hdrsize = git_hdr_len;
1581                         return offset;
1582                 }
1583
1584                 /* --- followed by +++ ? */
1585                 if (memcmp("--- ", line,  4) || memcmp("+++ ", line + len, 4))
1586                         continue;
1587
1588                 /*
1589                  * We only accept unified patches, so we want it to
1590                  * at least have "@@ -a,b +c,d @@\n", which is 14 chars
1591                  * minimum ("@@ -0,0 +1 @@\n" is the shortest).
1592                  */
1593                 nextlen = linelen(line + len, size - len);
1594                 if (size < nextlen + 14 || memcmp("@@ -", line + len + nextlen, 4))
1595                         continue;
1596
1597                 /* Ok, we'll consider it a patch */
1598                 if (parse_traditional_patch(state, line, line+len, patch))
1599                         return -128;
1600                 *hdrsize = len + nextlen;
1601                 state->linenr += 2;
1602                 return offset;
1603         }
1604         return -1;
1605 }
1606
1607 static void record_ws_error(struct apply_state *state,
1608                             unsigned result,
1609                             const char *line,
1610                             int len,
1611                             int linenr)
1612 {
1613         char *err;
1614
1615         if (!result)
1616                 return;
1617
1618         state->whitespace_error++;
1619         if (state->squelch_whitespace_errors &&
1620             state->squelch_whitespace_errors < state->whitespace_error)
1621                 return;
1622
1623         err = whitespace_error_string(result);
1624         if (state->apply_verbosity > verbosity_silent)
1625                 fprintf(stderr, "%s:%d: %s.\n%.*s\n",
1626                         state->patch_input_file, linenr, err, len, line);
1627         free(err);
1628 }
1629
1630 static void check_whitespace(struct apply_state *state,
1631                              const char *line,
1632                              int len,
1633                              unsigned ws_rule)
1634 {
1635         unsigned result = ws_check(line + 1, len - 1, ws_rule);
1636
1637         record_ws_error(state, result, line + 1, len - 2, state->linenr);
1638 }
1639
1640 /*
1641  * Check if the patch has context lines with CRLF or
1642  * the patch wants to remove lines with CRLF.
1643  */
1644 static void check_old_for_crlf(struct patch *patch, const char *line, int len)
1645 {
1646         if (len >= 2 && line[len-1] == '\n' && line[len-2] == '\r') {
1647                 patch->ws_rule |= WS_CR_AT_EOL;
1648                 patch->crlf_in_old = 1;
1649         }
1650 }
1651
1652
1653 /*
1654  * Parse a unified diff. Note that this really needs to parse each
1655  * fragment separately, since the only way to know the difference
1656  * between a "---" that is part of a patch, and a "---" that starts
1657  * the next patch is to look at the line counts..
1658  */
1659 static int parse_fragment(struct apply_state *state,
1660                           const char *line,
1661                           unsigned long size,
1662                           struct patch *patch,
1663                           struct fragment *fragment)
1664 {
1665         int added, deleted;
1666         int len = linelen(line, size), offset;
1667         unsigned long oldlines, newlines;
1668         unsigned long leading, trailing;
1669
1670         offset = parse_fragment_header(line, len, fragment);
1671         if (offset < 0)
1672                 return -1;
1673         if (offset > 0 && patch->recount)
1674                 recount_diff(line + offset, size - offset, fragment);
1675         oldlines = fragment->oldlines;
1676         newlines = fragment->newlines;
1677         leading = 0;
1678         trailing = 0;
1679
1680         /* Parse the thing.. */
1681         line += len;
1682         size -= len;
1683         state->linenr++;
1684         added = deleted = 0;
1685         for (offset = len;
1686              0 < size;
1687              offset += len, size -= len, line += len, state->linenr++) {
1688                 if (!oldlines && !newlines)
1689                         break;
1690                 len = linelen(line, size);
1691                 if (!len || line[len-1] != '\n')
1692                         return -1;
1693                 switch (*line) {
1694                 default:
1695                         return -1;
1696                 case '\n': /* newer GNU diff, an empty context line */
1697                 case ' ':
1698                         oldlines--;
1699                         newlines--;
1700                         if (!deleted && !added)
1701                                 leading++;
1702                         trailing++;
1703                         check_old_for_crlf(patch, line, len);
1704                         if (!state->apply_in_reverse &&
1705                             state->ws_error_action == correct_ws_error)
1706                                 check_whitespace(state, line, len, patch->ws_rule);
1707                         break;
1708                 case '-':
1709                         if (!state->apply_in_reverse)
1710                                 check_old_for_crlf(patch, line, len);
1711                         if (state->apply_in_reverse &&
1712                             state->ws_error_action != nowarn_ws_error)
1713                                 check_whitespace(state, line, len, patch->ws_rule);
1714                         deleted++;
1715                         oldlines--;
1716                         trailing = 0;
1717                         break;
1718                 case '+':
1719                         if (state->apply_in_reverse)
1720                                 check_old_for_crlf(patch, line, len);
1721                         if (!state->apply_in_reverse &&
1722                             state->ws_error_action != nowarn_ws_error)
1723                                 check_whitespace(state, line, len, patch->ws_rule);
1724                         added++;
1725                         newlines--;
1726                         trailing = 0;
1727                         break;
1728
1729                 /*
1730                  * We allow "\ No newline at end of file". Depending
1731                  * on locale settings when the patch was produced we
1732                  * don't know what this line looks like. The only
1733                  * thing we do know is that it begins with "\ ".
1734                  * Checking for 12 is just for sanity check -- any
1735                  * l10n of "\ No newline..." is at least that long.
1736                  */
1737                 case '\\':
1738                         if (len < 12 || memcmp(line, "\\ ", 2))
1739                                 return -1;
1740                         break;
1741                 }
1742         }
1743         if (oldlines || newlines)
1744                 return -1;
1745         if (!deleted && !added)
1746                 return -1;
1747
1748         fragment->leading = leading;
1749         fragment->trailing = trailing;
1750
1751         /*
1752          * If a fragment ends with an incomplete line, we failed to include
1753          * it in the above loop because we hit oldlines == newlines == 0
1754          * before seeing it.
1755          */
1756         if (12 < size && !memcmp(line, "\\ ", 2))
1757                 offset += linelen(line, size);
1758
1759         patch->lines_added += added;
1760         patch->lines_deleted += deleted;
1761
1762         if (0 < patch->is_new && oldlines)
1763                 return error(_("new file depends on old contents"));
1764         if (0 < patch->is_delete && newlines)
1765                 return error(_("deleted file still has contents"));
1766         return offset;
1767 }
1768
1769 /*
1770  * We have seen "diff --git a/... b/..." header (or a traditional patch
1771  * header).  Read hunks that belong to this patch into fragments and hang
1772  * them to the given patch structure.
1773  *
1774  * The (fragment->patch, fragment->size) pair points into the memory given
1775  * by the caller, not a copy, when we return.
1776  *
1777  * Returns:
1778  *   -1 in case of error,
1779  *   the number of bytes in the patch otherwise.
1780  */
1781 static int parse_single_patch(struct apply_state *state,
1782                               const char *line,
1783                               unsigned long size,
1784                               struct patch *patch)
1785 {
1786         unsigned long offset = 0;
1787         unsigned long oldlines = 0, newlines = 0, context = 0;
1788         struct fragment **fragp = &patch->fragments;
1789
1790         while (size > 4 && !memcmp(line, "@@ -", 4)) {
1791                 struct fragment *fragment;
1792                 int len;
1793
1794                 fragment = xcalloc(1, sizeof(*fragment));
1795                 fragment->linenr = state->linenr;
1796                 len = parse_fragment(state, line, size, patch, fragment);
1797                 if (len <= 0) {
1798                         free(fragment);
1799                         return error(_("corrupt patch at line %d"), state->linenr);
1800                 }
1801                 fragment->patch = line;
1802                 fragment->size = len;
1803                 oldlines += fragment->oldlines;
1804                 newlines += fragment->newlines;
1805                 context += fragment->leading + fragment->trailing;
1806
1807                 *fragp = fragment;
1808                 fragp = &fragment->next;
1809
1810                 offset += len;
1811                 line += len;
1812                 size -= len;
1813         }
1814
1815         /*
1816          * If something was removed (i.e. we have old-lines) it cannot
1817          * be creation, and if something was added it cannot be
1818          * deletion.  However, the reverse is not true; --unified=0
1819          * patches that only add are not necessarily creation even
1820          * though they do not have any old lines, and ones that only
1821          * delete are not necessarily deletion.
1822          *
1823          * Unfortunately, a real creation/deletion patch do _not_ have
1824          * any context line by definition, so we cannot safely tell it
1825          * apart with --unified=0 insanity.  At least if the patch has
1826          * more than one hunk it is not creation or deletion.
1827          */
1828         if (patch->is_new < 0 &&
1829             (oldlines || (patch->fragments && patch->fragments->next)))
1830                 patch->is_new = 0;
1831         if (patch->is_delete < 0 &&
1832             (newlines || (patch->fragments && patch->fragments->next)))
1833                 patch->is_delete = 0;
1834
1835         if (0 < patch->is_new && oldlines)
1836                 return error(_("new file %s depends on old contents"), patch->new_name);
1837         if (0 < patch->is_delete && newlines)
1838                 return error(_("deleted file %s still has contents"), patch->old_name);
1839         if (!patch->is_delete && !newlines && context && state->apply_verbosity > verbosity_silent)
1840                 fprintf_ln(stderr,
1841                            _("** warning: "
1842                              "file %s becomes empty but is not deleted"),
1843                            patch->new_name);
1844
1845         return offset;
1846 }
1847
1848 static inline int metadata_changes(struct patch *patch)
1849 {
1850         return  patch->is_rename > 0 ||
1851                 patch->is_copy > 0 ||
1852                 patch->is_new > 0 ||
1853                 patch->is_delete ||
1854                 (patch->old_mode && patch->new_mode &&
1855                  patch->old_mode != patch->new_mode);
1856 }
1857
1858 static char *inflate_it(const void *data, unsigned long size,
1859                         unsigned long inflated_size)
1860 {
1861         git_zstream stream;
1862         void *out;
1863         int st;
1864
1865         memset(&stream, 0, sizeof(stream));
1866
1867         stream.next_in = (unsigned char *)data;
1868         stream.avail_in = size;
1869         stream.next_out = out = xmalloc(inflated_size);
1870         stream.avail_out = inflated_size;
1871         git_inflate_init(&stream);
1872         st = git_inflate(&stream, Z_FINISH);
1873         git_inflate_end(&stream);
1874         if ((st != Z_STREAM_END) || stream.total_out != inflated_size) {
1875                 free(out);
1876                 return NULL;
1877         }
1878         return out;
1879 }
1880
1881 /*
1882  * Read a binary hunk and return a new fragment; fragment->patch
1883  * points at an allocated memory that the caller must free, so
1884  * it is marked as "->free_patch = 1".
1885  */
1886 static struct fragment *parse_binary_hunk(struct apply_state *state,
1887                                           char **buf_p,
1888                                           unsigned long *sz_p,
1889                                           int *status_p,
1890                                           int *used_p)
1891 {
1892         /*
1893          * Expect a line that begins with binary patch method ("literal"
1894          * or "delta"), followed by the length of data before deflating.
1895          * a sequence of 'length-byte' followed by base-85 encoded data
1896          * should follow, terminated by a newline.
1897          *
1898          * Each 5-byte sequence of base-85 encodes up to 4 bytes,
1899          * and we would limit the patch line to 66 characters,
1900          * so one line can fit up to 13 groups that would decode
1901          * to 52 bytes max.  The length byte 'A'-'Z' corresponds
1902          * to 1-26 bytes, and 'a'-'z' corresponds to 27-52 bytes.
1903          */
1904         int llen, used;
1905         unsigned long size = *sz_p;
1906         char *buffer = *buf_p;
1907         int patch_method;
1908         unsigned long origlen;
1909         char *data = NULL;
1910         int hunk_size = 0;
1911         struct fragment *frag;
1912
1913         llen = linelen(buffer, size);
1914         used = llen;
1915
1916         *status_p = 0;
1917
1918         if (starts_with(buffer, "delta ")) {
1919                 patch_method = BINARY_DELTA_DEFLATED;
1920                 origlen = strtoul(buffer + 6, NULL, 10);
1921         }
1922         else if (starts_with(buffer, "literal ")) {
1923                 patch_method = BINARY_LITERAL_DEFLATED;
1924                 origlen = strtoul(buffer + 8, NULL, 10);
1925         }
1926         else
1927                 return NULL;
1928
1929         state->linenr++;
1930         buffer += llen;
1931         while (1) {
1932                 int byte_length, max_byte_length, newsize;
1933                 llen = linelen(buffer, size);
1934                 used += llen;
1935                 state->linenr++;
1936                 if (llen == 1) {
1937                         /* consume the blank line */
1938                         buffer++;
1939                         size--;
1940                         break;
1941                 }
1942                 /*
1943                  * Minimum line is "A00000\n" which is 7-byte long,
1944                  * and the line length must be multiple of 5 plus 2.
1945                  */
1946                 if ((llen < 7) || (llen-2) % 5)
1947                         goto corrupt;
1948                 max_byte_length = (llen - 2) / 5 * 4;
1949                 byte_length = *buffer;
1950                 if ('A' <= byte_length && byte_length <= 'Z')
1951                         byte_length = byte_length - 'A' + 1;
1952                 else if ('a' <= byte_length && byte_length <= 'z')
1953                         byte_length = byte_length - 'a' + 27;
1954                 else
1955                         goto corrupt;
1956                 /* if the input length was not multiple of 4, we would
1957                  * have filler at the end but the filler should never
1958                  * exceed 3 bytes
1959                  */
1960                 if (max_byte_length < byte_length ||
1961                     byte_length <= max_byte_length - 4)
1962                         goto corrupt;
1963                 newsize = hunk_size + byte_length;
1964                 data = xrealloc(data, newsize);
1965                 if (decode_85(data + hunk_size, buffer + 1, byte_length))
1966                         goto corrupt;
1967                 hunk_size = newsize;
1968                 buffer += llen;
1969                 size -= llen;
1970         }
1971
1972         frag = xcalloc(1, sizeof(*frag));
1973         frag->patch = inflate_it(data, hunk_size, origlen);
1974         frag->free_patch = 1;
1975         if (!frag->patch)
1976                 goto corrupt;
1977         free(data);
1978         frag->size = origlen;
1979         *buf_p = buffer;
1980         *sz_p = size;
1981         *used_p = used;
1982         frag->binary_patch_method = patch_method;
1983         return frag;
1984
1985  corrupt:
1986         free(data);
1987         *status_p = -1;
1988         error(_("corrupt binary patch at line %d: %.*s"),
1989               state->linenr-1, llen-1, buffer);
1990         return NULL;
1991 }
1992
1993 /*
1994  * Returns:
1995  *   -1 in case of error,
1996  *   the length of the parsed binary patch otherwise
1997  */
1998 static int parse_binary(struct apply_state *state,
1999                         char *buffer,
2000                         unsigned long size,
2001                         struct patch *patch)
2002 {
2003         /*
2004          * We have read "GIT binary patch\n"; what follows is a line
2005          * that says the patch method (currently, either "literal" or
2006          * "delta") and the length of data before deflating; a
2007          * sequence of 'length-byte' followed by base-85 encoded data
2008          * follows.
2009          *
2010          * When a binary patch is reversible, there is another binary
2011          * hunk in the same format, starting with patch method (either
2012          * "literal" or "delta") with the length of data, and a sequence
2013          * of length-byte + base-85 encoded data, terminated with another
2014          * empty line.  This data, when applied to the postimage, produces
2015          * the preimage.
2016          */
2017         struct fragment *forward;
2018         struct fragment *reverse;
2019         int status;
2020         int used, used_1;
2021
2022         forward = parse_binary_hunk(state, &buffer, &size, &status, &used);
2023         if (!forward && !status)
2024                 /* there has to be one hunk (forward hunk) */
2025                 return error(_("unrecognized binary patch at line %d"), state->linenr-1);
2026         if (status)
2027                 /* otherwise we already gave an error message */
2028                 return status;
2029
2030         reverse = parse_binary_hunk(state, &buffer, &size, &status, &used_1);
2031         if (reverse)
2032                 used += used_1;
2033         else if (status) {
2034                 /*
2035                  * Not having reverse hunk is not an error, but having
2036                  * a corrupt reverse hunk is.
2037                  */
2038                 free((void*) forward->patch);
2039                 free(forward);
2040                 return status;
2041         }
2042         forward->next = reverse;
2043         patch->fragments = forward;
2044         patch->is_binary = 1;
2045         return used;
2046 }
2047
2048 static void prefix_one(struct apply_state *state, char **name)
2049 {
2050         char *old_name = *name;
2051         if (!old_name)
2052                 return;
2053         *name = prefix_filename(state->prefix, *name);
2054         free(old_name);
2055 }
2056
2057 static void prefix_patch(struct apply_state *state, struct patch *p)
2058 {
2059         if (!state->prefix || p->is_toplevel_relative)
2060                 return;
2061         prefix_one(state, &p->new_name);
2062         prefix_one(state, &p->old_name);
2063 }
2064
2065 /*
2066  * include/exclude
2067  */
2068
2069 static void add_name_limit(struct apply_state *state,
2070                            const char *name,
2071                            int exclude)
2072 {
2073         struct string_list_item *it;
2074
2075         it = string_list_append(&state->limit_by_name, name);
2076         it->util = exclude ? NULL : (void *) 1;
2077 }
2078
2079 static int use_patch(struct apply_state *state, struct patch *p)
2080 {
2081         const char *pathname = p->new_name ? p->new_name : p->old_name;
2082         int i;
2083
2084         /* Paths outside are not touched regardless of "--include" */
2085         if (state->prefix && *state->prefix) {
2086                 const char *rest;
2087                 if (!skip_prefix(pathname, state->prefix, &rest) || !*rest)
2088                         return 0;
2089         }
2090
2091         /* See if it matches any of exclude/include rule */
2092         for (i = 0; i < state->limit_by_name.nr; i++) {
2093                 struct string_list_item *it = &state->limit_by_name.items[i];
2094                 if (!wildmatch(it->string, pathname, 0))
2095                         return (it->util != NULL);
2096         }
2097
2098         /*
2099          * If we had any include, a path that does not match any rule is
2100          * not used.  Otherwise, we saw bunch of exclude rules (or none)
2101          * and such a path is used.
2102          */
2103         return !state->has_include;
2104 }
2105
2106 /*
2107  * Read the patch text in "buffer" that extends for "size" bytes; stop
2108  * reading after seeing a single patch (i.e. changes to a single file).
2109  * Create fragments (i.e. patch hunks) and hang them to the given patch.
2110  *
2111  * Returns:
2112  *   -1 if no header was found or parse_binary() failed,
2113  *   -128 on another error,
2114  *   the number of bytes consumed otherwise,
2115  *     so that the caller can call us again for the next patch.
2116  */
2117 static int parse_chunk(struct apply_state *state, char *buffer, unsigned long size, struct patch *patch)
2118 {
2119         int hdrsize, patchsize;
2120         int offset = find_header(state, buffer, size, &hdrsize, patch);
2121
2122         if (offset < 0)
2123                 return offset;
2124
2125         prefix_patch(state, patch);
2126
2127         if (!use_patch(state, patch))
2128                 patch->ws_rule = 0;
2129         else
2130                 patch->ws_rule = whitespace_rule(patch->new_name
2131                                                  ? patch->new_name
2132                                                  : patch->old_name);
2133
2134         patchsize = parse_single_patch(state,
2135                                        buffer + offset + hdrsize,
2136                                        size - offset - hdrsize,
2137                                        patch);
2138
2139         if (patchsize < 0)
2140                 return -128;
2141
2142         if (!patchsize) {
2143                 static const char git_binary[] = "GIT binary patch\n";
2144                 int hd = hdrsize + offset;
2145                 unsigned long llen = linelen(buffer + hd, size - hd);
2146
2147                 if (llen == sizeof(git_binary) - 1 &&
2148                     !memcmp(git_binary, buffer + hd, llen)) {
2149                         int used;
2150                         state->linenr++;
2151                         used = parse_binary(state, buffer + hd + llen,
2152                                             size - hd - llen, patch);
2153                         if (used < 0)
2154                                 return -1;
2155                         if (used)
2156                                 patchsize = used + llen;
2157                         else
2158                                 patchsize = 0;
2159                 }
2160                 else if (!memcmp(" differ\n", buffer + hd + llen - 8, 8)) {
2161                         static const char *binhdr[] = {
2162                                 "Binary files ",
2163                                 "Files ",
2164                                 NULL,
2165                         };
2166                         int i;
2167                         for (i = 0; binhdr[i]; i++) {
2168                                 int len = strlen(binhdr[i]);
2169                                 if (len < size - hd &&
2170                                     !memcmp(binhdr[i], buffer + hd, len)) {
2171                                         state->linenr++;
2172                                         patch->is_binary = 1;
2173                                         patchsize = llen;
2174                                         break;
2175                                 }
2176                         }
2177                 }
2178
2179                 /* Empty patch cannot be applied if it is a text patch
2180                  * without metadata change.  A binary patch appears
2181                  * empty to us here.
2182                  */
2183                 if ((state->apply || state->check) &&
2184                     (!patch->is_binary && !metadata_changes(patch))) {
2185                         error(_("patch with only garbage at line %d"), state->linenr);
2186                         return -128;
2187                 }
2188         }
2189
2190         return offset + hdrsize + patchsize;
2191 }
2192
2193 static void reverse_patches(struct patch *p)
2194 {
2195         for (; p; p = p->next) {
2196                 struct fragment *frag = p->fragments;
2197
2198                 SWAP(p->new_name, p->old_name);
2199                 SWAP(p->new_mode, p->old_mode);
2200                 SWAP(p->is_new, p->is_delete);
2201                 SWAP(p->lines_added, p->lines_deleted);
2202                 SWAP(p->old_sha1_prefix, p->new_sha1_prefix);
2203
2204                 for (; frag; frag = frag->next) {
2205                         SWAP(frag->newpos, frag->oldpos);
2206                         SWAP(frag->newlines, frag->oldlines);
2207                 }
2208         }
2209 }
2210
2211 static const char pluses[] =
2212 "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
2213 static const char minuses[]=
2214 "----------------------------------------------------------------------";
2215
2216 static void show_stats(struct apply_state *state, struct patch *patch)
2217 {
2218         struct strbuf qname = STRBUF_INIT;
2219         char *cp = patch->new_name ? patch->new_name : patch->old_name;
2220         int max, add, del;
2221
2222         quote_c_style(cp, &qname, NULL, 0);
2223
2224         /*
2225          * "scale" the filename
2226          */
2227         max = state->max_len;
2228         if (max > 50)
2229                 max = 50;
2230
2231         if (qname.len > max) {
2232                 cp = strchr(qname.buf + qname.len + 3 - max, '/');
2233                 if (!cp)
2234                         cp = qname.buf + qname.len + 3 - max;
2235                 strbuf_splice(&qname, 0, cp - qname.buf, "...", 3);
2236         }
2237
2238         if (patch->is_binary) {
2239                 printf(" %-*s |  Bin\n", max, qname.buf);
2240                 strbuf_release(&qname);
2241                 return;
2242         }
2243
2244         printf(" %-*s |", max, qname.buf);
2245         strbuf_release(&qname);
2246
2247         /*
2248          * scale the add/delete
2249          */
2250         max = max + state->max_change > 70 ? 70 - max : state->max_change;
2251         add = patch->lines_added;
2252         del = patch->lines_deleted;
2253
2254         if (state->max_change > 0) {
2255                 int total = ((add + del) * max + state->max_change / 2) / state->max_change;
2256                 add = (add * max + state->max_change / 2) / state->max_change;
2257                 del = total - add;
2258         }
2259         printf("%5d %.*s%.*s\n", patch->lines_added + patch->lines_deleted,
2260                 add, pluses, del, minuses);
2261 }
2262
2263 static int read_old_data(struct stat *st, struct patch *patch,
2264                          const char *path, struct strbuf *buf)
2265 {
2266         enum safe_crlf safe_crlf = patch->crlf_in_old ?
2267                 SAFE_CRLF_KEEP_CRLF : SAFE_CRLF_RENORMALIZE;
2268         switch (st->st_mode & S_IFMT) {
2269         case S_IFLNK:
2270                 if (strbuf_readlink(buf, path, st->st_size) < 0)
2271                         return error(_("unable to read symlink %s"), path);
2272                 return 0;
2273         case S_IFREG:
2274                 if (strbuf_read_file(buf, path, st->st_size) != st->st_size)
2275                         return error(_("unable to open or read %s"), path);
2276                 /*
2277                  * "git apply" without "--index/--cached" should never look
2278                  * at the index; the target file may not have been added to
2279                  * the index yet, and we may not even be in any Git repository.
2280                  * Pass NULL to convert_to_git() to stress this; the function
2281                  * should never look at the index when explicit crlf option
2282                  * is given.
2283                  */
2284                 convert_to_git(NULL, path, buf->buf, buf->len, buf, safe_crlf);
2285                 return 0;
2286         default:
2287                 return -1;
2288         }
2289 }
2290
2291 /*
2292  * Update the preimage, and the common lines in postimage,
2293  * from buffer buf of length len. If postlen is 0 the postimage
2294  * is updated in place, otherwise it's updated on a new buffer
2295  * of length postlen
2296  */
2297
2298 static void update_pre_post_images(struct image *preimage,
2299                                    struct image *postimage,
2300                                    char *buf,
2301                                    size_t len, size_t postlen)
2302 {
2303         int i, ctx, reduced;
2304         char *new, *old, *fixed;
2305         struct image fixed_preimage;
2306
2307         /*
2308          * Update the preimage with whitespace fixes.  Note that we
2309          * are not losing preimage->buf -- apply_one_fragment() will
2310          * free "oldlines".
2311          */
2312         prepare_image(&fixed_preimage, buf, len, 1);
2313         assert(postlen
2314                ? fixed_preimage.nr == preimage->nr
2315                : fixed_preimage.nr <= preimage->nr);
2316         for (i = 0; i < fixed_preimage.nr; i++)
2317                 fixed_preimage.line[i].flag = preimage->line[i].flag;
2318         free(preimage->line_allocated);
2319         *preimage = fixed_preimage;
2320
2321         /*
2322          * Adjust the common context lines in postimage. This can be
2323          * done in-place when we are shrinking it with whitespace
2324          * fixing, but needs a new buffer when ignoring whitespace or
2325          * expanding leading tabs to spaces.
2326          *
2327          * We trust the caller to tell us if the update can be done
2328          * in place (postlen==0) or not.
2329          */
2330         old = postimage->buf;
2331         if (postlen)
2332                 new = postimage->buf = xmalloc(postlen);
2333         else
2334                 new = old;
2335         fixed = preimage->buf;
2336
2337         for (i = reduced = ctx = 0; i < postimage->nr; i++) {
2338                 size_t l_len = postimage->line[i].len;
2339                 if (!(postimage->line[i].flag & LINE_COMMON)) {
2340                         /* an added line -- no counterparts in preimage */
2341                         memmove(new, old, l_len);
2342                         old += l_len;
2343                         new += l_len;
2344                         continue;
2345                 }
2346
2347                 /* a common context -- skip it in the original postimage */
2348                 old += l_len;
2349
2350                 /* and find the corresponding one in the fixed preimage */
2351                 while (ctx < preimage->nr &&
2352                        !(preimage->line[ctx].flag & LINE_COMMON)) {
2353                         fixed += preimage->line[ctx].len;
2354                         ctx++;
2355                 }
2356
2357                 /*
2358                  * preimage is expected to run out, if the caller
2359                  * fixed addition of trailing blank lines.
2360                  */
2361                 if (preimage->nr <= ctx) {
2362                         reduced++;
2363                         continue;
2364                 }
2365
2366                 /* and copy it in, while fixing the line length */
2367                 l_len = preimage->line[ctx].len;
2368                 memcpy(new, fixed, l_len);
2369                 new += l_len;
2370                 fixed += l_len;
2371                 postimage->line[i].len = l_len;
2372                 ctx++;
2373         }
2374
2375         if (postlen
2376             ? postlen < new - postimage->buf
2377             : postimage->len < new - postimage->buf)
2378                 die("BUG: caller miscounted postlen: asked %d, orig = %d, used = %d",
2379                     (int)postlen, (int) postimage->len, (int)(new - postimage->buf));
2380
2381         /* Fix the length of the whole thing */
2382         postimage->len = new - postimage->buf;
2383         postimage->nr -= reduced;
2384 }
2385
2386 static int line_by_line_fuzzy_match(struct image *img,
2387                                     struct image *preimage,
2388                                     struct image *postimage,
2389                                     unsigned long try,
2390                                     int try_lno,
2391                                     int preimage_limit)
2392 {
2393         int i;
2394         size_t imgoff = 0;
2395         size_t preoff = 0;
2396         size_t postlen = postimage->len;
2397         size_t extra_chars;
2398         char *buf;
2399         char *preimage_eof;
2400         char *preimage_end;
2401         struct strbuf fixed;
2402         char *fixed_buf;
2403         size_t fixed_len;
2404
2405         for (i = 0; i < preimage_limit; i++) {
2406                 size_t prelen = preimage->line[i].len;
2407                 size_t imglen = img->line[try_lno+i].len;
2408
2409                 if (!fuzzy_matchlines(img->buf + try + imgoff, imglen,
2410                                       preimage->buf + preoff, prelen))
2411                         return 0;
2412                 if (preimage->line[i].flag & LINE_COMMON)
2413                         postlen += imglen - prelen;
2414                 imgoff += imglen;
2415                 preoff += prelen;
2416         }
2417
2418         /*
2419          * Ok, the preimage matches with whitespace fuzz.
2420          *
2421          * imgoff now holds the true length of the target that
2422          * matches the preimage before the end of the file.
2423          *
2424          * Count the number of characters in the preimage that fall
2425          * beyond the end of the file and make sure that all of them
2426          * are whitespace characters. (This can only happen if
2427          * we are removing blank lines at the end of the file.)
2428          */
2429         buf = preimage_eof = preimage->buf + preoff;
2430         for ( ; i < preimage->nr; i++)
2431                 preoff += preimage->line[i].len;
2432         preimage_end = preimage->buf + preoff;
2433         for ( ; buf < preimage_end; buf++)
2434                 if (!isspace(*buf))
2435                         return 0;
2436
2437         /*
2438          * Update the preimage and the common postimage context
2439          * lines to use the same whitespace as the target.
2440          * If whitespace is missing in the target (i.e.
2441          * if the preimage extends beyond the end of the file),
2442          * use the whitespace from the preimage.
2443          */
2444         extra_chars = preimage_end - preimage_eof;
2445         strbuf_init(&fixed, imgoff + extra_chars);
2446         strbuf_add(&fixed, img->buf + try, imgoff);
2447         strbuf_add(&fixed, preimage_eof, extra_chars);
2448         fixed_buf = strbuf_detach(&fixed, &fixed_len);
2449         update_pre_post_images(preimage, postimage,
2450                                fixed_buf, fixed_len, postlen);
2451         return 1;
2452 }
2453
2454 static int match_fragment(struct apply_state *state,
2455                           struct image *img,
2456                           struct image *preimage,
2457                           struct image *postimage,
2458                           unsigned long try,
2459                           int try_lno,
2460                           unsigned ws_rule,
2461                           int match_beginning, int match_end)
2462 {
2463         int i;
2464         char *fixed_buf, *buf, *orig, *target;
2465         struct strbuf fixed;
2466         size_t fixed_len, postlen;
2467         int preimage_limit;
2468
2469         if (preimage->nr + try_lno <= img->nr) {
2470                 /*
2471                  * The hunk falls within the boundaries of img.
2472                  */
2473                 preimage_limit = preimage->nr;
2474                 if (match_end && (preimage->nr + try_lno != img->nr))
2475                         return 0;
2476         } else if (state->ws_error_action == correct_ws_error &&
2477                    (ws_rule & WS_BLANK_AT_EOF)) {
2478                 /*
2479                  * This hunk extends beyond the end of img, and we are
2480                  * removing blank lines at the end of the file.  This
2481                  * many lines from the beginning of the preimage must
2482                  * match with img, and the remainder of the preimage
2483                  * must be blank.
2484                  */
2485                 preimage_limit = img->nr - try_lno;
2486         } else {
2487                 /*
2488                  * The hunk extends beyond the end of the img and
2489                  * we are not removing blanks at the end, so we
2490                  * should reject the hunk at this position.
2491                  */
2492                 return 0;
2493         }
2494
2495         if (match_beginning && try_lno)
2496                 return 0;
2497
2498         /* Quick hash check */
2499         for (i = 0; i < preimage_limit; i++)
2500                 if ((img->line[try_lno + i].flag & LINE_PATCHED) ||
2501                     (preimage->line[i].hash != img->line[try_lno + i].hash))
2502                         return 0;
2503
2504         if (preimage_limit == preimage->nr) {
2505                 /*
2506                  * Do we have an exact match?  If we were told to match
2507                  * at the end, size must be exactly at try+fragsize,
2508                  * otherwise try+fragsize must be still within the preimage,
2509                  * and either case, the old piece should match the preimage
2510                  * exactly.
2511                  */
2512                 if ((match_end
2513                      ? (try + preimage->len == img->len)
2514                      : (try + preimage->len <= img->len)) &&
2515                     !memcmp(img->buf + try, preimage->buf, preimage->len))
2516                         return 1;
2517         } else {
2518                 /*
2519                  * The preimage extends beyond the end of img, so
2520                  * there cannot be an exact match.
2521                  *
2522                  * There must be one non-blank context line that match
2523                  * a line before the end of img.
2524                  */
2525                 char *buf_end;
2526
2527                 buf = preimage->buf;
2528                 buf_end = buf;
2529                 for (i = 0; i < preimage_limit; i++)
2530                         buf_end += preimage->line[i].len;
2531
2532                 for ( ; buf < buf_end; buf++)
2533                         if (!isspace(*buf))
2534                                 break;
2535                 if (buf == buf_end)
2536                         return 0;
2537         }
2538
2539         /*
2540          * No exact match. If we are ignoring whitespace, run a line-by-line
2541          * fuzzy matching. We collect all the line length information because
2542          * we need it to adjust whitespace if we match.
2543          */
2544         if (state->ws_ignore_action == ignore_ws_change)
2545                 return line_by_line_fuzzy_match(img, preimage, postimage,
2546                                                 try, try_lno, preimage_limit);
2547
2548         if (state->ws_error_action != correct_ws_error)
2549                 return 0;
2550
2551         /*
2552          * The hunk does not apply byte-by-byte, but the hash says
2553          * it might with whitespace fuzz. We weren't asked to
2554          * ignore whitespace, we were asked to correct whitespace
2555          * errors, so let's try matching after whitespace correction.
2556          *
2557          * While checking the preimage against the target, whitespace
2558          * errors in both fixed, we count how large the corresponding
2559          * postimage needs to be.  The postimage prepared by
2560          * apply_one_fragment() has whitespace errors fixed on added
2561          * lines already, but the common lines were propagated as-is,
2562          * which may become longer when their whitespace errors are
2563          * fixed.
2564          */
2565
2566         /* First count added lines in postimage */
2567         postlen = 0;
2568         for (i = 0; i < postimage->nr; i++) {
2569                 if (!(postimage->line[i].flag & LINE_COMMON))
2570                         postlen += postimage->line[i].len;
2571         }
2572
2573         /*
2574          * The preimage may extend beyond the end of the file,
2575          * but in this loop we will only handle the part of the
2576          * preimage that falls within the file.
2577          */
2578         strbuf_init(&fixed, preimage->len + 1);
2579         orig = preimage->buf;
2580         target = img->buf + try;
2581         for (i = 0; i < preimage_limit; i++) {
2582                 size_t oldlen = preimage->line[i].len;
2583                 size_t tgtlen = img->line[try_lno + i].len;
2584                 size_t fixstart = fixed.len;
2585                 struct strbuf tgtfix;
2586                 int match;
2587
2588                 /* Try fixing the line in the preimage */
2589                 ws_fix_copy(&fixed, orig, oldlen, ws_rule, NULL);
2590
2591                 /* Try fixing the line in the target */
2592                 strbuf_init(&tgtfix, tgtlen);
2593                 ws_fix_copy(&tgtfix, target, tgtlen, ws_rule, NULL);
2594
2595                 /*
2596                  * If they match, either the preimage was based on
2597                  * a version before our tree fixed whitespace breakage,
2598                  * or we are lacking a whitespace-fix patch the tree
2599                  * the preimage was based on already had (i.e. target
2600                  * has whitespace breakage, the preimage doesn't).
2601                  * In either case, we are fixing the whitespace breakages
2602                  * so we might as well take the fix together with their
2603                  * real change.
2604                  */
2605                 match = (tgtfix.len == fixed.len - fixstart &&
2606                          !memcmp(tgtfix.buf, fixed.buf + fixstart,
2607                                              fixed.len - fixstart));
2608
2609                 /* Add the length if this is common with the postimage */
2610                 if (preimage->line[i].flag & LINE_COMMON)
2611                         postlen += tgtfix.len;
2612
2613                 strbuf_release(&tgtfix);
2614                 if (!match)
2615                         goto unmatch_exit;
2616
2617                 orig += oldlen;
2618                 target += tgtlen;
2619         }
2620
2621
2622         /*
2623          * Now handle the lines in the preimage that falls beyond the
2624          * end of the file (if any). They will only match if they are
2625          * empty or only contain whitespace (if WS_BLANK_AT_EOL is
2626          * false).
2627          */
2628         for ( ; i < preimage->nr; i++) {
2629                 size_t fixstart = fixed.len; /* start of the fixed preimage */
2630                 size_t oldlen = preimage->line[i].len;
2631                 int j;
2632
2633                 /* Try fixing the line in the preimage */
2634                 ws_fix_copy(&fixed, orig, oldlen, ws_rule, NULL);
2635
2636                 for (j = fixstart; j < fixed.len; j++)
2637                         if (!isspace(fixed.buf[j]))
2638                                 goto unmatch_exit;
2639
2640                 orig += oldlen;
2641         }
2642
2643         /*
2644          * Yes, the preimage is based on an older version that still
2645          * has whitespace breakages unfixed, and fixing them makes the
2646          * hunk match.  Update the context lines in the postimage.
2647          */
2648         fixed_buf = strbuf_detach(&fixed, &fixed_len);
2649         if (postlen < postimage->len)
2650                 postlen = 0;
2651         update_pre_post_images(preimage, postimage,
2652                                fixed_buf, fixed_len, postlen);
2653         return 1;
2654
2655  unmatch_exit:
2656         strbuf_release(&fixed);
2657         return 0;
2658 }
2659
2660 static int find_pos(struct apply_state *state,
2661                     struct image *img,
2662                     struct image *preimage,
2663                     struct image *postimage,
2664                     int line,
2665                     unsigned ws_rule,
2666                     int match_beginning, int match_end)
2667 {
2668         int i;
2669         unsigned long backwards, forwards, try;
2670         int backwards_lno, forwards_lno, try_lno;
2671
2672         /*
2673          * If match_beginning or match_end is specified, there is no
2674          * point starting from a wrong line that will never match and
2675          * wander around and wait for a match at the specified end.
2676          */
2677         if (match_beginning)
2678                 line = 0;
2679         else if (match_end)
2680                 line = img->nr - preimage->nr;
2681
2682         /*
2683          * Because the comparison is unsigned, the following test
2684          * will also take care of a negative line number that can
2685          * result when match_end and preimage is larger than the target.
2686          */
2687         if ((size_t) line > img->nr)
2688                 line = img->nr;
2689
2690         try = 0;
2691         for (i = 0; i < line; i++)
2692                 try += img->line[i].len;
2693
2694         /*
2695          * There's probably some smart way to do this, but I'll leave
2696          * that to the smart and beautiful people. I'm simple and stupid.
2697          */
2698         backwards = try;
2699         backwards_lno = line;
2700         forwards = try;
2701         forwards_lno = line;
2702         try_lno = line;
2703
2704         for (i = 0; ; i++) {
2705                 if (match_fragment(state, img, preimage, postimage,
2706                                    try, try_lno, ws_rule,
2707                                    match_beginning, match_end))
2708                         return try_lno;
2709
2710         again:
2711                 if (backwards_lno == 0 && forwards_lno == img->nr)
2712                         break;
2713
2714                 if (i & 1) {
2715                         if (backwards_lno == 0) {
2716                                 i++;
2717                                 goto again;
2718                         }
2719                         backwards_lno--;
2720                         backwards -= img->line[backwards_lno].len;
2721                         try = backwards;
2722                         try_lno = backwards_lno;
2723                 } else {
2724                         if (forwards_lno == img->nr) {
2725                                 i++;
2726                                 goto again;
2727                         }
2728                         forwards += img->line[forwards_lno].len;
2729                         forwards_lno++;
2730                         try = forwards;
2731                         try_lno = forwards_lno;
2732                 }
2733
2734         }
2735         return -1;
2736 }
2737
2738 static void remove_first_line(struct image *img)
2739 {
2740         img->buf += img->line[0].len;
2741         img->len -= img->line[0].len;
2742         img->line++;
2743         img->nr--;
2744 }
2745
2746 static void remove_last_line(struct image *img)
2747 {
2748         img->len -= img->line[--img->nr].len;
2749 }
2750
2751 /*
2752  * The change from "preimage" and "postimage" has been found to
2753  * apply at applied_pos (counts in line numbers) in "img".
2754  * Update "img" to remove "preimage" and replace it with "postimage".
2755  */
2756 static void update_image(struct apply_state *state,
2757                          struct image *img,
2758                          int applied_pos,
2759                          struct image *preimage,
2760                          struct image *postimage)
2761 {
2762         /*
2763          * remove the copy of preimage at offset in img
2764          * and replace it with postimage
2765          */
2766         int i, nr;
2767         size_t remove_count, insert_count, applied_at = 0;
2768         char *result;
2769         int preimage_limit;
2770
2771         /*
2772          * If we are removing blank lines at the end of img,
2773          * the preimage may extend beyond the end.
2774          * If that is the case, we must be careful only to
2775          * remove the part of the preimage that falls within
2776          * the boundaries of img. Initialize preimage_limit
2777          * to the number of lines in the preimage that falls
2778          * within the boundaries.
2779          */
2780         preimage_limit = preimage->nr;
2781         if (preimage_limit > img->nr - applied_pos)
2782                 preimage_limit = img->nr - applied_pos;
2783
2784         for (i = 0; i < applied_pos; i++)
2785                 applied_at += img->line[i].len;
2786
2787         remove_count = 0;
2788         for (i = 0; i < preimage_limit; i++)
2789                 remove_count += img->line[applied_pos + i].len;
2790         insert_count = postimage->len;
2791
2792         /* Adjust the contents */
2793         result = xmalloc(st_add3(st_sub(img->len, remove_count), insert_count, 1));
2794         memcpy(result, img->buf, applied_at);
2795         memcpy(result + applied_at, postimage->buf, postimage->len);
2796         memcpy(result + applied_at + postimage->len,
2797                img->buf + (applied_at + remove_count),
2798                img->len - (applied_at + remove_count));
2799         free(img->buf);
2800         img->buf = result;
2801         img->len += insert_count - remove_count;
2802         result[img->len] = '\0';
2803
2804         /* Adjust the line table */
2805         nr = img->nr + postimage->nr - preimage_limit;
2806         if (preimage_limit < postimage->nr) {
2807                 /*
2808                  * NOTE: this knows that we never call remove_first_line()
2809                  * on anything other than pre/post image.
2810                  */
2811                 REALLOC_ARRAY(img->line, nr);
2812                 img->line_allocated = img->line;
2813         }
2814         if (preimage_limit != postimage->nr)
2815                 MOVE_ARRAY(img->line + applied_pos + postimage->nr,
2816                            img->line + applied_pos + preimage_limit,
2817                            img->nr - (applied_pos + preimage_limit));
2818         COPY_ARRAY(img->line + applied_pos, postimage->line, postimage->nr);
2819         if (!state->allow_overlap)
2820                 for (i = 0; i < postimage->nr; i++)
2821                         img->line[applied_pos + i].flag |= LINE_PATCHED;
2822         img->nr = nr;
2823 }
2824
2825 /*
2826  * Use the patch-hunk text in "frag" to prepare two images (preimage and
2827  * postimage) for the hunk.  Find lines that match "preimage" in "img" and
2828  * replace the part of "img" with "postimage" text.
2829  */
2830 static int apply_one_fragment(struct apply_state *state,
2831                               struct image *img, struct fragment *frag,
2832                               int inaccurate_eof, unsigned ws_rule,
2833                               int nth_fragment)
2834 {
2835         int match_beginning, match_end;
2836         const char *patch = frag->patch;
2837         int size = frag->size;
2838         char *old, *oldlines;
2839         struct strbuf newlines;
2840         int new_blank_lines_at_end = 0;
2841         int found_new_blank_lines_at_end = 0;
2842         int hunk_linenr = frag->linenr;
2843         unsigned long leading, trailing;
2844         int pos, applied_pos;
2845         struct image preimage;
2846         struct image postimage;
2847
2848         memset(&preimage, 0, sizeof(preimage));
2849         memset(&postimage, 0, sizeof(postimage));
2850         oldlines = xmalloc(size);
2851         strbuf_init(&newlines, size);
2852
2853         old = oldlines;
2854         while (size > 0) {
2855                 char first;
2856                 int len = linelen(patch, size);
2857                 int plen;
2858                 int added_blank_line = 0;
2859                 int is_blank_context = 0;
2860                 size_t start;
2861
2862                 if (!len)
2863                         break;
2864
2865                 /*
2866                  * "plen" is how much of the line we should use for
2867                  * the actual patch data. Normally we just remove the
2868                  * first character on the line, but if the line is
2869                  * followed by "\ No newline", then we also remove the
2870                  * last one (which is the newline, of course).
2871                  */
2872                 plen = len - 1;
2873                 if (len < size && patch[len] == '\\')
2874                         plen--;
2875                 first = *patch;
2876                 if (state->apply_in_reverse) {
2877                         if (first == '-')
2878                                 first = '+';
2879                         else if (first == '+')
2880                                 first = '-';
2881                 }
2882
2883                 switch (first) {
2884                 case '\n':
2885                         /* Newer GNU diff, empty context line */
2886                         if (plen < 0)
2887                                 /* ... followed by '\No newline'; nothing */
2888                                 break;
2889                         *old++ = '\n';
2890                         strbuf_addch(&newlines, '\n');
2891                         add_line_info(&preimage, "\n", 1, LINE_COMMON);
2892                         add_line_info(&postimage, "\n", 1, LINE_COMMON);
2893                         is_blank_context = 1;
2894                         break;
2895                 case ' ':
2896                         if (plen && (ws_rule & WS_BLANK_AT_EOF) &&
2897                             ws_blank_line(patch + 1, plen, ws_rule))
2898                                 is_blank_context = 1;
2899                         /* fallthrough */
2900                 case '-':
2901                         memcpy(old, patch + 1, plen);
2902                         add_line_info(&preimage, old, plen,
2903                                       (first == ' ' ? LINE_COMMON : 0));
2904                         old += plen;
2905                         if (first == '-')
2906                                 break;
2907                         /* fallthrough */
2908                 case '+':
2909                         /* --no-add does not add new lines */
2910                         if (first == '+' && state->no_add)
2911                                 break;
2912
2913                         start = newlines.len;
2914                         if (first != '+' ||
2915                             !state->whitespace_error ||
2916                             state->ws_error_action != correct_ws_error) {
2917                                 strbuf_add(&newlines, patch + 1, plen);
2918                         }
2919                         else {
2920                                 ws_fix_copy(&newlines, patch + 1, plen, ws_rule, &state->applied_after_fixing_ws);
2921                         }
2922                         add_line_info(&postimage, newlines.buf + start, newlines.len - start,
2923                                       (first == '+' ? 0 : LINE_COMMON));
2924                         if (first == '+' &&
2925                             (ws_rule & WS_BLANK_AT_EOF) &&
2926                             ws_blank_line(patch + 1, plen, ws_rule))
2927                                 added_blank_line = 1;
2928                         break;
2929                 case '@': case '\\':
2930                         /* Ignore it, we already handled it */
2931                         break;
2932                 default:
2933                         if (state->apply_verbosity > verbosity_normal)
2934                                 error(_("invalid start of line: '%c'"), first);
2935                         applied_pos = -1;
2936                         goto out;
2937                 }
2938                 if (added_blank_line) {
2939                         if (!new_blank_lines_at_end)
2940                                 found_new_blank_lines_at_end = hunk_linenr;
2941                         new_blank_lines_at_end++;
2942                 }
2943                 else if (is_blank_context)
2944                         ;
2945                 else
2946                         new_blank_lines_at_end = 0;
2947                 patch += len;
2948                 size -= len;
2949                 hunk_linenr++;
2950         }
2951         if (inaccurate_eof &&
2952             old > oldlines && old[-1] == '\n' &&
2953             newlines.len > 0 && newlines.buf[newlines.len - 1] == '\n') {
2954                 old--;
2955                 strbuf_setlen(&newlines, newlines.len - 1);
2956                 preimage.line_allocated[preimage.nr - 1].len--;
2957                 postimage.line_allocated[postimage.nr - 1].len--;
2958         }
2959
2960         leading = frag->leading;
2961         trailing = frag->trailing;
2962
2963         /*
2964          * A hunk to change lines at the beginning would begin with
2965          * @@ -1,L +N,M @@
2966          * but we need to be careful.  -U0 that inserts before the second
2967          * line also has this pattern.
2968          *
2969          * And a hunk to add to an empty file would begin with
2970          * @@ -0,0 +N,M @@
2971          *
2972          * In other words, a hunk that is (frag->oldpos <= 1) with or
2973          * without leading context must match at the beginning.
2974          */
2975         match_beginning = (!frag->oldpos ||
2976                            (frag->oldpos == 1 && !state->unidiff_zero));
2977
2978         /*
2979          * A hunk without trailing lines must match at the end.
2980          * However, we simply cannot tell if a hunk must match end
2981          * from the lack of trailing lines if the patch was generated
2982          * with unidiff without any context.
2983          */
2984         match_end = !state->unidiff_zero && !trailing;
2985
2986         pos = frag->newpos ? (frag->newpos - 1) : 0;
2987         preimage.buf = oldlines;
2988         preimage.len = old - oldlines;
2989         postimage.buf = newlines.buf;
2990         postimage.len = newlines.len;
2991         preimage.line = preimage.line_allocated;
2992         postimage.line = postimage.line_allocated;
2993
2994         for (;;) {
2995
2996                 applied_pos = find_pos(state, img, &preimage, &postimage, pos,
2997                                        ws_rule, match_beginning, match_end);
2998
2999                 if (applied_pos >= 0)
3000                         break;
3001
3002                 /* Am I at my context limits? */
3003                 if ((leading <= state->p_context) && (trailing <= state->p_context))
3004                         break;
3005                 if (match_beginning || match_end) {
3006                         match_beginning = match_end = 0;
3007                         continue;
3008                 }
3009
3010                 /*
3011                  * Reduce the number of context lines; reduce both
3012                  * leading and trailing if they are equal otherwise
3013                  * just reduce the larger context.
3014                  */
3015                 if (leading >= trailing) {
3016                         remove_first_line(&preimage);
3017                         remove_first_line(&postimage);
3018                         pos--;
3019                         leading--;
3020                 }
3021                 if (trailing > leading) {
3022                         remove_last_line(&preimage);
3023                         remove_last_line(&postimage);
3024                         trailing--;
3025                 }
3026         }
3027
3028         if (applied_pos >= 0) {
3029                 if (new_blank_lines_at_end &&
3030                     preimage.nr + applied_pos >= img->nr &&
3031                     (ws_rule & WS_BLANK_AT_EOF) &&
3032                     state->ws_error_action != nowarn_ws_error) {
3033                         record_ws_error(state, WS_BLANK_AT_EOF, "+", 1,
3034                                         found_new_blank_lines_at_end);
3035                         if (state->ws_error_action == correct_ws_error) {
3036                                 while (new_blank_lines_at_end--)
3037                                         remove_last_line(&postimage);
3038                         }
3039                         /*
3040                          * We would want to prevent write_out_results()
3041                          * from taking place in apply_patch() that follows
3042                          * the callchain led us here, which is:
3043                          * apply_patch->check_patch_list->check_patch->
3044                          * apply_data->apply_fragments->apply_one_fragment
3045                          */
3046                         if (state->ws_error_action == die_on_ws_error)
3047                                 state->apply = 0;
3048                 }
3049
3050                 if (state->apply_verbosity > verbosity_normal && applied_pos != pos) {
3051                         int offset = applied_pos - pos;
3052                         if (state->apply_in_reverse)
3053                                 offset = 0 - offset;
3054                         fprintf_ln(stderr,
3055                                    Q_("Hunk #%d succeeded at %d (offset %d line).",
3056                                       "Hunk #%d succeeded at %d (offset %d lines).",
3057                                       offset),
3058                                    nth_fragment, applied_pos + 1, offset);
3059                 }
3060
3061                 /*
3062                  * Warn if it was necessary to reduce the number
3063                  * of context lines.
3064                  */
3065                 if ((leading != frag->leading ||
3066                      trailing != frag->trailing) && state->apply_verbosity > verbosity_silent)
3067                         fprintf_ln(stderr, _("Context reduced to (%ld/%ld)"
3068                                              " to apply fragment at %d"),
3069                                    leading, trailing, applied_pos+1);
3070                 update_image(state, img, applied_pos, &preimage, &postimage);
3071         } else {
3072                 if (state->apply_verbosity > verbosity_normal)
3073                         error(_("while searching for:\n%.*s"),
3074                               (int)(old - oldlines), oldlines);
3075         }
3076
3077 out:
3078         free(oldlines);
3079         strbuf_release(&newlines);
3080         free(preimage.line_allocated);
3081         free(postimage.line_allocated);
3082
3083         return (applied_pos < 0);
3084 }
3085
3086 static int apply_binary_fragment(struct apply_state *state,
3087                                  struct image *img,
3088                                  struct patch *patch)
3089 {
3090         struct fragment *fragment = patch->fragments;
3091         unsigned long len;
3092         void *dst;
3093
3094         if (!fragment)
3095                 return error(_("missing binary patch data for '%s'"),
3096                              patch->new_name ?
3097                              patch->new_name :
3098                              patch->old_name);
3099
3100         /* Binary patch is irreversible without the optional second hunk */
3101         if (state->apply_in_reverse) {
3102                 if (!fragment->next)
3103                         return error(_("cannot reverse-apply a binary patch "
3104                                        "without the reverse hunk to '%s'"),
3105                                      patch->new_name
3106                                      ? patch->new_name : patch->old_name);
3107                 fragment = fragment->next;
3108         }
3109         switch (fragment->binary_patch_method) {
3110         case BINARY_DELTA_DEFLATED:
3111                 dst = patch_delta(img->buf, img->len, fragment->patch,
3112                                   fragment->size, &len);
3113                 if (!dst)
3114                         return -1;
3115                 clear_image(img);
3116                 img->buf = dst;
3117                 img->len = len;
3118                 return 0;
3119         case BINARY_LITERAL_DEFLATED:
3120                 clear_image(img);
3121                 img->len = fragment->size;
3122                 img->buf = xmemdupz(fragment->patch, img->len);
3123                 return 0;
3124         }
3125         return -1;
3126 }
3127
3128 /*
3129  * Replace "img" with the result of applying the binary patch.
3130  * The binary patch data itself in patch->fragment is still kept
3131  * but the preimage prepared by the caller in "img" is freed here
3132  * or in the helper function apply_binary_fragment() this calls.
3133  */
3134 static int apply_binary(struct apply_state *state,
3135                         struct image *img,
3136                         struct patch *patch)
3137 {
3138         const char *name = patch->old_name ? patch->old_name : patch->new_name;
3139         struct object_id oid;
3140
3141         /*
3142          * For safety, we require patch index line to contain
3143          * full 40-byte textual SHA1 for old and new, at least for now.
3144          */
3145         if (strlen(patch->old_sha1_prefix) != 40 ||
3146             strlen(patch->new_sha1_prefix) != 40 ||
3147             get_oid_hex(patch->old_sha1_prefix, &oid) ||
3148             get_oid_hex(patch->new_sha1_prefix, &oid))
3149                 return error(_("cannot apply binary patch to '%s' "
3150                                "without full index line"), name);
3151
3152         if (patch->old_name) {
3153                 /*
3154                  * See if the old one matches what the patch
3155                  * applies to.
3156                  */
3157                 hash_sha1_file(img->buf, img->len, blob_type, oid.hash);
3158                 if (strcmp(oid_to_hex(&oid), patch->old_sha1_prefix))
3159                         return error(_("the patch applies to '%s' (%s), "
3160                                        "which does not match the "
3161                                        "current contents."),
3162                                      name, oid_to_hex(&oid));
3163         }
3164         else {
3165                 /* Otherwise, the old one must be empty. */
3166                 if (img->len)
3167                         return error(_("the patch applies to an empty "
3168                                        "'%s' but it is not empty"), name);
3169         }
3170
3171         get_oid_hex(patch->new_sha1_prefix, &oid);
3172         if (is_null_oid(&oid)) {
3173                 clear_image(img);
3174                 return 0; /* deletion patch */
3175         }
3176
3177         if (has_sha1_file(oid.hash)) {
3178                 /* We already have the postimage */
3179                 enum object_type type;
3180                 unsigned long size;
3181                 char *result;
3182
3183                 result = read_sha1_file(oid.hash, &type, &size);
3184                 if (!result)
3185                         return error(_("the necessary postimage %s for "
3186                                        "'%s' cannot be read"),
3187                                      patch->new_sha1_prefix, name);
3188                 clear_image(img);
3189                 img->buf = result;
3190                 img->len = size;
3191         } else {
3192                 /*
3193                  * We have verified buf matches the preimage;
3194                  * apply the patch data to it, which is stored
3195                  * in the patch->fragments->{patch,size}.
3196                  */
3197                 if (apply_binary_fragment(state, img, patch))
3198                         return error(_("binary patch does not apply to '%s'"),
3199                                      name);
3200
3201                 /* verify that the result matches */
3202                 hash_sha1_file(img->buf, img->len, blob_type, oid.hash);
3203                 if (strcmp(oid_to_hex(&oid), patch->new_sha1_prefix))
3204                         return error(_("binary patch to '%s' creates incorrect result (expecting %s, got %s)"),
3205                                 name, patch->new_sha1_prefix, oid_to_hex(&oid));
3206         }
3207
3208         return 0;
3209 }
3210
3211 static int apply_fragments(struct apply_state *state, struct image *img, struct patch *patch)
3212 {
3213         struct fragment *frag = patch->fragments;
3214         const char *name = patch->old_name ? patch->old_name : patch->new_name;
3215         unsigned ws_rule = patch->ws_rule;
3216         unsigned inaccurate_eof = patch->inaccurate_eof;
3217         int nth = 0;
3218
3219         if (patch->is_binary)
3220                 return apply_binary(state, img, patch);
3221
3222         while (frag) {
3223                 nth++;
3224                 if (apply_one_fragment(state, img, frag, inaccurate_eof, ws_rule, nth)) {
3225                         error(_("patch failed: %s:%ld"), name, frag->oldpos);
3226                         if (!state->apply_with_reject)
3227                                 return -1;
3228                         frag->rejected = 1;
3229                 }
3230                 frag = frag->next;
3231         }
3232         return 0;
3233 }
3234
3235 static int read_blob_object(struct strbuf *buf, const struct object_id *oid, unsigned mode)
3236 {
3237         if (S_ISGITLINK(mode)) {
3238                 strbuf_grow(buf, 100);
3239                 strbuf_addf(buf, "Subproject commit %s\n", oid_to_hex(oid));
3240         } else {
3241                 enum object_type type;
3242                 unsigned long sz;
3243                 char *result;
3244
3245                 result = read_sha1_file(oid->hash, &type, &sz);
3246                 if (!result)
3247                         return -1;
3248                 /* XXX read_sha1_file NUL-terminates */
3249                 strbuf_attach(buf, result, sz, sz + 1);
3250         }
3251         return 0;
3252 }
3253
3254 static int read_file_or_gitlink(const struct cache_entry *ce, struct strbuf *buf)
3255 {
3256         if (!ce)
3257                 return 0;
3258         return read_blob_object(buf, &ce->oid, ce->ce_mode);
3259 }
3260
3261 static struct patch *in_fn_table(struct apply_state *state, const char *name)
3262 {
3263         struct string_list_item *item;
3264
3265         if (name == NULL)
3266                 return NULL;
3267
3268         item = string_list_lookup(&state->fn_table, name);
3269         if (item != NULL)
3270                 return (struct patch *)item->util;
3271
3272         return NULL;
3273 }
3274
3275 /*
3276  * item->util in the filename table records the status of the path.
3277  * Usually it points at a patch (whose result records the contents
3278  * of it after applying it), but it could be PATH_WAS_DELETED for a
3279  * path that a previously applied patch has already removed, or
3280  * PATH_TO_BE_DELETED for a path that a later patch would remove.
3281  *
3282  * The latter is needed to deal with a case where two paths A and B
3283  * are swapped by first renaming A to B and then renaming B to A;
3284  * moving A to B should not be prevented due to presence of B as we
3285  * will remove it in a later patch.
3286  */
3287 #define PATH_TO_BE_DELETED ((struct patch *) -2)
3288 #define PATH_WAS_DELETED ((struct patch *) -1)
3289
3290 static int to_be_deleted(struct patch *patch)
3291 {
3292         return patch == PATH_TO_BE_DELETED;
3293 }
3294
3295 static int was_deleted(struct patch *patch)
3296 {
3297         return patch == PATH_WAS_DELETED;
3298 }
3299
3300 static void add_to_fn_table(struct apply_state *state, struct patch *patch)
3301 {
3302         struct string_list_item *item;
3303
3304         /*
3305          * Always add new_name unless patch is a deletion
3306          * This should cover the cases for normal diffs,
3307          * file creations and copies
3308          */
3309         if (patch->new_name != NULL) {
3310                 item = string_list_insert(&state->fn_table, patch->new_name);
3311                 item->util = patch;
3312         }
3313
3314         /*
3315          * store a failure on rename/deletion cases because
3316          * later chunks shouldn't patch old names
3317          */
3318         if ((patch->new_name == NULL) || (patch->is_rename)) {
3319                 item = string_list_insert(&state->fn_table, patch->old_name);
3320                 item->util = PATH_WAS_DELETED;
3321         }
3322 }
3323
3324 static void prepare_fn_table(struct apply_state *state, struct patch *patch)
3325 {
3326         /*
3327          * store information about incoming file deletion
3328          */
3329         while (patch) {
3330                 if ((patch->new_name == NULL) || (patch->is_rename)) {
3331                         struct string_list_item *item;
3332                         item = string_list_insert(&state->fn_table, patch->old_name);
3333                         item->util = PATH_TO_BE_DELETED;
3334                 }
3335                 patch = patch->next;
3336         }
3337 }
3338
3339 static int checkout_target(struct index_state *istate,
3340                            struct cache_entry *ce, struct stat *st)
3341 {
3342         struct checkout costate = CHECKOUT_INIT;
3343
3344         costate.refresh_cache = 1;
3345         costate.istate = istate;
3346         if (checkout_entry(ce, &costate, NULL) || lstat(ce->name, st))
3347                 return error(_("cannot checkout %s"), ce->name);
3348         return 0;
3349 }
3350
3351 static struct patch *previous_patch(struct apply_state *state,
3352                                     struct patch *patch,
3353                                     int *gone)
3354 {
3355         struct patch *previous;
3356
3357         *gone = 0;
3358         if (patch->is_copy || patch->is_rename)
3359                 return NULL; /* "git" patches do not depend on the order */
3360
3361         previous = in_fn_table(state, patch->old_name);
3362         if (!previous)
3363                 return NULL;
3364
3365         if (to_be_deleted(previous))
3366                 return NULL; /* the deletion hasn't happened yet */
3367
3368         if (was_deleted(previous))
3369                 *gone = 1;
3370
3371         return previous;
3372 }
3373
3374 static int verify_index_match(const struct cache_entry *ce, struct stat *st)
3375 {
3376         if (S_ISGITLINK(ce->ce_mode)) {
3377                 if (!S_ISDIR(st->st_mode))
3378                         return -1;
3379                 return 0;
3380         }
3381         return ce_match_stat(ce, st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
3382 }
3383
3384 #define SUBMODULE_PATCH_WITHOUT_INDEX 1
3385
3386 static int load_patch_target(struct apply_state *state,
3387                              struct strbuf *buf,
3388                              const struct cache_entry *ce,
3389                              struct stat *st,
3390                              struct patch *patch,
3391                              const char *name,
3392                              unsigned expected_mode)
3393 {
3394         if (state->cached || state->check_index) {
3395                 if (read_file_or_gitlink(ce, buf))
3396                         return error(_("failed to read %s"), name);
3397         } else if (name) {
3398                 if (S_ISGITLINK(expected_mode)) {
3399                         if (ce)
3400                                 return read_file_or_gitlink(ce, buf);
3401                         else
3402                                 return SUBMODULE_PATCH_WITHOUT_INDEX;
3403                 } else if (has_symlink_leading_path(name, strlen(name))) {
3404                         return error(_("reading from '%s' beyond a symbolic link"), name);
3405                 } else {
3406                         if (read_old_data(st, patch, name, buf))
3407                                 return error(_("failed to read %s"), name);
3408                 }
3409         }
3410         return 0;
3411 }
3412
3413 /*
3414  * We are about to apply "patch"; populate the "image" with the
3415  * current version we have, from the working tree or from the index,
3416  * depending on the situation e.g. --cached/--index.  If we are
3417  * applying a non-git patch that incrementally updates the tree,
3418  * we read from the result of a previous diff.
3419  */
3420 static int load_preimage(struct apply_state *state,
3421                          struct image *image,
3422                          struct patch *patch, struct stat *st,
3423                          const struct cache_entry *ce)
3424 {
3425         struct strbuf buf = STRBUF_INIT;
3426         size_t len;
3427         char *img;
3428         struct patch *previous;
3429         int status;
3430
3431         previous = previous_patch(state, patch, &status);
3432         if (status)
3433                 return error(_("path %s has been renamed/deleted"),
3434                              patch->old_name);
3435         if (previous) {
3436                 /* We have a patched copy in memory; use that. */
3437                 strbuf_add(&buf, previous->result, previous->resultsize);
3438         } else {
3439                 status = load_patch_target(state, &buf, ce, st, patch,
3440                                            patch->old_name, patch->old_mode);
3441                 if (status < 0)
3442                         return status;
3443                 else if (status == SUBMODULE_PATCH_WITHOUT_INDEX) {
3444                         /*
3445                          * There is no way to apply subproject
3446                          * patch without looking at the index.
3447                          * NEEDSWORK: shouldn't this be flagged
3448                          * as an error???
3449                          */
3450                         free_fragment_list(patch->fragments);
3451                         patch->fragments = NULL;
3452                 } else if (status) {
3453                         return error(_("failed to read %s"), patch->old_name);
3454                 }
3455         }
3456
3457         img = strbuf_detach(&buf, &len);
3458         prepare_image(image, img, len, !patch->is_binary);
3459         return 0;
3460 }
3461
3462 static int three_way_merge(struct image *image,
3463                            char *path,
3464                            const struct object_id *base,
3465                            const struct object_id *ours,
3466                            const struct object_id *theirs)
3467 {
3468         mmfile_t base_file, our_file, their_file;
3469         mmbuffer_t result = { NULL };
3470         int status;
3471
3472         read_mmblob(&base_file, base);
3473         read_mmblob(&our_file, ours);
3474         read_mmblob(&their_file, theirs);
3475         status = ll_merge(&result, path,
3476                           &base_file, "base",
3477                           &our_file, "ours",
3478                           &their_file, "theirs", NULL);
3479         free(base_file.ptr);
3480         free(our_file.ptr);
3481         free(their_file.ptr);
3482         if (status < 0 || !result.ptr) {
3483                 free(result.ptr);
3484                 return -1;
3485         }
3486         clear_image(image);
3487         image->buf = result.ptr;
3488         image->len = result.size;
3489
3490         return status;
3491 }
3492
3493 /*
3494  * When directly falling back to add/add three-way merge, we read from
3495  * the current contents of the new_name.  In no cases other than that
3496  * this function will be called.
3497  */
3498 static int load_current(struct apply_state *state,
3499                         struct image *image,
3500                         struct patch *patch)
3501 {
3502         struct strbuf buf = STRBUF_INIT;
3503         int status, pos;
3504         size_t len;
3505         char *img;
3506         struct stat st;
3507         struct cache_entry *ce;
3508         char *name = patch->new_name;
3509         unsigned mode = patch->new_mode;
3510
3511         if (!patch->is_new)
3512                 die("BUG: patch to %s is not a creation", patch->old_name);
3513
3514         pos = cache_name_pos(name, strlen(name));
3515         if (pos < 0)
3516                 return error(_("%s: does not exist in index"), name);
3517         ce = active_cache[pos];
3518         if (lstat(name, &st)) {
3519                 if (errno != ENOENT)
3520                         return error_errno("%s", name);
3521                 if (checkout_target(&the_index, ce, &st))
3522                         return -1;
3523         }
3524         if (verify_index_match(ce, &st))
3525                 return error(_("%s: does not match index"), name);
3526
3527         status = load_patch_target(state, &buf, ce, &st, patch, name, mode);
3528         if (status < 0)
3529                 return status;
3530         else if (status)
3531                 return -1;
3532         img = strbuf_detach(&buf, &len);
3533         prepare_image(image, img, len, !patch->is_binary);
3534         return 0;
3535 }
3536
3537 static int try_threeway(struct apply_state *state,
3538                         struct image *image,
3539                         struct patch *patch,
3540                         struct stat *st,
3541                         const struct cache_entry *ce)
3542 {
3543         struct object_id pre_oid, post_oid, our_oid;
3544         struct strbuf buf = STRBUF_INIT;
3545         size_t len;
3546         int status;
3547         char *img;
3548         struct image tmp_image;
3549
3550         /* No point falling back to 3-way merge in these cases */
3551         if (patch->is_delete ||
3552             S_ISGITLINK(patch->old_mode) || S_ISGITLINK(patch->new_mode))
3553                 return -1;
3554
3555         /* Preimage the patch was prepared for */
3556         if (patch->is_new)
3557                 write_sha1_file("", 0, blob_type, pre_oid.hash);
3558         else if (get_oid(patch->old_sha1_prefix, &pre_oid) ||
3559                  read_blob_object(&buf, &pre_oid, patch->old_mode))
3560                 return error(_("repository lacks the necessary blob to fall back on 3-way merge."));
3561
3562         if (state->apply_verbosity > verbosity_silent)
3563                 fprintf(stderr, _("Falling back to three-way merge...\n"));
3564
3565         img = strbuf_detach(&buf, &len);
3566         prepare_image(&tmp_image, img, len, 1);
3567         /* Apply the patch to get the post image */
3568         if (apply_fragments(state, &tmp_image, patch) < 0) {
3569                 clear_image(&tmp_image);
3570                 return -1;
3571         }
3572         /* post_oid is theirs */
3573         write_sha1_file(tmp_image.buf, tmp_image.len, blob_type, post_oid.hash);
3574         clear_image(&tmp_image);
3575
3576         /* our_oid is ours */
3577         if (patch->is_new) {
3578                 if (load_current(state, &tmp_image, patch))
3579                         return error(_("cannot read the current contents of '%s'"),
3580                                      patch->new_name);
3581         } else {
3582                 if (load_preimage(state, &tmp_image, patch, st, ce))
3583                         return error(_("cannot read the current contents of '%s'"),
3584                                      patch->old_name);
3585         }
3586         write_sha1_file(tmp_image.buf, tmp_image.len, blob_type, our_oid.hash);
3587         clear_image(&tmp_image);
3588
3589         /* in-core three-way merge between post and our using pre as base */
3590         status = three_way_merge(image, patch->new_name,
3591                                  &pre_oid, &our_oid, &post_oid);
3592         if (status < 0) {
3593                 if (state->apply_verbosity > verbosity_silent)
3594                         fprintf(stderr,
3595                                 _("Failed to fall back on three-way merge...\n"));
3596                 return status;
3597         }
3598
3599         if (status) {
3600                 patch->conflicted_threeway = 1;
3601                 if (patch->is_new)
3602                         oidclr(&patch->threeway_stage[0]);
3603                 else
3604                         oidcpy(&patch->threeway_stage[0], &pre_oid);
3605                 oidcpy(&patch->threeway_stage[1], &our_oid);
3606                 oidcpy(&patch->threeway_stage[2], &post_oid);
3607                 if (state->apply_verbosity > verbosity_silent)
3608                         fprintf(stderr,
3609                                 _("Applied patch to '%s' with conflicts.\n"),
3610                                 patch->new_name);
3611         } else {
3612                 if (state->apply_verbosity > verbosity_silent)
3613                         fprintf(stderr,
3614                                 _("Applied patch to '%s' cleanly.\n"),
3615                                 patch->new_name);
3616         }
3617         return 0;
3618 }
3619
3620 static int apply_data(struct apply_state *state, struct patch *patch,
3621                       struct stat *st, const struct cache_entry *ce)
3622 {
3623         struct image image;
3624
3625         if (load_preimage(state, &image, patch, st, ce) < 0)
3626                 return -1;
3627
3628         if (patch->direct_to_threeway ||
3629             apply_fragments(state, &image, patch) < 0) {
3630                 /* Note: with --reject, apply_fragments() returns 0 */
3631                 if (!state->threeway || try_threeway(state, &image, patch, st, ce) < 0)
3632                         return -1;
3633         }
3634         patch->result = image.buf;
3635         patch->resultsize = image.len;
3636         add_to_fn_table(state, patch);
3637         free(image.line_allocated);
3638
3639         if (0 < patch->is_delete && patch->resultsize)
3640                 return error(_("removal patch leaves file contents"));
3641
3642         return 0;
3643 }
3644
3645 /*
3646  * If "patch" that we are looking at modifies or deletes what we have,
3647  * we would want it not to lose any local modification we have, either
3648  * in the working tree or in the index.
3649  *
3650  * This also decides if a non-git patch is a creation patch or a
3651  * modification to an existing empty file.  We do not check the state
3652  * of the current tree for a creation patch in this function; the caller
3653  * check_patch() separately makes sure (and errors out otherwise) that
3654  * the path the patch creates does not exist in the current tree.
3655  */
3656 static int check_preimage(struct apply_state *state,
3657                           struct patch *patch,
3658                           struct cache_entry **ce,
3659                           struct stat *st)
3660 {
3661         const char *old_name = patch->old_name;
3662         struct patch *previous = NULL;
3663         int stat_ret = 0, status;
3664         unsigned st_mode = 0;
3665
3666         if (!old_name)
3667                 return 0;
3668
3669         assert(patch->is_new <= 0);
3670         previous = previous_patch(state, patch, &status);
3671
3672         if (status)
3673                 return error(_("path %s has been renamed/deleted"), old_name);
3674         if (previous) {
3675                 st_mode = previous->new_mode;
3676         } else if (!state->cached) {
3677                 stat_ret = lstat(old_name, st);
3678                 if (stat_ret && errno != ENOENT)
3679                         return error_errno("%s", old_name);
3680         }
3681
3682         if (state->check_index && !previous) {
3683                 int pos = cache_name_pos(old_name, strlen(old_name));
3684                 if (pos < 0) {
3685                         if (patch->is_new < 0)
3686                                 goto is_new;
3687                         return error(_("%s: does not exist in index"), old_name);
3688                 }
3689                 *ce = active_cache[pos];
3690                 if (stat_ret < 0) {
3691                         if (checkout_target(&the_index, *ce, st))
3692                                 return -1;
3693                 }
3694                 if (!state->cached && verify_index_match(*ce, st))
3695                         return error(_("%s: does not match index"), old_name);
3696                 if (state->cached)
3697                         st_mode = (*ce)->ce_mode;
3698         } else if (stat_ret < 0) {
3699                 if (patch->is_new < 0)
3700                         goto is_new;
3701                 return error_errno("%s", old_name);
3702         }
3703
3704         if (!state->cached && !previous)
3705                 st_mode = ce_mode_from_stat(*ce, st->st_mode);
3706
3707         if (patch->is_new < 0)
3708                 patch->is_new = 0;
3709         if (!patch->old_mode)
3710                 patch->old_mode = st_mode;
3711         if ((st_mode ^ patch->old_mode) & S_IFMT)
3712                 return error(_("%s: wrong type"), old_name);
3713         if (st_mode != patch->old_mode)
3714                 warning(_("%s has type %o, expected %o"),
3715                         old_name, st_mode, patch->old_mode);
3716         if (!patch->new_mode && !patch->is_delete)
3717                 patch->new_mode = st_mode;
3718         return 0;
3719
3720  is_new:
3721         patch->is_new = 1;
3722         patch->is_delete = 0;
3723         FREE_AND_NULL(patch->old_name);
3724         return 0;
3725 }
3726
3727
3728 #define EXISTS_IN_INDEX 1
3729 #define EXISTS_IN_WORKTREE 2
3730
3731 static int check_to_create(struct apply_state *state,
3732                            const char *new_name,
3733                            int ok_if_exists)
3734 {
3735         struct stat nst;
3736
3737         if (state->check_index &&
3738             cache_name_pos(new_name, strlen(new_name)) >= 0 &&
3739             !ok_if_exists)
3740                 return EXISTS_IN_INDEX;
3741         if (state->cached)
3742                 return 0;
3743
3744         if (!lstat(new_name, &nst)) {
3745                 if (S_ISDIR(nst.st_mode) || ok_if_exists)
3746                         return 0;
3747                 /*
3748                  * A leading component of new_name might be a symlink
3749                  * that is going to be removed with this patch, but
3750                  * still pointing at somewhere that has the path.
3751                  * In such a case, path "new_name" does not exist as
3752                  * far as git is concerned.
3753                  */
3754                 if (has_symlink_leading_path(new_name, strlen(new_name)))
3755                         return 0;
3756
3757                 return EXISTS_IN_WORKTREE;
3758         } else if (!is_missing_file_error(errno)) {
3759                 return error_errno("%s", new_name);
3760         }
3761         return 0;
3762 }
3763
3764 static uintptr_t register_symlink_changes(struct apply_state *state,
3765                                           const char *path,
3766                                           uintptr_t what)
3767 {
3768         struct string_list_item *ent;
3769
3770         ent = string_list_lookup(&state->symlink_changes, path);
3771         if (!ent) {
3772                 ent = string_list_insert(&state->symlink_changes, path);
3773                 ent->util = (void *)0;
3774         }
3775         ent->util = (void *)(what | ((uintptr_t)ent->util));
3776         return (uintptr_t)ent->util;
3777 }
3778
3779 static uintptr_t check_symlink_changes(struct apply_state *state, const char *path)
3780 {
3781         struct string_list_item *ent;
3782
3783         ent = string_list_lookup(&state->symlink_changes, path);
3784         if (!ent)
3785                 return 0;
3786         return (uintptr_t)ent->util;
3787 }
3788
3789 static void prepare_symlink_changes(struct apply_state *state, struct patch *patch)
3790 {
3791         for ( ; patch; patch = patch->next) {
3792                 if ((patch->old_name && S_ISLNK(patch->old_mode)) &&
3793                     (patch->is_rename || patch->is_delete))
3794                         /* the symlink at patch->old_name is removed */
3795                         register_symlink_changes(state, patch->old_name, APPLY_SYMLINK_GOES_AWAY);
3796
3797                 if (patch->new_name && S_ISLNK(patch->new_mode))
3798                         /* the symlink at patch->new_name is created or remains */
3799                         register_symlink_changes(state, patch->new_name, APPLY_SYMLINK_IN_RESULT);
3800         }
3801 }
3802
3803 static int path_is_beyond_symlink_1(struct apply_state *state, struct strbuf *name)
3804 {
3805         do {
3806                 unsigned int change;
3807
3808                 while (--name->len && name->buf[name->len] != '/')
3809                         ; /* scan backwards */
3810                 if (!name->len)
3811                         break;
3812                 name->buf[name->len] = '\0';
3813                 change = check_symlink_changes(state, name->buf);
3814                 if (change & APPLY_SYMLINK_IN_RESULT)
3815                         return 1;
3816                 if (change & APPLY_SYMLINK_GOES_AWAY)
3817                         /*
3818                          * This cannot be "return 0", because we may
3819                          * see a new one created at a higher level.
3820                          */
3821                         continue;
3822
3823                 /* otherwise, check the preimage */
3824                 if (state->check_index) {
3825                         struct cache_entry *ce;
3826
3827                         ce = cache_file_exists(name->buf, name->len, ignore_case);
3828                         if (ce && S_ISLNK(ce->ce_mode))
3829                                 return 1;
3830                 } else {
3831                         struct stat st;
3832                         if (!lstat(name->buf, &st) && S_ISLNK(st.st_mode))
3833                                 return 1;
3834                 }
3835         } while (1);
3836         return 0;
3837 }
3838
3839 static int path_is_beyond_symlink(struct apply_state *state, const char *name_)
3840 {
3841         int ret;
3842         struct strbuf name = STRBUF_INIT;
3843
3844         assert(*name_ != '\0');
3845         strbuf_addstr(&name, name_);
3846         ret = path_is_beyond_symlink_1(state, &name);
3847         strbuf_release(&name);
3848
3849         return ret;
3850 }
3851
3852 static int check_unsafe_path(struct patch *patch)
3853 {
3854         const char *old_name = NULL;
3855         const char *new_name = NULL;
3856         if (patch->is_delete)
3857                 old_name = patch->old_name;
3858         else if (!patch->is_new && !patch->is_copy)
3859                 old_name = patch->old_name;
3860         if (!patch->is_delete)
3861                 new_name = patch->new_name;
3862
3863         if (old_name && !verify_path(old_name))
3864                 return error(_("invalid path '%s'"), old_name);
3865         if (new_name && !verify_path(new_name))
3866                 return error(_("invalid path '%s'"), new_name);
3867         return 0;
3868 }
3869
3870 /*
3871  * Check and apply the patch in-core; leave the result in patch->result
3872  * for the caller to write it out to the final destination.
3873  */
3874 static int check_patch(struct apply_state *state, struct patch *patch)
3875 {
3876         struct stat st;
3877         const char *old_name = patch->old_name;
3878         const char *new_name = patch->new_name;
3879         const char *name = old_name ? old_name : new_name;
3880         struct cache_entry *ce = NULL;
3881         struct patch *tpatch;
3882         int ok_if_exists;
3883         int status;
3884
3885         patch->rejected = 1; /* we will drop this after we succeed */
3886
3887         status = check_preimage(state, patch, &ce, &st);
3888         if (status)
3889                 return status;
3890         old_name = patch->old_name;
3891
3892         /*
3893          * A type-change diff is always split into a patch to delete
3894          * old, immediately followed by a patch to create new (see
3895          * diff.c::run_diff()); in such a case it is Ok that the entry
3896          * to be deleted by the previous patch is still in the working
3897          * tree and in the index.
3898          *
3899          * A patch to swap-rename between A and B would first rename A
3900          * to B and then rename B to A.  While applying the first one,
3901          * the presence of B should not stop A from getting renamed to
3902          * B; ask to_be_deleted() about the later rename.  Removal of
3903          * B and rename from A to B is handled the same way by asking
3904          * was_deleted().
3905          */
3906         if ((tpatch = in_fn_table(state, new_name)) &&
3907             (was_deleted(tpatch) || to_be_deleted(tpatch)))
3908                 ok_if_exists = 1;
3909         else
3910                 ok_if_exists = 0;
3911
3912         if (new_name &&
3913             ((0 < patch->is_new) || patch->is_rename || patch->is_copy)) {
3914                 int err = check_to_create(state, new_name, ok_if_exists);
3915
3916                 if (err && state->threeway) {
3917                         patch->direct_to_threeway = 1;
3918                 } else switch (err) {
3919                 case 0:
3920                         break; /* happy */
3921                 case EXISTS_IN_INDEX:
3922                         return error(_("%s: already exists in index"), new_name);
3923                         break;
3924                 case EXISTS_IN_WORKTREE:
3925                         return error(_("%s: already exists in working directory"),
3926                                      new_name);
3927                 default:
3928                         return err;
3929                 }
3930
3931                 if (!patch->new_mode) {
3932                         if (0 < patch->is_new)
3933                                 patch->new_mode = S_IFREG | 0644;
3934                         else
3935                                 patch->new_mode = patch->old_mode;
3936                 }
3937         }
3938
3939         if (new_name && old_name) {
3940                 int same = !strcmp(old_name, new_name);
3941                 if (!patch->new_mode)
3942                         patch->new_mode = patch->old_mode;
3943                 if ((patch->old_mode ^ patch->new_mode) & S_IFMT) {
3944                         if (same)
3945                                 return error(_("new mode (%o) of %s does not "
3946                                                "match old mode (%o)"),
3947                                         patch->new_mode, new_name,
3948                                         patch->old_mode);
3949                         else
3950                                 return error(_("new mode (%o) of %s does not "
3951                                                "match old mode (%o) of %s"),
3952                                         patch->new_mode, new_name,
3953                                         patch->old_mode, old_name);
3954                 }
3955         }
3956
3957         if (!state->unsafe_paths && check_unsafe_path(patch))
3958                 return -128;
3959
3960         /*
3961          * An attempt to read from or delete a path that is beyond a
3962          * symbolic link will be prevented by load_patch_target() that
3963          * is called at the beginning of apply_data() so we do not
3964          * have to worry about a patch marked with "is_delete" bit
3965          * here.  We however need to make sure that the patch result
3966          * is not deposited to a path that is beyond a symbolic link
3967          * here.
3968          */
3969         if (!patch->is_delete && path_is_beyond_symlink(state, patch->new_name))
3970                 return error(_("affected file '%s' is beyond a symbolic link"),
3971                              patch->new_name);
3972
3973         if (apply_data(state, patch, &st, ce) < 0)
3974                 return error(_("%s: patch does not apply"), name);
3975         patch->rejected = 0;
3976         return 0;
3977 }
3978
3979 static int check_patch_list(struct apply_state *state, struct patch *patch)
3980 {
3981         int err = 0;
3982
3983         prepare_symlink_changes(state, patch);
3984         prepare_fn_table(state, patch);
3985         while (patch) {
3986                 int res;
3987                 if (state->apply_verbosity > verbosity_normal)
3988                         say_patch_name(stderr,
3989                                        _("Checking patch %s..."), patch);
3990                 res = check_patch(state, patch);
3991                 if (res == -128)
3992                         return -128;
3993                 err |= res;
3994                 patch = patch->next;
3995         }
3996         return err;
3997 }
3998
3999 static int read_apply_cache(struct apply_state *state)
4000 {
4001         if (state->index_file)
4002                 return read_cache_from(state->index_file);
4003         else
4004                 return read_cache();
4005 }
4006
4007 /* This function tries to read the object name from the current index */
4008 static int get_current_oid(struct apply_state *state, const char *path,
4009                            struct object_id *oid)
4010 {
4011         int pos;
4012
4013         if (read_apply_cache(state) < 0)
4014                 return -1;
4015         pos = cache_name_pos(path, strlen(path));
4016         if (pos < 0)
4017                 return -1;
4018         oidcpy(oid, &active_cache[pos]->oid);
4019         return 0;
4020 }
4021
4022 static int preimage_oid_in_gitlink_patch(struct patch *p, struct object_id *oid)
4023 {
4024         /*
4025          * A usable gitlink patch has only one fragment (hunk) that looks like:
4026          * @@ -1 +1 @@
4027          * -Subproject commit <old sha1>
4028          * +Subproject commit <new sha1>
4029          * or
4030          * @@ -1 +0,0 @@
4031          * -Subproject commit <old sha1>
4032          * for a removal patch.
4033          */
4034         struct fragment *hunk = p->fragments;
4035         static const char heading[] = "-Subproject commit ";
4036         char *preimage;
4037
4038         if (/* does the patch have only one hunk? */
4039             hunk && !hunk->next &&
4040             /* is its preimage one line? */
4041             hunk->oldpos == 1 && hunk->oldlines == 1 &&
4042             /* does preimage begin with the heading? */
4043             (preimage = memchr(hunk->patch, '\n', hunk->size)) != NULL &&
4044             starts_with(++preimage, heading) &&
4045             /* does it record full SHA-1? */
4046             !get_oid_hex(preimage + sizeof(heading) - 1, oid) &&
4047             preimage[sizeof(heading) + GIT_SHA1_HEXSZ - 1] == '\n' &&
4048             /* does the abbreviated name on the index line agree with it? */
4049             starts_with(preimage + sizeof(heading) - 1, p->old_sha1_prefix))
4050                 return 0; /* it all looks fine */
4051
4052         /* we may have full object name on the index line */
4053         return get_oid_hex(p->old_sha1_prefix, oid);
4054 }
4055
4056 /* Build an index that contains the just the files needed for a 3way merge */
4057 static int build_fake_ancestor(struct apply_state *state, struct patch *list)
4058 {
4059         struct patch *patch;
4060         struct index_state result = { NULL };
4061         static struct lock_file lock;
4062         int res;
4063
4064         /* Once we start supporting the reverse patch, it may be
4065          * worth showing the new sha1 prefix, but until then...
4066          */
4067         for (patch = list; patch; patch = patch->next) {
4068                 struct object_id oid;
4069                 struct cache_entry *ce;
4070                 const char *name;
4071
4072                 name = patch->old_name ? patch->old_name : patch->new_name;
4073                 if (0 < patch->is_new)
4074                         continue;
4075
4076                 if (S_ISGITLINK(patch->old_mode)) {
4077                         if (!preimage_oid_in_gitlink_patch(patch, &oid))
4078                                 ; /* ok, the textual part looks sane */
4079                         else
4080                                 return error(_("sha1 information is lacking or "
4081                                                "useless for submodule %s"), name);
4082                 } else if (!get_oid_blob(patch->old_sha1_prefix, &oid)) {
4083                         ; /* ok */
4084                 } else if (!patch->lines_added && !patch->lines_deleted) {
4085                         /* mode-only change: update the current */
4086                         if (get_current_oid(state, patch->old_name, &oid))
4087                                 return error(_("mode change for %s, which is not "
4088                                                "in current HEAD"), name);
4089                 } else
4090                         return error(_("sha1 information is lacking or useless "
4091                                        "(%s)."), name);
4092
4093                 ce = make_cache_entry(patch->old_mode, oid.hash, name, 0, 0);
4094                 if (!ce)
4095                         return error(_("make_cache_entry failed for path '%s'"),
4096                                      name);
4097                 if (add_index_entry(&result, ce, ADD_CACHE_OK_TO_ADD)) {
4098                         free(ce);
4099                         return error(_("could not add %s to temporary index"),
4100                                      name);
4101                 }
4102         }
4103
4104         hold_lock_file_for_update(&lock, state->fake_ancestor, LOCK_DIE_ON_ERROR);
4105         res = write_locked_index(&result, &lock, COMMIT_LOCK);
4106         discard_index(&result);
4107
4108         if (res)
4109                 return error(_("could not write temporary index to %s"),
4110                              state->fake_ancestor);
4111
4112         return 0;
4113 }
4114
4115 static void stat_patch_list(struct apply_state *state, struct patch *patch)
4116 {
4117         int files, adds, dels;
4118
4119         for (files = adds = dels = 0 ; patch ; patch = patch->next) {
4120                 files++;
4121                 adds += patch->lines_added;
4122                 dels += patch->lines_deleted;
4123                 show_stats(state, patch);
4124         }
4125
4126         print_stat_summary(stdout, files, adds, dels);
4127 }
4128
4129 static void numstat_patch_list(struct apply_state *state,
4130                                struct patch *patch)
4131 {
4132         for ( ; patch; patch = patch->next) {
4133                 const char *name;
4134                 name = patch->new_name ? patch->new_name : patch->old_name;
4135                 if (patch->is_binary)
4136                         printf("-\t-\t");
4137                 else
4138                         printf("%d\t%d\t", patch->lines_added, patch->lines_deleted);
4139                 write_name_quoted(name, stdout, state->line_termination);
4140         }
4141 }
4142
4143 static void show_file_mode_name(const char *newdelete, unsigned int mode, const char *name)
4144 {
4145         if (mode)
4146                 printf(" %s mode %06o %s\n", newdelete, mode, name);
4147         else
4148                 printf(" %s %s\n", newdelete, name);
4149 }
4150
4151 static void show_mode_change(struct patch *p, int show_name)
4152 {
4153         if (p->old_mode && p->new_mode && p->old_mode != p->new_mode) {
4154                 if (show_name)
4155                         printf(" mode change %06o => %06o %s\n",
4156                                p->old_mode, p->new_mode, p->new_name);
4157                 else
4158                         printf(" mode change %06o => %06o\n",
4159                                p->old_mode, p->new_mode);
4160         }
4161 }
4162
4163 static void show_rename_copy(struct patch *p)
4164 {
4165         const char *renamecopy = p->is_rename ? "rename" : "copy";
4166         const char *old, *new;
4167
4168         /* Find common prefix */
4169         old = p->old_name;
4170         new = p->new_name;
4171         while (1) {
4172                 const char *slash_old, *slash_new;
4173                 slash_old = strchr(old, '/');
4174                 slash_new = strchr(new, '/');
4175                 if (!slash_old ||
4176                     !slash_new ||
4177                     slash_old - old != slash_new - new ||
4178                     memcmp(old, new, slash_new - new))
4179                         break;
4180                 old = slash_old + 1;
4181                 new = slash_new + 1;
4182         }
4183         /* p->old_name thru old is the common prefix, and old and new
4184          * through the end of names are renames
4185          */
4186         if (old != p->old_name)
4187                 printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
4188                        (int)(old - p->old_name), p->old_name,
4189                        old, new, p->score);
4190         else
4191                 printf(" %s %s => %s (%d%%)\n", renamecopy,
4192                        p->old_name, p->new_name, p->score);
4193         show_mode_change(p, 0);
4194 }
4195
4196 static void summary_patch_list(struct patch *patch)
4197 {
4198         struct patch *p;
4199
4200         for (p = patch; p; p = p->next) {
4201                 if (p->is_new)
4202                         show_file_mode_name("create", p->new_mode, p->new_name);
4203                 else if (p->is_delete)
4204                         show_file_mode_name("delete", p->old_mode, p->old_name);
4205                 else {
4206                         if (p->is_rename || p->is_copy)
4207                                 show_rename_copy(p);
4208                         else {
4209                                 if (p->score) {
4210                                         printf(" rewrite %s (%d%%)\n",
4211                                                p->new_name, p->score);
4212                                         show_mode_change(p, 0);
4213                                 }
4214                                 else
4215                                         show_mode_change(p, 1);
4216                         }
4217                 }
4218         }
4219 }
4220
4221 static void patch_stats(struct apply_state *state, struct patch *patch)
4222 {
4223         int lines = patch->lines_added + patch->lines_deleted;
4224
4225         if (lines > state->max_change)
4226                 state->max_change = lines;
4227         if (patch->old_name) {
4228                 int len = quote_c_style(patch->old_name, NULL, NULL, 0);
4229                 if (!len)
4230                         len = strlen(patch->old_name);
4231                 if (len > state->max_len)
4232                         state->max_len = len;
4233         }
4234         if (patch->new_name) {
4235                 int len = quote_c_style(patch->new_name, NULL, NULL, 0);
4236                 if (!len)
4237                         len = strlen(patch->new_name);
4238                 if (len > state->max_len)
4239                         state->max_len = len;
4240         }
4241 }
4242
4243 static int remove_file(struct apply_state *state, struct patch *patch, int rmdir_empty)
4244 {
4245         if (state->update_index) {
4246                 if (remove_file_from_cache(patch->old_name) < 0)
4247                         return error(_("unable to remove %s from index"), patch->old_name);
4248         }
4249         if (!state->cached) {
4250                 if (!remove_or_warn(patch->old_mode, patch->old_name) && rmdir_empty) {
4251                         remove_path(patch->old_name);
4252                 }
4253         }
4254         return 0;
4255 }
4256
4257 static int add_index_file(struct apply_state *state,
4258                           const char *path,
4259                           unsigned mode,
4260                           void *buf,
4261                           unsigned long size)
4262 {
4263         struct stat st;
4264         struct cache_entry *ce;
4265         int namelen = strlen(path);
4266         unsigned ce_size = cache_entry_size(namelen);
4267
4268         if (!state->update_index)
4269                 return 0;
4270
4271         ce = xcalloc(1, ce_size);
4272         memcpy(ce->name, path, namelen);
4273         ce->ce_mode = create_ce_mode(mode);
4274         ce->ce_flags = create_ce_flags(0);
4275         ce->ce_namelen = namelen;
4276         if (S_ISGITLINK(mode)) {
4277                 const char *s;
4278
4279                 if (!skip_prefix(buf, "Subproject commit ", &s) ||
4280                     get_oid_hex(s, &ce->oid)) {
4281                         free(ce);
4282                        return error(_("corrupt patch for submodule %s"), path);
4283                 }
4284         } else {
4285                 if (!state->cached) {
4286                         if (lstat(path, &st) < 0) {
4287                                 free(ce);
4288                                 return error_errno(_("unable to stat newly "
4289                                                      "created file '%s'"),
4290                                                    path);
4291                         }
4292                         fill_stat_cache_info(ce, &st);
4293                 }
4294                 if (write_sha1_file(buf, size, blob_type, ce->oid.hash) < 0) {
4295                         free(ce);
4296                         return error(_("unable to create backing store "
4297                                        "for newly created file %s"), path);
4298                 }
4299         }
4300         if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0) {
4301                 free(ce);
4302                 return error(_("unable to add cache entry for %s"), path);
4303         }
4304
4305         return 0;
4306 }
4307
4308 /*
4309  * Returns:
4310  *  -1 if an unrecoverable error happened
4311  *   0 if everything went well
4312  *   1 if a recoverable error happened
4313  */
4314 static int try_create_file(const char *path, unsigned int mode, const char *buf, unsigned long size)
4315 {
4316         int fd, res;
4317         struct strbuf nbuf = STRBUF_INIT;
4318
4319         if (S_ISGITLINK(mode)) {
4320                 struct stat st;
4321                 if (!lstat(path, &st) && S_ISDIR(st.st_mode))
4322                         return 0;
4323                 return !!mkdir(path, 0777);
4324         }
4325
4326         if (has_symlinks && S_ISLNK(mode))
4327                 /* Although buf:size is counted string, it also is NUL
4328                  * terminated.
4329                  */
4330                 return !!symlink(buf, path);
4331
4332         fd = open(path, O_CREAT | O_EXCL | O_WRONLY, (mode & 0100) ? 0777 : 0666);
4333         if (fd < 0)
4334                 return 1;
4335
4336         if (convert_to_working_tree(path, buf, size, &nbuf)) {
4337                 size = nbuf.len;
4338                 buf  = nbuf.buf;
4339         }
4340
4341         res = write_in_full(fd, buf, size) < 0;
4342         if (res)
4343                 error_errno(_("failed to write to '%s'"), path);
4344         strbuf_release(&nbuf);
4345
4346         if (close(fd) < 0 && !res)
4347                 return error_errno(_("closing file '%s'"), path);
4348
4349         return res ? -1 : 0;
4350 }
4351
4352 /*
4353  * We optimistically assume that the directories exist,
4354  * which is true 99% of the time anyway. If they don't,
4355  * we create them and try again.
4356  *
4357  * Returns:
4358  *   -1 on error
4359  *   0 otherwise
4360  */
4361 static int create_one_file(struct apply_state *state,
4362                            char *path,
4363                            unsigned mode,
4364                            const char *buf,
4365                            unsigned long size)
4366 {
4367         int res;
4368
4369         if (state->cached)
4370                 return 0;
4371
4372         res = try_create_file(path, mode, buf, size);
4373         if (res < 0)
4374                 return -1;
4375         if (!res)
4376                 return 0;
4377
4378         if (errno == ENOENT) {
4379                 if (safe_create_leading_directories(path))
4380                         return 0;
4381                 res = try_create_file(path, mode, buf, size);
4382                 if (res < 0)
4383                         return -1;
4384                 if (!res)
4385                         return 0;
4386         }
4387
4388         if (errno == EEXIST || errno == EACCES) {
4389                 /* We may be trying to create a file where a directory
4390                  * used to be.
4391                  */
4392                 struct stat st;
4393                 if (!lstat(path, &st) && (!S_ISDIR(st.st_mode) || !rmdir(path)))
4394                         errno = EEXIST;
4395         }
4396
4397         if (errno == EEXIST) {
4398                 unsigned int nr = getpid();
4399
4400                 for (;;) {
4401                         char newpath[PATH_MAX];
4402                         mksnpath(newpath, sizeof(newpath), "%s~%u", path, nr);
4403                         res = try_create_file(newpath, mode, buf, size);
4404                         if (res < 0)
4405                                 return -1;
4406                         if (!res) {
4407                                 if (!rename(newpath, path))
4408                                         return 0;
4409                                 unlink_or_warn(newpath);
4410                                 break;
4411                         }
4412                         if (errno != EEXIST)
4413                                 break;
4414                         ++nr;
4415                 }
4416         }
4417         return error_errno(_("unable to write file '%s' mode %o"),
4418                            path, mode);
4419 }
4420
4421 static int add_conflicted_stages_file(struct apply_state *state,
4422                                        struct patch *patch)
4423 {
4424         int stage, namelen;
4425         unsigned ce_size, mode;
4426         struct cache_entry *ce;
4427
4428         if (!state->update_index)
4429                 return 0;
4430         namelen = strlen(patch->new_name);
4431         ce_size = cache_entry_size(namelen);
4432         mode = patch->new_mode ? patch->new_mode : (S_IFREG | 0644);
4433
4434         remove_file_from_cache(patch->new_name);
4435         for (stage = 1; stage < 4; stage++) {
4436                 if (is_null_oid(&patch->threeway_stage[stage - 1]))
4437                         continue;
4438                 ce = xcalloc(1, ce_size);
4439                 memcpy(ce->name, patch->new_name, namelen);
4440                 ce->ce_mode = create_ce_mode(mode);
4441                 ce->ce_flags = create_ce_flags(stage);
4442                 ce->ce_namelen = namelen;
4443                 oidcpy(&ce->oid, &patch->threeway_stage[stage - 1]);
4444                 if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0) {
4445                         free(ce);
4446                         return error(_("unable to add cache entry for %s"),
4447                                      patch->new_name);
4448                 }
4449         }
4450
4451         return 0;
4452 }
4453
4454 static int create_file(struct apply_state *state, struct patch *patch)
4455 {
4456         char *path = patch->new_name;
4457         unsigned mode = patch->new_mode;
4458         unsigned long size = patch->resultsize;
4459         char *buf = patch->result;
4460
4461         if (!mode)
4462                 mode = S_IFREG | 0644;
4463         if (create_one_file(state, path, mode, buf, size))
4464                 return -1;
4465
4466         if (patch->conflicted_threeway)
4467                 return add_conflicted_stages_file(state, patch);
4468         else
4469                 return add_index_file(state, path, mode, buf, size);
4470 }
4471
4472 /* phase zero is to remove, phase one is to create */
4473 static int write_out_one_result(struct apply_state *state,
4474                                 struct patch *patch,
4475                                 int phase)
4476 {
4477         if (patch->is_delete > 0) {
4478                 if (phase == 0)
4479                         return remove_file(state, patch, 1);
4480                 return 0;
4481         }
4482         if (patch->is_new > 0 || patch->is_copy) {
4483                 if (phase == 1)
4484                         return create_file(state, patch);
4485                 return 0;
4486         }
4487         /*
4488          * Rename or modification boils down to the same
4489          * thing: remove the old, write the new
4490          */
4491         if (phase == 0)
4492                 return remove_file(state, patch, patch->is_rename);
4493         if (phase == 1)
4494                 return create_file(state, patch);
4495         return 0;
4496 }
4497
4498 static int write_out_one_reject(struct apply_state *state, struct patch *patch)
4499 {
4500         FILE *rej;
4501         char namebuf[PATH_MAX];
4502         struct fragment *frag;
4503         int cnt = 0;
4504         struct strbuf sb = STRBUF_INIT;
4505
4506         for (cnt = 0, frag = patch->fragments; frag; frag = frag->next) {
4507                 if (!frag->rejected)
4508                         continue;
4509                 cnt++;
4510         }
4511
4512         if (!cnt) {
4513                 if (state->apply_verbosity > verbosity_normal)
4514                         say_patch_name(stderr,
4515                                        _("Applied patch %s cleanly."), patch);
4516                 return 0;
4517         }
4518
4519         /* This should not happen, because a removal patch that leaves
4520          * contents are marked "rejected" at the patch level.
4521          */
4522         if (!patch->new_name)
4523                 die(_("internal error"));
4524
4525         /* Say this even without --verbose */
4526         strbuf_addf(&sb, Q_("Applying patch %%s with %d reject...",
4527                             "Applying patch %%s with %d rejects...",
4528                             cnt),
4529                     cnt);
4530         if (state->apply_verbosity > verbosity_silent)
4531                 say_patch_name(stderr, sb.buf, patch);
4532         strbuf_release(&sb);
4533
4534         cnt = strlen(patch->new_name);
4535         if (ARRAY_SIZE(namebuf) <= cnt + 5) {
4536                 cnt = ARRAY_SIZE(namebuf) - 5;
4537                 warning(_("truncating .rej filename to %.*s.rej"),
4538                         cnt - 1, patch->new_name);
4539         }
4540         memcpy(namebuf, patch->new_name, cnt);
4541         memcpy(namebuf + cnt, ".rej", 5);
4542
4543         rej = fopen(namebuf, "w");
4544         if (!rej)
4545                 return error_errno(_("cannot open %s"), namebuf);
4546
4547         /* Normal git tools never deal with .rej, so do not pretend
4548          * this is a git patch by saying --git or giving extended
4549          * headers.  While at it, maybe please "kompare" that wants
4550          * the trailing TAB and some garbage at the end of line ;-).
4551          */
4552         fprintf(rej, "diff a/%s b/%s\t(rejected hunks)\n",
4553                 patch->new_name, patch->new_name);
4554         for (cnt = 1, frag = patch->fragments;
4555              frag;
4556              cnt++, frag = frag->next) {
4557                 if (!frag->rejected) {
4558                         if (state->apply_verbosity > verbosity_silent)
4559                                 fprintf_ln(stderr, _("Hunk #%d applied cleanly."), cnt);
4560                         continue;
4561                 }
4562                 if (state->apply_verbosity > verbosity_silent)
4563                         fprintf_ln(stderr, _("Rejected hunk #%d."), cnt);
4564                 fprintf(rej, "%.*s", frag->size, frag->patch);
4565                 if (frag->patch[frag->size-1] != '\n')
4566                         fputc('\n', rej);
4567         }
4568         fclose(rej);
4569         return -1;
4570 }
4571
4572 /*
4573  * Returns:
4574  *  -1 if an error happened
4575  *   0 if the patch applied cleanly
4576  *   1 if the patch did not apply cleanly
4577  */
4578 static int write_out_results(struct apply_state *state, struct patch *list)
4579 {
4580         int phase;
4581         int errs = 0;
4582         struct patch *l;
4583         struct string_list cpath = STRING_LIST_INIT_DUP;
4584
4585         for (phase = 0; phase < 2; phase++) {
4586                 l = list;
4587                 while (l) {
4588                         if (l->rejected)
4589                                 errs = 1;
4590                         else {
4591                                 if (write_out_one_result(state, l, phase)) {
4592                                         string_list_clear(&cpath, 0);
4593                                         return -1;
4594                                 }
4595                                 if (phase == 1) {
4596                                         if (write_out_one_reject(state, l))
4597                                                 errs = 1;
4598                                         if (l->conflicted_threeway) {
4599                                                 string_list_append(&cpath, l->new_name);
4600                                                 errs = 1;
4601                                         }
4602                                 }
4603                         }
4604                         l = l->next;
4605                 }
4606         }
4607
4608         if (cpath.nr) {
4609                 struct string_list_item *item;
4610
4611                 string_list_sort(&cpath);
4612                 if (state->apply_verbosity > verbosity_silent) {
4613                         for_each_string_list_item(item, &cpath)
4614                                 fprintf(stderr, "U %s\n", item->string);
4615                 }
4616                 string_list_clear(&cpath, 0);
4617
4618                 rerere(0);
4619         }
4620
4621         return errs;
4622 }
4623
4624 /*
4625  * Try to apply a patch.
4626  *
4627  * Returns:
4628  *  -128 if a bad error happened (like patch unreadable)
4629  *  -1 if patch did not apply and user cannot deal with it
4630  *   0 if the patch applied
4631  *   1 if the patch did not apply but user might fix it
4632  */
4633 static int apply_patch(struct apply_state *state,
4634                        int fd,
4635                        const char *filename,
4636                        int options)
4637 {
4638         size_t offset;
4639         struct strbuf buf = STRBUF_INIT; /* owns the patch text */
4640         struct patch *list = NULL, **listp = &list;
4641         int skipped_patch = 0;
4642         int res = 0;
4643
4644         state->patch_input_file = filename;
4645         if (read_patch_file(&buf, fd) < 0)
4646                 return -128;
4647         offset = 0;
4648         while (offset < buf.len) {
4649                 struct patch *patch;
4650                 int nr;
4651
4652                 patch = xcalloc(1, sizeof(*patch));
4653                 patch->inaccurate_eof = !!(options & APPLY_OPT_INACCURATE_EOF);
4654                 patch->recount =  !!(options & APPLY_OPT_RECOUNT);
4655                 nr = parse_chunk(state, buf.buf + offset, buf.len - offset, patch);
4656                 if (nr < 0) {
4657                         free_patch(patch);
4658                         if (nr == -128) {
4659                                 res = -128;
4660                                 goto end;
4661                         }
4662                         break;
4663                 }
4664                 if (state->apply_in_reverse)
4665                         reverse_patches(patch);
4666                 if (use_patch(state, patch)) {
4667                         patch_stats(state, patch);
4668                         *listp = patch;
4669                         listp = &patch->next;
4670                 }
4671                 else {
4672                         if (state->apply_verbosity > verbosity_normal)
4673                                 say_patch_name(stderr, _("Skipped patch '%s'."), patch);
4674                         free_patch(patch);
4675                         skipped_patch++;
4676                 }
4677                 offset += nr;
4678         }
4679
4680         if (!list && !skipped_patch) {
4681                 error(_("unrecognized input"));
4682                 res = -128;
4683                 goto end;
4684         }
4685
4686         if (state->whitespace_error && (state->ws_error_action == die_on_ws_error))
4687                 state->apply = 0;
4688
4689         state->update_index = state->check_index && state->apply;
4690         if (state->update_index && !is_lock_file_locked(&state->lock_file)) {
4691                 if (state->index_file)
4692                         hold_lock_file_for_update(&state->lock_file,
4693                                                   state->index_file,
4694                                                   LOCK_DIE_ON_ERROR);
4695                 else
4696                         hold_locked_index(&state->lock_file, LOCK_DIE_ON_ERROR);
4697         }
4698
4699         if (state->check_index && read_apply_cache(state) < 0) {
4700                 error(_("unable to read index file"));
4701                 res = -128;
4702                 goto end;
4703         }
4704
4705         if (state->check || state->apply) {
4706                 int r = check_patch_list(state, list);
4707                 if (r == -128) {
4708                         res = -128;
4709                         goto end;
4710                 }
4711                 if (r < 0 && !state->apply_with_reject) {
4712                         res = -1;
4713                         goto end;
4714                 }
4715         }
4716
4717         if (state->apply) {
4718                 int write_res = write_out_results(state, list);
4719                 if (write_res < 0) {
4720                         res = -128;
4721                         goto end;
4722                 }
4723                 if (write_res > 0) {
4724                         /* with --3way, we still need to write the index out */
4725                         res = state->apply_with_reject ? -1 : 1;
4726                         goto end;
4727                 }
4728         }
4729
4730         if (state->fake_ancestor &&
4731             build_fake_ancestor(state, list)) {
4732                 res = -128;
4733                 goto end;
4734         }
4735
4736         if (state->diffstat && state->apply_verbosity > verbosity_silent)
4737                 stat_patch_list(state, list);
4738
4739         if (state->numstat && state->apply_verbosity > verbosity_silent)
4740                 numstat_patch_list(state, list);
4741
4742         if (state->summary && state->apply_verbosity > verbosity_silent)
4743                 summary_patch_list(list);
4744
4745 end:
4746         free_patch_list(list);
4747         strbuf_release(&buf);
4748         string_list_clear(&state->fn_table, 0);
4749         return res;
4750 }
4751
4752 static int apply_option_parse_exclude(const struct option *opt,
4753                                       const char *arg, int unset)
4754 {
4755         struct apply_state *state = opt->value;
4756         add_name_limit(state, arg, 1);
4757         return 0;
4758 }
4759
4760 static int apply_option_parse_include(const struct option *opt,
4761                                       const char *arg, int unset)
4762 {
4763         struct apply_state *state = opt->value;
4764         add_name_limit(state, arg, 0);
4765         state->has_include = 1;
4766         return 0;
4767 }
4768
4769 static int apply_option_parse_p(const struct option *opt,
4770                                 const char *arg,
4771                                 int unset)
4772 {
4773         struct apply_state *state = opt->value;
4774         state->p_value = atoi(arg);
4775         state->p_value_known = 1;
4776         return 0;
4777 }
4778
4779 static int apply_option_parse_space_change(const struct option *opt,
4780                                            const char *arg, int unset)
4781 {
4782         struct apply_state *state = opt->value;
4783         if (unset)
4784                 state->ws_ignore_action = ignore_ws_none;
4785         else
4786                 state->ws_ignore_action = ignore_ws_change;
4787         return 0;
4788 }
4789
4790 static int apply_option_parse_whitespace(const struct option *opt,
4791                                          const char *arg, int unset)
4792 {
4793         struct apply_state *state = opt->value;
4794         state->whitespace_option = arg;
4795         if (parse_whitespace_option(state, arg))
4796                 exit(1);
4797         return 0;
4798 }
4799
4800 static int apply_option_parse_directory(const struct option *opt,
4801                                         const char *arg, int unset)
4802 {
4803         struct apply_state *state = opt->value;
4804         strbuf_reset(&state->root);
4805         strbuf_addstr(&state->root, arg);
4806         strbuf_complete(&state->root, '/');
4807         return 0;
4808 }
4809
4810 int apply_all_patches(struct apply_state *state,
4811                       int argc,
4812                       const char **argv,
4813                       int options)
4814 {
4815         int i;
4816         int res;
4817         int errs = 0;
4818         int read_stdin = 1;
4819
4820         for (i = 0; i < argc; i++) {
4821                 const char *arg = argv[i];
4822                 char *to_free = NULL;
4823                 int fd;
4824
4825                 if (!strcmp(arg, "-")) {
4826                         res = apply_patch(state, 0, "<stdin>", options);
4827                         if (res < 0)
4828                                 goto end;
4829                         errs |= res;
4830                         read_stdin = 0;
4831                         continue;
4832                 } else
4833                         arg = to_free = prefix_filename(state->prefix, arg);
4834
4835                 fd = open(arg, O_RDONLY);
4836                 if (fd < 0) {
4837                         error(_("can't open patch '%s': %s"), arg, strerror(errno));
4838                         res = -128;
4839                         free(to_free);
4840                         goto end;
4841                 }
4842                 read_stdin = 0;
4843                 set_default_whitespace_mode(state);
4844                 res = apply_patch(state, fd, arg, options);
4845                 close(fd);
4846                 free(to_free);
4847                 if (res < 0)
4848                         goto end;
4849                 errs |= res;
4850         }
4851         set_default_whitespace_mode(state);
4852         if (read_stdin) {
4853                 res = apply_patch(state, 0, "<stdin>", options);
4854                 if (res < 0)
4855                         goto end;
4856                 errs |= res;
4857         }
4858
4859         if (state->whitespace_error) {
4860                 if (state->squelch_whitespace_errors &&
4861                     state->squelch_whitespace_errors < state->whitespace_error) {
4862                         int squelched =
4863                                 state->whitespace_error - state->squelch_whitespace_errors;
4864                         warning(Q_("squelched %d whitespace error",
4865                                    "squelched %d whitespace errors",
4866                                    squelched),
4867                                 squelched);
4868                 }
4869                 if (state->ws_error_action == die_on_ws_error) {
4870                         error(Q_("%d line adds whitespace errors.",
4871                                  "%d lines add whitespace errors.",
4872                                  state->whitespace_error),
4873                               state->whitespace_error);
4874                         res = -128;
4875                         goto end;
4876                 }
4877                 if (state->applied_after_fixing_ws && state->apply)
4878                         warning(Q_("%d line applied after"
4879                                    " fixing whitespace errors.",
4880                                    "%d lines applied after"
4881                                    " fixing whitespace errors.",
4882                                    state->applied_after_fixing_ws),
4883                                 state->applied_after_fixing_ws);
4884                 else if (state->whitespace_error)
4885                         warning(Q_("%d line adds whitespace errors.",
4886                                    "%d lines add whitespace errors.",
4887                                    state->whitespace_error),
4888                                 state->whitespace_error);
4889         }
4890
4891         if (state->update_index) {
4892                 res = write_locked_index(&the_index, &state->lock_file, COMMIT_LOCK);
4893                 if (res) {
4894                         error(_("Unable to write new index file"));
4895                         res = -128;
4896                         goto end;
4897                 }
4898         }
4899
4900         res = !!errs;
4901
4902 end:
4903         rollback_lock_file(&state->lock_file);
4904
4905         if (state->apply_verbosity <= verbosity_silent) {
4906                 set_error_routine(state->saved_error_routine);
4907                 set_warn_routine(state->saved_warn_routine);
4908         }
4909
4910         if (res > -1)
4911                 return res;
4912         return (res == -1 ? 1 : 128);
4913 }
4914
4915 int apply_parse_options(int argc, const char **argv,
4916                         struct apply_state *state,
4917                         int *force_apply, int *options,
4918                         const char * const *apply_usage)
4919 {
4920         struct option builtin_apply_options[] = {
4921                 { OPTION_CALLBACK, 0, "exclude", state, N_("path"),
4922                         N_("don't apply changes matching the given path"),
4923                         0, apply_option_parse_exclude },
4924                 { OPTION_CALLBACK, 0, "include", state, N_("path"),
4925                         N_("apply changes matching the given path"),
4926                         0, apply_option_parse_include },
4927                 { OPTION_CALLBACK, 'p', NULL, state, N_("num"),
4928                         N_("remove <num> leading slashes from traditional diff paths"),
4929                         0, apply_option_parse_p },
4930                 OPT_BOOL(0, "no-add", &state->no_add,
4931                         N_("ignore additions made by the patch")),
4932                 OPT_BOOL(0, "stat", &state->diffstat,
4933                         N_("instead of applying the patch, output diffstat for the input")),
4934                 OPT_NOOP_NOARG(0, "allow-binary-replacement"),
4935                 OPT_NOOP_NOARG(0, "binary"),
4936                 OPT_BOOL(0, "numstat", &state->numstat,
4937                         N_("show number of added and deleted lines in decimal notation")),
4938                 OPT_BOOL(0, "summary", &state->summary,
4939                         N_("instead of applying the patch, output a summary for the input")),
4940                 OPT_BOOL(0, "check", &state->check,
4941                         N_("instead of applying the patch, see if the patch is applicable")),
4942                 OPT_BOOL(0, "index", &state->check_index,
4943                         N_("make sure the patch is applicable to the current index")),
4944                 OPT_BOOL(0, "cached", &state->cached,
4945                         N_("apply a patch without touching the working tree")),
4946                 OPT_BOOL(0, "unsafe-paths", &state->unsafe_paths,
4947                         N_("accept a patch that touches outside the working area")),
4948                 OPT_BOOL(0, "apply", force_apply,
4949                         N_("also apply the patch (use with --stat/--summary/--check)")),
4950                 OPT_BOOL('3', "3way", &state->threeway,
4951                          N_( "attempt three-way merge if a patch does not apply")),
4952                 OPT_FILENAME(0, "build-fake-ancestor", &state->fake_ancestor,
4953                         N_("build a temporary index based on embedded index information")),
4954                 /* Think twice before adding "--nul" synonym to this */
4955                 OPT_SET_INT('z', NULL, &state->line_termination,
4956                         N_("paths are separated with NUL character"), '\0'),
4957                 OPT_INTEGER('C', NULL, &state->p_context,
4958                                 N_("ensure at least <n> lines of context match")),
4959                 { OPTION_CALLBACK, 0, "whitespace", state, N_("action"),
4960                         N_("detect new or modified lines that have whitespace errors"),
4961                         0, apply_option_parse_whitespace },
4962                 { OPTION_CALLBACK, 0, "ignore-space-change", state, NULL,
4963                         N_("ignore changes in whitespace when finding context"),
4964                         PARSE_OPT_NOARG, apply_option_parse_space_change },
4965                 { OPTION_CALLBACK, 0, "ignore-whitespace", state, NULL,
4966                         N_("ignore changes in whitespace when finding context"),
4967                         PARSE_OPT_NOARG, apply_option_parse_space_change },
4968                 OPT_BOOL('R', "reverse", &state->apply_in_reverse,
4969                         N_("apply the patch in reverse")),
4970                 OPT_BOOL(0, "unidiff-zero", &state->unidiff_zero,
4971                         N_("don't expect at least one line of context")),
4972                 OPT_BOOL(0, "reject", &state->apply_with_reject,
4973                         N_("leave the rejected hunks in corresponding *.rej files")),
4974                 OPT_BOOL(0, "allow-overlap", &state->allow_overlap,
4975                         N_("allow overlapping hunks")),
4976                 OPT__VERBOSE(&state->apply_verbosity, N_("be verbose")),
4977                 OPT_BIT(0, "inaccurate-eof", options,
4978                         N_("tolerate incorrectly detected missing new-line at the end of file"),
4979                         APPLY_OPT_INACCURATE_EOF),
4980                 OPT_BIT(0, "recount", options,
4981                         N_("do not trust the line counts in the hunk headers"),
4982                         APPLY_OPT_RECOUNT),
4983                 { OPTION_CALLBACK, 0, "directory", state, N_("root"),
4984                         N_("prepend <root> to all filenames"),
4985                         0, apply_option_parse_directory },
4986                 OPT_END()
4987         };
4988
4989         return parse_options(argc, argv, state->prefix, builtin_apply_options, apply_usage, 0);
4990 }