diff-files: mark an index entry we know is up-to-date as such
[git] / diff-lib.c
1 /*
2  * Copyright (C) 2005 Junio C Hamano
3  */
4 #include "cache.h"
5 #include "quote.h"
6 #include "commit.h"
7 #include "diff.h"
8 #include "diffcore.h"
9 #include "revision.h"
10 #include "cache-tree.h"
11 #include "path-list.h"
12 #include "unpack-trees.h"
13 #include "refs.h"
14
15 /*
16  * diff-files
17  */
18
19 static int read_directory(const char *path, struct path_list *list)
20 {
21         DIR *dir;
22         struct dirent *e;
23
24         if (!(dir = opendir(path)))
25                 return error("Could not open directory %s", path);
26
27         while ((e = readdir(dir)))
28                 if (strcmp(".", e->d_name) && strcmp("..", e->d_name))
29                         path_list_insert(e->d_name, list);
30
31         closedir(dir);
32         return 0;
33 }
34
35 static int get_mode(const char *path, int *mode)
36 {
37         struct stat st;
38
39         if (!path || !strcmp(path, "/dev/null"))
40                 *mode = 0;
41         else if (!strcmp(path, "-"))
42                 *mode = create_ce_mode(0666);
43         else if (stat(path, &st))
44                 return error("Could not access '%s'", path);
45         else
46                 *mode = st.st_mode;
47         return 0;
48 }
49
50 static int queue_diff(struct diff_options *o,
51                 const char *name1, const char *name2)
52 {
53         int mode1 = 0, mode2 = 0;
54
55         if (get_mode(name1, &mode1) || get_mode(name2, &mode2))
56                 return -1;
57
58         if (mode1 && mode2 && S_ISDIR(mode1) != S_ISDIR(mode2))
59                 return error("file/directory conflict: %s, %s", name1, name2);
60
61         if (S_ISDIR(mode1) || S_ISDIR(mode2)) {
62                 char buffer1[PATH_MAX], buffer2[PATH_MAX];
63                 struct path_list p1 = {NULL, 0, 0, 1}, p2 = {NULL, 0, 0, 1};
64                 int len1 = 0, len2 = 0, i1, i2, ret = 0;
65
66                 if (name1 && read_directory(name1, &p1))
67                         return -1;
68                 if (name2 && read_directory(name2, &p2)) {
69                         path_list_clear(&p1, 0);
70                         return -1;
71                 }
72
73                 if (name1) {
74                         len1 = strlen(name1);
75                         if (len1 > 0 && name1[len1 - 1] == '/')
76                                 len1--;
77                         memcpy(buffer1, name1, len1);
78                         buffer1[len1++] = '/';
79                 }
80
81                 if (name2) {
82                         len2 = strlen(name2);
83                         if (len2 > 0 && name2[len2 - 1] == '/')
84                                 len2--;
85                         memcpy(buffer2, name2, len2);
86                         buffer2[len2++] = '/';
87                 }
88
89                 for (i1 = i2 = 0; !ret && (i1 < p1.nr || i2 < p2.nr); ) {
90                         const char *n1, *n2;
91                         int comp;
92
93                         if (i1 == p1.nr)
94                                 comp = 1;
95                         else if (i2 == p2.nr)
96                                 comp = -1;
97                         else
98                                 comp = strcmp(p1.items[i1].path,
99                                         p2.items[i2].path);
100
101                         if (comp > 0)
102                                 n1 = NULL;
103                         else {
104                                 n1 = buffer1;
105                                 strncpy(buffer1 + len1, p1.items[i1++].path,
106                                                 PATH_MAX - len1);
107                         }
108
109                         if (comp < 0)
110                                 n2 = NULL;
111                         else {
112                                 n2 = buffer2;
113                                 strncpy(buffer2 + len2, p2.items[i2++].path,
114                                                 PATH_MAX - len2);
115                         }
116
117                         ret = queue_diff(o, n1, n2);
118                 }
119                 path_list_clear(&p1, 0);
120                 path_list_clear(&p2, 0);
121
122                 return ret;
123         } else {
124                 struct diff_filespec *d1, *d2;
125
126                 if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
127                         unsigned tmp;
128                         const char *tmp_c;
129                         tmp = mode1; mode1 = mode2; mode2 = tmp;
130                         tmp_c = name1; name1 = name2; name2 = tmp_c;
131                 }
132
133                 if (!name1)
134                         name1 = "/dev/null";
135                 if (!name2)
136                         name2 = "/dev/null";
137                 d1 = alloc_filespec(name1);
138                 d2 = alloc_filespec(name2);
139                 fill_filespec(d1, null_sha1, mode1);
140                 fill_filespec(d2, null_sha1, mode2);
141
142                 diff_queue(&diff_queued_diff, d1, d2);
143                 return 0;
144         }
145 }
146
147 /*
148  * Does the path name a blob in the working tree, or a directory
149  * in the working tree?
150  */
151 static int is_in_index(const char *path)
152 {
153         int len, pos;
154         struct cache_entry *ce;
155
156         len = strlen(path);
157         while (path[len-1] == '/')
158                 len--;
159         if (!len)
160                 return 1; /* "." */
161         pos = cache_name_pos(path, len);
162         if (0 <= pos)
163                 return 1;
164         pos = -1 - pos;
165         while (pos < active_nr) {
166                 ce = active_cache[pos++];
167                 if (ce_namelen(ce) <= len ||
168                     strncmp(ce->name, path, len) ||
169                     (ce->name[len] > '/'))
170                         break; /* path cannot be a prefix */
171                 if (ce->name[len] == '/')
172                         return 1;
173         }
174         return 0;
175 }
176
177 static int handle_diff_files_args(struct rev_info *revs,
178                                   int argc, const char **argv,
179                                   unsigned int *options)
180 {
181         *options = 0;
182
183         /* revs->max_count == -2 means --no-index */
184         while (1 < argc && argv[1][0] == '-') {
185                 if (!strcmp(argv[1], "--base"))
186                         revs->max_count = 1;
187                 else if (!strcmp(argv[1], "--ours"))
188                         revs->max_count = 2;
189                 else if (!strcmp(argv[1], "--theirs"))
190                         revs->max_count = 3;
191                 else if (!strcmp(argv[1], "-n") ||
192                                 !strcmp(argv[1], "--no-index")) {
193                         revs->max_count = -2;
194                         DIFF_OPT_SET(&revs->diffopt, EXIT_WITH_STATUS);
195                         DIFF_OPT_SET(&revs->diffopt, NO_INDEX);
196                 }
197                 else if (!strcmp(argv[1], "-q"))
198                         *options |= DIFF_SILENT_ON_REMOVED;
199                 else
200                         return error("invalid option: %s", argv[1]);
201                 argv++; argc--;
202         }
203
204         if (revs->max_count == -1 && revs->diffopt.nr_paths == 2) {
205                 /*
206                  * If two files are specified, and at least one is untracked,
207                  * default to no-index.
208                  */
209                 read_cache();
210                 if (!is_in_index(revs->diffopt.paths[0]) ||
211                                         !is_in_index(revs->diffopt.paths[1])) {
212                         revs->max_count = -2;
213                         DIFF_OPT_SET(&revs->diffopt, NO_INDEX);
214                 }
215         }
216
217         /*
218          * Make sure there are NO revision (i.e. pending object) parameter,
219          * rev.max_count is reasonable (0 <= n <= 3),
220          * there is no other revision filtering parameters.
221          */
222         if (revs->pending.nr || revs->max_count > 3 ||
223             revs->min_age != -1 || revs->max_age != -1)
224                 return error("no revision allowed with diff-files");
225
226         if (revs->max_count == -1 &&
227             (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
228                 revs->combine_merges = revs->dense_combined_merges = 1;
229
230         return 0;
231 }
232
233 static int is_outside_repo(const char *path, int nongit, const char *prefix)
234 {
235         int i;
236         if (nongit || !strcmp(path, "-") || is_absolute_path(path))
237                 return 1;
238         if (prefixcmp(path, "../"))
239                 return 0;
240         if (!prefix)
241                 return 1;
242         for (i = strlen(prefix); !prefixcmp(path, "../"); ) {
243                 while (i > 0 && prefix[i - 1] != '/')
244                         i--;
245                 if (--i < 0)
246                         return 1;
247                 path += 3;
248         }
249         return 0;
250 }
251
252 int setup_diff_no_index(struct rev_info *revs,
253                 int argc, const char ** argv, int nongit, const char *prefix)
254 {
255         int i;
256         for (i = 1; i < argc; i++)
257                 if (argv[i][0] != '-' || argv[i][1] == '\0')
258                         break;
259                 else if (!strcmp(argv[i], "--")) {
260                         i++;
261                         break;
262                 } else if (i < argc - 3 && !strcmp(argv[i], "--no-index")) {
263                         i = argc - 3;
264                         DIFF_OPT_SET(&revs->diffopt, EXIT_WITH_STATUS);
265                         break;
266                 }
267         if (argc != i + 2 || (!is_outside_repo(argv[i + 1], nongit, prefix) &&
268                                 !is_outside_repo(argv[i], nongit, prefix)))
269                 return -1;
270
271         diff_setup(&revs->diffopt);
272         for (i = 1; i < argc - 2; )
273                 if (!strcmp(argv[i], "--no-index"))
274                         i++;
275                 else {
276                         int j = diff_opt_parse(&revs->diffopt,
277                                         argv + i, argc - i);
278                         if (!j)
279                                 die("invalid diff option/value: %s", argv[i]);
280                         i += j;
281                 }
282
283         if (prefix) {
284                 int len = strlen(prefix);
285
286                 revs->diffopt.paths = xcalloc(2, sizeof(char*));
287                 for (i = 0; i < 2; i++) {
288                         const char *p = argv[argc - 2 + i];
289                         /*
290                          * stdin should be spelled as '-'; if you have
291                          * path that is '-', spell it as ./-.
292                          */
293                         p = (strcmp(p, "-")
294                              ? xstrdup(prefix_filename(prefix, len, p))
295                              : p);
296                         revs->diffopt.paths[i] = p;
297                 }
298         }
299         else
300                 revs->diffopt.paths = argv + argc - 2;
301         revs->diffopt.nr_paths = 2;
302         DIFF_OPT_SET(&revs->diffopt, NO_INDEX);
303         revs->max_count = -2;
304         if (diff_setup_done(&revs->diffopt) < 0)
305                 die("diff_setup_done failed");
306         return 0;
307 }
308
309 int run_diff_files_cmd(struct rev_info *revs, int argc, const char **argv)
310 {
311         unsigned int options;
312
313         if (handle_diff_files_args(revs, argc, argv, &options))
314                 return -1;
315
316         if (DIFF_OPT_TST(&revs->diffopt, NO_INDEX)) {
317                 if (revs->diffopt.nr_paths != 2)
318                         return error("need two files/directories with --no-index");
319                 if (queue_diff(&revs->diffopt, revs->diffopt.paths[0],
320                                 revs->diffopt.paths[1]))
321                         return -1;
322                 diffcore_std(&revs->diffopt);
323                 diff_flush(&revs->diffopt);
324                 /*
325                  * The return code for --no-index imitates diff(1):
326                  * 0 = no changes, 1 = changes, else error
327                  */
328                 return revs->diffopt.found_changes;
329         }
330
331         if (read_cache() < 0) {
332                 perror("read_cache");
333                 return -1;
334         }
335         return run_diff_files(revs, options);
336 }
337 /*
338  * See if work tree has an entity that can be staged.  Return 0 if so,
339  * return 1 if not and return -1 if error.
340  */
341 static int check_work_tree_entity(const struct cache_entry *ce, struct stat *st, char *symcache)
342 {
343         if (lstat(ce->name, st) < 0) {
344                 if (errno != ENOENT && errno != ENOTDIR)
345                         return -1;
346                 return 1;
347         }
348         if (has_symlink_leading_path(ce->name, symcache))
349                 return 1;
350         if (S_ISDIR(st->st_mode)) {
351                 unsigned char sub[20];
352                 if (resolve_gitlink_ref(ce->name, "HEAD", sub))
353                         return 1;
354         }
355         return 0;
356 }
357
358 int run_diff_files(struct rev_info *revs, unsigned int option)
359 {
360         int entries, i;
361         int diff_unmerged_stage = revs->max_count;
362         int silent_on_removed = option & DIFF_SILENT_ON_REMOVED;
363         unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
364                               ? CE_MATCH_RACY_IS_DIRTY : 0);
365         char symcache[PATH_MAX];
366
367         if (diff_unmerged_stage < 0)
368                 diff_unmerged_stage = 2;
369         entries = active_nr;
370         symcache[0] = '\0';
371         for (i = 0; i < entries; i++) {
372                 struct stat st;
373                 unsigned int oldmode, newmode;
374                 struct cache_entry *ce = active_cache[i];
375                 int changed;
376
377                 if (DIFF_OPT_TST(&revs->diffopt, QUIET) &&
378                         DIFF_OPT_TST(&revs->diffopt, HAS_CHANGES))
379                         break;
380
381                 if (!ce_path_match(ce, revs->prune_data))
382                         continue;
383
384                 if (ce_stage(ce)) {
385                         struct combine_diff_path *dpath;
386                         int num_compare_stages = 0;
387                         size_t path_len;
388
389                         path_len = ce_namelen(ce);
390
391                         dpath = xmalloc(combine_diff_path_size(5, path_len));
392                         dpath->path = (char *) &(dpath->parent[5]);
393
394                         dpath->next = NULL;
395                         dpath->len = path_len;
396                         memcpy(dpath->path, ce->name, path_len);
397                         dpath->path[path_len] = '\0';
398                         hashclr(dpath->sha1);
399                         memset(&(dpath->parent[0]), 0,
400                                sizeof(struct combine_diff_parent)*5);
401
402                         changed = check_work_tree_entity(ce, &st, symcache);
403                         if (!changed)
404                                 dpath->mode = ce_mode_from_stat(ce, st.st_mode);
405                         else {
406                                 if (changed < 0) {
407                                         perror(ce->name);
408                                         continue;
409                                 }
410                                 if (silent_on_removed)
411                                         continue;
412                         }
413
414                         while (i < entries) {
415                                 struct cache_entry *nce = active_cache[i];
416                                 int stage;
417
418                                 if (strcmp(ce->name, nce->name))
419                                         break;
420
421                                 /* Stage #2 (ours) is the first parent,
422                                  * stage #3 (theirs) is the second.
423                                  */
424                                 stage = ce_stage(nce);
425                                 if (2 <= stage) {
426                                         int mode = nce->ce_mode;
427                                         num_compare_stages++;
428                                         hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
429                                         dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
430                                         dpath->parent[stage-2].status =
431                                                 DIFF_STATUS_MODIFIED;
432                                 }
433
434                                 /* diff against the proper unmerged stage */
435                                 if (stage == diff_unmerged_stage)
436                                         ce = nce;
437                                 i++;
438                         }
439                         /*
440                          * Compensate for loop update
441                          */
442                         i--;
443
444                         if (revs->combine_merges && num_compare_stages == 2) {
445                                 show_combined_diff(dpath, 2,
446                                                    revs->dense_combined_merges,
447                                                    revs);
448                                 free(dpath);
449                                 continue;
450                         }
451                         free(dpath);
452                         dpath = NULL;
453
454                         /*
455                          * Show the diff for the 'ce' if we found the one
456                          * from the desired stage.
457                          */
458                         diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
459                         if (ce_stage(ce) != diff_unmerged_stage)
460                                 continue;
461                 }
462
463                 if (ce_uptodate(ce))
464                         continue;
465
466                 changed = check_work_tree_entity(ce, &st, symcache);
467                 if (changed) {
468                         if (changed < 0) {
469                                 perror(ce->name);
470                                 continue;
471                         }
472                         if (silent_on_removed)
473                                 continue;
474                         diff_addremove(&revs->diffopt, '-', ce->ce_mode,
475                                        ce->sha1, ce->name, NULL);
476                         continue;
477                 }
478                 changed = ce_match_stat(ce, &st, ce_option);
479                 if (!changed) {
480                         ce_mark_uptodate(ce);
481                         if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
482                                 continue;
483                 }
484                 oldmode = ce->ce_mode;
485                 newmode = ce_mode_from_stat(ce, st.st_mode);
486                 diff_change(&revs->diffopt, oldmode, newmode,
487                             ce->sha1, (changed ? null_sha1 : ce->sha1),
488                             ce->name, NULL);
489
490         }
491         diffcore_std(&revs->diffopt);
492         diff_flush(&revs->diffopt);
493         return 0;
494 }
495
496 /*
497  * diff-index
498  */
499
500 struct oneway_unpack_data {
501         struct rev_info *revs;
502         char symcache[PATH_MAX];
503 };
504
505 /* A file entry went away or appeared */
506 static void diff_index_show_file(struct rev_info *revs,
507                                  const char *prefix,
508                                  struct cache_entry *ce,
509                                  const unsigned char *sha1, unsigned int mode)
510 {
511         diff_addremove(&revs->diffopt, prefix[0], mode,
512                        sha1, ce->name, NULL);
513 }
514
515 static int get_stat_data(struct cache_entry *ce,
516                          const unsigned char **sha1p,
517                          unsigned int *modep,
518                          int cached, int match_missing,
519                          struct oneway_unpack_data *cbdata)
520 {
521         const unsigned char *sha1 = ce->sha1;
522         unsigned int mode = ce->ce_mode;
523
524         if (!cached) {
525                 int changed;
526                 struct stat st;
527                 changed = check_work_tree_entity(ce, &st, cbdata->symcache);
528                 if (changed < 0)
529                         return -1;
530                 else if (changed) {
531                         if (match_missing) {
532                                 *sha1p = sha1;
533                                 *modep = mode;
534                                 return 0;
535                         }
536                         return -1;
537                 }
538                 changed = ce_match_stat(ce, &st, 0);
539                 if (changed) {
540                         mode = ce_mode_from_stat(ce, st.st_mode);
541                         sha1 = null_sha1;
542                 }
543         }
544
545         *sha1p = sha1;
546         *modep = mode;
547         return 0;
548 }
549
550 static void show_new_file(struct oneway_unpack_data *cbdata,
551                           struct cache_entry *new,
552                           int cached, int match_missing)
553 {
554         const unsigned char *sha1;
555         unsigned int mode;
556         struct rev_info *revs = cbdata->revs;
557
558         /*
559          * New file in the index: it might actually be different in
560          * the working copy.
561          */
562         if (get_stat_data(new, &sha1, &mode, cached, match_missing, cbdata) < 0)
563                 return;
564
565         diff_index_show_file(revs, "+", new, sha1, mode);
566 }
567
568 static int show_modified(struct oneway_unpack_data *cbdata,
569                          struct cache_entry *old,
570                          struct cache_entry *new,
571                          int report_missing,
572                          int cached, int match_missing)
573 {
574         unsigned int mode, oldmode;
575         const unsigned char *sha1;
576         struct rev_info *revs = cbdata->revs;
577
578         if (get_stat_data(new, &sha1, &mode, cached, match_missing, cbdata) < 0) {
579                 if (report_missing)
580                         diff_index_show_file(revs, "-", old,
581                                              old->sha1, old->ce_mode);
582                 return -1;
583         }
584
585         if (revs->combine_merges && !cached &&
586             (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
587                 struct combine_diff_path *p;
588                 int pathlen = ce_namelen(new);
589
590                 p = xmalloc(combine_diff_path_size(2, pathlen));
591                 p->path = (char *) &p->parent[2];
592                 p->next = NULL;
593                 p->len = pathlen;
594                 memcpy(p->path, new->name, pathlen);
595                 p->path[pathlen] = 0;
596                 p->mode = mode;
597                 hashclr(p->sha1);
598                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
599                 p->parent[0].status = DIFF_STATUS_MODIFIED;
600                 p->parent[0].mode = new->ce_mode;
601                 hashcpy(p->parent[0].sha1, new->sha1);
602                 p->parent[1].status = DIFF_STATUS_MODIFIED;
603                 p->parent[1].mode = old->ce_mode;
604                 hashcpy(p->parent[1].sha1, old->sha1);
605                 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
606                 free(p);
607                 return 0;
608         }
609
610         oldmode = old->ce_mode;
611         if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
612             !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
613                 return 0;
614
615         diff_change(&revs->diffopt, oldmode, mode,
616                     old->sha1, sha1, old->name, NULL);
617         return 0;
618 }
619
620 /*
621  * This turns all merge entries into "stage 3". That guarantees that
622  * when we read in the new tree (into "stage 1"), we won't lose sight
623  * of the fact that we had unmerged entries.
624  */
625 static void mark_merge_entries(void)
626 {
627         int i;
628         for (i = 0; i < active_nr; i++) {
629                 struct cache_entry *ce = active_cache[i];
630                 if (!ce_stage(ce))
631                         continue;
632                 ce->ce_flags |= CE_STAGEMASK;
633         }
634 }
635
636 /*
637  * This gets a mix of an existing index and a tree, one pathname entry
638  * at a time. The index entry may be a single stage-0 one, but it could
639  * also be multiple unmerged entries (in which case idx_pos/idx_nr will
640  * give you the position and number of entries in the index).
641  */
642 static void do_oneway_diff(struct unpack_trees_options *o,
643         struct cache_entry *idx,
644         struct cache_entry *tree)
645 {
646         struct oneway_unpack_data *cbdata = o->unpack_data;
647         struct rev_info *revs = cbdata->revs;
648         int match_missing, cached;
649
650         /*
651          * Backward compatibility wart - "diff-index -m" does
652          * not mean "do not ignore merges", but "match_missing".
653          *
654          * But with the revision flag parsing, that's found in
655          * "!revs->ignore_merges".
656          */
657         cached = o->index_only;
658         match_missing = !revs->ignore_merges;
659
660         if (cached && idx && ce_stage(idx)) {
661                 if (tree)
662                         diff_unmerge(&revs->diffopt, idx->name, idx->ce_mode, idx->sha1);
663                 return;
664         }
665
666         /*
667          * Something added to the tree?
668          */
669         if (!tree) {
670                 show_new_file(cbdata, idx, cached, match_missing);
671                 return;
672         }
673
674         /*
675          * Something removed from the tree?
676          */
677         if (!idx) {
678                 diff_index_show_file(revs, "-", tree, tree->sha1, tree->ce_mode);
679                 return;
680         }
681
682         /* Show difference between old and new */
683         show_modified(cbdata, tree, idx, 1, cached, match_missing);
684 }
685
686 static inline void skip_same_name(struct cache_entry *ce, struct unpack_trees_options *o)
687 {
688         int len = ce_namelen(ce);
689         const struct index_state *index = o->src_index;
690
691         while (o->pos < index->cache_nr) {
692                 struct cache_entry *next = index->cache[o->pos];
693                 if (len != ce_namelen(next))
694                         break;
695                 if (memcmp(ce->name, next->name, len))
696                         break;
697                 o->pos++;
698         }
699 }
700
701 /*
702  * The unpack_trees() interface is designed for merging, so
703  * the different source entries are designed primarily for
704  * the source trees, with the old index being really mainly
705  * used for being replaced by the result.
706  *
707  * For diffing, the index is more important, and we only have a
708  * single tree.
709  *
710  * We're supposed to return how many index entries we want to skip.
711  *
712  * This wrapper makes it all more readable, and takes care of all
713  * the fairly complex unpack_trees() semantic requirements, including
714  * the skipping, the path matching, the type conflict cases etc.
715  */
716 static int oneway_diff(struct cache_entry **src, struct unpack_trees_options *o)
717 {
718         struct cache_entry *idx = src[0];
719         struct cache_entry *tree = src[1];
720         struct oneway_unpack_data *cbdata = o->unpack_data;
721         struct rev_info *revs = cbdata->revs;
722
723         if (idx && ce_stage(idx))
724                 skip_same_name(idx, o);
725
726         /*
727          * Unpack-trees generates a DF/conflict entry if
728          * there was a directory in the index and a tree
729          * in the tree. From a diff standpoint, that's a
730          * delete of the tree and a create of the file.
731          */
732         if (tree == o->df_conflict_entry)
733                 tree = NULL;
734
735         if (ce_path_match(idx ? idx : tree, revs->prune_data))
736                 do_oneway_diff(o, idx, tree);
737
738         return 0;
739 }
740
741 int run_diff_index(struct rev_info *revs, int cached)
742 {
743         struct object *ent;
744         struct tree *tree;
745         const char *tree_name;
746         struct unpack_trees_options opts;
747         struct tree_desc t;
748         struct oneway_unpack_data unpack_cb;
749
750         mark_merge_entries();
751
752         ent = revs->pending.objects[0].item;
753         tree_name = revs->pending.objects[0].name;
754         tree = parse_tree_indirect(ent->sha1);
755         if (!tree)
756                 return error("bad tree object %s", tree_name);
757
758         unpack_cb.revs = revs;
759         unpack_cb.symcache[0] = '\0';
760         memset(&opts, 0, sizeof(opts));
761         opts.head_idx = 1;
762         opts.index_only = cached;
763         opts.merge = 1;
764         opts.fn = oneway_diff;
765         opts.unpack_data = &unpack_cb;
766         opts.src_index = &the_index;
767         opts.dst_index = NULL;
768
769         init_tree_desc(&t, tree->buffer, tree->size);
770         if (unpack_trees(1, &t, &opts))
771                 exit(128);
772
773         diffcore_std(&revs->diffopt);
774         diff_flush(&revs->diffopt);
775         return 0;
776 }
777
778 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
779 {
780         struct tree *tree;
781         struct rev_info revs;
782         int i;
783         struct cache_entry **dst;
784         struct cache_entry *last = NULL;
785         struct unpack_trees_options opts;
786         struct tree_desc t;
787         struct oneway_unpack_data unpack_cb;
788
789         /*
790          * This is used by git-blame to run diff-cache internally;
791          * it potentially needs to repeatedly run this, so we will
792          * start by removing the higher order entries the last round
793          * left behind.
794          */
795         dst = active_cache;
796         for (i = 0; i < active_nr; i++) {
797                 struct cache_entry *ce = active_cache[i];
798                 if (ce_stage(ce)) {
799                         if (last && !strcmp(ce->name, last->name))
800                                 continue;
801                         cache_tree_invalidate_path(active_cache_tree,
802                                                    ce->name);
803                         last = ce;
804                         ce->ce_flags |= CE_REMOVE;
805                 }
806                 *dst++ = ce;
807         }
808         active_nr = dst - active_cache;
809
810         init_revisions(&revs, NULL);
811         revs.prune_data = opt->paths;
812         tree = parse_tree_indirect(tree_sha1);
813         if (!tree)
814                 die("bad tree object %s", sha1_to_hex(tree_sha1));
815
816         unpack_cb.revs = &revs;
817         unpack_cb.symcache[0] = '\0';
818         memset(&opts, 0, sizeof(opts));
819         opts.head_idx = 1;
820         opts.index_only = 1;
821         opts.merge = 1;
822         opts.fn = oneway_diff;
823         opts.unpack_data = &unpack_cb;
824         opts.src_index = &the_index;
825         opts.dst_index = &the_index;
826
827         init_tree_desc(&t, tree->buffer, tree->size);
828         if (unpack_trees(1, &t, &opts))
829                 exit(128);
830         return 0;
831 }