59811116b6ddb2a7f79cf904f31a43fb8d372ed9
[git/git.git] / merge-recursive.c
1 /*
2 * Recursive Merge algorithm stolen from git-merge-recursive.py by
3 * Fredrik Kuivinen.
4 * The thieves were Alex Riesen and Johannes Schindelin, in June/July 2006
5 */
6 #include "cache.h"
7 #include "config.h"
8 #include "advice.h"
9 #include "lockfile.h"
10 #include "cache-tree.h"
11 #include "object-store.h"
12 #include "repository.h"
13 #include "commit.h"
14 #include "blob.h"
15 #include "builtin.h"
16 #include "tree-walk.h"
17 #include "diff.h"
18 #include "diffcore.h"
19 #include "tag.h"
20 #include "alloc.h"
21 #include "unpack-trees.h"
22 #include "string-list.h"
23 #include "xdiff-interface.h"
24 #include "ll-merge.h"
25 #include "attr.h"
26 #include "merge-recursive.h"
27 #include "dir.h"
28 #include "submodule.h"
29 #include "revision.h"
30 #include "commit-reach.h"
31
32 struct path_hashmap_entry {
33 struct hashmap_entry e;
34 char path[FLEX_ARRAY];
35 };
36
37 static int path_hashmap_cmp(const void *cmp_data,
38 const void *entry,
39 const void *entry_or_key,
40 const void *keydata)
41 {
42 const struct path_hashmap_entry *a = entry;
43 const struct path_hashmap_entry *b = entry_or_key;
44 const char *key = keydata;
45
46 if (ignore_case)
47 return strcasecmp(a->path, key ? key : b->path);
48 else
49 return strcmp(a->path, key ? key : b->path);
50 }
51
52 static unsigned int path_hash(const char *path)
53 {
54 return ignore_case ? strihash(path) : strhash(path);
55 }
56
57 static struct dir_rename_entry *dir_rename_find_entry(struct hashmap *hashmap,
58 char *dir)
59 {
60 struct dir_rename_entry key;
61
62 if (dir == NULL)
63 return NULL;
64 hashmap_entry_init(&key, strhash(dir));
65 key.dir = dir;
66 return hashmap_get(hashmap, &key, NULL);
67 }
68
69 static int dir_rename_cmp(const void *unused_cmp_data,
70 const void *entry,
71 const void *entry_or_key,
72 const void *unused_keydata)
73 {
74 const struct dir_rename_entry *e1 = entry;
75 const struct dir_rename_entry *e2 = entry_or_key;
76
77 return strcmp(e1->dir, e2->dir);
78 }
79
80 static void dir_rename_init(struct hashmap *map)
81 {
82 hashmap_init(map, dir_rename_cmp, NULL, 0);
83 }
84
85 static void dir_rename_entry_init(struct dir_rename_entry *entry,
86 char *directory)
87 {
88 hashmap_entry_init(entry, strhash(directory));
89 entry->dir = directory;
90 entry->non_unique_new_dir = 0;
91 strbuf_init(&entry->new_dir, 0);
92 string_list_init(&entry->possible_new_dirs, 0);
93 }
94
95 static struct collision_entry *collision_find_entry(struct hashmap *hashmap,
96 char *target_file)
97 {
98 struct collision_entry key;
99
100 hashmap_entry_init(&key, strhash(target_file));
101 key.target_file = target_file;
102 return hashmap_get(hashmap, &key, NULL);
103 }
104
105 static int collision_cmp(void *unused_cmp_data,
106 const struct collision_entry *e1,
107 const struct collision_entry *e2,
108 const void *unused_keydata)
109 {
110 return strcmp(e1->target_file, e2->target_file);
111 }
112
113 static void collision_init(struct hashmap *map)
114 {
115 hashmap_init(map, (hashmap_cmp_fn) collision_cmp, NULL, 0);
116 }
117
118 static void flush_output(struct merge_options *o)
119 {
120 if (o->buffer_output < 2 && o->obuf.len) {
121 fputs(o->obuf.buf, stdout);
122 strbuf_reset(&o->obuf);
123 }
124 }
125
126 static int err(struct merge_options *o, const char *err, ...)
127 {
128 va_list params;
129
130 if (o->buffer_output < 2)
131 flush_output(o);
132 else {
133 strbuf_complete(&o->obuf, '\n');
134 strbuf_addstr(&o->obuf, "error: ");
135 }
136 va_start(params, err);
137 strbuf_vaddf(&o->obuf, err, params);
138 va_end(params);
139 if (o->buffer_output > 1)
140 strbuf_addch(&o->obuf, '\n');
141 else {
142 error("%s", o->obuf.buf);
143 strbuf_reset(&o->obuf);
144 }
145
146 return -1;
147 }
148
149 static struct tree *shift_tree_object(struct tree *one, struct tree *two,
150 const char *subtree_shift)
151 {
152 struct object_id shifted;
153
154 if (!*subtree_shift) {
155 shift_tree(&one->object.oid, &two->object.oid, &shifted, 0);
156 } else {
157 shift_tree_by(&one->object.oid, &two->object.oid, &shifted,
158 subtree_shift);
159 }
160 if (oideq(&two->object.oid, &shifted))
161 return two;
162 return lookup_tree(the_repository, &shifted);
163 }
164
165 static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
166 {
167 struct commit *commit = alloc_commit_node(the_repository);
168
169 set_merge_remote_desc(commit, comment, (struct object *)commit);
170 commit->maybe_tree = tree;
171 commit->object.parsed = 1;
172 return commit;
173 }
174
175 /*
176 * Since we use get_tree_entry(), which does not put the read object into
177 * the object pool, we cannot rely on a == b.
178 */
179 static int oid_eq(const struct object_id *a, const struct object_id *b)
180 {
181 if (!a && !b)
182 return 2;
183 return a && b && oideq(a, b);
184 }
185
186 enum rename_type {
187 RENAME_NORMAL = 0,
188 RENAME_VIA_DIR,
189 RENAME_ADD,
190 RENAME_DELETE,
191 RENAME_ONE_FILE_TO_ONE,
192 RENAME_ONE_FILE_TO_TWO,
193 RENAME_TWO_FILES_TO_ONE
194 };
195
196 struct rename_conflict_info {
197 enum rename_type rename_type;
198 struct diff_filepair *pair1;
199 struct diff_filepair *pair2;
200 const char *branch1;
201 const char *branch2;
202 struct stage_data *dst_entry1;
203 struct stage_data *dst_entry2;
204 struct diff_filespec ren1_other;
205 struct diff_filespec ren2_other;
206 };
207
208 /*
209 * Since we want to write the index eventually, we cannot reuse the index
210 * for these (temporary) data.
211 */
212 struct stage_data {
213 struct {
214 unsigned mode;
215 struct object_id oid;
216 } stages[4];
217 struct rename_conflict_info *rename_conflict_info;
218 unsigned processed:1;
219 };
220
221 static inline void setup_rename_conflict_info(enum rename_type rename_type,
222 struct diff_filepair *pair1,
223 struct diff_filepair *pair2,
224 const char *branch1,
225 const char *branch2,
226 struct stage_data *dst_entry1,
227 struct stage_data *dst_entry2,
228 struct merge_options *o,
229 struct stage_data *src_entry1,
230 struct stage_data *src_entry2)
231 {
232 int ostage1 = 0, ostage2;
233 struct rename_conflict_info *ci;
234
235 /*
236 * When we have two renames involved, it's easiest to get the
237 * correct things into stage 2 and 3, and to make sure that the
238 * content merge puts HEAD before the other branch if we just
239 * ensure that branch1 == o->branch1. So, simply flip arguments
240 * around if we don't have that.
241 */
242 if (dst_entry2 && branch1 != o->branch1) {
243 setup_rename_conflict_info(rename_type,
244 pair2, pair1,
245 branch2, branch1,
246 dst_entry2, dst_entry1,
247 o,
248 src_entry2, src_entry1);
249 return;
250 }
251
252 ci = xcalloc(1, sizeof(struct rename_conflict_info));
253 ci->rename_type = rename_type;
254 ci->pair1 = pair1;
255 ci->branch1 = branch1;
256 ci->branch2 = branch2;
257
258 ci->dst_entry1 = dst_entry1;
259 dst_entry1->rename_conflict_info = ci;
260 dst_entry1->processed = 0;
261
262 assert(!pair2 == !dst_entry2);
263 if (dst_entry2) {
264 ci->dst_entry2 = dst_entry2;
265 ci->pair2 = pair2;
266 dst_entry2->rename_conflict_info = ci;
267 }
268
269 /*
270 * For each rename, there could have been
271 * modifications on the side of history where that
272 * file was not renamed.
273 */
274 if (rename_type == RENAME_ADD ||
275 rename_type == RENAME_TWO_FILES_TO_ONE) {
276 ostage1 = o->branch1 == branch1 ? 3 : 2;
277
278 ci->ren1_other.path = pair1->one->path;
279 oidcpy(&ci->ren1_other.oid, &src_entry1->stages[ostage1].oid);
280 ci->ren1_other.mode = src_entry1->stages[ostage1].mode;
281 }
282
283 if (rename_type == RENAME_TWO_FILES_TO_ONE) {
284 ostage2 = ostage1 ^ 1;
285
286 ci->ren2_other.path = pair2->one->path;
287 oidcpy(&ci->ren2_other.oid, &src_entry2->stages[ostage2].oid);
288 ci->ren2_other.mode = src_entry2->stages[ostage2].mode;
289 }
290 }
291
292 static int show(struct merge_options *o, int v)
293 {
294 return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
295 }
296
297 __attribute__((format (printf, 3, 4)))
298 static void output(struct merge_options *o, int v, const char *fmt, ...)
299 {
300 va_list ap;
301
302 if (!show(o, v))
303 return;
304
305 strbuf_addchars(&o->obuf, ' ', o->call_depth * 2);
306
307 va_start(ap, fmt);
308 strbuf_vaddf(&o->obuf, fmt, ap);
309 va_end(ap);
310
311 strbuf_addch(&o->obuf, '\n');
312 if (!o->buffer_output)
313 flush_output(o);
314 }
315
316 static void output_commit_title(struct merge_options *o, struct commit *commit)
317 {
318 struct merge_remote_desc *desc;
319
320 strbuf_addchars(&o->obuf, ' ', o->call_depth * 2);
321 desc = merge_remote_util(commit);
322 if (desc)
323 strbuf_addf(&o->obuf, "virtual %s\n", desc->name);
324 else {
325 strbuf_add_unique_abbrev(&o->obuf, &commit->object.oid,
326 DEFAULT_ABBREV);
327 strbuf_addch(&o->obuf, ' ');
328 if (parse_commit(commit) != 0)
329 strbuf_addstr(&o->obuf, _("(bad commit)\n"));
330 else {
331 const char *title;
332 const char *msg = get_commit_buffer(commit, NULL);
333 int len = find_commit_subject(msg, &title);
334 if (len)
335 strbuf_addf(&o->obuf, "%.*s\n", len, title);
336 unuse_commit_buffer(commit, msg);
337 }
338 }
339 flush_output(o);
340 }
341
342 static int add_cacheinfo(struct merge_options *o,
343 unsigned int mode, const struct object_id *oid,
344 const char *path, int stage, int refresh, int options)
345 {
346 struct cache_entry *ce;
347 int ret;
348
349 ce = make_cache_entry(&the_index, mode, oid ? oid : &null_oid, path, stage, 0);
350 if (!ce)
351 return err(o, _("add_cacheinfo failed for path '%s'; merge aborting."), path);
352
353 ret = add_cache_entry(ce, options);
354 if (refresh) {
355 struct cache_entry *nce;
356
357 nce = refresh_cache_entry(&the_index, ce, CE_MATCH_REFRESH | CE_MATCH_IGNORE_MISSING);
358 if (!nce)
359 return err(o, _("add_cacheinfo failed to refresh for path '%s'; merge aborting."), path);
360 if (nce != ce)
361 ret = add_cache_entry(nce, options);
362 }
363 return ret;
364 }
365
366 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
367 {
368 parse_tree(tree);
369 init_tree_desc(desc, tree->buffer, tree->size);
370 }
371
372 static int unpack_trees_start(struct merge_options *o,
373 struct tree *common,
374 struct tree *head,
375 struct tree *merge)
376 {
377 int rc;
378 struct tree_desc t[3];
379 struct index_state tmp_index = { NULL };
380
381 memset(&o->unpack_opts, 0, sizeof(o->unpack_opts));
382 if (o->call_depth)
383 o->unpack_opts.index_only = 1;
384 else
385 o->unpack_opts.update = 1;
386 o->unpack_opts.merge = 1;
387 o->unpack_opts.head_idx = 2;
388 o->unpack_opts.fn = threeway_merge;
389 o->unpack_opts.src_index = &the_index;
390 o->unpack_opts.dst_index = &tmp_index;
391 o->unpack_opts.aggressive = !merge_detect_rename(o);
392 setup_unpack_trees_porcelain(&o->unpack_opts, "merge");
393
394 init_tree_desc_from_tree(t+0, common);
395 init_tree_desc_from_tree(t+1, head);
396 init_tree_desc_from_tree(t+2, merge);
397
398 rc = unpack_trees(3, t, &o->unpack_opts);
399 cache_tree_free(&active_cache_tree);
400
401 /*
402 * Update the_index to match the new results, AFTER saving a copy
403 * in o->orig_index. Update src_index to point to the saved copy.
404 * (verify_uptodate() checks src_index, and the original index is
405 * the one that had the necessary modification timestamps.)
406 */
407 o->orig_index = the_index;
408 the_index = tmp_index;
409 o->unpack_opts.src_index = &o->orig_index;
410
411 return rc;
412 }
413
414 static void unpack_trees_finish(struct merge_options *o)
415 {
416 discard_index(&o->orig_index);
417 clear_unpack_trees_porcelain(&o->unpack_opts);
418 }
419
420 struct tree *write_tree_from_memory(struct merge_options *o)
421 {
422 struct tree *result = NULL;
423
424 if (unmerged_cache()) {
425 int i;
426 fprintf(stderr, "BUG: There are unmerged index entries:\n");
427 for (i = 0; i < active_nr; i++) {
428 const struct cache_entry *ce = active_cache[i];
429 if (ce_stage(ce))
430 fprintf(stderr, "BUG: %d %.*s\n", ce_stage(ce),
431 (int)ce_namelen(ce), ce->name);
432 }
433 BUG("unmerged index entries in merge-recursive.c");
434 }
435
436 if (!active_cache_tree)
437 active_cache_tree = cache_tree();
438
439 if (!cache_tree_fully_valid(active_cache_tree) &&
440 cache_tree_update(&the_index, 0) < 0) {
441 err(o, _("error building trees"));
442 return NULL;
443 }
444
445 result = lookup_tree(the_repository, &active_cache_tree->oid);
446
447 return result;
448 }
449
450 static int save_files_dirs(const struct object_id *oid,
451 struct strbuf *base, const char *path,
452 unsigned int mode, int stage, void *context)
453 {
454 struct path_hashmap_entry *entry;
455 int baselen = base->len;
456 struct merge_options *o = context;
457
458 strbuf_addstr(base, path);
459
460 FLEX_ALLOC_MEM(entry, path, base->buf, base->len);
461 hashmap_entry_init(entry, path_hash(entry->path));
462 hashmap_add(&o->current_file_dir_set, entry);
463
464 strbuf_setlen(base, baselen);
465 return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
466 }
467
468 static void get_files_dirs(struct merge_options *o, struct tree *tree)
469 {
470 struct pathspec match_all;
471 memset(&match_all, 0, sizeof(match_all));
472 read_tree_recursive(tree, "", 0, 0, &match_all, save_files_dirs, o);
473 }
474
475 static int get_tree_entry_if_blob(const struct object_id *tree,
476 const char *path,
477 struct object_id *hashy,
478 unsigned int *mode_o)
479 {
480 int ret;
481
482 ret = get_tree_entry(tree, path, hashy, mode_o);
483 if (S_ISDIR(*mode_o)) {
484 oidcpy(hashy, &null_oid);
485 *mode_o = 0;
486 }
487 return ret;
488 }
489
490 /*
491 * Returns an index_entry instance which doesn't have to correspond to
492 * a real cache entry in Git's index.
493 */
494 static struct stage_data *insert_stage_data(const char *path,
495 struct tree *o, struct tree *a, struct tree *b,
496 struct string_list *entries)
497 {
498 struct string_list_item *item;
499 struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
500 get_tree_entry_if_blob(&o->object.oid, path,
501 &e->stages[1].oid, &e->stages[1].mode);
502 get_tree_entry_if_blob(&a->object.oid, path,
503 &e->stages[2].oid, &e->stages[2].mode);
504 get_tree_entry_if_blob(&b->object.oid, path,
505 &e->stages[3].oid, &e->stages[3].mode);
506 item = string_list_insert(entries, path);
507 item->util = e;
508 return e;
509 }
510
511 /*
512 * Create a dictionary mapping file names to stage_data objects. The
513 * dictionary contains one entry for every path with a non-zero stage entry.
514 */
515 static struct string_list *get_unmerged(void)
516 {
517 struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
518 int i;
519
520 unmerged->strdup_strings = 1;
521
522 for (i = 0; i < active_nr; i++) {
523 struct string_list_item *item;
524 struct stage_data *e;
525 const struct cache_entry *ce = active_cache[i];
526 if (!ce_stage(ce))
527 continue;
528
529 item = string_list_lookup(unmerged, ce->name);
530 if (!item) {
531 item = string_list_insert(unmerged, ce->name);
532 item->util = xcalloc(1, sizeof(struct stage_data));
533 }
534 e = item->util;
535 e->stages[ce_stage(ce)].mode = ce->ce_mode;
536 oidcpy(&e->stages[ce_stage(ce)].oid, &ce->oid);
537 }
538
539 return unmerged;
540 }
541
542 static int string_list_df_name_compare(const char *one, const char *two)
543 {
544 int onelen = strlen(one);
545 int twolen = strlen(two);
546 /*
547 * Here we only care that entries for D/F conflicts are
548 * adjacent, in particular with the file of the D/F conflict
549 * appearing before files below the corresponding directory.
550 * The order of the rest of the list is irrelevant for us.
551 *
552 * To achieve this, we sort with df_name_compare and provide
553 * the mode S_IFDIR so that D/F conflicts will sort correctly.
554 * We use the mode S_IFDIR for everything else for simplicity,
555 * since in other cases any changes in their order due to
556 * sorting cause no problems for us.
557 */
558 int cmp = df_name_compare(one, onelen, S_IFDIR,
559 two, twolen, S_IFDIR);
560 /*
561 * Now that 'foo' and 'foo/bar' compare equal, we have to make sure
562 * that 'foo' comes before 'foo/bar'.
563 */
564 if (cmp)
565 return cmp;
566 return onelen - twolen;
567 }
568
569 static void record_df_conflict_files(struct merge_options *o,
570 struct string_list *entries)
571 {
572 /* If there is a D/F conflict and the file for such a conflict
573 * currently exists in the working tree, we want to allow it to be
574 * removed to make room for the corresponding directory if needed.
575 * The files underneath the directories of such D/F conflicts will
576 * be processed before the corresponding file involved in the D/F
577 * conflict. If the D/F directory ends up being removed by the
578 * merge, then we won't have to touch the D/F file. If the D/F
579 * directory needs to be written to the working copy, then the D/F
580 * file will simply be removed (in make_room_for_path()) to make
581 * room for the necessary paths. Note that if both the directory
582 * and the file need to be present, then the D/F file will be
583 * reinstated with a new unique name at the time it is processed.
584 */
585 struct string_list df_sorted_entries = STRING_LIST_INIT_NODUP;
586 const char *last_file = NULL;
587 int last_len = 0;
588 int i;
589
590 /*
591 * If we're merging merge-bases, we don't want to bother with
592 * any working directory changes.
593 */
594 if (o->call_depth)
595 return;
596
597 /* Ensure D/F conflicts are adjacent in the entries list. */
598 for (i = 0; i < entries->nr; i++) {
599 struct string_list_item *next = &entries->items[i];
600 string_list_append(&df_sorted_entries, next->string)->util =
601 next->util;
602 }
603 df_sorted_entries.cmp = string_list_df_name_compare;
604 string_list_sort(&df_sorted_entries);
605
606 string_list_clear(&o->df_conflict_file_set, 1);
607 for (i = 0; i < df_sorted_entries.nr; i++) {
608 const char *path = df_sorted_entries.items[i].string;
609 int len = strlen(path);
610 struct stage_data *e = df_sorted_entries.items[i].util;
611
612 /*
613 * Check if last_file & path correspond to a D/F conflict;
614 * i.e. whether path is last_file+'/'+<something>.
615 * If so, record that it's okay to remove last_file to make
616 * room for path and friends if needed.
617 */
618 if (last_file &&
619 len > last_len &&
620 memcmp(path, last_file, last_len) == 0 &&
621 path[last_len] == '/') {
622 string_list_insert(&o->df_conflict_file_set, last_file);
623 }
624
625 /*
626 * Determine whether path could exist as a file in the
627 * working directory as a possible D/F conflict. This
628 * will only occur when it exists in stage 2 as a
629 * file.
630 */
631 if (S_ISREG(e->stages[2].mode) || S_ISLNK(e->stages[2].mode)) {
632 last_file = path;
633 last_len = len;
634 } else {
635 last_file = NULL;
636 }
637 }
638 string_list_clear(&df_sorted_entries, 0);
639 }
640
641 struct rename {
642 struct diff_filepair *pair;
643 /*
644 * Purpose of src_entry and dst_entry:
645 *
646 * If 'before' is renamed to 'after' then src_entry will contain
647 * the versions of 'before' from the merge_base, HEAD, and MERGE in
648 * stages 1, 2, and 3; dst_entry will contain the respective
649 * versions of 'after' in corresponding locations. Thus, we have a
650 * total of six modes and oids, though some will be null. (Stage 0
651 * is ignored; we're interested in handling conflicts.)
652 *
653 * Since we don't turn on break-rewrites by default, neither
654 * src_entry nor dst_entry can have all three of their stages have
655 * non-null oids, meaning at most four of the six will be non-null.
656 * Also, since this is a rename, both src_entry and dst_entry will
657 * have at least one non-null oid, meaning at least two will be
658 * non-null. Of the six oids, a typical rename will have three be
659 * non-null. Only two implies a rename/delete, and four implies a
660 * rename/add.
661 */
662 struct stage_data *src_entry;
663 struct stage_data *dst_entry;
664 unsigned add_turned_into_rename:1;
665 unsigned processed:1;
666 };
667
668 static int update_stages(struct merge_options *opt, const char *path,
669 const struct diff_filespec *o,
670 const struct diff_filespec *a,
671 const struct diff_filespec *b)
672 {
673
674 /*
675 * NOTE: It is usually a bad idea to call update_stages on a path
676 * before calling update_file on that same path, since it can
677 * sometimes lead to spurious "refusing to lose untracked file..."
678 * messages from update_file (via make_room_for path via
679 * would_lose_untracked). Instead, reverse the order of the calls
680 * (executing update_file first and then update_stages).
681 */
682 int clear = 1;
683 int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_SKIP_DFCHECK;
684 if (clear)
685 if (remove_file_from_cache(path))
686 return -1;
687 if (o)
688 if (add_cacheinfo(opt, o->mode, &o->oid, path, 1, 0, options))
689 return -1;
690 if (a)
691 if (add_cacheinfo(opt, a->mode, &a->oid, path, 2, 0, options))
692 return -1;
693 if (b)
694 if (add_cacheinfo(opt, b->mode, &b->oid, path, 3, 0, options))
695 return -1;
696 return 0;
697 }
698
699 static void update_entry(struct stage_data *entry,
700 struct diff_filespec *o,
701 struct diff_filespec *a,
702 struct diff_filespec *b)
703 {
704 entry->processed = 0;
705 entry->stages[1].mode = o->mode;
706 entry->stages[2].mode = a->mode;
707 entry->stages[3].mode = b->mode;
708 oidcpy(&entry->stages[1].oid, &o->oid);
709 oidcpy(&entry->stages[2].oid, &a->oid);
710 oidcpy(&entry->stages[3].oid, &b->oid);
711 }
712
713 static int remove_file(struct merge_options *o, int clean,
714 const char *path, int no_wd)
715 {
716 int update_cache = o->call_depth || clean;
717 int update_working_directory = !o->call_depth && !no_wd;
718
719 if (update_cache) {
720 if (remove_file_from_cache(path))
721 return -1;
722 }
723 if (update_working_directory) {
724 if (ignore_case) {
725 struct cache_entry *ce;
726 ce = cache_file_exists(path, strlen(path), ignore_case);
727 if (ce && ce_stage(ce) == 0 && strcmp(path, ce->name))
728 return 0;
729 }
730 if (remove_path(path))
731 return -1;
732 }
733 return 0;
734 }
735
736 /* add a string to a strbuf, but converting "/" to "_" */
737 static void add_flattened_path(struct strbuf *out, const char *s)
738 {
739 size_t i = out->len;
740 strbuf_addstr(out, s);
741 for (; i < out->len; i++)
742 if (out->buf[i] == '/')
743 out->buf[i] = '_';
744 }
745
746 static char *unique_path(struct merge_options *o, const char *path, const char *branch)
747 {
748 struct path_hashmap_entry *entry;
749 struct strbuf newpath = STRBUF_INIT;
750 int suffix = 0;
751 size_t base_len;
752
753 strbuf_addf(&newpath, "%s~", path);
754 add_flattened_path(&newpath, branch);
755
756 base_len = newpath.len;
757 while (hashmap_get_from_hash(&o->current_file_dir_set,
758 path_hash(newpath.buf), newpath.buf) ||
759 (!o->call_depth && file_exists(newpath.buf))) {
760 strbuf_setlen(&newpath, base_len);
761 strbuf_addf(&newpath, "_%d", suffix++);
762 }
763
764 FLEX_ALLOC_MEM(entry, path, newpath.buf, newpath.len);
765 hashmap_entry_init(entry, path_hash(entry->path));
766 hashmap_add(&o->current_file_dir_set, entry);
767 return strbuf_detach(&newpath, NULL);
768 }
769
770 /**
771 * Check whether a directory in the index is in the way of an incoming
772 * file. Return 1 if so. If check_working_copy is non-zero, also
773 * check the working directory. If empty_ok is non-zero, also return
774 * 0 in the case where the working-tree dir exists but is empty.
775 */
776 static int dir_in_way(const char *path, int check_working_copy, int empty_ok)
777 {
778 int pos;
779 struct strbuf dirpath = STRBUF_INIT;
780 struct stat st;
781
782 strbuf_addstr(&dirpath, path);
783 strbuf_addch(&dirpath, '/');
784
785 pos = cache_name_pos(dirpath.buf, dirpath.len);
786
787 if (pos < 0)
788 pos = -1 - pos;
789 if (pos < active_nr &&
790 !strncmp(dirpath.buf, active_cache[pos]->name, dirpath.len)) {
791 strbuf_release(&dirpath);
792 return 1;
793 }
794
795 strbuf_release(&dirpath);
796 return check_working_copy && !lstat(path, &st) && S_ISDIR(st.st_mode) &&
797 !(empty_ok && is_empty_dir(path));
798 }
799
800 /*
801 * Returns whether path was tracked in the index before the merge started,
802 * and its oid and mode match the specified values
803 */
804 static int was_tracked_and_matches(struct merge_options *o, const char *path,
805 const struct object_id *oid, unsigned mode)
806 {
807 int pos = index_name_pos(&o->orig_index, path, strlen(path));
808 struct cache_entry *ce;
809
810 if (0 > pos)
811 /* we were not tracking this path before the merge */
812 return 0;
813
814 /* See if the file we were tracking before matches */
815 ce = o->orig_index.cache[pos];
816 return (oid_eq(&ce->oid, oid) && ce->ce_mode == mode);
817 }
818
819 /*
820 * Returns whether path was tracked in the index before the merge started
821 */
822 static int was_tracked(struct merge_options *o, const char *path)
823 {
824 int pos = index_name_pos(&o->orig_index, path, strlen(path));
825
826 if (0 <= pos)
827 /* we were tracking this path before the merge */
828 return 1;
829
830 return 0;
831 }
832
833 static int would_lose_untracked(const char *path)
834 {
835 /*
836 * This may look like it can be simplified to:
837 * return !was_tracked(o, path) && file_exists(path)
838 * but it can't. This function needs to know whether path was in
839 * the working tree due to EITHER having been tracked in the index
840 * before the merge OR having been put into the working copy and
841 * index by unpack_trees(). Due to that either-or requirement, we
842 * check the current index instead of the original one.
843 *
844 * Note that we do not need to worry about merge-recursive itself
845 * updating the index after unpack_trees() and before calling this
846 * function, because we strictly require all code paths in
847 * merge-recursive to update the working tree first and the index
848 * second. Doing otherwise would break
849 * update_file()/would_lose_untracked(); see every comment in this
850 * file which mentions "update_stages".
851 */
852 int pos = cache_name_pos(path, strlen(path));
853
854 if (pos < 0)
855 pos = -1 - pos;
856 while (pos < active_nr &&
857 !strcmp(path, active_cache[pos]->name)) {
858 /*
859 * If stage #0, it is definitely tracked.
860 * If it has stage #2 then it was tracked
861 * before this merge started. All other
862 * cases the path was not tracked.
863 */
864 switch (ce_stage(active_cache[pos])) {
865 case 0:
866 case 2:
867 return 0;
868 }
869 pos++;
870 }
871 return file_exists(path);
872 }
873
874 static int was_dirty(struct merge_options *o, const char *path)
875 {
876 struct cache_entry *ce;
877 int dirty = 1;
878
879 if (o->call_depth || !was_tracked(o, path))
880 return !dirty;
881
882 ce = index_file_exists(o->unpack_opts.src_index,
883 path, strlen(path), ignore_case);
884 dirty = verify_uptodate(ce, &o->unpack_opts) != 0;
885 return dirty;
886 }
887
888 static int make_room_for_path(struct merge_options *o, const char *path)
889 {
890 int status, i;
891 const char *msg = _("failed to create path '%s'%s");
892
893 /* Unlink any D/F conflict files that are in the way */
894 for (i = 0; i < o->df_conflict_file_set.nr; i++) {
895 const char *df_path = o->df_conflict_file_set.items[i].string;
896 size_t pathlen = strlen(path);
897 size_t df_pathlen = strlen(df_path);
898 if (df_pathlen < pathlen &&
899 path[df_pathlen] == '/' &&
900 strncmp(path, df_path, df_pathlen) == 0) {
901 output(o, 3,
902 _("Removing %s to make room for subdirectory\n"),
903 df_path);
904 unlink(df_path);
905 unsorted_string_list_delete_item(&o->df_conflict_file_set,
906 i, 0);
907 break;
908 }
909 }
910
911 /* Make sure leading directories are created */
912 status = safe_create_leading_directories_const(path);
913 if (status) {
914 if (status == SCLD_EXISTS)
915 /* something else exists */
916 return err(o, msg, path, _(": perhaps a D/F conflict?"));
917 return err(o, msg, path, "");
918 }
919
920 /*
921 * Do not unlink a file in the work tree if we are not
922 * tracking it.
923 */
924 if (would_lose_untracked(path))
925 return err(o, _("refusing to lose untracked file at '%s'"),
926 path);
927
928 /* Successful unlink is good.. */
929 if (!unlink(path))
930 return 0;
931 /* .. and so is no existing file */
932 if (errno == ENOENT)
933 return 0;
934 /* .. but not some other error (who really cares what?) */
935 return err(o, msg, path, _(": perhaps a D/F conflict?"));
936 }
937
938 static int update_file_flags(struct merge_options *o,
939 const struct object_id *oid,
940 unsigned mode,
941 const char *path,
942 int update_cache,
943 int update_wd)
944 {
945 int ret = 0;
946
947 if (o->call_depth)
948 update_wd = 0;
949
950 if (update_wd) {
951 enum object_type type;
952 void *buf;
953 unsigned long size;
954
955 if (S_ISGITLINK(mode)) {
956 /*
957 * We may later decide to recursively descend into
958 * the submodule directory and update its index
959 * and/or work tree, but we do not do that now.
960 */
961 update_wd = 0;
962 goto update_index;
963 }
964
965 buf = read_object_file(oid, &type, &size);
966 if (!buf)
967 return err(o, _("cannot read object %s '%s'"), oid_to_hex(oid), path);
968 if (type != OBJ_BLOB) {
969 ret = err(o, _("blob expected for %s '%s'"), oid_to_hex(oid), path);
970 goto free_buf;
971 }
972 if (S_ISREG(mode)) {
973 struct strbuf strbuf = STRBUF_INIT;
974 if (convert_to_working_tree(&the_index, path, buf, size, &strbuf)) {
975 free(buf);
976 size = strbuf.len;
977 buf = strbuf_detach(&strbuf, NULL);
978 }
979 }
980
981 if (make_room_for_path(o, path) < 0) {
982 update_wd = 0;
983 goto free_buf;
984 }
985 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
986 int fd;
987 if (mode & 0100)
988 mode = 0777;
989 else
990 mode = 0666;
991 fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
992 if (fd < 0) {
993 ret = err(o, _("failed to open '%s': %s"),
994 path, strerror(errno));
995 goto free_buf;
996 }
997 write_in_full(fd, buf, size);
998 close(fd);
999 } else if (S_ISLNK(mode)) {
1000 char *lnk = xmemdupz(buf, size);
1001 safe_create_leading_directories_const(path);
1002 unlink(path);
1003 if (symlink(lnk, path))
1004 ret = err(o, _("failed to symlink '%s': %s"),
1005 path, strerror(errno));
1006 free(lnk);
1007 } else
1008 ret = err(o,
1009 _("do not know what to do with %06o %s '%s'"),
1010 mode, oid_to_hex(oid), path);
1011 free_buf:
1012 free(buf);
1013 }
1014 update_index:
1015 if (!ret && update_cache)
1016 if (add_cacheinfo(o, mode, oid, path, 0, update_wd,
1017 ADD_CACHE_OK_TO_ADD))
1018 return -1;
1019 return ret;
1020 }
1021
1022 static int update_file(struct merge_options *o,
1023 int clean,
1024 const struct object_id *oid,
1025 unsigned mode,
1026 const char *path)
1027 {
1028 return update_file_flags(o, oid, mode, path, o->call_depth || clean, !o->call_depth);
1029 }
1030
1031 /* Low level file merging, update and removal */
1032
1033 struct merge_file_info {
1034 struct object_id oid;
1035 unsigned mode;
1036 unsigned clean:1,
1037 merge:1;
1038 };
1039
1040 static int merge_3way(struct merge_options *o,
1041 mmbuffer_t *result_buf,
1042 const struct diff_filespec *one,
1043 const struct diff_filespec *a,
1044 const struct diff_filespec *b,
1045 const char *branch1,
1046 const char *branch2,
1047 const int extra_marker_size)
1048 {
1049 mmfile_t orig, src1, src2;
1050 struct ll_merge_options ll_opts = {0};
1051 char *base_name, *name1, *name2;
1052 int merge_status;
1053
1054 ll_opts.renormalize = o->renormalize;
1055 ll_opts.extra_marker_size = extra_marker_size;
1056 ll_opts.xdl_opts = o->xdl_opts;
1057
1058 if (o->call_depth) {
1059 ll_opts.virtual_ancestor = 1;
1060 ll_opts.variant = 0;
1061 } else {
1062 switch (o->recursive_variant) {
1063 case MERGE_RECURSIVE_OURS:
1064 ll_opts.variant = XDL_MERGE_FAVOR_OURS;
1065 break;
1066 case MERGE_RECURSIVE_THEIRS:
1067 ll_opts.variant = XDL_MERGE_FAVOR_THEIRS;
1068 break;
1069 default:
1070 ll_opts.variant = 0;
1071 break;
1072 }
1073 }
1074
1075 if (strcmp(a->path, b->path) ||
1076 (o->ancestor != NULL && strcmp(a->path, one->path) != 0)) {
1077 base_name = o->ancestor == NULL ? NULL :
1078 mkpathdup("%s:%s", o->ancestor, one->path);
1079 name1 = mkpathdup("%s:%s", branch1, a->path);
1080 name2 = mkpathdup("%s:%s", branch2, b->path);
1081 } else {
1082 base_name = o->ancestor == NULL ? NULL :
1083 mkpathdup("%s", o->ancestor);
1084 name1 = mkpathdup("%s", branch1);
1085 name2 = mkpathdup("%s", branch2);
1086 }
1087
1088 read_mmblob(&orig, &one->oid);
1089 read_mmblob(&src1, &a->oid);
1090 read_mmblob(&src2, &b->oid);
1091
1092 merge_status = ll_merge(result_buf, a->path, &orig, base_name,
1093 &src1, name1, &src2, name2, &ll_opts);
1094
1095 free(base_name);
1096 free(name1);
1097 free(name2);
1098 free(orig.ptr);
1099 free(src1.ptr);
1100 free(src2.ptr);
1101 return merge_status;
1102 }
1103
1104 static int find_first_merges(struct object_array *result, const char *path,
1105 struct commit *a, struct commit *b)
1106 {
1107 int i, j;
1108 struct object_array merges = OBJECT_ARRAY_INIT;
1109 struct commit *commit;
1110 int contains_another;
1111
1112 char merged_revision[42];
1113 const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
1114 "--all", merged_revision, NULL };
1115 struct rev_info revs;
1116 struct setup_revision_opt rev_opts;
1117
1118 memset(result, 0, sizeof(struct object_array));
1119 memset(&rev_opts, 0, sizeof(rev_opts));
1120
1121 /* get all revisions that merge commit a */
1122 xsnprintf(merged_revision, sizeof(merged_revision), "^%s",
1123 oid_to_hex(&a->object.oid));
1124 init_revisions(&revs, NULL);
1125 rev_opts.submodule = path;
1126 /* FIXME: can't handle linked worktrees in submodules yet */
1127 revs.single_worktree = path != NULL;
1128 setup_revisions(ARRAY_SIZE(rev_args)-1, rev_args, &revs, &rev_opts);
1129
1130 /* save all revisions from the above list that contain b */
1131 if (prepare_revision_walk(&revs))
1132 die("revision walk setup failed");
1133 while ((commit = get_revision(&revs)) != NULL) {
1134 struct object *o = &(commit->object);
1135 if (in_merge_bases(b, commit))
1136 add_object_array(o, NULL, &merges);
1137 }
1138 reset_revision_walk();
1139
1140 /* Now we've got all merges that contain a and b. Prune all
1141 * merges that contain another found merge and save them in
1142 * result.
1143 */
1144 for (i = 0; i < merges.nr; i++) {
1145 struct commit *m1 = (struct commit *) merges.objects[i].item;
1146
1147 contains_another = 0;
1148 for (j = 0; j < merges.nr; j++) {
1149 struct commit *m2 = (struct commit *) merges.objects[j].item;
1150 if (i != j && in_merge_bases(m2, m1)) {
1151 contains_another = 1;
1152 break;
1153 }
1154 }
1155
1156 if (!contains_another)
1157 add_object_array(merges.objects[i].item, NULL, result);
1158 }
1159
1160 object_array_clear(&merges);
1161 return result->nr;
1162 }
1163
1164 static void print_commit(struct commit *commit)
1165 {
1166 struct strbuf sb = STRBUF_INIT;
1167 struct pretty_print_context ctx = {0};
1168 ctx.date_mode.type = DATE_NORMAL;
1169 format_commit_message(commit, " %h: %m %s", &sb, &ctx);
1170 fprintf(stderr, "%s\n", sb.buf);
1171 strbuf_release(&sb);
1172 }
1173
1174 static int merge_submodule(struct merge_options *o,
1175 struct object_id *result, const char *path,
1176 const struct object_id *base, const struct object_id *a,
1177 const struct object_id *b)
1178 {
1179 struct commit *commit_base, *commit_a, *commit_b;
1180 int parent_count;
1181 struct object_array merges;
1182
1183 int i;
1184 int search = !o->call_depth;
1185
1186 /* store a in result in case we fail */
1187 oidcpy(result, a);
1188
1189 /* we can not handle deletion conflicts */
1190 if (is_null_oid(base))
1191 return 0;
1192 if (is_null_oid(a))
1193 return 0;
1194 if (is_null_oid(b))
1195 return 0;
1196
1197 if (add_submodule_odb(path)) {
1198 output(o, 1, _("Failed to merge submodule %s (not checked out)"), path);
1199 return 0;
1200 }
1201
1202 if (!(commit_base = lookup_commit_reference(the_repository, base)) ||
1203 !(commit_a = lookup_commit_reference(the_repository, a)) ||
1204 !(commit_b = lookup_commit_reference(the_repository, b))) {
1205 output(o, 1, _("Failed to merge submodule %s (commits not present)"), path);
1206 return 0;
1207 }
1208
1209 /* check whether both changes are forward */
1210 if (!in_merge_bases(commit_base, commit_a) ||
1211 !in_merge_bases(commit_base, commit_b)) {
1212 output(o, 1, _("Failed to merge submodule %s (commits don't follow merge-base)"), path);
1213 return 0;
1214 }
1215
1216 /* Case #1: a is contained in b or vice versa */
1217 if (in_merge_bases(commit_a, commit_b)) {
1218 oidcpy(result, b);
1219 if (show(o, 3)) {
1220 output(o, 3, _("Fast-forwarding submodule %s to the following commit:"), path);
1221 output_commit_title(o, commit_b);
1222 } else if (show(o, 2))
1223 output(o, 2, _("Fast-forwarding submodule %s"), path);
1224 else
1225 ; /* no output */
1226
1227 return 1;
1228 }
1229 if (in_merge_bases(commit_b, commit_a)) {
1230 oidcpy(result, a);
1231 if (show(o, 3)) {
1232 output(o, 3, _("Fast-forwarding submodule %s to the following commit:"), path);
1233 output_commit_title(o, commit_a);
1234 } else if (show(o, 2))
1235 output(o, 2, _("Fast-forwarding submodule %s"), path);
1236 else
1237 ; /* no output */
1238
1239 return 1;
1240 }
1241
1242 /*
1243 * Case #2: There are one or more merges that contain a and b in
1244 * the submodule. If there is only one, then present it as a
1245 * suggestion to the user, but leave it marked unmerged so the
1246 * user needs to confirm the resolution.
1247 */
1248
1249 /* Skip the search if makes no sense to the calling context. */
1250 if (!search)
1251 return 0;
1252
1253 /* find commit which merges them */
1254 parent_count = find_first_merges(&merges, path, commit_a, commit_b);
1255 switch (parent_count) {
1256 case 0:
1257 output(o, 1, _("Failed to merge submodule %s (merge following commits not found)"), path);
1258 break;
1259
1260 case 1:
1261 output(o, 1, _("Failed to merge submodule %s (not fast-forward)"), path);
1262 output(o, 2, _("Found a possible merge resolution for the submodule:\n"));
1263 print_commit((struct commit *) merges.objects[0].item);
1264 output(o, 2, _(
1265 "If this is correct simply add it to the index "
1266 "for example\n"
1267 "by using:\n\n"
1268 " git update-index --cacheinfo 160000 %s \"%s\"\n\n"
1269 "which will accept this suggestion.\n"),
1270 oid_to_hex(&merges.objects[0].item->oid), path);
1271 break;
1272
1273 default:
1274 output(o, 1, _("Failed to merge submodule %s (multiple merges found)"), path);
1275 for (i = 0; i < merges.nr; i++)
1276 print_commit((struct commit *) merges.objects[i].item);
1277 }
1278
1279 object_array_clear(&merges);
1280 return 0;
1281 }
1282
1283 static int merge_mode_and_contents(struct merge_options *o,
1284 const struct diff_filespec *one,
1285 const struct diff_filespec *a,
1286 const struct diff_filespec *b,
1287 const char *filename,
1288 const char *branch1,
1289 const char *branch2,
1290 const int extra_marker_size,
1291 struct merge_file_info *result)
1292 {
1293 if (o->branch1 != branch1) {
1294 /*
1295 * It's weird getting a reverse merge with HEAD on the bottom
1296 * side of the conflict markers and the other branch on the
1297 * top. Fix that.
1298 */
1299 return merge_mode_and_contents(o, one, b, a,
1300 filename,
1301 branch2, branch1,
1302 extra_marker_size, result);
1303 }
1304
1305 result->merge = 0;
1306 result->clean = 1;
1307
1308 if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
1309 result->clean = 0;
1310 if (S_ISREG(a->mode)) {
1311 result->mode = a->mode;
1312 oidcpy(&result->oid, &a->oid);
1313 } else {
1314 result->mode = b->mode;
1315 oidcpy(&result->oid, &b->oid);
1316 }
1317 } else {
1318 if (!oid_eq(&a->oid, &one->oid) && !oid_eq(&b->oid, &one->oid))
1319 result->merge = 1;
1320
1321 /*
1322 * Merge modes
1323 */
1324 if (a->mode == b->mode || a->mode == one->mode)
1325 result->mode = b->mode;
1326 else {
1327 result->mode = a->mode;
1328 if (b->mode != one->mode) {
1329 result->clean = 0;
1330 result->merge = 1;
1331 }
1332 }
1333
1334 if (oid_eq(&a->oid, &b->oid) || oid_eq(&a->oid, &one->oid))
1335 oidcpy(&result->oid, &b->oid);
1336 else if (oid_eq(&b->oid, &one->oid))
1337 oidcpy(&result->oid, &a->oid);
1338 else if (S_ISREG(a->mode)) {
1339 mmbuffer_t result_buf;
1340 int ret = 0, merge_status;
1341
1342 merge_status = merge_3way(o, &result_buf, one, a, b,
1343 branch1, branch2,
1344 extra_marker_size);
1345
1346 if ((merge_status < 0) || !result_buf.ptr)
1347 ret = err(o, _("Failed to execute internal merge"));
1348
1349 if (!ret &&
1350 write_object_file(result_buf.ptr, result_buf.size,
1351 blob_type, &result->oid))
1352 ret = err(o, _("Unable to add %s to database"),
1353 a->path);
1354
1355 free(result_buf.ptr);
1356 if (ret)
1357 return ret;
1358 result->clean = (merge_status == 0);
1359 } else if (S_ISGITLINK(a->mode)) {
1360 result->clean = merge_submodule(o, &result->oid,
1361 one->path,
1362 &one->oid,
1363 &a->oid,
1364 &b->oid);
1365 } else if (S_ISLNK(a->mode)) {
1366 switch (o->recursive_variant) {
1367 case MERGE_RECURSIVE_NORMAL:
1368 oidcpy(&result->oid, &a->oid);
1369 if (!oid_eq(&a->oid, &b->oid))
1370 result->clean = 0;
1371 break;
1372 case MERGE_RECURSIVE_OURS:
1373 oidcpy(&result->oid, &a->oid);
1374 break;
1375 case MERGE_RECURSIVE_THEIRS:
1376 oidcpy(&result->oid, &b->oid);
1377 break;
1378 }
1379 } else
1380 BUG("unsupported object type in the tree");
1381 }
1382
1383 if (result->merge)
1384 output(o, 2, _("Auto-merging %s"), filename);
1385
1386 return 0;
1387 }
1388
1389 static int handle_rename_via_dir(struct merge_options *o,
1390 struct diff_filepair *pair,
1391 const char *rename_branch,
1392 const char *other_branch)
1393 {
1394 /*
1395 * Handle file adds that need to be renamed due to directory rename
1396 * detection. This differs from handle_rename_normal, because
1397 * there is no content merge to do; just move the file into the
1398 * desired final location.
1399 */
1400 const struct diff_filespec *dest = pair->two;
1401
1402 if (!o->call_depth && would_lose_untracked(dest->path)) {
1403 char *alt_path = unique_path(o, dest->path, rename_branch);
1404
1405 output(o, 1, _("Error: Refusing to lose untracked file at %s; "
1406 "writing to %s instead."),
1407 dest->path, alt_path);
1408 /*
1409 * Write the file in worktree at alt_path, but not in the
1410 * index. Instead, write to dest->path for the index but
1411 * only at the higher appropriate stage.
1412 */
1413 if (update_file(o, 0, &dest->oid, dest->mode, alt_path))
1414 return -1;
1415 free(alt_path);
1416 return update_stages(o, dest->path, NULL,
1417 rename_branch == o->branch1 ? dest : NULL,
1418 rename_branch == o->branch1 ? NULL : dest);
1419 }
1420
1421 /* Update dest->path both in index and in worktree */
1422 if (update_file(o, 1, &dest->oid, dest->mode, dest->path))
1423 return -1;
1424 return 0;
1425 }
1426
1427 static int handle_change_delete(struct merge_options *o,
1428 const char *path, const char *old_path,
1429 const struct object_id *o_oid, int o_mode,
1430 const struct object_id *changed_oid,
1431 int changed_mode,
1432 const char *change_branch,
1433 const char *delete_branch,
1434 const char *change, const char *change_past)
1435 {
1436 char *alt_path = NULL;
1437 const char *update_path = path;
1438 int ret = 0;
1439
1440 if (dir_in_way(path, !o->call_depth, 0) ||
1441 (!o->call_depth && would_lose_untracked(path))) {
1442 update_path = alt_path = unique_path(o, path, change_branch);
1443 }
1444
1445 if (o->call_depth) {
1446 /*
1447 * We cannot arbitrarily accept either a_sha or b_sha as
1448 * correct; since there is no true "middle point" between
1449 * them, simply reuse the base version for virtual merge base.
1450 */
1451 ret = remove_file_from_cache(path);
1452 if (!ret)
1453 ret = update_file(o, 0, o_oid, o_mode, update_path);
1454 } else {
1455 /*
1456 * Despite the four nearly duplicate messages and argument
1457 * lists below and the ugliness of the nested if-statements,
1458 * having complete messages makes the job easier for
1459 * translators.
1460 *
1461 * The slight variance among the cases is due to the fact
1462 * that:
1463 * 1) directory/file conflicts (in effect if
1464 * !alt_path) could cause us to need to write the
1465 * file to a different path.
1466 * 2) renames (in effect if !old_path) could mean that
1467 * there are two names for the path that the user
1468 * may know the file by.
1469 */
1470 if (!alt_path) {
1471 if (!old_path) {
1472 output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
1473 "and %s in %s. Version %s of %s left in tree."),
1474 change, path, delete_branch, change_past,
1475 change_branch, change_branch, path);
1476 } else {
1477 output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
1478 "and %s to %s in %s. Version %s of %s left in tree."),
1479 change, old_path, delete_branch, change_past, path,
1480 change_branch, change_branch, path);
1481 }
1482 } else {
1483 if (!old_path) {
1484 output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
1485 "and %s in %s. Version %s of %s left in tree at %s."),
1486 change, path, delete_branch, change_past,
1487 change_branch, change_branch, path, alt_path);
1488 } else {
1489 output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
1490 "and %s to %s in %s. Version %s of %s left in tree at %s."),
1491 change, old_path, delete_branch, change_past, path,
1492 change_branch, change_branch, path, alt_path);
1493 }
1494 }
1495 /*
1496 * No need to call update_file() on path when change_branch ==
1497 * o->branch1 && !alt_path, since that would needlessly touch
1498 * path. We could call update_file_flags() with update_cache=0
1499 * and update_wd=0, but that's a no-op.
1500 */
1501 if (change_branch != o->branch1 || alt_path)
1502 ret = update_file(o, 0, changed_oid, changed_mode, update_path);
1503 }
1504 free(alt_path);
1505
1506 return ret;
1507 }
1508
1509 static int handle_rename_delete(struct merge_options *o,
1510 struct diff_filepair *pair,
1511 const char *rename_branch,
1512 const char *delete_branch)
1513 {
1514 const struct diff_filespec *orig = pair->one;
1515 const struct diff_filespec *dest = pair->two;
1516
1517 if (handle_change_delete(o,
1518 o->call_depth ? orig->path : dest->path,
1519 o->call_depth ? NULL : orig->path,
1520 &orig->oid, orig->mode,
1521 &dest->oid, dest->mode,
1522 rename_branch, delete_branch,
1523 _("rename"), _("renamed")))
1524 return -1;
1525
1526 if (o->call_depth)
1527 return remove_file_from_cache(dest->path);
1528 else
1529 return update_stages(o, dest->path, NULL,
1530 rename_branch == o->branch1 ? dest : NULL,
1531 rename_branch == o->branch1 ? NULL : dest);
1532 }
1533
1534 static struct diff_filespec *filespec_from_entry(struct diff_filespec *target,
1535 struct stage_data *entry,
1536 int stage)
1537 {
1538 struct object_id *oid = &entry->stages[stage].oid;
1539 unsigned mode = entry->stages[stage].mode;
1540 if (mode == 0 || is_null_oid(oid))
1541 return NULL;
1542 oidcpy(&target->oid, oid);
1543 target->mode = mode;
1544 return target;
1545 }
1546
1547 static int handle_file_collision(struct merge_options *o,
1548 const char *collide_path,
1549 const char *prev_path1,
1550 const char *prev_path2,
1551 const char *branch1, const char *branch2,
1552 const struct object_id *a_oid,
1553 unsigned int a_mode,
1554 const struct object_id *b_oid,
1555 unsigned int b_mode)
1556 {
1557 struct merge_file_info mfi;
1558 struct diff_filespec null, a, b;
1559 char *alt_path = NULL;
1560 const char *update_path = collide_path;
1561
1562 /*
1563 * It's easiest to get the correct things into stage 2 and 3, and
1564 * to make sure that the content merge puts HEAD before the other
1565 * branch if we just ensure that branch1 == o->branch1. So, simply
1566 * flip arguments around if we don't have that.
1567 */
1568 if (branch1 != o->branch1) {
1569 return handle_file_collision(o, collide_path,
1570 prev_path2, prev_path1,
1571 branch2, branch1,
1572 b_oid, b_mode,
1573 a_oid, a_mode);
1574 }
1575
1576 /*
1577 * In the recursive case, we just opt to undo renames
1578 */
1579 if (o->call_depth && (prev_path1 || prev_path2)) {
1580 /* Put first file (a_oid, a_mode) in its original spot */
1581 if (prev_path1) {
1582 if (update_file(o, 1, a_oid, a_mode, prev_path1))
1583 return -1;
1584 } else {
1585 if (update_file(o, 1, a_oid, a_mode, collide_path))
1586 return -1;
1587 }
1588
1589 /* Put second file (b_oid, b_mode) in its original spot */
1590 if (prev_path2) {
1591 if (update_file(o, 1, b_oid, b_mode, prev_path2))
1592 return -1;
1593 } else {
1594 if (update_file(o, 1, b_oid, b_mode, collide_path))
1595 return -1;
1596 }
1597
1598 /* Don't leave something at collision path if unrenaming both */
1599 if (prev_path1 && prev_path2)
1600 remove_file(o, 1, collide_path, 0);
1601
1602 return 0;
1603 }
1604
1605 /* Remove rename sources if rename/add or rename/rename(2to1) */
1606 if (prev_path1)
1607 remove_file(o, 1, prev_path1,
1608 o->call_depth || would_lose_untracked(prev_path1));
1609 if (prev_path2)
1610 remove_file(o, 1, prev_path2,
1611 o->call_depth || would_lose_untracked(prev_path2));
1612
1613 /*
1614 * Remove the collision path, if it wouldn't cause dirty contents
1615 * or an untracked file to get lost. We'll either overwrite with
1616 * merged contents, or just write out to differently named files.
1617 */
1618 if (was_dirty(o, collide_path)) {
1619 output(o, 1, _("Refusing to lose dirty file at %s"),
1620 collide_path);
1621 update_path = alt_path = unique_path(o, collide_path, "merged");
1622 } else if (would_lose_untracked(collide_path)) {
1623 /*
1624 * Only way we get here is if both renames were from
1625 * a directory rename AND user had an untracked file
1626 * at the location where both files end up after the
1627 * two directory renames. See testcase 10d of t6043.
1628 */
1629 output(o, 1, _("Refusing to lose untracked file at "
1630 "%s, even though it's in the way."),
1631 collide_path);
1632 update_path = alt_path = unique_path(o, collide_path, "merged");
1633 } else {
1634 /*
1635 * FIXME: It's possible that the two files are identical
1636 * and that the current working copy happens to match, in
1637 * which case we are unnecessarily touching the working
1638 * tree file. It's not a likely enough scenario that I
1639 * want to code up the checks for it and a better fix is
1640 * available if we restructure how unpack_trees() and
1641 * merge-recursive interoperate anyway, so punting for
1642 * now...
1643 */
1644 remove_file(o, 0, collide_path, 0);
1645 }
1646
1647 /* Store things in diff_filespecs for functions that need it */
1648 memset(&a, 0, sizeof(struct diff_filespec));
1649 memset(&b, 0, sizeof(struct diff_filespec));
1650 null.path = a.path = b.path = (char *)collide_path;
1651 oidcpy(&null.oid, &null_oid);
1652 null.mode = 0;
1653 oidcpy(&a.oid, a_oid);
1654 a.mode = a_mode;
1655 a.oid_valid = 1;
1656 oidcpy(&b.oid, b_oid);
1657 b.mode = b_mode;
1658 b.oid_valid = 1;
1659
1660 if (merge_mode_and_contents(o, &null, &a, &b, collide_path,
1661 branch1, branch2, o->call_depth * 2, &mfi))
1662 return -1;
1663 mfi.clean &= !alt_path;
1664 if (update_file(o, mfi.clean, &mfi.oid, mfi.mode, update_path))
1665 return -1;
1666 if (!mfi.clean && !o->call_depth &&
1667 update_stages(o, collide_path, NULL, &a, &b))
1668 return -1;
1669 free(alt_path);
1670 /*
1671 * FIXME: If both a & b both started with conflicts (only possible
1672 * if they came from a rename/rename(2to1)), but had IDENTICAL
1673 * contents including those conflicts, then in the next line we claim
1674 * it was clean. If someone cares about this case, we should have the
1675 * caller notify us if we started with conflicts.
1676 */
1677 return mfi.clean;
1678 }
1679
1680 static int handle_rename_add(struct merge_options *o,
1681 struct rename_conflict_info *ci)
1682 {
1683 /* a was renamed to c, and a separate c was added. */
1684 struct diff_filespec *a = ci->pair1->one;
1685 struct diff_filespec *c = ci->pair1->two;
1686 char *path = c->path;
1687 char *prev_path_desc;
1688 struct merge_file_info mfi;
1689
1690 int other_stage = (ci->branch1 == o->branch1 ? 3 : 2);
1691
1692 output(o, 1, _("CONFLICT (rename/add): "
1693 "Rename %s->%s in %s. Added %s in %s"),
1694 a->path, c->path, ci->branch1,
1695 c->path, ci->branch2);
1696
1697 prev_path_desc = xstrfmt("version of %s from %s", path, a->path);
1698 if (merge_mode_and_contents(o, a, c, &ci->ren1_other, prev_path_desc,
1699 o->branch1, o->branch2,
1700 1 + o->call_depth * 2, &mfi))
1701 return -1;
1702 free(prev_path_desc);
1703
1704 return handle_file_collision(o,
1705 c->path, a->path, NULL,
1706 ci->branch1, ci->branch2,
1707 &mfi.oid, mfi.mode,
1708 &ci->dst_entry1->stages[other_stage].oid,
1709 ci->dst_entry1->stages[other_stage].mode);
1710 }
1711
1712 static int handle_rename_rename_1to2(struct merge_options *o,
1713 struct rename_conflict_info *ci)
1714 {
1715 /* One file was renamed in both branches, but to different names. */
1716 struct merge_file_info mfi;
1717 struct diff_filespec other;
1718 struct diff_filespec *add;
1719 struct diff_filespec *one = ci->pair1->one;
1720 struct diff_filespec *a = ci->pair1->two;
1721 struct diff_filespec *b = ci->pair2->two;
1722 char *path_desc;
1723
1724 output(o, 1, _("CONFLICT (rename/rename): "
1725 "Rename \"%s\"->\"%s\" in branch \"%s\" "
1726 "rename \"%s\"->\"%s\" in \"%s\"%s"),
1727 one->path, a->path, ci->branch1,
1728 one->path, b->path, ci->branch2,
1729 o->call_depth ? _(" (left unresolved)") : "");
1730
1731 path_desc = xstrfmt("%s and %s, both renamed from %s",
1732 a->path, b->path, one->path);
1733 if (merge_mode_and_contents(o, one, a, b, path_desc,
1734 ci->branch1, ci->branch2,
1735 o->call_depth * 2, &mfi))
1736 return -1;
1737 free(path_desc);
1738
1739 if (o->call_depth) {
1740 /*
1741 * FIXME: For rename/add-source conflicts (if we could detect
1742 * such), this is wrong. We should instead find a unique
1743 * pathname and then either rename the add-source file to that
1744 * unique path, or use that unique path instead of src here.
1745 */
1746 if (update_file(o, 0, &mfi.oid, mfi.mode, one->path))
1747 return -1;
1748
1749 /*
1750 * Above, we put the merged content at the merge-base's
1751 * path. Now we usually need to delete both a->path and
1752 * b->path. However, the rename on each side of the merge
1753 * could also be involved in a rename/add conflict. In
1754 * such cases, we should keep the added file around,
1755 * resolving the conflict at that path in its favor.
1756 */
1757 add = filespec_from_entry(&other, ci->dst_entry1, 2 ^ 1);
1758 if (add) {
1759 if (update_file(o, 0, &add->oid, add->mode, a->path))
1760 return -1;
1761 }
1762 else
1763 remove_file_from_cache(a->path);
1764 add = filespec_from_entry(&other, ci->dst_entry2, 3 ^ 1);
1765 if (add) {
1766 if (update_file(o, 0, &add->oid, add->mode, b->path))
1767 return -1;
1768 }
1769 else
1770 remove_file_from_cache(b->path);
1771 } else {
1772 /*
1773 * For each destination path, we need to see if there is a
1774 * rename/add collision. If not, we can write the file out
1775 * to the specified location.
1776 */
1777 add = filespec_from_entry(&other, ci->dst_entry1, 2 ^ 1);
1778 if (add) {
1779 if (handle_file_collision(o, a->path,
1780 NULL, NULL,
1781 ci->branch1, ci->branch2,
1782 &mfi.oid, mfi.mode,
1783 &add->oid, add->mode) < 0)
1784 return -1;
1785 } else {
1786 char *new_path = NULL;
1787 if (dir_in_way(a->path, !o->call_depth, 0)) {
1788 new_path = unique_path(o, a->path, ci->branch1);
1789 output(o, 1, _("%s is a directory in %s adding "
1790 "as %s instead"),
1791 a->path, ci->branch2, new_path);
1792 } else if (would_lose_untracked(a->path)) {
1793 new_path = unique_path(o, a->path, ci->branch1);
1794 output(o, 1, _("Refusing to lose untracked file"
1795 " at %s; adding as %s instead"),
1796 a->path, new_path);
1797 }
1798
1799 if (update_file(o, 0, &mfi.oid, mfi.mode, new_path ? new_path : a->path))
1800 return -1;
1801 free(new_path);
1802 if (update_stages(o, a->path, NULL, a, NULL))
1803 return -1;
1804 }
1805
1806 add = filespec_from_entry(&other, ci->dst_entry2, 3 ^ 1);
1807 if (add) {
1808 if (handle_file_collision(o, b->path,
1809 NULL, NULL,
1810 ci->branch1, ci->branch2,
1811 &add->oid, add->mode,
1812 &mfi.oid, mfi.mode) < 0)
1813 return -1;
1814 } else {
1815 char *new_path = NULL;
1816 if (dir_in_way(b->path, !o->call_depth, 0)) {
1817 new_path = unique_path(o, b->path, ci->branch2);
1818 output(o, 1, _("%s is a directory in %s adding "
1819 "as %s instead"),
1820 b->path, ci->branch1, new_path);
1821 } else if (would_lose_untracked(b->path)) {
1822 new_path = unique_path(o, b->path, ci->branch2);
1823 output(o, 1, _("Refusing to lose untracked file"
1824 " at %s; adding as %s instead"),
1825 b->path, new_path);
1826 }
1827
1828 if (update_file(o, 0, &mfi.oid, mfi.mode, new_path ? new_path : b->path))
1829 return -1;
1830 free(new_path);
1831 if (update_stages(o, b->path, NULL, NULL, b))
1832 return -1;
1833 }
1834 }
1835
1836 return 0;
1837 }
1838
1839 static int handle_rename_rename_2to1(struct merge_options *o,
1840 struct rename_conflict_info *ci)
1841 {
1842 /* Two files, a & b, were renamed to the same thing, c. */
1843 struct diff_filespec *a = ci->pair1->one;
1844 struct diff_filespec *b = ci->pair2->one;
1845 struct diff_filespec *c1 = ci->pair1->two;
1846 struct diff_filespec *c2 = ci->pair2->two;
1847 char *path = c1->path; /* == c2->path */
1848 char *path_side_1_desc;
1849 char *path_side_2_desc;
1850 struct merge_file_info mfi_c1;
1851 struct merge_file_info mfi_c2;
1852
1853 output(o, 1, _("CONFLICT (rename/rename): "
1854 "Rename %s->%s in %s. "
1855 "Rename %s->%s in %s"),
1856 a->path, c1->path, ci->branch1,
1857 b->path, c2->path, ci->branch2);
1858
1859 path_side_1_desc = xstrfmt("version of %s from %s", path, a->path);
1860 path_side_2_desc = xstrfmt("version of %s from %s", path, b->path);
1861 if (merge_mode_and_contents(o, a, c1, &ci->ren1_other, path_side_1_desc,
1862 o->branch1, o->branch2,
1863 1 + o->call_depth * 2, &mfi_c1) ||
1864 merge_mode_and_contents(o, b, &ci->ren2_other, c2, path_side_2_desc,
1865 o->branch1, o->branch2,
1866 1 + o->call_depth * 2, &mfi_c2))
1867 return -1;
1868 free(path_side_1_desc);
1869 free(path_side_2_desc);
1870
1871 return handle_file_collision(o, path, a->path, b->path,
1872 ci->branch1, ci->branch2,
1873 &mfi_c1.oid, mfi_c1.mode,
1874 &mfi_c2.oid, mfi_c2.mode);
1875 }
1876
1877 /*
1878 * Get the diff_filepairs changed between o_tree and tree.
1879 */
1880 static struct diff_queue_struct *get_diffpairs(struct merge_options *o,
1881 struct tree *o_tree,
1882 struct tree *tree)
1883 {
1884 struct diff_queue_struct *ret;
1885 struct diff_options opts;
1886
1887 diff_setup(&opts);
1888 opts.flags.recursive = 1;
1889 opts.flags.rename_empty = 0;
1890 opts.detect_rename = merge_detect_rename(o);
1891 /*
1892 * We do not have logic to handle the detection of copies. In
1893 * fact, it may not even make sense to add such logic: would we
1894 * really want a change to a base file to be propagated through
1895 * multiple other files by a merge?
1896 */
1897 if (opts.detect_rename > DIFF_DETECT_RENAME)
1898 opts.detect_rename = DIFF_DETECT_RENAME;
1899 opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
1900 o->diff_rename_limit >= 0 ? o->diff_rename_limit :
1901 1000;
1902 opts.rename_score = o->rename_score;
1903 opts.show_rename_progress = o->show_rename_progress;
1904 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
1905 diff_setup_done(&opts);
1906 diff_tree_oid(&o_tree->object.oid, &tree->object.oid, "", &opts);
1907 diffcore_std(&opts);
1908 if (opts.needed_rename_limit > o->needed_rename_limit)
1909 o->needed_rename_limit = opts.needed_rename_limit;
1910
1911 ret = xmalloc(sizeof(*ret));
1912 *ret = diff_queued_diff;
1913
1914 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
1915 diff_queued_diff.nr = 0;
1916 diff_queued_diff.queue = NULL;
1917 diff_flush(&opts);
1918 return ret;
1919 }
1920
1921 static int tree_has_path(struct tree *tree, const char *path)
1922 {
1923 struct object_id hashy;
1924 unsigned int mode_o;
1925
1926 return !get_tree_entry(&tree->object.oid, path,
1927 &hashy, &mode_o);
1928 }
1929
1930 /*
1931 * Return a new string that replaces the beginning portion (which matches
1932 * entry->dir), with entry->new_dir. In perl-speak:
1933 * new_path_name = (old_path =~ s/entry->dir/entry->new_dir/);
1934 * NOTE:
1935 * Caller must ensure that old_path starts with entry->dir + '/'.
1936 */
1937 static char *apply_dir_rename(struct dir_rename_entry *entry,
1938 const char *old_path)
1939 {
1940 struct strbuf new_path = STRBUF_INIT;
1941 int oldlen, newlen;
1942
1943 if (entry->non_unique_new_dir)
1944 return NULL;
1945
1946 oldlen = strlen(entry->dir);
1947 newlen = entry->new_dir.len + (strlen(old_path) - oldlen) + 1;
1948 strbuf_grow(&new_path, newlen);
1949 strbuf_addbuf(&new_path, &entry->new_dir);
1950 strbuf_addstr(&new_path, &old_path[oldlen]);
1951
1952 return strbuf_detach(&new_path, NULL);
1953 }
1954
1955 static void get_renamed_dir_portion(const char *old_path, const char *new_path,
1956 char **old_dir, char **new_dir)
1957 {
1958 char *end_of_old, *end_of_new;
1959 int old_len, new_len;
1960
1961 *old_dir = NULL;
1962 *new_dir = NULL;
1963
1964 /*
1965 * For
1966 * "a/b/c/d/e/foo.c" -> "a/b/some/thing/else/e/foo.c"
1967 * the "e/foo.c" part is the same, we just want to know that
1968 * "a/b/c/d" was renamed to "a/b/some/thing/else"
1969 * so, for this example, this function returns "a/b/c/d" in
1970 * *old_dir and "a/b/some/thing/else" in *new_dir.
1971 *
1972 * Also, if the basename of the file changed, we don't care. We
1973 * want to know which portion of the directory, if any, changed.
1974 */
1975 end_of_old = strrchr(old_path, '/');
1976 end_of_new = strrchr(new_path, '/');
1977
1978 if (end_of_old == NULL || end_of_new == NULL)
1979 return;
1980 while (*--end_of_new == *--end_of_old &&
1981 end_of_old != old_path &&
1982 end_of_new != new_path)
1983 ; /* Do nothing; all in the while loop */
1984 /*
1985 * We've found the first non-matching character in the directory
1986 * paths. That means the current directory we were comparing
1987 * represents the rename. Move end_of_old and end_of_new back
1988 * to the full directory name.
1989 */
1990 if (*end_of_old == '/')
1991 end_of_old++;
1992 if (*end_of_old != '/')
1993 end_of_new++;
1994 end_of_old = strchr(end_of_old, '/');
1995 end_of_new = strchr(end_of_new, '/');
1996
1997 /*
1998 * It may have been the case that old_path and new_path were the same
1999 * directory all along. Don't claim a rename if they're the same.
2000 */
2001 old_len = end_of_old - old_path;
2002 new_len = end_of_new - new_path;
2003
2004 if (old_len != new_len || strncmp(old_path, new_path, old_len)) {
2005 *old_dir = xstrndup(old_path, old_len);
2006 *new_dir = xstrndup(new_path, new_len);
2007 }
2008 }
2009
2010 static void remove_hashmap_entries(struct hashmap *dir_renames,
2011 struct string_list *items_to_remove)
2012 {
2013 int i;
2014 struct dir_rename_entry *entry;
2015
2016 for (i = 0; i < items_to_remove->nr; i++) {
2017 entry = items_to_remove->items[i].util;
2018 hashmap_remove(dir_renames, entry, NULL);
2019 }
2020 string_list_clear(items_to_remove, 0);
2021 }
2022
2023 /*
2024 * See if there is a directory rename for path, and if there are any file
2025 * level conflicts for the renamed location. If there is a rename and
2026 * there are no conflicts, return the new name. Otherwise, return NULL.
2027 */
2028 static char *handle_path_level_conflicts(struct merge_options *o,
2029 const char *path,
2030 struct dir_rename_entry *entry,
2031 struct hashmap *collisions,
2032 struct tree *tree)
2033 {
2034 char *new_path = NULL;
2035 struct collision_entry *collision_ent;
2036 int clean = 1;
2037 struct strbuf collision_paths = STRBUF_INIT;
2038
2039 /*
2040 * entry has the mapping of old directory name to new directory name
2041 * that we want to apply to path.
2042 */
2043 new_path = apply_dir_rename(entry, path);
2044
2045 if (!new_path) {
2046 /* This should only happen when entry->non_unique_new_dir set */
2047 if (!entry->non_unique_new_dir)
2048 BUG("entry->non_unqiue_dir not set and !new_path");
2049 output(o, 1, _("CONFLICT (directory rename split): "
2050 "Unclear where to place %s because directory "
2051 "%s was renamed to multiple other directories, "
2052 "with no destination getting a majority of the "
2053 "files."),
2054 path, entry->dir);
2055 clean = 0;
2056 return NULL;
2057 }
2058
2059 /*
2060 * The caller needs to have ensured that it has pre-populated
2061 * collisions with all paths that map to new_path. Do a quick check
2062 * to ensure that's the case.
2063 */
2064 collision_ent = collision_find_entry(collisions, new_path);
2065 if (collision_ent == NULL)
2066 BUG("collision_ent is NULL");
2067
2068 /*
2069 * Check for one-sided add/add/.../add conflicts, i.e.
2070 * where implicit renames from the other side doing
2071 * directory rename(s) can affect this side of history
2072 * to put multiple paths into the same location. Warn
2073 * and bail on directory renames for such paths.
2074 */
2075 if (collision_ent->reported_already) {
2076 clean = 0;
2077 } else if (tree_has_path(tree, new_path)) {
2078 collision_ent->reported_already = 1;
2079 strbuf_add_separated_string_list(&collision_paths, ", ",
2080 &collision_ent->source_files);
2081 output(o, 1, _("CONFLICT (implicit dir rename): Existing "
2082 "file/dir at %s in the way of implicit "
2083 "directory rename(s) putting the following "
2084 "path(s) there: %s."),
2085 new_path, collision_paths.buf);
2086 clean = 0;
2087 } else if (collision_ent->source_files.nr > 1) {
2088 collision_ent->reported_already = 1;
2089 strbuf_add_separated_string_list(&collision_paths, ", ",
2090 &collision_ent->source_files);
2091 output(o, 1, _("CONFLICT (implicit dir rename): Cannot map "
2092 "more than one path to %s; implicit directory "
2093 "renames tried to put these paths there: %s"),
2094 new_path, collision_paths.buf);
2095 clean = 0;
2096 }
2097
2098 /* Free memory we no longer need */
2099 strbuf_release(&collision_paths);
2100 if (!clean && new_path) {
2101 free(new_path);
2102 return NULL;
2103 }
2104
2105 return new_path;
2106 }
2107
2108 /*
2109 * There are a couple things we want to do at the directory level:
2110 * 1. Check for both sides renaming to the same thing, in order to avoid
2111 * implicit renaming of files that should be left in place. (See
2112 * testcase 6b in t6043 for details.)
2113 * 2. Prune directory renames if there are still files left in the
2114 * the original directory. These represent a partial directory rename,
2115 * i.e. a rename where only some of the files within the directory
2116 * were renamed elsewhere. (Technically, this could be done earlier
2117 * in get_directory_renames(), except that would prevent us from
2118 * doing the previous check and thus failing testcase 6b.)
2119 * 3. Check for rename/rename(1to2) conflicts (at the directory level).
2120 * In the future, we could potentially record this info as well and
2121 * omit reporting rename/rename(1to2) conflicts for each path within
2122 * the affected directories, thus cleaning up the merge output.
2123 * NOTE: We do NOT check for rename/rename(2to1) conflicts at the
2124 * directory level, because merging directories is fine. If it
2125 * causes conflicts for files within those merged directories, then
2126 * that should be detected at the individual path level.
2127 */
2128 static void handle_directory_level_conflicts(struct merge_options *o,
2129 struct hashmap *dir_re_head,
2130 struct tree *head,
2131 struct hashmap *dir_re_merge,
2132 struct tree *merge)
2133 {
2134 struct hashmap_iter iter;
2135 struct dir_rename_entry *head_ent;
2136 struct dir_rename_entry *merge_ent;
2137
2138 struct string_list remove_from_head = STRING_LIST_INIT_NODUP;
2139 struct string_list remove_from_merge = STRING_LIST_INIT_NODUP;
2140
2141 hashmap_iter_init(dir_re_head, &iter);
2142 while ((head_ent = hashmap_iter_next(&iter))) {
2143 merge_ent = dir_rename_find_entry(dir_re_merge, head_ent->dir);
2144 if (merge_ent &&
2145 !head_ent->non_unique_new_dir &&
2146 !merge_ent->non_unique_new_dir &&
2147 !strbuf_cmp(&head_ent->new_dir, &merge_ent->new_dir)) {
2148 /* 1. Renamed identically; remove it from both sides */
2149 string_list_append(&remove_from_head,
2150 head_ent->dir)->util = head_ent;
2151 strbuf_release(&head_ent->new_dir);
2152 string_list_append(&remove_from_merge,
2153 merge_ent->dir)->util = merge_ent;
2154 strbuf_release(&merge_ent->new_dir);
2155 } else if (tree_has_path(head, head_ent->dir)) {
2156 /* 2. This wasn't a directory rename after all */
2157 string_list_append(&remove_from_head,
2158 head_ent->dir)->util = head_ent;
2159 strbuf_release(&head_ent->new_dir);
2160 }
2161 }
2162
2163 remove_hashmap_entries(dir_re_head, &remove_from_head);
2164 remove_hashmap_entries(dir_re_merge, &remove_from_merge);
2165
2166 hashmap_iter_init(dir_re_merge, &iter);
2167 while ((merge_ent = hashmap_iter_next(&iter))) {
2168 head_ent = dir_rename_find_entry(dir_re_head, merge_ent->dir);
2169 if (tree_has_path(merge, merge_ent->dir)) {
2170 /* 2. This wasn't a directory rename after all */
2171 string_list_append(&remove_from_merge,
2172 merge_ent->dir)->util = merge_ent;
2173 } else if (head_ent &&
2174 !head_ent->non_unique_new_dir &&
2175 !merge_ent->non_unique_new_dir) {
2176 /* 3. rename/rename(1to2) */
2177 /*
2178 * We can assume it's not rename/rename(1to1) because
2179 * that was case (1), already checked above. So we
2180 * know that head_ent->new_dir and merge_ent->new_dir
2181 * are different strings.
2182 */
2183 output(o, 1, _("CONFLICT (rename/rename): "
2184 "Rename directory %s->%s in %s. "
2185 "Rename directory %s->%s in %s"),
2186 head_ent->dir, head_ent->new_dir.buf, o->branch1,
2187 head_ent->dir, merge_ent->new_dir.buf, o->branch2);
2188 string_list_append(&remove_from_head,
2189 head_ent->dir)->util = head_ent;
2190 strbuf_release(&head_ent->new_dir);
2191 string_list_append(&remove_from_merge,
2192 merge_ent->dir)->util = merge_ent;
2193 strbuf_release(&merge_ent->new_dir);
2194 }
2195 }
2196
2197 remove_hashmap_entries(dir_re_head, &remove_from_head);
2198 remove_hashmap_entries(dir_re_merge, &remove_from_merge);
2199 }
2200
2201 static struct hashmap *get_directory_renames(struct diff_queue_struct *pairs,
2202 struct tree *tree)
2203 {
2204 struct hashmap *dir_renames;
2205 struct hashmap_iter iter;
2206 struct dir_rename_entry *entry;
2207 int i;
2208
2209 /*
2210 * Typically, we think of a directory rename as all files from a
2211 * certain directory being moved to a target directory. However,
2212 * what if someone first moved two files from the original
2213 * directory in one commit, and then renamed the directory
2214 * somewhere else in a later commit? At merge time, we just know
2215 * that files from the original directory went to two different
2216 * places, and that the bulk of them ended up in the same place.
2217 * We want each directory rename to represent where the bulk of the
2218 * files from that directory end up; this function exists to find
2219 * where the bulk of the files went.
2220 *
2221 * The first loop below simply iterates through the list of file
2222 * renames, finding out how often each directory rename pair
2223 * possibility occurs.
2224 */
2225 dir_renames = xmalloc(sizeof(*dir_renames));
2226 dir_rename_init(dir_renames);
2227 for (i = 0; i < pairs->nr; ++i) {
2228 struct string_list_item *item;
2229 int *count;
2230 struct diff_filepair *pair = pairs->queue[i];
2231 char *old_dir, *new_dir;
2232
2233 /* File not part of directory rename if it wasn't renamed */
2234 if (pair->status != 'R')
2235 continue;
2236
2237 get_renamed_dir_portion(pair->one->path, pair->two->path,
2238 &old_dir, &new_dir);
2239 if (!old_dir)
2240 /* Directory didn't change at all; ignore this one. */
2241 continue;
2242
2243 entry = dir_rename_find_entry(dir_renames, old_dir);
2244 if (!entry) {
2245 entry = xmalloc(sizeof(*entry));
2246 dir_rename_entry_init(entry, old_dir);
2247 hashmap_put(dir_renames, entry);
2248 } else {
2249 free(old_dir);
2250 }
2251 item = string_list_lookup(&entry->possible_new_dirs, new_dir);
2252 if (!item) {
2253 item = string_list_insert(&entry->possible_new_dirs,
2254 new_dir);
2255 item->util = xcalloc(1, sizeof(int));
2256 } else {
2257 free(new_dir);
2258 }
2259 count = item->util;
2260 *count += 1;
2261 }
2262
2263 /*
2264 * For each directory with files moved out of it, we find out which
2265 * target directory received the most files so we can declare it to
2266 * be the "winning" target location for the directory rename. This
2267 * winner gets recorded in new_dir. If there is no winner
2268 * (multiple target directories received the same number of files),
2269 * we set non_unique_new_dir. Once we've determined the winner (or
2270 * that there is no winner), we no longer need possible_new_dirs.
2271 */
2272 hashmap_iter_init(dir_renames, &iter);
2273 while ((entry = hashmap_iter_next(&iter))) {
2274 int max = 0;
2275 int bad_max = 0;
2276 char *best = NULL;
2277
2278 for (i = 0; i < entry->possible_new_dirs.nr; i++) {
2279 int *count = entry->possible_new_dirs.items[i].util;
2280
2281 if (*count == max)
2282 bad_max = max;
2283 else if (*count > max) {
2284 max = *count;
2285 best = entry->possible_new_dirs.items[i].string;
2286 }
2287 }
2288 if (bad_max == max)
2289 entry->non_unique_new_dir = 1;
2290 else {
2291 assert(entry->new_dir.len == 0);
2292 strbuf_addstr(&entry->new_dir, best);
2293 }
2294 /*
2295 * The relevant directory sub-portion of the original full
2296 * filepaths were xstrndup'ed before inserting into
2297 * possible_new_dirs, and instead of manually iterating the
2298 * list and free'ing each, just lie and tell
2299 * possible_new_dirs that it did the strdup'ing so that it
2300 * will free them for us.
2301 */
2302 entry->possible_new_dirs.strdup_strings = 1;
2303 string_list_clear(&entry->possible_new_dirs, 1);
2304 }
2305
2306 return dir_renames;
2307 }
2308
2309 static struct dir_rename_entry *check_dir_renamed(const char *path,
2310 struct hashmap *dir_renames)
2311 {
2312 char *temp = xstrdup(path);
2313 char *end;
2314 struct dir_rename_entry *entry = NULL;;
2315
2316 while ((end = strrchr(temp, '/'))) {
2317 *end = '\0';
2318 entry = dir_rename_find_entry(dir_renames, temp);
2319 if (entry)
2320 break;
2321 }
2322 free(temp);
2323 return entry;
2324 }
2325
2326 static void compute_collisions(struct hashmap *collisions,
2327 struct hashmap *dir_renames,
2328 struct diff_queue_struct *pairs)
2329 {
2330 int i;
2331
2332 /*
2333 * Multiple files can be mapped to the same path due to directory
2334 * renames done by the other side of history. Since that other
2335 * side of history could have merged multiple directories into one,
2336 * if our side of history added the same file basename to each of
2337 * those directories, then all N of them would get implicitly
2338 * renamed by the directory rename detection into the same path,
2339 * and we'd get an add/add/.../add conflict, and all those adds
2340 * from *this* side of history. This is not representable in the
2341 * index, and users aren't going to easily be able to make sense of
2342 * it. So we need to provide a good warning about what's
2343 * happening, and fall back to no-directory-rename detection
2344 * behavior for those paths.
2345 *
2346 * See testcases 9e and all of section 5 from t6043 for examples.
2347 */
2348 collision_init(collisions);
2349
2350 for (i = 0; i < pairs->nr; ++i) {
2351 struct dir_rename_entry *dir_rename_ent;
2352 struct collision_entry *collision_ent;
2353 char *new_path;
2354 struct diff_filepair *pair = pairs->queue[i];
2355
2356 if (pair->status != 'A' && pair->status != 'R')
2357 continue;
2358 dir_rename_ent = check_dir_renamed(pair->two->path,
2359 dir_renames);
2360 if (!dir_rename_ent)
2361 continue;
2362
2363 new_path = apply_dir_rename(dir_rename_ent, pair->two->path);
2364 if (!new_path)
2365 /*
2366 * dir_rename_ent->non_unique_new_path is true, which
2367 * means there is no directory rename for us to use,
2368 * which means it won't cause us any additional
2369 * collisions.
2370 */
2371 continue;
2372 collision_ent = collision_find_entry(collisions, new_path);
2373 if (!collision_ent) {
2374 collision_ent = xcalloc(1,
2375 sizeof(struct collision_entry));
2376 hashmap_entry_init(collision_ent, strhash(new_path));
2377 hashmap_put(collisions, collision_ent);
2378 collision_ent->target_file = new_path;
2379 } else {
2380 free(new_path);
2381 }
2382 string_list_insert(&collision_ent->source_files,
2383 pair->two->path);
2384 }
2385 }
2386
2387 static char *check_for_directory_rename(struct merge_options *o,
2388 const char *path,
2389 struct tree *tree,
2390 struct hashmap *dir_renames,
2391 struct hashmap *dir_rename_exclusions,
2392 struct hashmap *collisions,
2393 int *clean_merge)
2394 {
2395 char *new_path = NULL;
2396 struct dir_rename_entry *entry = check_dir_renamed(path, dir_renames);
2397 struct dir_rename_entry *oentry = NULL;
2398
2399 if (!entry)
2400 return new_path;
2401
2402 /*
2403 * This next part is a little weird. We do not want to do an
2404 * implicit rename into a directory we renamed on our side, because
2405 * that will result in a spurious rename/rename(1to2) conflict. An
2406 * example:
2407 * Base commit: dumbdir/afile, otherdir/bfile
2408 * Side 1: smrtdir/afile, otherdir/bfile
2409 * Side 2: dumbdir/afile, dumbdir/bfile
2410 * Here, while working on Side 1, we could notice that otherdir was
2411 * renamed/merged to dumbdir, and change the diff_filepair for
2412 * otherdir/bfile into a rename into dumbdir/bfile. However, Side
2413 * 2 will notice the rename from dumbdir to smrtdir, and do the
2414 * transitive rename to move it from dumbdir/bfile to
2415 * smrtdir/bfile. That gives us bfile in dumbdir vs being in
2416 * smrtdir, a rename/rename(1to2) conflict. We really just want
2417 * the file to end up in smrtdir. And the way to achieve that is
2418 * to not let Side1 do the rename to dumbdir, since we know that is
2419 * the source of one of our directory renames.
2420 *
2421 * That's why oentry and dir_rename_exclusions is here.
2422 *
2423 * As it turns out, this also prevents N-way transient rename
2424 * confusion; See testcases 9c and 9d of t6043.
2425 */
2426 oentry = dir_rename_find_entry(dir_rename_exclusions, entry->new_dir.buf);
2427 if (oentry) {
2428 output(o, 1, _("WARNING: Avoiding applying %s -> %s rename "
2429 "to %s, because %s itself was renamed."),
2430 entry->dir, entry->new_dir.buf, path, entry->new_dir.buf);
2431 } else {
2432 new_path = handle_path_level_conflicts(o, path, entry,
2433 collisions, tree);
2434 *clean_merge &= (new_path != NULL);
2435 }
2436
2437 return new_path;
2438 }
2439
2440 static void apply_directory_rename_modifications(struct merge_options *o,
2441 struct diff_filepair *pair,
2442 char *new_path,
2443 struct rename *re,
2444 struct tree *tree,
2445 struct tree *o_tree,
2446 struct tree *a_tree,
2447 struct tree *b_tree,
2448 struct string_list *entries,
2449 int *clean)
2450 {
2451 struct string_list_item *item;
2452 int stage = (tree == a_tree ? 2 : 3);
2453 int update_wd;
2454
2455 /*
2456 * In all cases where we can do directory rename detection,
2457 * unpack_trees() will have read pair->two->path into the
2458 * index and the working copy. We need to remove it so that
2459 * we can instead place it at new_path. It is guaranteed to
2460 * not be untracked (unpack_trees() would have errored out
2461 * saying the file would have been overwritten), but it might
2462 * be dirty, though.
2463 */
2464 update_wd = !was_dirty(o, pair->two->path);
2465 if (!update_wd)
2466 output(o, 1, _("Refusing to lose dirty file at %s"),
2467 pair->two->path);
2468 remove_file(o, 1, pair->two->path, !update_wd);
2469
2470 /* Find or create a new re->dst_entry */
2471 item = string_list_lookup(entries, new_path);
2472 if (item) {
2473 /*
2474 * Since we're renaming on this side of history, and it's
2475 * due to a directory rename on the other side of history
2476 * (which we only allow when the directory in question no
2477 * longer exists on the other side of history), the
2478 * original entry for re->dst_entry is no longer
2479 * necessary...
2480 */
2481 re->dst_entry->processed = 1;
2482
2483 /*
2484 * ...because we'll be using this new one.
2485 */
2486 re->dst_entry = item->util;
2487 } else {
2488 /*
2489 * re->dst_entry is for the before-dir-rename path, and we
2490 * need it to hold information for the after-dir-rename
2491 * path. Before creating a new entry, we need to mark the
2492 * old one as unnecessary (...unless it is shared by
2493 * src_entry, i.e. this didn't use to be a rename, in which
2494 * case we can just allow the normal processing to happen
2495 * for it).
2496 */
2497 if (pair->status == 'R')
2498 re->dst_entry->processed = 1;
2499
2500 re->dst_entry = insert_stage_data(new_path,
2501 o_tree, a_tree, b_tree,
2502 entries);
2503 item = string_list_insert(entries, new_path);
2504 item->util = re->dst_entry;
2505 }
2506
2507 /*
2508 * Update the stage_data with the information about the path we are
2509 * moving into place. That slot will be empty and available for us
2510 * to write to because of the collision checks in
2511 * handle_path_level_conflicts(). In other words,
2512 * re->dst_entry->stages[stage].oid will be the null_oid, so it's
2513 * open for us to write to.
2514 *
2515 * It may be tempting to actually update the index at this point as
2516 * well, using update_stages_for_stage_data(), but as per the big
2517 * "NOTE" in update_stages(), doing so will modify the current
2518 * in-memory index which will break calls to would_lose_untracked()
2519 * that we need to make. Instead, we need to just make sure that
2520 * the various handle_rename_*() functions update the index
2521 * explicitly rather than relying on unpack_trees() to have done it.
2522 */
2523 get_tree_entry(&tree->object.oid,
2524 pair->two->path,
2525 &re->dst_entry->stages[stage].oid,
2526 &re->dst_entry->stages[stage].mode);
2527
2528 /* Update pair status */
2529 if (pair->status == 'A') {
2530 /*
2531 * Recording rename information for this add makes it look
2532 * like a rename/delete conflict. Make sure we can
2533 * correctly handle this as an add that was moved to a new
2534 * directory instead of reporting a rename/delete conflict.
2535 */
2536 re->add_turned_into_rename = 1;
2537 }
2538 /*
2539 * We don't actually look at pair->status again, but it seems
2540 * pedagogically correct to adjust it.
2541 */
2542 pair->status = 'R';
2543
2544 /*
2545 * Finally, record the new location.
2546 */
2547 pair->two->path = new_path;
2548 }
2549
2550 /*
2551 * Get information of all renames which occurred in 'pairs', making use of
2552 * any implicit directory renames inferred from the other side of history.
2553 * We need the three trees in the merge ('o_tree', 'a_tree' and 'b_tree')
2554 * to be able to associate the correct cache entries with the rename
2555 * information; tree is always equal to either a_tree or b_tree.
2556 */
2557 static struct string_list *get_renames(struct merge_options *o,
2558 struct diff_queue_struct *pairs,
2559 struct hashmap *dir_renames,
2560 struct hashmap *dir_rename_exclusions,
2561 struct tree *tree,
2562 struct tree *o_tree,
2563 struct tree *a_tree,
2564 struct tree *b_tree,
2565 struct string_list *entries,
2566 int *clean_merge)
2567 {
2568 int i;
2569 struct hashmap collisions;
2570 struct hashmap_iter iter;
2571 struct collision_entry *e;
2572 struct string_list *renames;
2573
2574 compute_collisions(&collisions, dir_renames, pairs);
2575 renames = xcalloc(1, sizeof(struct string_list));
2576
2577 for (i = 0; i < pairs->nr; ++i) {
2578 struct string_list_item *item;
2579 struct rename *re;
2580 struct diff_filepair *pair = pairs->queue[i];
2581 char *new_path; /* non-NULL only with directory renames */
2582
2583 if (pair->status != 'A' && pair->status != 'R') {
2584 diff_free_filepair(pair);
2585 continue;
2586 }
2587 new_path = check_for_directory_rename(o, pair->two->path, tree,
2588 dir_renames,
2589 dir_rename_exclusions,
2590 &collisions,
2591 clean_merge);
2592 if (pair->status != 'R' && !new_path) {
2593 diff_free_filepair(pair);
2594 continue;
2595 }
2596
2597 re = xmalloc(sizeof(*re));
2598 re->processed = 0;
2599 re->add_turned_into_rename = 0;
2600 re->pair = pair;
2601 item = string_list_lookup(entries, re->pair->one->path);
2602 if (!item)
2603 re->src_entry = insert_stage_data(re->pair->one->path,
2604 o_tree, a_tree, b_tree, entries);
2605 else
2606 re->src_entry = item->util;
2607
2608 item = string_list_lookup(entries, re->pair->two->path);
2609 if (!item)
2610 re->dst_entry = insert_stage_data(re->pair->two->path,
2611 o_tree, a_tree, b_tree, entries);
2612 else
2613 re->dst_entry = item->util;
2614 item = string_list_insert(renames, pair->one->path);
2615 item->util = re;
2616 if (new_path)
2617 apply_directory_rename_modifications(o, pair, new_path,
2618 re, tree, o_tree,
2619 a_tree, b_tree,
2620 entries,
2621 clean_merge);
2622 }
2623
2624 hashmap_iter_init(&collisions, &iter);
2625 while ((e = hashmap_iter_next(&iter))) {
2626 free(e->target_file);
2627 string_list_clear(&e->source_files, 0);
2628 }
2629 hashmap_free(&collisions, 1);
2630 return renames;
2631 }
2632
2633 static int process_renames(struct merge_options *o,
2634 struct string_list *a_renames,
2635 struct string_list *b_renames)
2636 {
2637 int clean_merge = 1, i, j;
2638 struct string_list a_by_dst = STRING_LIST_INIT_NODUP;
2639 struct string_list b_by_dst = STRING_LIST_INIT_NODUP;
2640 const struct rename *sre;
2641
2642 for (i = 0; i < a_renames->nr; i++) {
2643 sre = a_renames->items[i].util;
2644 string_list_insert(&a_by_dst, sre->pair->two->path)->util
2645 = (void *)sre;
2646 }
2647 for (i = 0; i < b_renames->nr; i++) {
2648 sre = b_renames->items[i].util;
2649 string_list_insert(&b_by_dst, sre->pair->two->path)->util
2650 = (void *)sre;
2651 }
2652
2653 for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
2654 struct string_list *renames1, *renames2Dst;
2655 struct rename *ren1 = NULL, *ren2 = NULL;
2656 const char *branch1, *branch2;
2657 const char *ren1_src, *ren1_dst;
2658 struct string_list_item *lookup;
2659
2660 if (i >= a_renames->nr) {
2661 ren2 = b_renames->items[j++].util;
2662 } else if (j >= b_renames->nr) {
2663 ren1 = a_renames->items[i++].util;
2664 } else {
2665 int compare = strcmp(a_renames->items[i].string,
2666 b_renames->items[j].string);
2667 if (compare <= 0)
2668 ren1 = a_renames->items[i++].util;
2669 if (compare >= 0)
2670 ren2 = b_renames->items[j++].util;
2671 }
2672
2673 /* TODO: refactor, so that 1/2 are not needed */
2674 if (ren1) {
2675 renames1 = a_renames;
2676 renames2Dst = &b_by_dst;
2677 branch1 = o->branch1;
2678 branch2 = o->branch2;
2679 } else {
2680 renames1 = b_renames;
2681 renames2Dst = &a_by_dst;
2682 branch1 = o->branch2;
2683 branch2 = o->branch1;
2684 SWAP(ren2, ren1);
2685 }
2686
2687 if (ren1->processed)
2688 continue;
2689 ren1->processed = 1;
2690 ren1->dst_entry->processed = 1;
2691 /* BUG: We should only mark src_entry as processed if we
2692 * are not dealing with a rename + add-source case.
2693 */
2694 ren1->src_entry->processed = 1;
2695
2696 ren1_src = ren1->pair->one->path;
2697 ren1_dst = ren1->pair->two->path;
2698
2699 if (ren2) {
2700 /* One file renamed on both sides */
2701 const char *ren2_src = ren2->pair->one->path;
2702 const char *ren2_dst = ren2->pair->two->path;
2703 enum rename_type rename_type;
2704 if (strcmp(ren1_src, ren2_src) != 0)
2705 BUG("ren1_src != ren2_src");
2706 ren2->dst_entry->processed = 1;
2707 ren2->processed = 1;
2708 if (strcmp(ren1_dst, ren2_dst) != 0) {
2709 rename_type = RENAME_ONE_FILE_TO_TWO;
2710 clean_merge = 0;
2711 } else {
2712 rename_type = RENAME_ONE_FILE_TO_ONE;
2713 /* BUG: We should only remove ren1_src in
2714 * the base stage (think of rename +
2715 * add-source cases).
2716 */
2717 remove_file(o, 1, ren1_src, 1);
2718 update_entry(ren1->dst_entry,
2719 ren1->pair->one,
2720 ren1->pair->two,
2721 ren2->pair->two);
2722 }
2723 setup_rename_conflict_info(rename_type,
2724 ren1->pair,
2725 ren2->pair,
2726 branch1,
2727 branch2,
2728 ren1->dst_entry,
2729 ren2->dst_entry,
2730 o,
2731 NULL,
2732 NULL);
2733 } else if ((lookup = string_list_lookup(renames2Dst, ren1_dst))) {
2734 /* Two different files renamed to the same thing */
2735 char *ren2_dst;
2736 ren2 = lookup->util;
2737 ren2_dst = ren2->pair->two->path;
2738 if (strcmp(ren1_dst, ren2_dst) != 0)
2739 BUG("ren1_dst != ren2_dst");
2740
2741 clean_merge = 0;
2742 ren2->processed = 1;
2743 /*
2744 * BUG: We should only mark src_entry as processed
2745 * if we are not dealing with a rename + add-source
2746 * case.
2747 */
2748 ren2->src_entry->processed = 1;
2749
2750 setup_rename_conflict_info(RENAME_TWO_FILES_TO_ONE,
2751 ren1->pair,
2752 ren2->pair,
2753 branch1,
2754 branch2,
2755 ren1->dst_entry,
2756 ren2->dst_entry,
2757 o,
2758 ren1->src_entry,
2759 ren2->src_entry);
2760
2761 } else {
2762 /* Renamed in 1, maybe changed in 2 */
2763 /* we only use sha1 and mode of these */
2764 struct diff_filespec src_other, dst_other;
2765 int try_merge;
2766
2767 /*
2768 * unpack_trees loads entries from common-commit
2769 * into stage 1, from head-commit into stage 2, and
2770 * from merge-commit into stage 3. We keep track
2771 * of which side corresponds to the rename.
2772 */
2773 int renamed_stage = a_renames == renames1 ? 2 : 3;
2774 int other_stage = a_renames == renames1 ? 3 : 2;
2775
2776 /* BUG: We should only remove ren1_src in the base
2777 * stage and in other_stage (think of rename +
2778 * add-source case).
2779 */
2780 remove_file(o, 1, ren1_src,
2781 renamed_stage == 2 || !was_tracked(o, ren1_src));
2782
2783 oidcpy(&src_other.oid,
2784 &ren1->src_entry->stages[other_stage].oid);
2785 src_other.mode = ren1->src_entry->stages[other_stage].mode;
2786 oidcpy(&dst_other.oid,
2787 &ren1->dst_entry->stages[other_stage].oid);
2788 dst_other.mode = ren1->dst_entry->stages[other_stage].mode;
2789 try_merge = 0;
2790
2791 if (oid_eq(&src_other.oid, &null_oid) &&
2792 ren1->add_turned_into_rename) {
2793 setup_rename_conflict_info(RENAME_VIA_DIR,
2794 ren1->pair,
2795 NULL,
2796 branch1,
2797 branch2,
2798 ren1->dst_entry,
2799 NULL,
2800 o,
2801 NULL,
2802 NULL);
2803 } else if (oid_eq(&src_other.oid, &null_oid)) {
2804 setup_rename_conflict_info(RENAME_DELETE,
2805 ren1->pair,
2806 NULL,
2807 branch1,
2808 branch2,
2809 ren1->dst_entry,
2810 NULL,
2811 o,
2812 NULL,
2813 NULL);
2814 } else if ((dst_other.mode == ren1->pair->two->mode) &&
2815 oid_eq(&dst_other.oid, &ren1->pair->two->oid)) {
2816 /*
2817 * Added file on the other side identical to
2818 * the file being renamed: clean merge.
2819 * Also, there is no need to overwrite the
2820 * file already in the working copy, so call
2821 * update_file_flags() instead of
2822 * update_file().
2823 */
2824 if (update_file_flags(o,
2825 &ren1->pair->two->oid,
2826 ren1->pair->two->mode,
2827 ren1_dst,
2828 1, /* update_cache */
2829 0 /* update_wd */))
2830 clean_merge = -1;
2831 } else if (!oid_eq(&dst_other.oid, &null_oid)) {
2832 /*
2833 * Probably not a clean merge, but it's
2834 * premature to set clean_merge to 0 here,
2835 * because if the rename merges cleanly and
2836 * the merge exactly matches the newly added
2837 * file, then the merge will be clean.
2838 */
2839 setup_rename_conflict_info(RENAME_ADD,
2840 ren1->pair,
2841 NULL,
2842 branch1,
2843 branch2,
2844 ren1->dst_entry,
2845 NULL,
2846 o,
2847 ren1->src_entry,
2848 NULL);
2849 } else
2850 try_merge = 1;
2851
2852 if (clean_merge < 0)
2853 goto cleanup_and_return;
2854 if (try_merge) {
2855 struct diff_filespec *one, *a, *b;
2856 src_other.path = (char *)ren1_src;
2857
2858 one = ren1->pair->one;
2859 if (a_renames == renames1) {
2860 a = ren1->pair->two;
2861 b = &src_other;
2862 } else {
2863 b = ren1->pair->two;
2864 a = &src_other;
2865 }
2866 update_entry(ren1->dst_entry, one, a, b);
2867 setup_rename_conflict_info(RENAME_NORMAL,
2868 ren1->pair,
2869 NULL,
2870 branch1,
2871 NULL,
2872 ren1->dst_entry,
2873 NULL,
2874 o,
2875 NULL,
2876 NULL);
2877 }
2878 }
2879 }
2880 cleanup_and_return:
2881 string_list_clear(&a_by_dst, 0);
2882 string_list_clear(&b_by_dst, 0);
2883
2884 return clean_merge;
2885 }
2886
2887 struct rename_info {
2888 struct string_list *head_renames;
2889 struct string_list *merge_renames;
2890 };
2891
2892 static void initial_cleanup_rename(struct diff_queue_struct *pairs,
2893 struct hashmap *dir_renames)
2894 {
2895 struct hashmap_iter iter;
2896 struct dir_rename_entry *e;
2897
2898 hashmap_iter_init(dir_renames, &iter);
2899 while ((e = hashmap_iter_next(&iter))) {
2900 free(e->dir);
2901 strbuf_release(&e->new_dir);
2902 /* possible_new_dirs already cleared in get_directory_renames */
2903 }
2904 hashmap_free(dir_renames, 1);
2905 free(dir_renames);
2906
2907 free(pairs->queue);
2908 free(pairs);
2909 }
2910
2911 static int detect_and_process_renames(struct merge_options *o,
2912 struct tree *common,
2913 struct tree *head,
2914 struct tree *merge,
2915 struct string_list *entries,
2916 struct rename_info *ri)
2917 {
2918 struct diff_queue_struct *head_pairs, *merge_pairs;
2919 struct hashmap *dir_re_head, *dir_re_merge;
2920 int clean = 1;
2921
2922 ri->head_renames = NULL;
2923 ri->merge_renames = NULL;
2924
2925 if (!merge_detect_rename(o))
2926 return 1;
2927
2928 head_pairs = get_diffpairs(o, common, head);
2929 merge_pairs = get_diffpairs(o, common, merge);
2930
2931 if (o->detect_directory_renames) {
2932 dir_re_head = get_directory_renames(head_pairs, head);
2933 dir_re_merge = get_directory_renames(merge_pairs, merge);
2934
2935 handle_directory_level_conflicts(o,
2936 dir_re_head, head,
2937 dir_re_merge, merge);
2938 } else {
2939 dir_re_head = xmalloc(sizeof(*dir_re_head));
2940 dir_re_merge = xmalloc(sizeof(*dir_re_merge));
2941 dir_rename_init(dir_re_head);
2942 dir_rename_init(dir_re_merge);
2943 }
2944
2945 ri->head_renames = get_renames(o, head_pairs,
2946 dir_re_merge, dir_re_head, head,
2947 common, head, merge, entries,
2948 &clean);
2949 if (clean < 0)
2950 goto cleanup;
2951 ri->merge_renames = get_renames(o, merge_pairs,
2952 dir_re_head, dir_re_merge, merge,
2953 common, head, merge, entries,
2954 &clean);
2955 if (clean < 0)
2956 goto cleanup;
2957 clean &= process_renames(o, ri->head_renames, ri->merge_renames);
2958
2959 cleanup:
2960 /*
2961 * Some cleanup is deferred until cleanup_renames() because the
2962 * data structures are still needed and referenced in
2963 * process_entry(). But there are a few things we can free now.
2964 */
2965 initial_cleanup_rename(head_pairs, dir_re_head);
2966 initial_cleanup_rename(merge_pairs, dir_re_merge);
2967
2968 return clean;
2969 }
2970
2971 static void final_cleanup_rename(struct string_list *rename)
2972 {
2973 const struct rename *re;
2974 int i;
2975
2976 if (rename == NULL)
2977 return;
2978
2979 for (i = 0; i < rename->nr; i++) {
2980 re = rename->items[i].util;
2981 diff_free_filepair(re->pair);
2982 }
2983 string_list_clear(rename, 1);
2984 free(rename);
2985 }
2986
2987 static void final_cleanup_renames(struct rename_info *re_info)
2988 {
2989 final_cleanup_rename(re_info->head_renames);
2990 final_cleanup_rename(re_info->merge_renames);
2991 }
2992
2993 static struct object_id *stage_oid(const struct object_id *oid, unsigned mode)
2994 {
2995 return (is_null_oid(oid) || mode == 0) ? NULL: (struct object_id *)oid;
2996 }
2997
2998 static int read_oid_strbuf(struct merge_options *o,
2999 const struct object_id *oid,
3000 struct strbuf *dst)
3001 {
3002 void *buf;
3003 enum object_type type;
3004 unsigned long size;
3005 buf = read_object_file(oid, &type, &size);
3006 if (!buf)
3007 return err(o, _("cannot read object %s"), oid_to_hex(oid));
3008 if (type != OBJ_BLOB) {
3009 free(buf);
3010 return err(o, _("object %s is not a blob"), oid_to_hex(oid));
3011 }
3012 strbuf_attach(dst, buf, size, size + 1);
3013 return 0;
3014 }
3015
3016 static int blob_unchanged(struct merge_options *opt,
3017 const struct object_id *o_oid,
3018 unsigned o_mode,
3019 const struct object_id *a_oid,
3020 unsigned a_mode,
3021 int renormalize, const char *path)
3022 {
3023 struct strbuf o = STRBUF_INIT;
3024 struct strbuf a = STRBUF_INIT;
3025 int ret = 0; /* assume changed for safety */
3026
3027 if (a_mode != o_mode)
3028 return 0;
3029 if (oid_eq(o_oid, a_oid))
3030 return 1;
3031 if (!renormalize)
3032 return 0;
3033
3034 assert(o_oid && a_oid);
3035 if (read_oid_strbuf(opt, o_oid, &o) || read_oid_strbuf(opt, a_oid, &a))
3036 goto error_return;
3037 /*
3038 * Note: binary | is used so that both renormalizations are
3039 * performed. Comparison can be skipped if both files are
3040 * unchanged since their sha1s have already been compared.
3041 */
3042 if (renormalize_buffer(&the_index, path, o.buf, o.len, &o) |
3043 renormalize_buffer(&the_index, path, a.buf, a.len, &a))
3044 ret = (o.len == a.len && !memcmp(o.buf, a.buf, o.len));
3045
3046 error_return:
3047 strbuf_release(&o);
3048 strbuf_release(&a);
3049 return ret;
3050 }
3051
3052 static int handle_modify_delete(struct merge_options *o,
3053 const char *path,
3054 struct object_id *o_oid, int o_mode,
3055 struct object_id *a_oid, int a_mode,
3056 struct object_id *b_oid, int b_mode)
3057 {
3058 const char *modify_branch, *delete_branch;
3059 struct object_id *changed_oid;
3060 int changed_mode;
3061
3062 if (a_oid) {
3063 modify_branch = o->branch1;
3064 delete_branch = o->branch2;
3065 changed_oid = a_oid;
3066 changed_mode = a_mode;
3067 } else {
3068 modify_branch = o->branch2;
3069 delete_branch = o->branch1;
3070 changed_oid = b_oid;
3071 changed_mode = b_mode;
3072 }
3073
3074 return handle_change_delete(o,
3075 path, NULL,
3076 o_oid, o_mode,
3077 changed_oid, changed_mode,
3078 modify_branch, delete_branch,
3079 _("modify"), _("modified"));
3080 }
3081
3082 static int handle_content_merge(struct merge_options *o,
3083 const char *path,
3084 int is_dirty,
3085 struct object_id *o_oid, int o_mode,
3086 struct object_id *a_oid, int a_mode,
3087 struct object_id *b_oid, int b_mode,
3088 struct rename_conflict_info *rename_conflict_info)
3089 {
3090 const char *reason = _("content");
3091 const char *path1 = NULL, *path2 = NULL;
3092 struct merge_file_info mfi;
3093 struct diff_filespec one, a, b;
3094 unsigned df_conflict_remains = 0;
3095
3096 if (!o_oid) {
3097 reason = _("add/add");
3098 o_oid = (struct object_id *)&null_oid;
3099 }
3100 one.path = a.path = b.path = (char *)path;
3101 oidcpy(&one.oid, o_oid);
3102 one.mode = o_mode;
3103 oidcpy(&a.oid, a_oid);
3104 a.mode = a_mode;
3105 oidcpy(&b.oid, b_oid);
3106 b.mode = b_mode;
3107
3108 if (rename_conflict_info) {
3109 struct diff_filepair *pair1 = rename_conflict_info->pair1;
3110
3111 path1 = (o->branch1 == rename_conflict_info->branch1) ?
3112 pair1->two->path : pair1->one->path;
3113 /* If rename_conflict_info->pair2 != NULL, we are in
3114 * RENAME_ONE_FILE_TO_ONE case. Otherwise, we have a
3115 * normal rename.
3116 */
3117 path2 = (rename_conflict_info->pair2 ||
3118 o->branch2 == rename_conflict_info->branch1) ?
3119 pair1->two->path : pair1->one->path;
3120 one.path = pair1->one->path;
3121 a.path = (char *)path1;
3122 b.path = (char *)path2;
3123
3124 if (dir_in_way(path, !o->call_depth,
3125 S_ISGITLINK(pair1->two->mode)))
3126 df_conflict_remains = 1;
3127 }
3128 if (merge_mode_and_contents(o, &one, &a, &b, path,
3129 o->branch1, o->branch2,
3130 o->call_depth * 2, &mfi))
3131 return -1;
3132
3133 /*
3134 * We can skip updating the working tree file iff:
3135 * a) The merge is clean
3136 * b) The merge matches what was in HEAD (content, mode, pathname)
3137 * c) The target path is usable (i.e. not involved in D/F conflict)
3138 */
3139 if (mfi.clean &&
3140 was_tracked_and_matches(o, path, &mfi.oid, mfi.mode) &&
3141 !df_conflict_remains) {
3142 int pos;
3143 struct cache_entry *ce;
3144
3145 output(o, 3, _("Skipped %s (merged same as existing)"), path);
3146 if (add_cacheinfo(o, mfi.mode, &mfi.oid, path,
3147 0, (!o->call_depth && !is_dirty), 0))
3148 return -1;
3149 /*
3150 * However, add_cacheinfo() will delete the old cache entry
3151 * and add a new one. We need to copy over any skip_worktree
3152 * flag to avoid making the file appear as if it were
3153 * deleted by the user.
3154 */
3155 pos = index_name_pos(&o->orig_index, path, strlen(path));
3156 ce = o->orig_index.cache[pos];
3157 if (ce_skip_worktree(ce)) {
3158 pos = index_name_pos(&the_index, path, strlen(path));
3159 ce = the_index.cache[pos];
3160 ce->ce_flags |= CE_SKIP_WORKTREE;
3161 }
3162 return mfi.clean;
3163 }
3164
3165 if (!mfi.clean) {
3166 if (S_ISGITLINK(mfi.mode))
3167 reason = _("submodule");
3168 output(o, 1, _("CONFLICT (%s): Merge conflict in %s"),
3169 reason, path);
3170 if (rename_conflict_info && !df_conflict_remains)
3171 if (update_stages(o, path, &one, &a, &b))
3172 return -1;
3173 }
3174
3175 if (df_conflict_remains || is_dirty) {
3176 char *new_path;
3177 if (o->call_depth) {
3178 remove_file_from_cache(path);
3179 } else {
3180 if (!mfi.clean) {
3181 if (update_stages(o, path, &one, &a, &b))
3182 return -1;
3183 } else {
3184 int file_from_stage2 = was_tracked(o, path);
3185 struct diff_filespec merged;
3186 oidcpy(&merged.oid, &mfi.oid);
3187 merged.mode = mfi.mode;
3188
3189 if (update_stages(o, path, NULL,
3190 file_from_stage2 ? &merged : NULL,
3191 file_from_stage2 ? NULL : &merged))
3192 return -1;
3193 }
3194
3195 }
3196 new_path = unique_path(o, path, rename_conflict_info->branch1);
3197 if (is_dirty) {
3198 output(o, 1, _("Refusing to lose dirty file at %s"),
3199 path);
3200 }
3201 output(o, 1, _("Adding as %s instead"), new_path);
3202 if (update_file(o, 0, &mfi.oid, mfi.mode, new_path)) {
3203 free(new_path);
3204 return -1;
3205 }
3206 free(new_path);
3207 mfi.clean = 0;
3208 } else if (update_file(o, mfi.clean, &mfi.oid, mfi.mode, path))
3209 return -1;
3210 return !is_dirty && mfi.clean;
3211 }
3212
3213 static int handle_rename_normal(struct merge_options *o,
3214 const char *path,
3215 struct object_id *o_oid, unsigned int o_mode,
3216 struct object_id *a_oid, unsigned int a_mode,
3217 struct object_id *b_oid, unsigned int b_mode,
3218 struct rename_conflict_info *ci)
3219 {
3220 /* Merge the content and write it out */
3221 return handle_content_merge(o, path, was_dirty(o, path),
3222 o_oid, o_mode, a_oid, a_mode, b_oid, b_mode,
3223 ci);
3224 }
3225
3226 /* Per entry merge function */
3227 static int process_entry(struct merge_options *o,
3228 const char *path, struct stage_data *entry)
3229 {
3230 int clean_merge = 1;
3231 int normalize = o->renormalize;
3232 unsigned o_mode = entry->stages[1].mode;
3233 unsigned a_mode = entry->stages[2].mode;
3234 unsigned b_mode = entry->stages[3].mode;
3235 struct object_id *o_oid = stage_oid(&entry->stages[1].oid, o_mode);
3236 struct object_id *a_oid = stage_oid(&entry->stages[2].oid, a_mode);
3237 struct object_id *b_oid = stage_oid(&entry->stages[3].oid, b_mode);
3238
3239 entry->processed = 1;
3240 if (entry->rename_conflict_info) {
3241 struct rename_conflict_info *conflict_info = entry->rename_conflict_info;
3242 switch (conflict_info->rename_type) {
3243 case RENAME_NORMAL:
3244 case RENAME_ONE_FILE_TO_ONE:
3245 clean_merge = handle_rename_normal(o,
3246 path,
3247 o_oid, o_mode,
3248 a_oid, a_mode,
3249 b_oid, b_mode,
3250 conflict_info);
3251 break;
3252 case RENAME_VIA_DIR:
3253 clean_merge = 1;
3254 if (handle_rename_via_dir(o,
3255 conflict_info->pair1,
3256 conflict_info->branch1,
3257 conflict_info->branch2))
3258 clean_merge = -1;
3259 break;
3260 case RENAME_ADD:
3261 /*
3262 * Probably unclean merge, but if the renamed file
3263 * merges cleanly and the result can then be
3264 * two-way merged cleanly with the added file, I
3265 * guess it's a clean merge?
3266 */
3267 clean_merge = handle_rename_add(o, conflict_info);
3268 break;
3269 case RENAME_DELETE:
3270 clean_merge = 0;
3271 if (handle_rename_delete(o,
3272 conflict_info->pair1,
3273 conflict_info->branch1,
3274 conflict_info->branch2))
3275 clean_merge = -1;
3276 break;
3277 case RENAME_ONE_FILE_TO_TWO:
3278 clean_merge = 0;
3279 if (handle_rename_rename_1to2(o, conflict_info))
3280 clean_merge = -1;
3281 break;
3282 case RENAME_TWO_FILES_TO_ONE:
3283 /*
3284 * Probably unclean merge, but if the two renamed
3285 * files merge cleanly and the two resulting files
3286 * can then be two-way merged cleanly, I guess it's
3287 * a clean merge?
3288 */
3289 clean_merge = handle_rename_rename_2to1(o,
3290 conflict_info);
3291 break;
3292 default:
3293 entry->processed = 0;
3294 break;
3295 }
3296 } else if (o_oid && (!a_oid || !b_oid)) {
3297 /* Case A: Deleted in one */
3298 if ((!a_oid && !b_oid) ||
3299 (!b_oid && blob_unchanged(o, o_oid, o_mode, a_oid, a_mode, normalize, path)) ||
3300 (!a_oid && blob_unchanged(o, o_oid, o_mode, b_oid, b_mode, normalize, path))) {
3301 /* Deleted in both or deleted in one and
3302 * unchanged in the other */
3303 if (a_oid)
3304 output(o, 2, _("Removing %s"), path);
3305 /* do not touch working file if it did not exist */
3306 remove_file(o, 1, path, !a_oid);
3307 } else {
3308 /* Modify/delete; deleted side may have put a directory in the way */
3309 clean_merge = 0;
3310 if (handle_modify_delete(o, path, o_oid, o_mode,
3311 a_oid, a_mode, b_oid, b_mode))
3312 clean_merge = -1;
3313 }
3314 } else if ((!o_oid && a_oid && !b_oid) ||
3315 (!o_oid && !a_oid && b_oid)) {
3316 /* Case B: Added in one. */
3317 /* [nothing|directory] -> ([nothing|directory], file) */
3318
3319 const char *add_branch;
3320 const char *other_branch;
3321 unsigned mode;
3322 const struct object_id *oid;
3323 const char *conf;
3324
3325 if (a_oid) {
3326 add_branch = o->branch1;
3327 other_branch = o->branch2;
3328 mode = a_mode;
3329 oid = a_oid;
3330 conf = _("file/directory");
3331 } else {
3332 add_branch = o->branch2;
3333 other_branch = o->branch1;
3334 mode = b_mode;
3335 oid = b_oid;
3336 conf = _("directory/file");
3337 }
3338 if (dir_in_way(path,
3339 !o->call_depth && !S_ISGITLINK(a_mode),
3340 0)) {
3341 char *new_path = unique_path(o, path, add_branch);
3342 clean_merge = 0;
3343 output(o, 1, _("CONFLICT (%s): There is a directory with name %s in %s. "
3344 "Adding %s as %s"),
3345 conf, path, other_branch, path, new_path);
3346 if (update_file(o, 0, oid, mode, new_path))
3347 clean_merge = -1;
3348 else if (o->call_depth)
3349 remove_file_from_cache(path);
3350 free(new_path);
3351 } else {
3352 output(o, 2, _("Adding %s"), path);
3353 /* do not overwrite file if already present */
3354 if (update_file_flags(o, oid, mode, path, 1, !a_oid))
3355 clean_merge = -1;
3356 }
3357 } else if (a_oid && b_oid) {
3358 if (!o_oid) {
3359 /* Case C: Added in both (check for same permissions) */
3360 output(o, 1,
3361 _("CONFLICT (add/add): Merge conflict in %s"),
3362 path);
3363 clean_merge = handle_file_collision(o,
3364 path, NULL, NULL,
3365 o->branch1,
3366 o->branch2,
3367 a_oid, a_mode,
3368 b_oid, b_mode);
3369 } else {
3370 /* case D: Modified in both, but differently. */
3371 int is_dirty = 0; /* unpack_trees would have bailed if dirty */
3372 clean_merge = handle_content_merge(o, path,
3373 is_dirty,
3374 o_oid, o_mode,
3375 a_oid, a_mode,
3376 b_oid, b_mode,
3377 NULL);
3378 }
3379 } else if (!o_oid && !a_oid && !b_oid) {
3380 /*
3381 * this entry was deleted altogether. a_mode == 0 means
3382 * we had that path and want to actively remove it.
3383 */
3384 remove_file(o, 1, path, !a_mode);
3385 } else
3386 BUG("fatal merge failure, shouldn't happen.");
3387
3388 return clean_merge;
3389 }
3390
3391 int merge_trees(struct merge_options *o,
3392 struct tree *head,
3393 struct tree *merge,
3394 struct tree *common,
3395 struct tree **result)
3396 {
3397 int code, clean;
3398 struct strbuf sb = STRBUF_INIT;
3399
3400 if (!o->call_depth && index_has_changes(&the_index, head, &sb)) {
3401 err(o, _("Your local changes to the following files would be overwritten by merge:\n %s"),
3402 sb.buf);
3403 return -1;
3404 }
3405
3406 if (o->subtree_shift) {
3407 merge = shift_tree_object(head, merge, o->subtree_shift);
3408 common = shift_tree_object(head, common, o->subtree_shift);
3409 }
3410
3411 if (oid_eq(&common->object.oid, &merge->object.oid)) {
3412 output(o, 0, _("Already up to date!"));
3413 *result = head;
3414 return 1;
3415 }
3416
3417 code = unpack_trees_start(o, common, head, merge);
3418
3419 if (code != 0) {
3420 if (show(o, 4) || o->call_depth)
3421 err(o, _("merging of trees %s and %s failed"),
3422 oid_to_hex(&head->object.oid),
3423 oid_to_hex(&merge->object.oid));
3424 unpack_trees_finish(o);
3425 return -1;
3426 }
3427
3428 if (unmerged_cache()) {
3429 struct string_list *entries;
3430 struct rename_info re_info;
3431 int i;
3432 /*
3433 * Only need the hashmap while processing entries, so
3434 * initialize it here and free it when we are done running
3435 * through the entries. Keeping it in the merge_options as
3436 * opposed to decaring a local hashmap is for convenience
3437 * so that we don't have to pass it to around.
3438 */
3439 hashmap_init(&o->current_file_dir_set, path_hashmap_cmp, NULL, 512);
3440 get_files_dirs(o, head);
3441 get_files_dirs(o, merge);
3442
3443 entries = get_unmerged();
3444 clean = detect_and_process_renames(o, common, head, merge,
3445 entries, &re_info);
3446 record_df_conflict_files(o, entries);
3447 if (clean < 0)
3448 goto cleanup;
3449 for (i = entries->nr-1; 0 <= i; i--) {
3450 const char *path = entries->items[i].string;
3451 struct stage_data *e = entries->items[i].util;
3452 if (!e->processed) {
3453 int ret = process_entry(o, path, e);
3454 if (!ret)
3455 clean = 0;
3456 else if (ret < 0) {
3457 clean = ret;
3458 goto cleanup;
3459 }
3460 }
3461 }
3462 for (i = 0; i < entries->nr; i++) {
3463 struct stage_data *e = entries->items[i].util;
3464 if (!e->processed)
3465 BUG("unprocessed path??? %s",
3466 entries->items[i].string);
3467 }
3468
3469 cleanup:
3470 final_cleanup_renames(&re_info);
3471
3472 string_list_clear(entries, 1);
3473 free(entries);
3474
3475 hashmap_free(&o->current_file_dir_set, 1);
3476
3477 if (clean < 0) {
3478 unpack_trees_finish(o);
3479 return clean;
3480 }
3481 }
3482 else
3483 clean = 1;
3484
3485 unpack_trees_finish(o);
3486
3487 if (o->call_depth && !(*result = write_tree_from_memory(o)))
3488 return -1;
3489
3490 return clean;
3491 }
3492
3493 static struct commit_list *reverse_commit_list(struct commit_list *list)
3494 {
3495 struct commit_list *next = NULL, *current, *backup;
3496 for (current = list; current; current = backup) {
3497 backup = current->next;
3498 current->next = next;
3499 next = current;
3500 }
3501 return next;
3502 }
3503
3504 /*
3505 * Merge the commits h1 and h2, return the resulting virtual
3506 * commit object and a flag indicating the cleanness of the merge.
3507 */
3508 int merge_recursive(struct merge_options *o,
3509 struct commit *h1,
3510 struct commit *h2,
3511 struct commit_list *ca,
3512 struct commit **result)
3513 {
3514 struct commit_list *iter;
3515 struct commit *merged_common_ancestors;
3516 struct tree *mrtree;
3517 int clean;
3518
3519 if (show(o, 4)) {
3520 output(o, 4, _("Merging:"));
3521 output_commit_title(o, h1);
3522 output_commit_title(o, h2);
3523 }
3524
3525 if (!ca) {
3526 ca = get_merge_bases(h1, h2);
3527 ca = reverse_commit_list(ca);
3528 }
3529
3530 if (show(o, 5)) {
3531 unsigned cnt = commit_list_count(ca);
3532
3533 output(o, 5, Q_("found %u common ancestor:",
3534 "found %u common ancestors:", cnt), cnt);
3535 for (iter = ca; iter; iter = iter->next)
3536 output_commit_title(o, iter->item);
3537 }
3538
3539 merged_common_ancestors = pop_commit(&ca);
3540 if (merged_common_ancestors == NULL) {
3541 /* if there is no common ancestor, use an empty tree */
3542 struct tree *tree;
3543
3544 tree = lookup_tree(the_repository, the_repository->hash_algo->empty_tree);
3545 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
3546 }
3547
3548 for (iter = ca; iter; iter = iter->next) {
3549 const char *saved_b1, *saved_b2;
3550 o->call_depth++;
3551 /*
3552 * When the merge fails, the result contains files
3553 * with conflict markers. The cleanness flag is
3554 * ignored (unless indicating an error), it was never
3555 * actually used, as result of merge_trees has always
3556 * overwritten it: the committed "conflicts" were
3557 * already resolved.
3558 */
3559 discard_cache();
3560 saved_b1 = o->branch1;
3561 saved_b2 = o->branch2;
3562 o->branch1 = "Temporary merge branch 1";
3563 o->branch2 = "Temporary merge branch 2";
3564 if (merge_recursive(o, merged_common_ancestors, iter->item,
3565 NULL, &merged_common_ancestors) < 0)
3566 return -1;
3567 o->branch1 = saved_b1;
3568 o->branch2 = saved_b2;
3569 o->call_depth--;
3570
3571 if (!merged_common_ancestors)
3572 return err(o, _("merge returned no commit"));
3573 }
3574
3575 discard_cache();
3576 if (!o->call_depth)
3577 read_cache();
3578
3579 o->ancestor = "merged common ancestors";
3580 clean = merge_trees(o, get_commit_tree(h1), get_commit_tree(h2),
3581 get_commit_tree(merged_common_ancestors),
3582 &mrtree);
3583 if (clean < 0) {
3584 flush_output(o);
3585 return clean;
3586 }
3587
3588 if (o->call_depth) {
3589 *result = make_virtual_commit(mrtree, "merged tree");
3590 commit_list_insert(h1, &(*result)->parents);
3591 commit_list_insert(h2, &(*result)->parents->next);
3592 }
3593 flush_output(o);
3594 if (!o->call_depth && o->buffer_output < 2)
3595 strbuf_release(&o->obuf);
3596 if (show(o, 2))
3597 diff_warn_rename_limit("merge.renamelimit",
3598 o->needed_rename_limit, 0);
3599 return clean;
3600 }
3601
3602 static struct commit *get_ref(const struct object_id *oid, const char *name)
3603 {
3604 struct object *object;
3605
3606 object = deref_tag(the_repository, parse_object(the_repository, oid),
3607 name,
3608 strlen(name));
3609 if (!object)
3610 return NULL;
3611 if (object->type == OBJ_TREE)
3612 return make_virtual_commit((struct tree*)object, name);
3613 if (object->type != OBJ_COMMIT)
3614 return NULL;
3615 if (parse_commi