cache_name_compare(): do not truncate while comparing paths
[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 "unpack-trees.h"
12 #include "refs.h"
13 #include "submodule.h"
14
15 /*
16  * diff-files
17  */
18
19 /*
20  * Has the work tree entity been removed?
21  *
22  * Return 1 if it was removed from the work tree, 0 if an entity to be
23  * compared with the cache entry ce still exists (the latter includes
24  * the case where a directory that is not a submodule repository
25  * exists for ce that is a submodule -- it is a submodule that is not
26  * checked out).  Return negative for an error.
27  */
28 static int check_removed(const struct cache_entry *ce, struct stat *st)
29 {
30         if (lstat(ce->name, st) < 0) {
31                 if (errno != ENOENT && errno != ENOTDIR)
32                         return -1;
33                 return 1;
34         }
35         if (has_symlink_leading_path(ce->name, ce_namelen(ce)))
36                 return 1;
37         if (S_ISDIR(st->st_mode)) {
38                 unsigned char sub[20];
39
40                 /*
41                  * If ce is already a gitlink, we can have a plain
42                  * directory (i.e. the submodule is not checked out),
43                  * or a checked out submodule.  Either case this is not
44                  * a case where something was removed from the work tree,
45                  * so we will return 0.
46                  *
47                  * Otherwise, if the directory is not a submodule
48                  * repository, that means ce which was a blob turned into
49                  * a directory --- the blob was removed!
50                  */
51                 if (!S_ISGITLINK(ce->ce_mode) &&
52                     resolve_gitlink_ref(ce->name, "HEAD", sub))
53                         return 1;
54         }
55         return 0;
56 }
57
58 int run_diff_files(struct rev_info *revs, unsigned int option)
59 {
60         int entries, i;
61         int diff_unmerged_stage = revs->max_count;
62         int silent_on_removed = option & DIFF_SILENT_ON_REMOVED;
63         unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
64                               ? CE_MATCH_RACY_IS_DIRTY : 0);
65
66         diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
67
68         if (diff_unmerged_stage < 0)
69                 diff_unmerged_stage = 2;
70         entries = active_nr;
71         for (i = 0; i < entries; i++) {
72                 struct stat st;
73                 unsigned int oldmode, newmode;
74                 struct cache_entry *ce = active_cache[i];
75                 int changed;
76                 unsigned dirty_submodule = 0;
77
78                 if (DIFF_OPT_TST(&revs->diffopt, QUICK) &&
79                         DIFF_OPT_TST(&revs->diffopt, HAS_CHANGES))
80                         break;
81
82                 if (!ce_path_match(ce, revs->prune_data))
83                         continue;
84
85                 if (ce_stage(ce)) {
86                         struct combine_diff_path *dpath;
87                         int num_compare_stages = 0;
88                         size_t path_len;
89
90                         path_len = ce_namelen(ce);
91
92                         dpath = xmalloc(combine_diff_path_size(5, path_len));
93                         dpath->path = (char *) &(dpath->parent[5]);
94
95                         dpath->next = NULL;
96                         dpath->len = path_len;
97                         memcpy(dpath->path, ce->name, path_len);
98                         dpath->path[path_len] = '\0';
99                         hashclr(dpath->sha1);
100                         memset(&(dpath->parent[0]), 0,
101                                sizeof(struct combine_diff_parent)*5);
102
103                         changed = check_removed(ce, &st);
104                         if (!changed)
105                                 dpath->mode = ce_mode_from_stat(ce, st.st_mode);
106                         else {
107                                 if (changed < 0) {
108                                         perror(ce->name);
109                                         continue;
110                                 }
111                                 if (silent_on_removed)
112                                         continue;
113                         }
114
115                         while (i < entries) {
116                                 struct cache_entry *nce = active_cache[i];
117                                 int stage;
118
119                                 if (strcmp(ce->name, nce->name))
120                                         break;
121
122                                 /* Stage #2 (ours) is the first parent,
123                                  * stage #3 (theirs) is the second.
124                                  */
125                                 stage = ce_stage(nce);
126                                 if (2 <= stage) {
127                                         int mode = nce->ce_mode;
128                                         num_compare_stages++;
129                                         hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
130                                         dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
131                                         dpath->parent[stage-2].status =
132                                                 DIFF_STATUS_MODIFIED;
133                                 }
134
135                                 /* diff against the proper unmerged stage */
136                                 if (stage == diff_unmerged_stage)
137                                         ce = nce;
138                                 i++;
139                         }
140                         /*
141                          * Compensate for loop update
142                          */
143                         i--;
144
145                         if (revs->combine_merges && num_compare_stages == 2) {
146                                 show_combined_diff(dpath, 2,
147                                                    revs->dense_combined_merges,
148                                                    revs);
149                                 free(dpath);
150                                 continue;
151                         }
152                         free(dpath);
153                         dpath = NULL;
154
155                         /*
156                          * Show the diff for the 'ce' if we found the one
157                          * from the desired stage.
158                          */
159                         diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
160                         if (ce_stage(ce) != diff_unmerged_stage)
161                                 continue;
162                 }
163
164                 if (ce_uptodate(ce) || ce_skip_worktree(ce))
165                         continue;
166
167                 /* If CE_VALID is set, don't look at workdir for file removal */
168                 changed = (ce->ce_flags & CE_VALID) ? 0 : check_removed(ce, &st);
169                 if (changed) {
170                         if (changed < 0) {
171                                 perror(ce->name);
172                                 continue;
173                         }
174                         if (silent_on_removed)
175                                 continue;
176                         diff_addremove(&revs->diffopt, '-', ce->ce_mode,
177                                        ce->sha1, ce->name, 0);
178                         continue;
179                 }
180                 changed = ce_match_stat(ce, &st, ce_option);
181                 if (S_ISGITLINK(ce->ce_mode)
182                     && !DIFF_OPT_TST(&revs->diffopt, IGNORE_SUBMODULES)
183                     && (!changed || (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
184                     && is_submodule_modified(ce->name)) {
185                         changed = 1;
186                         dirty_submodule = 1;
187                 }
188                 if (!changed) {
189                         ce_mark_uptodate(ce);
190                         if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
191                                 continue;
192                 }
193                 oldmode = ce->ce_mode;
194                 newmode = ce_mode_from_stat(ce, st.st_mode);
195                 diff_change(&revs->diffopt, oldmode, newmode,
196                             ce->sha1, (changed ? null_sha1 : ce->sha1),
197                             ce->name, 0, dirty_submodule);
198
199         }
200         diffcore_std(&revs->diffopt);
201         diff_flush(&revs->diffopt);
202         return 0;
203 }
204
205 /*
206  * diff-index
207  */
208
209 /* A file entry went away or appeared */
210 static void diff_index_show_file(struct rev_info *revs,
211                                  const char *prefix,
212                                  struct cache_entry *ce,
213                                  const unsigned char *sha1, unsigned int mode,
214                                  unsigned dirty_submodule)
215 {
216         diff_addremove(&revs->diffopt, prefix[0], mode,
217                        sha1, ce->name, dirty_submodule);
218 }
219
220 static int get_stat_data(struct cache_entry *ce,
221                          const unsigned char **sha1p,
222                          unsigned int *modep,
223                          int cached, int match_missing,
224                          unsigned *dirty_submodule, struct diff_options *diffopt)
225 {
226         const unsigned char *sha1 = ce->sha1;
227         unsigned int mode = ce->ce_mode;
228
229         if (!cached && !ce_uptodate(ce)) {
230                 int changed;
231                 struct stat st;
232                 changed = check_removed(ce, &st);
233                 if (changed < 0)
234                         return -1;
235                 else if (changed) {
236                         if (match_missing) {
237                                 *sha1p = sha1;
238                                 *modep = mode;
239                                 return 0;
240                         }
241                         return -1;
242                 }
243                 changed = ce_match_stat(ce, &st, 0);
244                 if (S_ISGITLINK(ce->ce_mode)
245                     && !DIFF_OPT_TST(diffopt, IGNORE_SUBMODULES)
246                     && (!changed || (diffopt->output_format & DIFF_FORMAT_PATCH))
247                     && is_submodule_modified(ce->name)) {
248                         changed = 1;
249                         *dirty_submodule = 1;
250                 }
251                 if (changed) {
252                         mode = ce_mode_from_stat(ce, st.st_mode);
253                         sha1 = null_sha1;
254                 }
255         }
256
257         *sha1p = sha1;
258         *modep = mode;
259         return 0;
260 }
261
262 static void show_new_file(struct rev_info *revs,
263                           struct cache_entry *new,
264                           int cached, int match_missing)
265 {
266         const unsigned char *sha1;
267         unsigned int mode;
268         unsigned dirty_submodule = 0;
269
270         /*
271          * New file in the index: it might actually be different in
272          * the working copy.
273          */
274         if (get_stat_data(new, &sha1, &mode, cached, match_missing,
275             &dirty_submodule, &revs->diffopt) < 0)
276                 return;
277
278         diff_index_show_file(revs, "+", new, sha1, mode, dirty_submodule);
279 }
280
281 static int show_modified(struct rev_info *revs,
282                          struct cache_entry *old,
283                          struct cache_entry *new,
284                          int report_missing,
285                          int cached, int match_missing)
286 {
287         unsigned int mode, oldmode;
288         const unsigned char *sha1;
289         unsigned dirty_submodule = 0;
290
291         if (get_stat_data(new, &sha1, &mode, cached, match_missing,
292                           &dirty_submodule, &revs->diffopt) < 0) {
293                 if (report_missing)
294                         diff_index_show_file(revs, "-", old,
295                                              old->sha1, old->ce_mode, 0);
296                 return -1;
297         }
298
299         if (revs->combine_merges && !cached &&
300             (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
301                 struct combine_diff_path *p;
302                 int pathlen = ce_namelen(new);
303
304                 p = xmalloc(combine_diff_path_size(2, pathlen));
305                 p->path = (char *) &p->parent[2];
306                 p->next = NULL;
307                 p->len = pathlen;
308                 memcpy(p->path, new->name, pathlen);
309                 p->path[pathlen] = 0;
310                 p->mode = mode;
311                 hashclr(p->sha1);
312                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
313                 p->parent[0].status = DIFF_STATUS_MODIFIED;
314                 p->parent[0].mode = new->ce_mode;
315                 hashcpy(p->parent[0].sha1, new->sha1);
316                 p->parent[1].status = DIFF_STATUS_MODIFIED;
317                 p->parent[1].mode = old->ce_mode;
318                 hashcpy(p->parent[1].sha1, old->sha1);
319                 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
320                 free(p);
321                 return 0;
322         }
323
324         oldmode = old->ce_mode;
325         if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
326             !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
327                 return 0;
328
329         diff_change(&revs->diffopt, oldmode, mode,
330                     old->sha1, sha1, old->name, 0, dirty_submodule);
331         return 0;
332 }
333
334 /*
335  * This gets a mix of an existing index and a tree, one pathname entry
336  * at a time. The index entry may be a single stage-0 one, but it could
337  * also be multiple unmerged entries (in which case idx_pos/idx_nr will
338  * give you the position and number of entries in the index).
339  */
340 static void do_oneway_diff(struct unpack_trees_options *o,
341         struct cache_entry *idx,
342         struct cache_entry *tree)
343 {
344         struct rev_info *revs = o->unpack_data;
345         int match_missing, cached;
346
347         /* if the entry is not checked out, don't examine work tree */
348         cached = o->index_only ||
349                 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
350         /*
351          * Backward compatibility wart - "diff-index -m" does
352          * not mean "do not ignore merges", but "match_missing".
353          *
354          * But with the revision flag parsing, that's found in
355          * "!revs->ignore_merges".
356          */
357         match_missing = !revs->ignore_merges;
358
359         if (cached && idx && ce_stage(idx)) {
360                 diff_unmerge(&revs->diffopt, idx->name, idx->ce_mode,
361                              idx->sha1);
362                 return;
363         }
364
365         /*
366          * Something added to the tree?
367          */
368         if (!tree) {
369                 show_new_file(revs, idx, cached, match_missing);
370                 return;
371         }
372
373         /*
374          * Something removed from the tree?
375          */
376         if (!idx) {
377                 diff_index_show_file(revs, "-", tree, tree->sha1, tree->ce_mode, 0);
378                 return;
379         }
380
381         /* Show difference between old and new */
382         show_modified(revs, tree, idx, 1, cached, match_missing);
383 }
384
385 /*
386  * The unpack_trees() interface is designed for merging, so
387  * the different source entries are designed primarily for
388  * the source trees, with the old index being really mainly
389  * used for being replaced by the result.
390  *
391  * For diffing, the index is more important, and we only have a
392  * single tree.
393  *
394  * We're supposed to advance o->pos to skip what we have already processed.
395  *
396  * This wrapper makes it all more readable, and takes care of all
397  * the fairly complex unpack_trees() semantic requirements, including
398  * the skipping, the path matching, the type conflict cases etc.
399  */
400 static int oneway_diff(struct cache_entry **src, struct unpack_trees_options *o)
401 {
402         struct cache_entry *idx = src[0];
403         struct cache_entry *tree = src[1];
404         struct rev_info *revs = o->unpack_data;
405
406         /*
407          * Unpack-trees generates a DF/conflict entry if
408          * there was a directory in the index and a tree
409          * in the tree. From a diff standpoint, that's a
410          * delete of the tree and a create of the file.
411          */
412         if (tree == o->df_conflict_entry)
413                 tree = NULL;
414
415         if (ce_path_match(idx ? idx : tree, revs->prune_data))
416                 do_oneway_diff(o, idx, tree);
417
418         return 0;
419 }
420
421 int run_diff_index(struct rev_info *revs, int cached)
422 {
423         struct object *ent;
424         struct tree *tree;
425         const char *tree_name;
426         struct unpack_trees_options opts;
427         struct tree_desc t;
428
429         ent = revs->pending.objects[0].item;
430         tree_name = revs->pending.objects[0].name;
431         tree = parse_tree_indirect(ent->sha1);
432         if (!tree)
433                 return error("bad tree object %s", tree_name);
434
435         memset(&opts, 0, sizeof(opts));
436         opts.head_idx = 1;
437         opts.index_only = cached;
438         opts.diff_index_cached = (cached &&
439                                   !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
440         opts.merge = 1;
441         opts.fn = oneway_diff;
442         opts.unpack_data = revs;
443         opts.src_index = &the_index;
444         opts.dst_index = NULL;
445
446         init_tree_desc(&t, tree->buffer, tree->size);
447         if (unpack_trees(1, &t, &opts))
448                 exit(128);
449
450         diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
451         diffcore_fix_diff_index(&revs->diffopt);
452         diffcore_std(&revs->diffopt);
453         diff_flush(&revs->diffopt);
454         return 0;
455 }
456
457 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
458 {
459         struct tree *tree;
460         struct rev_info revs;
461         int i;
462         struct cache_entry **dst;
463         struct cache_entry *last = NULL;
464         struct unpack_trees_options opts;
465         struct tree_desc t;
466
467         /*
468          * This is used by git-blame to run diff-cache internally;
469          * it potentially needs to repeatedly run this, so we will
470          * start by removing the higher order entries the last round
471          * left behind.
472          */
473         dst = active_cache;
474         for (i = 0; i < active_nr; i++) {
475                 struct cache_entry *ce = active_cache[i];
476                 if (ce_stage(ce)) {
477                         if (last && !strcmp(ce->name, last->name))
478                                 continue;
479                         cache_tree_invalidate_path(active_cache_tree,
480                                                    ce->name);
481                         last = ce;
482                         ce->ce_flags |= CE_REMOVE;
483                 }
484                 *dst++ = ce;
485         }
486         active_nr = dst - active_cache;
487
488         init_revisions(&revs, NULL);
489         revs.prune_data = opt->paths;
490         tree = parse_tree_indirect(tree_sha1);
491         if (!tree)
492                 die("bad tree object %s", sha1_to_hex(tree_sha1));
493
494         memset(&opts, 0, sizeof(opts));
495         opts.head_idx = 1;
496         opts.index_only = 1;
497         opts.diff_index_cached = !DIFF_OPT_TST(opt, FIND_COPIES_HARDER);
498         opts.merge = 1;
499         opts.fn = oneway_diff;
500         opts.unpack_data = &revs;
501         opts.src_index = &the_index;
502         opts.dst_index = &the_index;
503
504         init_tree_desc(&t, tree->buffer, tree->size);
505         if (unpack_trees(1, &t, &opts))
506                 exit(128);
507         return 0;
508 }
509
510 int index_differs_from(const char *def, int diff_flags)
511 {
512         struct rev_info rev;
513
514         init_revisions(&rev, NULL);
515         setup_revisions(0, NULL, &rev, def);
516         DIFF_OPT_SET(&rev.diffopt, QUICK);
517         DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
518         rev.diffopt.flags |= diff_flags;
519         run_diff_index(&rev, 1);
520         if (rev.pending.alloc)
521                 free(rev.pending.objects);
522         return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);
523 }