Merge branch 'master' into next
[git/dscho.git] / unpack-trees.c
blob6847c2d966c5e1d0299b21682d6fef2637329071
1 #define NO_THE_INDEX_COMPATIBILITY_MACROS
2 #include "cache.h"
3 #include "dir.h"
4 #include "tree.h"
5 #include "tree-walk.h"
6 #include "cache-tree.h"
7 #include "unpack-trees.h"
8 #include "progress.h"
9 #include "refs.h"
10 #include "attr.h"
13 * Error messages expected by scripts out of plumbing commands such as
14 * read-tree. Non-scripted Porcelain is not required to use these messages
15 * and in fact are encouraged to reword them to better suit their particular
16 * situation better. See how "git checkout" replaces not_uptodate_file to
17 * explain why it does not allow switching between branches when you have
18 * local changes, for example.
20 static struct unpack_trees_error_msgs unpack_plumbing_errors = {
21 /* would_overwrite */
22 "Entry '%s' would be overwritten by merge. Cannot merge.",
24 /* not_uptodate_file */
25 "Entry '%s' not uptodate. Cannot merge.",
27 /* not_uptodate_dir */
28 "Updating '%s' would lose untracked files in it",
30 /* would_lose_untracked */
31 "Untracked working tree file '%s' would be %s by merge.",
33 /* bind_overlap */
34 "Entry '%s' overlaps with '%s'. Cannot bind.",
37 #define ERRORMSG(o,fld) \
38 ( ((o) && (o)->msgs.fld) \
39 ? ((o)->msgs.fld) \
40 : (unpack_plumbing_errors.fld) )
42 static void add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
43 unsigned int set, unsigned int clear)
45 unsigned int size = ce_size(ce);
46 struct cache_entry *new = xmalloc(size);
48 clear |= CE_HASHED | CE_UNHASHED;
50 memcpy(new, ce, size);
51 new->next = NULL;
52 new->ce_flags = (new->ce_flags & ~clear) | set;
53 add_index_entry(&o->result, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
57 * Unlink the last component and schedule the leading directories for
58 * removal, such that empty directories get removed.
60 static void unlink_entry(struct cache_entry *ce)
62 if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
63 return;
64 if (unlink(ce->name))
65 return;
66 schedule_dir_for_removal(ce->name, ce_namelen(ce));
69 static struct checkout state;
70 static int check_updates(struct unpack_trees_options *o)
72 unsigned cnt = 0, total = 0;
73 struct progress *progress = NULL;
74 struct index_state *index = &o->result;
75 int i;
76 int errs = 0;
78 if (o->update && o->verbose_update) {
79 for (total = cnt = 0; cnt < index->cache_nr; cnt++) {
80 struct cache_entry *ce = index->cache[cnt];
81 if (ce->ce_flags & (CE_UPDATE | CE_REMOVE))
82 total++;
85 progress = start_progress_delay("Checking out files",
86 total, 50, 1);
87 cnt = 0;
90 git_attr_set_direction(GIT_ATTR_CHECKOUT, &o->result);
91 for (i = 0; i < index->cache_nr; i++) {
92 struct cache_entry *ce = index->cache[i];
94 if (ce->ce_flags & CE_REMOVE) {
95 display_progress(progress, ++cnt);
96 if (o->update)
97 unlink_entry(ce);
100 remove_marked_cache_entries(&o->result);
101 remove_scheduled_dirs();
103 for (i = 0; i < index->cache_nr; i++) {
104 struct cache_entry *ce = index->cache[i];
106 if (ce->ce_flags & CE_UPDATE) {
107 display_progress(progress, ++cnt);
108 ce->ce_flags &= ~CE_UPDATE;
109 if (o->update) {
110 errs |= checkout_entry(ce, &state, NULL);
114 stop_progress(&progress);
115 git_attr_set_direction(GIT_ATTR_CHECKIN, NULL);
116 return errs != 0;
119 static inline int call_unpack_fn(struct cache_entry **src, struct unpack_trees_options *o)
121 int ret = o->fn(src, o);
122 if (ret > 0)
123 ret = 0;
124 return ret;
127 static int unpack_index_entry(struct cache_entry *ce, struct unpack_trees_options *o)
129 struct cache_entry *src[5] = { ce, };
131 o->pos++;
132 if (ce_stage(ce)) {
133 if (o->skip_unmerged) {
134 add_entry(o, ce, 0, 0);
135 return 0;
138 return call_unpack_fn(src, o);
141 int traverse_trees_recursive(int n, unsigned long dirmask, unsigned long df_conflicts, struct name_entry *names, struct traverse_info *info)
143 int i;
144 struct tree_desc t[MAX_UNPACK_TREES];
145 struct traverse_info newinfo;
146 struct name_entry *p;
148 p = names;
149 while (!p->mode)
150 p++;
152 newinfo = *info;
153 newinfo.prev = info;
154 newinfo.name = *p;
155 newinfo.pathlen += tree_entry_len(p->path, p->sha1) + 1;
156 newinfo.conflicts |= df_conflicts;
158 for (i = 0; i < n; i++, dirmask >>= 1) {
159 const unsigned char *sha1 = NULL;
160 if (dirmask & 1)
161 sha1 = names[i].sha1;
162 fill_tree_descriptor(t+i, sha1);
164 return traverse_trees(n, t, &newinfo);
168 * Compare the traverse-path to the cache entry without actually
169 * having to generate the textual representation of the traverse
170 * path.
172 * NOTE! This *only* compares up to the size of the traverse path
173 * itself - the caller needs to do the final check for the cache
174 * entry having more data at the end!
176 static int do_compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
178 int len, pathlen, ce_len;
179 const char *ce_name;
181 if (info->prev) {
182 int cmp = do_compare_entry(ce, info->prev, &info->name);
183 if (cmp)
184 return cmp;
186 pathlen = info->pathlen;
187 ce_len = ce_namelen(ce);
189 /* If ce_len < pathlen then we must have previously hit "name == directory" entry */
190 if (ce_len < pathlen)
191 return -1;
193 ce_len -= pathlen;
194 ce_name = ce->name + pathlen;
196 len = tree_entry_len(n->path, n->sha1);
197 return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode);
200 static int compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
202 int cmp = do_compare_entry(ce, info, n);
203 if (cmp)
204 return cmp;
207 * Even if the beginning compared identically, the ce should
208 * compare as bigger than a directory leading up to it!
210 return ce_namelen(ce) > traverse_path_len(info, n);
213 static struct cache_entry *create_ce_entry(const struct traverse_info *info, const struct name_entry *n, int stage)
215 int len = traverse_path_len(info, n);
216 struct cache_entry *ce = xcalloc(1, cache_entry_size(len));
218 ce->ce_mode = create_ce_mode(n->mode);
219 ce->ce_flags = create_ce_flags(len, stage);
220 hashcpy(ce->sha1, n->sha1);
221 make_traverse_path(ce->name, info, n);
223 return ce;
226 static int unpack_nondirectories(int n, unsigned long mask,
227 unsigned long dirmask,
228 struct cache_entry **src,
229 const struct name_entry *names,
230 const struct traverse_info *info)
232 int i;
233 struct unpack_trees_options *o = info->data;
234 unsigned long conflicts;
236 /* Do we have *only* directories? Nothing to do */
237 if (mask == dirmask && !src[0])
238 return 0;
240 conflicts = info->conflicts;
241 if (o->merge)
242 conflicts >>= 1;
243 conflicts |= dirmask;
246 * Ok, we've filled in up to any potential index entry in src[0],
247 * now do the rest.
249 for (i = 0; i < n; i++) {
250 int stage;
251 unsigned int bit = 1ul << i;
252 if (conflicts & bit) {
253 src[i + o->merge] = o->df_conflict_entry;
254 continue;
256 if (!(mask & bit))
257 continue;
258 if (!o->merge)
259 stage = 0;
260 else if (i + 1 < o->head_idx)
261 stage = 1;
262 else if (i + 1 > o->head_idx)
263 stage = 3;
264 else
265 stage = 2;
266 src[i + o->merge] = create_ce_entry(info, names + i, stage);
269 if (o->merge)
270 return call_unpack_fn(src, o);
272 for (i = 0; i < n; i++)
273 if (src[i] && src[i] != o->df_conflict_entry)
274 add_entry(o, src[i], 0, 0);
275 return 0;
278 static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *names, struct traverse_info *info)
280 struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
281 struct unpack_trees_options *o = info->data;
282 const struct name_entry *p = names;
284 /* Find first entry with a real name (we could use "mask" too) */
285 while (!p->mode)
286 p++;
288 /* Are we supposed to look at the index too? */
289 if (o->merge) {
290 while (o->pos < o->src_index->cache_nr) {
291 struct cache_entry *ce = o->src_index->cache[o->pos];
292 int cmp = compare_entry(ce, info, p);
293 if (cmp < 0) {
294 if (unpack_index_entry(ce, o) < 0)
295 return -1;
296 continue;
298 if (!cmp) {
299 o->pos++;
300 if (ce_stage(ce)) {
302 * If we skip unmerged index entries, we'll skip this
303 * entry *and* the tree entries associated with it!
305 if (o->skip_unmerged) {
306 add_entry(o, ce, 0, 0);
307 return mask;
310 src[0] = ce;
312 break;
316 if (unpack_nondirectories(n, mask, dirmask, src, names, info) < 0)
317 return -1;
319 /* Now handle any directories.. */
320 if (dirmask) {
321 unsigned long conflicts = mask & ~dirmask;
322 if (o->merge) {
323 conflicts <<= 1;
324 if (src[0])
325 conflicts |= 1;
327 if (traverse_trees_recursive(n, dirmask, conflicts,
328 names, info) < 0)
329 return -1;
330 return mask;
333 return mask;
336 static int unpack_failed(struct unpack_trees_options *o, const char *message)
338 discard_index(&o->result);
339 if (!o->gently) {
340 if (message)
341 return error("%s", message);
342 return -1;
344 return -1;
348 * N-way merge "len" trees. Returns 0 on success, -1 on failure to manipulate the
349 * resulting index, -2 on failure to reflect the changes to the work tree.
351 int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
353 int ret;
354 static struct cache_entry *dfc;
356 if (len > MAX_UNPACK_TREES)
357 die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
358 memset(&state, 0, sizeof(state));
359 state.base_dir = "";
360 state.force = 1;
361 state.quiet = 1;
362 state.refresh_cache = 1;
364 memset(&o->result, 0, sizeof(o->result));
365 o->result.initialized = 1;
366 if (o->src_index) {
367 o->result.timestamp.sec = o->src_index->timestamp.sec;
368 o->result.timestamp.nsec = o->src_index->timestamp.nsec;
370 o->merge_size = len;
372 if (!dfc)
373 dfc = xcalloc(1, cache_entry_size(0));
374 o->df_conflict_entry = dfc;
376 if (len) {
377 const char *prefix = o->prefix ? o->prefix : "";
378 struct traverse_info info;
380 setup_traverse_info(&info, prefix);
381 info.fn = unpack_callback;
382 info.data = o;
384 if (traverse_trees(len, t, &info) < 0)
385 return unpack_failed(o, NULL);
388 /* Any left-over entries in the index? */
389 if (o->merge) {
390 while (o->pos < o->src_index->cache_nr) {
391 struct cache_entry *ce = o->src_index->cache[o->pos];
392 if (unpack_index_entry(ce, o) < 0)
393 return unpack_failed(o, NULL);
397 if (o->trivial_merges_only && o->nontrivial_merge)
398 return unpack_failed(o, "Merge requires file-level merging");
400 o->src_index = NULL;
401 ret = check_updates(o) ? (-2) : 0;
402 if (o->dst_index)
403 *o->dst_index = o->result;
404 return ret;
407 /* Here come the merge functions */
409 static int reject_merge(struct cache_entry *ce, struct unpack_trees_options *o)
411 return error(ERRORMSG(o, would_overwrite), ce->name);
414 static int same(struct cache_entry *a, struct cache_entry *b)
416 if (!!a != !!b)
417 return 0;
418 if (!a && !b)
419 return 1;
420 return a->ce_mode == b->ce_mode &&
421 !hashcmp(a->sha1, b->sha1);
426 * When a CE gets turned into an unmerged entry, we
427 * want it to be up-to-date
429 static int verify_uptodate(struct cache_entry *ce,
430 struct unpack_trees_options *o)
432 struct stat st;
434 if (o->index_only || o->reset || ce_uptodate(ce))
435 return 0;
437 if (!lstat(ce->name, &st)) {
438 unsigned changed = ie_match_stat(o->src_index, ce, &st, CE_MATCH_IGNORE_VALID);
439 if (!changed)
440 return 0;
442 * NEEDSWORK: the current default policy is to allow
443 * submodule to be out of sync wrt the supermodule
444 * index. This needs to be tightened later for
445 * submodules that are marked to be automatically
446 * checked out.
448 if (S_ISGITLINK(ce->ce_mode))
449 return 0;
450 errno = 0;
452 if (errno == ENOENT)
453 return 0;
454 return o->gently ? -1 :
455 error(ERRORMSG(o, not_uptodate_file), ce->name);
458 static void invalidate_ce_path(struct cache_entry *ce, struct unpack_trees_options *o)
460 if (ce)
461 cache_tree_invalidate_path(o->src_index->cache_tree, ce->name);
465 * Check that checking out ce->sha1 in subdir ce->name is not
466 * going to overwrite any working files.
468 * Currently, git does not checkout subprojects during a superproject
469 * checkout, so it is not going to overwrite anything.
471 static int verify_clean_submodule(struct cache_entry *ce, const char *action,
472 struct unpack_trees_options *o)
474 return 0;
477 static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
478 struct unpack_trees_options *o)
481 * we are about to extract "ce->name"; we would not want to lose
482 * anything in the existing directory there.
484 int namelen;
485 int i;
486 struct dir_struct d;
487 char *pathbuf;
488 int cnt = 0;
489 unsigned char sha1[20];
491 if (S_ISGITLINK(ce->ce_mode) &&
492 resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
493 /* If we are not going to update the submodule, then
494 * we don't care.
496 if (!hashcmp(sha1, ce->sha1))
497 return 0;
498 return verify_clean_submodule(ce, action, o);
502 * First let's make sure we do not have a local modification
503 * in that directory.
505 namelen = strlen(ce->name);
506 for (i = o->pos; i < o->src_index->cache_nr; i++) {
507 struct cache_entry *ce2 = o->src_index->cache[i];
508 int len = ce_namelen(ce2);
509 if (len < namelen ||
510 strncmp(ce->name, ce2->name, namelen) ||
511 ce2->name[namelen] != '/')
512 break;
514 * ce2->name is an entry in the subdirectory.
516 if (!ce_stage(ce2)) {
517 if (verify_uptodate(ce2, o))
518 return -1;
519 add_entry(o, ce2, CE_REMOVE, 0);
521 cnt++;
525 * Then we need to make sure that we do not lose a locally
526 * present file that is not ignored.
528 pathbuf = xmalloc(namelen + 2);
529 memcpy(pathbuf, ce->name, namelen);
530 strcpy(pathbuf+namelen, "/");
532 memset(&d, 0, sizeof(d));
533 if (o->dir)
534 d.exclude_per_dir = o->dir->exclude_per_dir;
535 i = read_directory(&d, ce->name, pathbuf, namelen+1, NULL);
536 if (i)
537 return o->gently ? -1 :
538 error(ERRORMSG(o, not_uptodate_dir), ce->name);
539 free(pathbuf);
540 return cnt;
544 * This gets called when there was no index entry for the tree entry 'dst',
545 * but we found a file in the working tree that 'lstat()' said was fine,
546 * and we're on a case-insensitive filesystem.
548 * See if we can find a case-insensitive match in the index that also
549 * matches the stat information, and assume it's that other file!
551 static int icase_exists(struct unpack_trees_options *o, struct cache_entry *dst, struct stat *st)
553 struct cache_entry *src;
555 src = index_name_exists(o->src_index, dst->name, ce_namelen(dst), 1);
556 return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID);
560 * We do not want to remove or overwrite a working tree file that
561 * is not tracked, unless it is ignored.
563 static int verify_absent(struct cache_entry *ce, const char *action,
564 struct unpack_trees_options *o)
566 struct stat st;
568 if (o->index_only || o->reset || !o->update)
569 return 0;
571 if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
572 return 0;
574 if (!lstat(ce->name, &st)) {
575 int ret;
576 int dtype = ce_to_dtype(ce);
577 struct cache_entry *result;
580 * It may be that the 'lstat()' succeeded even though
581 * target 'ce' was absent, because there is an old
582 * entry that is different only in case..
584 * Ignore that lstat() if it matches.
586 if (ignore_case && icase_exists(o, ce, &st))
587 return 0;
589 if (o->dir && excluded(o->dir, ce->name, &dtype))
591 * ce->name is explicitly excluded, so it is Ok to
592 * overwrite it.
594 return 0;
595 if (S_ISDIR(st.st_mode)) {
597 * We are checking out path "foo" and
598 * found "foo/." in the working tree.
599 * This is tricky -- if we have modified
600 * files that are in "foo/" we would lose
601 * it.
603 ret = verify_clean_subdirectory(ce, action, o);
604 if (ret < 0)
605 return ret;
608 * If this removed entries from the index,
609 * what that means is:
611 * (1) the caller unpack_callback() saw path/foo
612 * in the index, and it has not removed it because
613 * it thinks it is handling 'path' as blob with
614 * D/F conflict;
615 * (2) we will return "ok, we placed a merged entry
616 * in the index" which would cause o->pos to be
617 * incremented by one;
618 * (3) however, original o->pos now has 'path/foo'
619 * marked with "to be removed".
621 * We need to increment it by the number of
622 * deleted entries here.
624 o->pos += ret;
625 return 0;
629 * The previous round may already have decided to
630 * delete this path, which is in a subdirectory that
631 * is being replaced with a blob.
633 result = index_name_exists(&o->result, ce->name, ce_namelen(ce), 0);
634 if (result) {
635 if (result->ce_flags & CE_REMOVE)
636 return 0;
639 return o->gently ? -1 :
640 error(ERRORMSG(o, would_lose_untracked), ce->name, action);
642 return 0;
645 static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
646 struct unpack_trees_options *o)
648 int update = CE_UPDATE;
650 if (old) {
652 * See if we can re-use the old CE directly?
653 * That way we get the uptodate stat info.
655 * This also removes the UPDATE flag on a match; otherwise
656 * we will end up overwriting local changes in the work tree.
658 if (same(old, merge)) {
659 copy_cache_entry(merge, old);
660 update = 0;
661 } else {
662 if (verify_uptodate(old, o))
663 return -1;
664 invalidate_ce_path(old, o);
667 else {
668 if (verify_absent(merge, "overwritten", o))
669 return -1;
670 invalidate_ce_path(merge, o);
673 add_entry(o, merge, update, CE_STAGEMASK);
674 return 1;
677 static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
678 struct unpack_trees_options *o)
680 /* Did it exist in the index? */
681 if (!old) {
682 if (verify_absent(ce, "removed", o))
683 return -1;
684 return 0;
686 if (verify_uptodate(old, o))
687 return -1;
688 add_entry(o, ce, CE_REMOVE, 0);
689 invalidate_ce_path(ce, o);
690 return 1;
693 static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o)
695 add_entry(o, ce, 0, 0);
696 return 1;
699 #if DBRT_DEBUG
700 static void show_stage_entry(FILE *o,
701 const char *label, const struct cache_entry *ce)
703 if (!ce)
704 fprintf(o, "%s (missing)\n", label);
705 else
706 fprintf(o, "%s%06o %s %d\t%s\n",
707 label,
708 ce->ce_mode,
709 sha1_to_hex(ce->sha1),
710 ce_stage(ce),
711 ce->name);
713 #endif
715 int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o)
717 struct cache_entry *index;
718 struct cache_entry *head;
719 struct cache_entry *remote = stages[o->head_idx + 1];
720 int count;
721 int head_match = 0;
722 int remote_match = 0;
724 int df_conflict_head = 0;
725 int df_conflict_remote = 0;
727 int any_anc_missing = 0;
728 int no_anc_exists = 1;
729 int i;
731 for (i = 1; i < o->head_idx; i++) {
732 if (!stages[i] || stages[i] == o->df_conflict_entry)
733 any_anc_missing = 1;
734 else
735 no_anc_exists = 0;
738 index = stages[0];
739 head = stages[o->head_idx];
741 if (head == o->df_conflict_entry) {
742 df_conflict_head = 1;
743 head = NULL;
746 if (remote == o->df_conflict_entry) {
747 df_conflict_remote = 1;
748 remote = NULL;
751 /* First, if there's a #16 situation, note that to prevent #13
752 * and #14.
754 if (!same(remote, head)) {
755 for (i = 1; i < o->head_idx; i++) {
756 if (same(stages[i], head)) {
757 head_match = i;
759 if (same(stages[i], remote)) {
760 remote_match = i;
765 /* We start with cases where the index is allowed to match
766 * something other than the head: #14(ALT) and #2ALT, where it
767 * is permitted to match the result instead.
769 /* #14, #14ALT, #2ALT */
770 if (remote && !df_conflict_head && head_match && !remote_match) {
771 if (index && !same(index, remote) && !same(index, head))
772 return o->gently ? -1 : reject_merge(index, o);
773 return merged_entry(remote, index, o);
776 * If we have an entry in the index cache, then we want to
777 * make sure that it matches head.
779 if (index && !same(index, head))
780 return o->gently ? -1 : reject_merge(index, o);
782 if (head) {
783 /* #5ALT, #15 */
784 if (same(head, remote))
785 return merged_entry(head, index, o);
786 /* #13, #3ALT */
787 if (!df_conflict_remote && remote_match && !head_match)
788 return merged_entry(head, index, o);
791 /* #1 */
792 if (!head && !remote && any_anc_missing)
793 return 0;
795 /* Under the new "aggressive" rule, we resolve mostly trivial
796 * cases that we historically had git-merge-one-file resolve.
798 if (o->aggressive) {
799 int head_deleted = !head && !df_conflict_head;
800 int remote_deleted = !remote && !df_conflict_remote;
801 struct cache_entry *ce = NULL;
803 if (index)
804 ce = index;
805 else if (head)
806 ce = head;
807 else if (remote)
808 ce = remote;
809 else {
810 for (i = 1; i < o->head_idx; i++) {
811 if (stages[i] && stages[i] != o->df_conflict_entry) {
812 ce = stages[i];
813 break;
819 * Deleted in both.
820 * Deleted in one and unchanged in the other.
822 if ((head_deleted && remote_deleted) ||
823 (head_deleted && remote && remote_match) ||
824 (remote_deleted && head && head_match)) {
825 if (index)
826 return deleted_entry(index, index, o);
827 if (ce && !head_deleted) {
828 if (verify_absent(ce, "removed", o))
829 return -1;
831 return 0;
834 * Added in both, identically.
836 if (no_anc_exists && head && remote && same(head, remote))
837 return merged_entry(head, index, o);
841 /* Below are "no merge" cases, which require that the index be
842 * up-to-date to avoid the files getting overwritten with
843 * conflict resolution files.
845 if (index) {
846 if (verify_uptodate(index, o))
847 return -1;
850 o->nontrivial_merge = 1;
852 /* #2, #3, #4, #6, #7, #9, #10, #11. */
853 count = 0;
854 if (!head_match || !remote_match) {
855 for (i = 1; i < o->head_idx; i++) {
856 if (stages[i] && stages[i] != o->df_conflict_entry) {
857 keep_entry(stages[i], o);
858 count++;
859 break;
863 #if DBRT_DEBUG
864 else {
865 fprintf(stderr, "read-tree: warning #16 detected\n");
866 show_stage_entry(stderr, "head ", stages[head_match]);
867 show_stage_entry(stderr, "remote ", stages[remote_match]);
869 #endif
870 if (head) { count += keep_entry(head, o); }
871 if (remote) { count += keep_entry(remote, o); }
872 return count;
876 * Two-way merge.
878 * The rule is to "carry forward" what is in the index without losing
879 * information across a "fast forward", favoring a successful merge
880 * over a merge failure when it makes sense. For details of the
881 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
884 int twoway_merge(struct cache_entry **src, struct unpack_trees_options *o)
886 struct cache_entry *current = src[0];
887 struct cache_entry *oldtree = src[1];
888 struct cache_entry *newtree = src[2];
890 if (o->merge_size != 2)
891 return error("Cannot do a twoway merge of %d trees",
892 o->merge_size);
894 if (oldtree == o->df_conflict_entry)
895 oldtree = NULL;
896 if (newtree == o->df_conflict_entry)
897 newtree = NULL;
899 if (current) {
900 if ((!oldtree && !newtree) || /* 4 and 5 */
901 (!oldtree && newtree &&
902 same(current, newtree)) || /* 6 and 7 */
903 (oldtree && newtree &&
904 same(oldtree, newtree)) || /* 14 and 15 */
905 (oldtree && newtree &&
906 !same(oldtree, newtree) && /* 18 and 19 */
907 same(current, newtree))) {
908 return keep_entry(current, o);
910 else if (oldtree && !newtree && same(current, oldtree)) {
911 /* 10 or 11 */
912 return deleted_entry(oldtree, current, o);
914 else if (oldtree && newtree &&
915 same(current, oldtree) && !same(current, newtree)) {
916 /* 20 or 21 */
917 return merged_entry(newtree, current, o);
919 else {
920 /* all other failures */
921 if (oldtree)
922 return o->gently ? -1 : reject_merge(oldtree, o);
923 if (current)
924 return o->gently ? -1 : reject_merge(current, o);
925 if (newtree)
926 return o->gently ? -1 : reject_merge(newtree, o);
927 return -1;
930 else if (newtree) {
931 if (oldtree && !o->initial_checkout) {
933 * deletion of the path was staged;
935 if (same(oldtree, newtree))
936 return 1;
937 return reject_merge(oldtree, o);
939 return merged_entry(newtree, current, o);
941 return deleted_entry(oldtree, current, o);
945 * Bind merge.
947 * Keep the index entries at stage0, collapse stage1 but make sure
948 * stage0 does not have anything there.
950 int bind_merge(struct cache_entry **src,
951 struct unpack_trees_options *o)
953 struct cache_entry *old = src[0];
954 struct cache_entry *a = src[1];
956 if (o->merge_size != 1)
957 return error("Cannot do a bind merge of %d trees\n",
958 o->merge_size);
959 if (a && old)
960 return o->gently ? -1 :
961 error(ERRORMSG(o, bind_overlap), a->name, old->name);
962 if (!a)
963 return keep_entry(old, o);
964 else
965 return merged_entry(a, NULL, o);
969 * One-way merge.
971 * The rule is:
972 * - take the stat information from stage0, take the data from stage1
974 int oneway_merge(struct cache_entry **src, struct unpack_trees_options *o)
976 struct cache_entry *old = src[0];
977 struct cache_entry *a = src[1];
979 if (o->merge_size != 1)
980 return error("Cannot do a oneway merge of %d trees",
981 o->merge_size);
983 if (!a)
984 return deleted_entry(old, old, o);
986 if (old && same(old, a)) {
987 int update = 0;
988 if (o->reset) {
989 struct stat st;
990 if (lstat(old->name, &st) ||
991 ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID))
992 update |= CE_UPDATE;
994 add_entry(o, old, update, 0);
995 return 0;
997 return merged_entry(a, old, o);