Merge commit 'git/master'
[git/git-bigfiles.git] / unpack-trees.c
blob86e28650b887b4fcc1b05cc4d3102367df18a9ac
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"
12 * Error messages expected by scripts out of plumbing commands such as
13 * read-tree. Non-scripted Porcelain is not required to use these messages
14 * and in fact are encouraged to reword them to better suit their particular
15 * situation better. See how "git checkout" replaces not_uptodate_file to
16 * explain why it does not allow switching between branches when you have
17 * local changes, for example.
19 static struct unpack_trees_error_msgs unpack_plumbing_errors = {
20 /* would_overwrite */
21 "Entry '%s' would be overwritten by merge. Cannot merge.",
23 /* not_uptodate_file */
24 "Entry '%s' not uptodate. Cannot merge.",
26 /* not_uptodate_dir */
27 "Updating '%s' would lose untracked files in it",
29 /* would_lose_untracked */
30 "Untracked working tree file '%s' would be %s by merge.",
32 /* bind_overlap */
33 "Entry '%s' overlaps with '%s'. Cannot bind.",
36 #define ERRORMSG(o,fld) \
37 ( ((o) && (o)->msgs.fld) \
38 ? ((o)->msgs.fld) \
39 : (unpack_plumbing_errors.fld) )
41 static void add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
42 unsigned int set, unsigned int clear)
44 unsigned int size = ce_size(ce);
45 struct cache_entry *new = xmalloc(size);
47 clear |= CE_HASHED | CE_UNHASHED;
49 memcpy(new, ce, size);
50 new->next = NULL;
51 new->ce_flags = (new->ce_flags & ~clear) | set;
52 add_index_entry(&o->result, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
56 * Unlink the last component and schedule the leading directories for
57 * removal, such that empty directories get removed.
59 static void unlink_entry(struct cache_entry *ce)
61 if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
62 return;
63 if (unlink(ce->name))
64 return;
65 schedule_dir_for_removal(ce->name, ce_namelen(ce));
68 static struct checkout state;
69 static int check_updates(struct unpack_trees_options *o)
71 unsigned cnt = 0, total = 0;
72 struct progress *progress = NULL;
73 struct index_state *index = &o->result;
74 int i;
75 int errs = 0;
77 if (o->update && o->verbose_update) {
78 for (total = cnt = 0; cnt < index->cache_nr; cnt++) {
79 struct cache_entry *ce = index->cache[cnt];
80 if (ce->ce_flags & (CE_UPDATE | CE_REMOVE))
81 total++;
84 progress = start_progress_delay("Checking out files",
85 total, 50, 1);
86 cnt = 0;
89 for (i = 0; i < index->cache_nr; i++) {
90 struct cache_entry *ce = index->cache[i];
92 if (ce->ce_flags & CE_REMOVE) {
93 display_progress(progress, ++cnt);
94 if (o->update)
95 unlink_entry(ce);
98 remove_marked_cache_entries(&o->result);
99 remove_scheduled_dirs();
101 for (i = 0; i < index->cache_nr; i++) {
102 struct cache_entry *ce = index->cache[i];
104 if (ce->ce_flags & CE_UPDATE) {
105 display_progress(progress, ++cnt);
106 ce->ce_flags &= ~CE_UPDATE;
107 if (o->update) {
108 errs |= checkout_entry(ce, &state, NULL);
112 stop_progress(&progress);
113 return errs != 0;
116 static inline int call_unpack_fn(struct cache_entry **src, struct unpack_trees_options *o)
118 int ret = o->fn(src, o);
119 if (ret > 0)
120 ret = 0;
121 return ret;
124 static int unpack_index_entry(struct cache_entry *ce, struct unpack_trees_options *o)
126 struct cache_entry *src[5] = { ce, };
128 o->pos++;
129 if (ce_stage(ce)) {
130 if (o->skip_unmerged) {
131 add_entry(o, ce, 0, 0);
132 return 0;
135 return call_unpack_fn(src, o);
138 int traverse_trees_recursive(int n, unsigned long dirmask, unsigned long df_conflicts, struct name_entry *names, struct traverse_info *info)
140 int i;
141 struct tree_desc t[MAX_UNPACK_TREES];
142 struct traverse_info newinfo;
143 struct name_entry *p;
145 p = names;
146 while (!p->mode)
147 p++;
149 newinfo = *info;
150 newinfo.prev = info;
151 newinfo.name = *p;
152 newinfo.pathlen += tree_entry_len(p->path, p->sha1) + 1;
153 newinfo.conflicts |= df_conflicts;
155 for (i = 0; i < n; i++, dirmask >>= 1) {
156 const unsigned char *sha1 = NULL;
157 if (dirmask & 1)
158 sha1 = names[i].sha1;
159 fill_tree_descriptor(t+i, sha1);
161 return traverse_trees(n, t, &newinfo);
165 * Compare the traverse-path to the cache entry without actually
166 * having to generate the textual representation of the traverse
167 * path.
169 * NOTE! This *only* compares up to the size of the traverse path
170 * itself - the caller needs to do the final check for the cache
171 * entry having more data at the end!
173 static int do_compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
175 int len, pathlen, ce_len;
176 const char *ce_name;
178 if (info->prev) {
179 int cmp = do_compare_entry(ce, info->prev, &info->name);
180 if (cmp)
181 return cmp;
183 pathlen = info->pathlen;
184 ce_len = ce_namelen(ce);
186 /* If ce_len < pathlen then we must have previously hit "name == directory" entry */
187 if (ce_len < pathlen)
188 return -1;
190 ce_len -= pathlen;
191 ce_name = ce->name + pathlen;
193 len = tree_entry_len(n->path, n->sha1);
194 return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode);
197 static int compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
199 int cmp = do_compare_entry(ce, info, n);
200 if (cmp)
201 return cmp;
204 * Even if the beginning compared identically, the ce should
205 * compare as bigger than a directory leading up to it!
207 return ce_namelen(ce) > traverse_path_len(info, n);
210 static struct cache_entry *create_ce_entry(const struct traverse_info *info, const struct name_entry *n, int stage)
212 int len = traverse_path_len(info, n);
213 struct cache_entry *ce = xcalloc(1, cache_entry_size(len));
215 ce->ce_mode = create_ce_mode(n->mode);
216 ce->ce_flags = create_ce_flags(len, stage);
217 hashcpy(ce->sha1, n->sha1);
218 make_traverse_path(ce->name, info, n);
220 return ce;
223 static int unpack_nondirectories(int n, unsigned long mask,
224 unsigned long dirmask,
225 struct cache_entry **src,
226 const struct name_entry *names,
227 const struct traverse_info *info)
229 int i;
230 struct unpack_trees_options *o = info->data;
231 unsigned long conflicts;
233 /* Do we have *only* directories? Nothing to do */
234 if (mask == dirmask && !src[0])
235 return 0;
237 conflicts = info->conflicts;
238 if (o->merge)
239 conflicts >>= 1;
240 conflicts |= dirmask;
243 * Ok, we've filled in up to any potential index entry in src[0],
244 * now do the rest.
246 for (i = 0; i < n; i++) {
247 int stage;
248 unsigned int bit = 1ul << i;
249 if (conflicts & bit) {
250 src[i + o->merge] = o->df_conflict_entry;
251 continue;
253 if (!(mask & bit))
254 continue;
255 if (!o->merge)
256 stage = 0;
257 else if (i + 1 < o->head_idx)
258 stage = 1;
259 else if (i + 1 > o->head_idx)
260 stage = 3;
261 else
262 stage = 2;
263 src[i + o->merge] = create_ce_entry(info, names + i, stage);
266 if (o->merge)
267 return call_unpack_fn(src, o);
269 for (i = 0; i < n; i++)
270 if (src[i] && src[i] != o->df_conflict_entry)
271 add_entry(o, src[i], 0, 0);
272 return 0;
275 static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *names, struct traverse_info *info)
277 struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
278 struct unpack_trees_options *o = info->data;
279 const struct name_entry *p = names;
281 /* Find first entry with a real name (we could use "mask" too) */
282 while (!p->mode)
283 p++;
285 /* Are we supposed to look at the index too? */
286 if (o->merge) {
287 while (o->pos < o->src_index->cache_nr) {
288 struct cache_entry *ce = o->src_index->cache[o->pos];
289 int cmp = compare_entry(ce, info, p);
290 if (cmp < 0) {
291 if (unpack_index_entry(ce, o) < 0)
292 return -1;
293 continue;
295 if (!cmp) {
296 o->pos++;
297 if (ce_stage(ce)) {
299 * If we skip unmerged index entries, we'll skip this
300 * entry *and* the tree entries associated with it!
302 if (o->skip_unmerged) {
303 add_entry(o, ce, 0, 0);
304 return mask;
307 src[0] = ce;
309 break;
313 if (unpack_nondirectories(n, mask, dirmask, src, names, info) < 0)
314 return -1;
316 /* Now handle any directories.. */
317 if (dirmask) {
318 unsigned long conflicts = mask & ~dirmask;
319 if (o->merge) {
320 conflicts <<= 1;
321 if (src[0])
322 conflicts |= 1;
324 if (traverse_trees_recursive(n, dirmask, conflicts,
325 names, info) < 0)
326 return -1;
327 return mask;
330 return mask;
333 static int unpack_failed(struct unpack_trees_options *o, const char *message)
335 discard_index(&o->result);
336 if (!o->gently) {
337 if (message)
338 return error("%s", message);
339 return -1;
341 return -1;
345 * N-way merge "len" trees. Returns 0 on success, -1 on failure to manipulate the
346 * resulting index, -2 on failure to reflect the changes to the work tree.
348 int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
350 int ret;
351 static struct cache_entry *dfc;
353 if (len > MAX_UNPACK_TREES)
354 die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
355 memset(&state, 0, sizeof(state));
356 state.base_dir = "";
357 state.force = 1;
358 state.quiet = 1;
359 state.refresh_cache = 1;
361 memset(&o->result, 0, sizeof(o->result));
362 o->result.initialized = 1;
363 if (o->src_index) {
364 o->result.timestamp.sec = o->src_index->timestamp.sec;
365 o->result.timestamp.nsec = o->src_index->timestamp.nsec;
367 o->merge_size = len;
369 if (!dfc)
370 dfc = xcalloc(1, cache_entry_size(0));
371 o->df_conflict_entry = dfc;
373 if (len) {
374 const char *prefix = o->prefix ? o->prefix : "";
375 struct traverse_info info;
377 setup_traverse_info(&info, prefix);
378 info.fn = unpack_callback;
379 info.data = o;
381 if (traverse_trees(len, t, &info) < 0)
382 return unpack_failed(o, NULL);
385 /* Any left-over entries in the index? */
386 if (o->merge) {
387 while (o->pos < o->src_index->cache_nr) {
388 struct cache_entry *ce = o->src_index->cache[o->pos];
389 if (unpack_index_entry(ce, o) < 0)
390 return unpack_failed(o, NULL);
394 if (o->trivial_merges_only && o->nontrivial_merge)
395 return unpack_failed(o, "Merge requires file-level merging");
397 o->src_index = NULL;
398 ret = check_updates(o) ? (-2) : 0;
399 if (o->dst_index)
400 *o->dst_index = o->result;
401 return ret;
404 /* Here come the merge functions */
406 static int reject_merge(struct cache_entry *ce, struct unpack_trees_options *o)
408 return error(ERRORMSG(o, would_overwrite), ce->name);
411 static int same(struct cache_entry *a, struct cache_entry *b)
413 if (!!a != !!b)
414 return 0;
415 if (!a && !b)
416 return 1;
417 return a->ce_mode == b->ce_mode &&
418 !hashcmp(a->sha1, b->sha1);
423 * When a CE gets turned into an unmerged entry, we
424 * want it to be up-to-date
426 static int verify_uptodate(struct cache_entry *ce,
427 struct unpack_trees_options *o)
429 struct stat st;
431 if (o->index_only || o->reset || ce_uptodate(ce))
432 return 0;
434 if (!lstat(ce->name, &st)) {
435 unsigned changed = ie_match_stat(o->src_index, ce, &st, CE_MATCH_IGNORE_VALID);
436 if (!changed)
437 return 0;
439 * NEEDSWORK: the current default policy is to allow
440 * submodule to be out of sync wrt the supermodule
441 * index. This needs to be tightened later for
442 * submodules that are marked to be automatically
443 * checked out.
445 if (S_ISGITLINK(ce->ce_mode))
446 return 0;
447 errno = 0;
449 if (errno == ENOENT)
450 return 0;
451 return o->gently ? -1 :
452 error(ERRORMSG(o, not_uptodate_file), ce->name);
455 static void invalidate_ce_path(struct cache_entry *ce, struct unpack_trees_options *o)
457 if (ce)
458 cache_tree_invalidate_path(o->src_index->cache_tree, ce->name);
462 * Check that checking out ce->sha1 in subdir ce->name is not
463 * going to overwrite any working files.
465 * Currently, git does not checkout subprojects during a superproject
466 * checkout, so it is not going to overwrite anything.
468 static int verify_clean_submodule(struct cache_entry *ce, const char *action,
469 struct unpack_trees_options *o)
471 return 0;
474 static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
475 struct unpack_trees_options *o)
478 * we are about to extract "ce->name"; we would not want to lose
479 * anything in the existing directory there.
481 int namelen;
482 int i;
483 struct dir_struct d;
484 char *pathbuf;
485 int cnt = 0;
486 unsigned char sha1[20];
488 if (S_ISGITLINK(ce->ce_mode) &&
489 resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
490 /* If we are not going to update the submodule, then
491 * we don't care.
493 if (!hashcmp(sha1, ce->sha1))
494 return 0;
495 return verify_clean_submodule(ce, action, o);
499 * First let's make sure we do not have a local modification
500 * in that directory.
502 namelen = strlen(ce->name);
503 for (i = o->pos; i < o->src_index->cache_nr; i++) {
504 struct cache_entry *ce2 = o->src_index->cache[i];
505 int len = ce_namelen(ce2);
506 if (len < namelen ||
507 strncmp(ce->name, ce2->name, namelen) ||
508 ce2->name[namelen] != '/')
509 break;
511 * ce2->name is an entry in the subdirectory.
513 if (!ce_stage(ce2)) {
514 if (verify_uptodate(ce2, o))
515 return -1;
516 add_entry(o, ce2, CE_REMOVE, 0);
518 cnt++;
522 * Then we need to make sure that we do not lose a locally
523 * present file that is not ignored.
525 pathbuf = xmalloc(namelen + 2);
526 memcpy(pathbuf, ce->name, namelen);
527 strcpy(pathbuf+namelen, "/");
529 memset(&d, 0, sizeof(d));
530 if (o->dir)
531 d.exclude_per_dir = o->dir->exclude_per_dir;
532 i = read_directory(&d, ce->name, pathbuf, namelen+1, NULL);
533 if (i)
534 return o->gently ? -1 :
535 error(ERRORMSG(o, not_uptodate_dir), ce->name);
536 free(pathbuf);
537 return cnt;
541 * This gets called when there was no index entry for the tree entry 'dst',
542 * but we found a file in the working tree that 'lstat()' said was fine,
543 * and we're on a case-insensitive filesystem.
545 * See if we can find a case-insensitive match in the index that also
546 * matches the stat information, and assume it's that other file!
548 static int icase_exists(struct unpack_trees_options *o, struct cache_entry *dst, struct stat *st)
550 struct cache_entry *src;
552 src = index_name_exists(o->src_index, dst->name, ce_namelen(dst), 1);
553 return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID);
557 * We do not want to remove or overwrite a working tree file that
558 * is not tracked, unless it is ignored.
560 static int verify_absent(struct cache_entry *ce, const char *action,
561 struct unpack_trees_options *o)
563 struct stat st;
565 if (o->index_only || o->reset || !o->update)
566 return 0;
568 if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
569 return 0;
571 if (!lstat(ce->name, &st)) {
572 int ret;
573 int dtype = ce_to_dtype(ce);
574 struct cache_entry *result;
577 * It may be that the 'lstat()' succeeded even though
578 * target 'ce' was absent, because there is an old
579 * entry that is different only in case..
581 * Ignore that lstat() if it matches.
583 if (ignore_case && icase_exists(o, ce, &st))
584 return 0;
586 if (o->dir && excluded(o->dir, ce->name, &dtype))
588 * ce->name is explicitly excluded, so it is Ok to
589 * overwrite it.
591 return 0;
592 if (S_ISDIR(st.st_mode)) {
594 * We are checking out path "foo" and
595 * found "foo/." in the working tree.
596 * This is tricky -- if we have modified
597 * files that are in "foo/" we would lose
598 * it.
600 ret = verify_clean_subdirectory(ce, action, o);
601 if (ret < 0)
602 return ret;
605 * If this removed entries from the index,
606 * what that means is:
608 * (1) the caller unpack_callback() saw path/foo
609 * in the index, and it has not removed it because
610 * it thinks it is handling 'path' as blob with
611 * D/F conflict;
612 * (2) we will return "ok, we placed a merged entry
613 * in the index" which would cause o->pos to be
614 * incremented by one;
615 * (3) however, original o->pos now has 'path/foo'
616 * marked with "to be removed".
618 * We need to increment it by the number of
619 * deleted entries here.
621 o->pos += ret;
622 return 0;
626 * The previous round may already have decided to
627 * delete this path, which is in a subdirectory that
628 * is being replaced with a blob.
630 result = index_name_exists(&o->result, ce->name, ce_namelen(ce), 0);
631 if (result) {
632 if (result->ce_flags & CE_REMOVE)
633 return 0;
636 return o->gently ? -1 :
637 error(ERRORMSG(o, would_lose_untracked), ce->name, action);
639 return 0;
642 static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
643 struct unpack_trees_options *o)
645 int update = CE_UPDATE;
647 if (old) {
649 * See if we can re-use the old CE directly?
650 * That way we get the uptodate stat info.
652 * This also removes the UPDATE flag on a match; otherwise
653 * we will end up overwriting local changes in the work tree.
655 if (same(old, merge)) {
656 copy_cache_entry(merge, old);
657 update = 0;
658 } else {
659 if (verify_uptodate(old, o))
660 return -1;
661 invalidate_ce_path(old, o);
664 else {
665 if (verify_absent(merge, "overwritten", o))
666 return -1;
667 invalidate_ce_path(merge, o);
670 add_entry(o, merge, update, CE_STAGEMASK);
671 return 1;
674 static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
675 struct unpack_trees_options *o)
677 /* Did it exist in the index? */
678 if (!old) {
679 if (verify_absent(ce, "removed", o))
680 return -1;
681 return 0;
683 if (verify_uptodate(old, o))
684 return -1;
685 add_entry(o, ce, CE_REMOVE, 0);
686 invalidate_ce_path(ce, o);
687 return 1;
690 static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o)
692 add_entry(o, ce, 0, 0);
693 return 1;
696 #if DBRT_DEBUG
697 static void show_stage_entry(FILE *o,
698 const char *label, const struct cache_entry *ce)
700 if (!ce)
701 fprintf(o, "%s (missing)\n", label);
702 else
703 fprintf(o, "%s%06o %s %d\t%s\n",
704 label,
705 ce->ce_mode,
706 sha1_to_hex(ce->sha1),
707 ce_stage(ce),
708 ce->name);
710 #endif
712 int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o)
714 struct cache_entry *index;
715 struct cache_entry *head;
716 struct cache_entry *remote = stages[o->head_idx + 1];
717 int count;
718 int head_match = 0;
719 int remote_match = 0;
721 int df_conflict_head = 0;
722 int df_conflict_remote = 0;
724 int any_anc_missing = 0;
725 int no_anc_exists = 1;
726 int i;
728 for (i = 1; i < o->head_idx; i++) {
729 if (!stages[i] || stages[i] == o->df_conflict_entry)
730 any_anc_missing = 1;
731 else
732 no_anc_exists = 0;
735 index = stages[0];
736 head = stages[o->head_idx];
738 if (head == o->df_conflict_entry) {
739 df_conflict_head = 1;
740 head = NULL;
743 if (remote == o->df_conflict_entry) {
744 df_conflict_remote = 1;
745 remote = NULL;
748 /* First, if there's a #16 situation, note that to prevent #13
749 * and #14.
751 if (!same(remote, head)) {
752 for (i = 1; i < o->head_idx; i++) {
753 if (same(stages[i], head)) {
754 head_match = i;
756 if (same(stages[i], remote)) {
757 remote_match = i;
762 /* We start with cases where the index is allowed to match
763 * something other than the head: #14(ALT) and #2ALT, where it
764 * is permitted to match the result instead.
766 /* #14, #14ALT, #2ALT */
767 if (remote && !df_conflict_head && head_match && !remote_match) {
768 if (index && !same(index, remote) && !same(index, head))
769 return o->gently ? -1 : reject_merge(index, o);
770 return merged_entry(remote, index, o);
773 * If we have an entry in the index cache, then we want to
774 * make sure that it matches head.
776 if (index && !same(index, head))
777 return o->gently ? -1 : reject_merge(index, o);
779 if (head) {
780 /* #5ALT, #15 */
781 if (same(head, remote))
782 return merged_entry(head, index, o);
783 /* #13, #3ALT */
784 if (!df_conflict_remote && remote_match && !head_match)
785 return merged_entry(head, index, o);
788 /* #1 */
789 if (!head && !remote && any_anc_missing)
790 return 0;
792 /* Under the new "aggressive" rule, we resolve mostly trivial
793 * cases that we historically had git-merge-one-file resolve.
795 if (o->aggressive) {
796 int head_deleted = !head && !df_conflict_head;
797 int remote_deleted = !remote && !df_conflict_remote;
798 struct cache_entry *ce = NULL;
800 if (index)
801 ce = index;
802 else if (head)
803 ce = head;
804 else if (remote)
805 ce = remote;
806 else {
807 for (i = 1; i < o->head_idx; i++) {
808 if (stages[i] && stages[i] != o->df_conflict_entry) {
809 ce = stages[i];
810 break;
816 * Deleted in both.
817 * Deleted in one and unchanged in the other.
819 if ((head_deleted && remote_deleted) ||
820 (head_deleted && remote && remote_match) ||
821 (remote_deleted && head && head_match)) {
822 if (index)
823 return deleted_entry(index, index, o);
824 if (ce && !head_deleted) {
825 if (verify_absent(ce, "removed", o))
826 return -1;
828 return 0;
831 * Added in both, identically.
833 if (no_anc_exists && head && remote && same(head, remote))
834 return merged_entry(head, index, o);
838 /* Below are "no merge" cases, which require that the index be
839 * up-to-date to avoid the files getting overwritten with
840 * conflict resolution files.
842 if (index) {
843 if (verify_uptodate(index, o))
844 return -1;
847 o->nontrivial_merge = 1;
849 /* #2, #3, #4, #6, #7, #9, #10, #11. */
850 count = 0;
851 if (!head_match || !remote_match) {
852 for (i = 1; i < o->head_idx; i++) {
853 if (stages[i] && stages[i] != o->df_conflict_entry) {
854 keep_entry(stages[i], o);
855 count++;
856 break;
860 #if DBRT_DEBUG
861 else {
862 fprintf(stderr, "read-tree: warning #16 detected\n");
863 show_stage_entry(stderr, "head ", stages[head_match]);
864 show_stage_entry(stderr, "remote ", stages[remote_match]);
866 #endif
867 if (head) { count += keep_entry(head, o); }
868 if (remote) { count += keep_entry(remote, o); }
869 return count;
873 * Two-way merge.
875 * The rule is to "carry forward" what is in the index without losing
876 * information across a "fast forward", favoring a successful merge
877 * over a merge failure when it makes sense. For details of the
878 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
881 int twoway_merge(struct cache_entry **src, struct unpack_trees_options *o)
883 struct cache_entry *current = src[0];
884 struct cache_entry *oldtree = src[1];
885 struct cache_entry *newtree = src[2];
887 if (o->merge_size != 2)
888 return error("Cannot do a twoway merge of %d trees",
889 o->merge_size);
891 if (oldtree == o->df_conflict_entry)
892 oldtree = NULL;
893 if (newtree == o->df_conflict_entry)
894 newtree = NULL;
896 if (current) {
897 if ((!oldtree && !newtree) || /* 4 and 5 */
898 (!oldtree && newtree &&
899 same(current, newtree)) || /* 6 and 7 */
900 (oldtree && newtree &&
901 same(oldtree, newtree)) || /* 14 and 15 */
902 (oldtree && newtree &&
903 !same(oldtree, newtree) && /* 18 and 19 */
904 same(current, newtree))) {
905 return keep_entry(current, o);
907 else if (oldtree && !newtree && same(current, oldtree)) {
908 /* 10 or 11 */
909 return deleted_entry(oldtree, current, o);
911 else if (oldtree && newtree &&
912 same(current, oldtree) && !same(current, newtree)) {
913 /* 20 or 21 */
914 return merged_entry(newtree, current, o);
916 else {
917 /* all other failures */
918 if (oldtree)
919 return o->gently ? -1 : reject_merge(oldtree, o);
920 if (current)
921 return o->gently ? -1 : reject_merge(current, o);
922 if (newtree)
923 return o->gently ? -1 : reject_merge(newtree, o);
924 return -1;
927 else if (newtree) {
928 if (oldtree && !o->initial_checkout) {
930 * deletion of the path was staged;
932 if (same(oldtree, newtree))
933 return 1;
934 return reject_merge(oldtree, o);
936 return merged_entry(newtree, current, o);
938 return deleted_entry(oldtree, current, o);
942 * Bind merge.
944 * Keep the index entries at stage0, collapse stage1 but make sure
945 * stage0 does not have anything there.
947 int bind_merge(struct cache_entry **src,
948 struct unpack_trees_options *o)
950 struct cache_entry *old = src[0];
951 struct cache_entry *a = src[1];
953 if (o->merge_size != 1)
954 return error("Cannot do a bind merge of %d trees\n",
955 o->merge_size);
956 if (a && old)
957 return o->gently ? -1 :
958 error(ERRORMSG(o, bind_overlap), a->name, old->name);
959 if (!a)
960 return keep_entry(old, o);
961 else
962 return merged_entry(a, NULL, o);
966 * One-way merge.
968 * The rule is:
969 * - take the stat information from stage0, take the data from stage1
971 int oneway_merge(struct cache_entry **src, struct unpack_trees_options *o)
973 struct cache_entry *old = src[0];
974 struct cache_entry *a = src[1];
976 if (o->merge_size != 1)
977 return error("Cannot do a oneway merge of %d trees",
978 o->merge_size);
980 if (!a)
981 return deleted_entry(old, old, o);
983 if (old && same(old, a)) {
984 int update = 0;
985 if (o->reset) {
986 struct stat st;
987 if (lstat(old->name, &st) ||
988 ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID))
989 update |= CE_UPDATE;
991 add_entry(o, old, update, 0);
992 return 0;
994 return merged_entry(a, old, o);