1#include "cache.h"
2#include "dir.h"
3#include "tree.h"
4#include "tree-walk.h"
5#include "cache-tree.h"
6#include "unpack-trees.h"
7#include "progress.h"
8#include "refs.h"
9#define DBRT_DEBUG 1
11struct tree_entry_list {
13 struct tree_entry_list *next;
14 unsigned directory : 1;
15 unsigned executable : 1;
16 unsigned symlink : 1;
17 unsigned int mode;
18 const char *name;
19 const unsigned char *sha1;
20};
21static struct tree_entry_list *create_tree_entry_list(struct tree *tree)
23{
24 struct tree_desc desc;
25 struct name_entry one;
26 struct tree_entry_list *ret = NULL;
27 struct tree_entry_list **list_p = &ret;
28 if (!tree->object.parsed)
30 parse_tree(tree);
31 init_tree_desc(&desc, tree->buffer, tree->size);
33 while (tree_entry(&desc, &one)) {
35 struct tree_entry_list *entry;
36 entry = xmalloc(sizeof(struct tree_entry_list));
38 entry->name = one.path;
39 entry->sha1 = one.sha1;
40 entry->mode = one.mode;
41 entry->directory = S_ISDIR(one.mode) != 0;
42 entry->executable = (one.mode & S_IXUSR) != 0;
43 entry->symlink = S_ISLNK(one.mode) != 0;
44 entry->next = NULL;
45 *list_p = entry;
47 list_p = &entry->next;
48 }
49 return ret;
50}
51static int entcmp(const char *name1, int dir1, const char *name2, int dir2)
53{
54 int len1 = strlen(name1);
55 int len2 = strlen(name2);
56 int len = len1 < len2 ? len1 : len2;
57 int ret = memcmp(name1, name2, len);
58 unsigned char c1, c2;
59 if (ret)
60 return ret;
61 c1 = name1[len];
62 c2 = name2[len];
63 if (!c1 && dir1)
64 c1 = '/';
65 if (!c2 && dir2)
66 c2 = '/';
67 ret = (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
68 if (c1 && c2 && !ret)
69 ret = len1 - len2;
70 return ret;
71}
72static int unpack_trees_rec(struct tree_entry_list **posns, int len,
74 const char *base, struct unpack_trees_options *o,
75 struct tree_entry_list *df_conflict_list)
76{
77 int baselen = strlen(base);
78 int src_size = len + 1;
79 int i_stk = i_stk;
80 int retval = 0;
81 if (o->dir)
83 i_stk = push_exclude_per_directory(o->dir, base, strlen(base));
84 do {
86 int i;
87 const char *first;
88 int firstdir = 0;
89 int pathlen;
90 unsigned ce_size;
91 struct tree_entry_list **subposns;
92 struct cache_entry **src;
93 int any_files = 0;
94 int any_dirs = 0;
95 char *cache_name;
96 int ce_stage;
97 /* Find the first name in the input. */
99 first = NULL;
101 cache_name = NULL;
102 /* Check the cache */
104 if (o->merge && o->pos < active_nr) {
105 /* This is a bit tricky: */
106 /* If the index has a subdirectory (with
107 * contents) as the first name, it'll get a
108 * filename like "foo/bar". But that's after
109 * "foo", so the entry in trees will get
110 * handled first, at which point we'll go into
111 * "foo", and deal with "bar" from the index,
112 * because the base will be "foo/". The only
113 * way we can actually have "foo/bar" first of
114 * all the things is if the trees don't
115 * contain "foo" at all, in which case we'll
116 * handle "foo/bar" without going into the
117 * directory, but that's fine (and will return
118 * an error anyway, with the added unknown
119 * file case.
120 */
121 cache_name = active_cache[o->pos]->name;
123 if (strlen(cache_name) > baselen &&
124 !memcmp(cache_name, base, baselen)) {
125 cache_name += baselen;
126 first = cache_name;
127 } else {
128 cache_name = NULL;
129 }
130 }
131#if DBRT_DEBUG > 1
133 if (first)
134 printf("index %s\n", first);
135#endif
136 for (i = 0; i < len; i++) {
137 if (!posns[i] || posns[i] == df_conflict_list)
138 continue;
139#if DBRT_DEBUG > 1
140 printf("%d %s\n", i + 1, posns[i]->name);
141#endif
142 if (!first || entcmp(first, firstdir,
143 posns[i]->name,
144 posns[i]->directory) > 0) {
145 first = posns[i]->name;
146 firstdir = posns[i]->directory;
147 }
148 }
149 /* No name means we're done */
150 if (!first)
151 goto leave_directory;
152 pathlen = strlen(first);
154 ce_size = cache_entry_size(baselen + pathlen);
155 src = xcalloc(src_size, sizeof(struct cache_entry *));
157 subposns = xcalloc(len, sizeof(struct tree_list_entry *));
159 if (cache_name && !strcmp(cache_name, first)) {
161 any_files = 1;
162 src[0] = active_cache[o->pos];
163 remove_cache_entry_at(o->pos);
164 }
165 for (i = 0; i < len; i++) {
167 struct cache_entry *ce;
168 if (!posns[i] ||
170 (posns[i] != df_conflict_list &&
171 strcmp(first, posns[i]->name))) {
172 continue;
173 }
174 if (posns[i] == df_conflict_list) {
176 src[i + o->merge] = o->df_conflict_entry;
177 continue;
178 }
179 if (posns[i]->directory) {
181 struct tree *tree = lookup_tree(posns[i]->sha1);
182 any_dirs = 1;
183 parse_tree(tree);
184 subposns[i] = create_tree_entry_list(tree);
185 posns[i] = posns[i]->next;
186 src[i + o->merge] = o->df_conflict_entry;
187 continue;
188 }
189 if (!o->merge)
191 ce_stage = 0;
192 else if (i + 1 < o->head_idx)
193 ce_stage = 1;
194 else if (i + 1 > o->head_idx)
195 ce_stage = 3;
196 else
197 ce_stage = 2;
198 ce = xcalloc(1, ce_size);
200 ce->ce_mode = create_ce_mode(posns[i]->mode);
201 ce->ce_flags = create_ce_flags(baselen + pathlen,
202 ce_stage);
203 memcpy(ce->name, base, baselen);
204 memcpy(ce->name + baselen, first, pathlen + 1);
205 any_files = 1;
207 hashcpy(ce->sha1, posns[i]->sha1);
209 src[i + o->merge] = ce;
210 subposns[i] = df_conflict_list;
211 posns[i] = posns[i]->next;
212 }
213 if (any_files) {
214 if (o->merge) {
215 int ret;
216#if DBRT_DEBUG > 1
218 printf("%s:\n", first);
219 for (i = 0; i < src_size; i++) {
220 printf(" %d ", i);
221 if (src[i])
222 printf("%s\n", sha1_to_hex(src[i]->sha1));
223 else
224 printf("\n");
225 }
226#endif
227 ret = o->fn(src, o);
228#if DBRT_DEBUG > 1
230 printf("Added %d entries\n", ret);
231#endif
232 o->pos += ret;
233 } else {
234 for (i = 0; i < src_size; i++) {
235 if (src[i]) {
236 add_cache_entry(src[i], ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
237 }
238 }
239 }
240 }
241 if (any_dirs) {
242 char *newbase = xmalloc(baselen + 2 + pathlen);
243 memcpy(newbase, base, baselen);
244 memcpy(newbase + baselen, first, pathlen);
245 newbase[baselen + pathlen] = '/';
246 newbase[baselen + pathlen + 1] = '\0';
247 if (unpack_trees_rec(subposns, len, newbase, o,
248 df_conflict_list)) {
249 retval = -1;
250 goto leave_directory;
251 }
252 free(newbase);
253 }
254 free(subposns);
255 free(src);
256 } while (1);
257 leave_directory:
259 if (o->dir)
260 pop_exclude_per_directory(o->dir, i_stk);
261 return retval;
262}
263/* Unlink the last component and attempt to remove leading
265 * directories, in case this unlink is the removal of the
266 * last entry in the directory -- empty directories are removed.
267 */
268static void unlink_entry(char *name, char *last_symlink)
269{
270 char *cp, *prev;
271 if (has_symlink_leading_path(name, last_symlink))
273 return;
274 if (unlink(name))
275 return;
276 prev = NULL;
277 while (1) {
278 int status;
279 cp = strrchr(name, '/');
280 if (prev)
281 *prev = '/';
282 if (!cp)
283 break;
284 *cp = 0;
286 status = rmdir(name);
287 if (status) {
288 *cp = '/';
289 break;
290 }
291 prev = cp;
292 }
293}
294static struct checkout state;
296static void check_updates(struct cache_entry **src, int nr,
297 struct unpack_trees_options *o)
298{
299 unsigned short mask = htons(CE_UPDATE);
300 unsigned cnt = 0, total = 0;
301 struct progress progress;
302 char last_symlink[PATH_MAX];
303 if (o->update && o->verbose_update) {
305 for (total = cnt = 0; cnt < nr; cnt++) {
306 struct cache_entry *ce = src[cnt];
307 if (!ce->ce_mode || ce->ce_flags & mask)
308 total++;
309 }
310 start_progress_delay(&progress, "Checking %u files out...",
312 "", total, 50, 2);
313 cnt = 0;
314 }
315 *last_symlink = '\0';
317 while (nr--) {
318 struct cache_entry *ce = *src++;
319 if (total)
321 if (!ce->ce_mode || ce->ce_flags & mask)
322 display_progress(&progress, ++cnt);
323 if (!ce->ce_mode) {
324 if (o->update)
325 unlink_entry(ce->name, last_symlink);
326 continue;
327 }
328 if (ce->ce_flags & mask) {
329 ce->ce_flags &= ~mask;
330 if (o->update) {
331 checkout_entry(ce, &state, NULL);
332 *last_symlink = '\0';
333 }
334 }
335 }
336 if (total)
337 stop_progress(&progress);;
338}
339int unpack_trees(struct object_list *trees, struct unpack_trees_options *o)
341{
342 unsigned len = object_list_length(trees);
343 struct tree_entry_list **posns;
344 int i;
345 struct object_list *posn = trees;
346 struct tree_entry_list df_conflict_list;
347 static struct cache_entry *dfc;
348 memset(&df_conflict_list, 0, sizeof(df_conflict_list));
350 df_conflict_list.next = &df_conflict_list;
351 memset(&state, 0, sizeof(state));
352 state.base_dir = "";
353 state.force = 1;
354 state.quiet = 1;
355 state.refresh_cache = 1;
356 o->merge_size = len;
358 if (!dfc)
360 dfc = xcalloc(1, sizeof(struct cache_entry) + 1);
361 o->df_conflict_entry = dfc;
362 if (len) {
364 posns = xmalloc(len * sizeof(struct tree_entry_list *));
365 for (i = 0; i < len; i++) {
366 posns[i] = create_tree_entry_list((struct tree *) posn->item);
367 posn = posn->next;
368 }
369 if (unpack_trees_rec(posns, len, o->prefix ? o->prefix : "",
370 o, &df_conflict_list))
371 return -1;
372 }
373 if (o->trivial_merges_only && o->nontrivial_merge)
375 die("Merge requires file-level merging");
376 check_updates(active_cache, active_nr, o);
378 return 0;
379}
380/* Here come the merge functions */
382static void reject_merge(struct cache_entry *ce)
384{
385 die("Entry '%s' would be overwritten by merge. Cannot merge.",
386 ce->name);
387}
388static int same(struct cache_entry *a, struct cache_entry *b)
390{
391 if (!!a != !!b)
392 return 0;
393 if (!a && !b)
394 return 1;
395 return a->ce_mode == b->ce_mode &&
396 !hashcmp(a->sha1, b->sha1);
397}
398/*
401 * When a CE gets turned into an unmerged entry, we
402 * want it to be up-to-date
403 */
404static void verify_uptodate(struct cache_entry *ce,
405 struct unpack_trees_options *o)
406{
407 struct stat st;
408 if (o->index_only || o->reset)
410 return;
411 if (!lstat(ce->name, &st)) {
413 unsigned changed = ce_match_stat(ce, &st, 1);
414 if (!changed)
415 return;
416 errno = 0;
417 }
418 if (errno == ENOENT)
419 return;
420 die("Entry '%s' not uptodate. Cannot merge.", ce->name);
421}
422static void invalidate_ce_path(struct cache_entry *ce)
424{
425 if (ce)
426 cache_tree_invalidate_path(active_cache_tree, ce->name);
427}
428/*
430 * Check that checking out ce->sha1 in subdir ce->name is not
431 * going to overwrite any working files.
432 *
433 * Currently, git does not checkout subprojects during a superproject
434 * checkout, so it is not going to overwrite anything.
435 */
436static int verify_clean_submodule(struct cache_entry *ce, const char *action,
437 struct unpack_trees_options *o)
438{
439 return 0;
440}
441static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
443 struct unpack_trees_options *o)
444{
445 /*
446 * we are about to extract "ce->name"; we would not want to lose
447 * anything in the existing directory there.
448 */
449 int namelen;
450 int pos, i;
451 struct dir_struct d;
452 char *pathbuf;
453 int cnt = 0;
454 unsigned char sha1[20];
455 if (S_ISGITLINK(ntohl(ce->ce_mode)) &&
457 resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
458 /* If we are not going to update the submodule, then
459 * we don't care.
460 */
461 if (!hashcmp(sha1, ce->sha1))
462 return 0;
463 return verify_clean_submodule(ce, action, o);
464 }
465 /*
467 * First let's make sure we do not have a local modification
468 * in that directory.
469 */
470 namelen = strlen(ce->name);
471 pos = cache_name_pos(ce->name, namelen);
472 if (0 <= pos)
473 return cnt; /* we have it as nondirectory */
474 pos = -pos - 1;
475 for (i = pos; i < active_nr; i++) {
476 struct cache_entry *ce = active_cache[i];
477 int len = ce_namelen(ce);
478 if (len < namelen ||
479 strncmp(ce->name, ce->name, namelen) ||
480 ce->name[namelen] != '/')
481 break;
482 /*
483 * ce->name is an entry in the subdirectory.
484 */
485 if (!ce_stage(ce)) {
486 verify_uptodate(ce, o);
487 ce->ce_mode = 0;
488 }
489 cnt++;
490 }
491 /*
493 * Then we need to make sure that we do not lose a locally
494 * present file that is not ignored.
495 */
496 pathbuf = xmalloc(namelen + 2);
497 memcpy(pathbuf, ce->name, namelen);
498 strcpy(pathbuf+namelen, "/");
499 memset(&d, 0, sizeof(d));
501 if (o->dir)
502 d.exclude_per_dir = o->dir->exclude_per_dir;
503 i = read_directory(&d, ce->name, pathbuf, namelen+1, NULL);
504 if (i)
505 die("Updating '%s' would lose untracked files in it",
506 ce->name);
507 free(pathbuf);
508 return cnt;
509}
510/*
512 * We do not want to remove or overwrite a working tree file that
513 * is not tracked, unless it is ignored.
514 */
515static void verify_absent(struct cache_entry *ce, const char *action,
516 struct unpack_trees_options *o)
517{
518 struct stat st;
519 if (o->index_only || o->reset || !o->update)
521 return;
522 if (has_symlink_leading_path(ce->name, NULL))
524 return;
525 if (!lstat(ce->name, &st)) {
527 int cnt;
528 if (o->dir && excluded(o->dir, ce->name))
530 /*
531 * ce->name is explicitly excluded, so it is Ok to
532 * overwrite it.
533 */
534 return;
535 if (S_ISDIR(st.st_mode)) {
536 /*
537 * We are checking out path "foo" and
538 * found "foo/." in the working tree.
539 * This is tricky -- if we have modified
540 * files that are in "foo/" we would lose
541 * it.
542 */
543 cnt = verify_clean_subdirectory(ce, action, o);
544 /*
546 * If this removed entries from the index,
547 * what that means is:
548 *
549 * (1) the caller unpack_trees_rec() saw path/foo
550 * in the index, and it has not removed it because
551 * it thinks it is handling 'path' as blob with
552 * D/F conflict;
553 * (2) we will return "ok, we placed a merged entry
554 * in the index" which would cause o->pos to be
555 * incremented by one;
556 * (3) however, original o->pos now has 'path/foo'
557 * marked with "to be removed".
558 *
559 * We need to increment it by the number of
560 * deleted entries here.
561 */
562 o->pos += cnt;
563 return;
564 }
565 /*
567 * The previous round may already have decided to
568 * delete this path, which is in a subdirectory that
569 * is being replaced with a blob.
570 */
571 cnt = cache_name_pos(ce->name, strlen(ce->name));
572 if (0 <= cnt) {
573 struct cache_entry *ce = active_cache[cnt];
574 if (!ce_stage(ce) && !ce->ce_mode)
575 return;
576 }
577 die("Untracked working tree file '%s' "
579 "would be %s by merge.", ce->name, action);
580 }
581}
582static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
584 struct unpack_trees_options *o)
585{
586 merge->ce_flags |= htons(CE_UPDATE);
587 if (old) {
588 /*
589 * See if we can re-use the old CE directly?
590 * That way we get the uptodate stat info.
591 *
592 * This also removes the UPDATE flag on
593 * a match.
594 */
595 if (same(old, merge)) {
596 *merge = *old;
597 } else {
598 verify_uptodate(old, o);
599 invalidate_ce_path(old);
600 }
601 }
602 else {
603 verify_absent(merge, "overwritten", o);
604 invalidate_ce_path(merge);
605 }
606 merge->ce_flags &= ~htons(CE_STAGEMASK);
608 add_cache_entry(merge, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
609 return 1;
610}
611static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
613 struct unpack_trees_options *o)
614{
615 if (old)
616 verify_uptodate(old, o);
617 else
618 verify_absent(ce, "removed", o);
619 ce->ce_mode = 0;
620 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
621 invalidate_ce_path(ce);
622 return 1;
623}
624static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o)
626{
627 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
628 return 1;
629}
630#if DBRT_DEBUG
632static void show_stage_entry(FILE *o,
633 const char *label, const struct cache_entry *ce)
634{
635 if (!ce)
636 fprintf(o, "%s (missing)\n", label);
637 else
638 fprintf(o, "%s%06o %s %d\t%s\n",
639 label,
640 ntohl(ce->ce_mode),
641 sha1_to_hex(ce->sha1),
642 ce_stage(ce),
643 ce->name);
644}
645#endif
646int threeway_merge(struct cache_entry **stages,
648 struct unpack_trees_options *o)
649{
650 struct cache_entry *index;
651 struct cache_entry *head;
652 struct cache_entry *remote = stages[o->head_idx + 1];
653 int count;
654 int head_match = 0;
655 int remote_match = 0;
656 int df_conflict_head = 0;
658 int df_conflict_remote = 0;
659 int any_anc_missing = 0;
661 int no_anc_exists = 1;
662 int i;
663 for (i = 1; i < o->head_idx; i++) {
665 if (!stages[i] || stages[i] == o->df_conflict_entry)
666 any_anc_missing = 1;
667 else
668 no_anc_exists = 0;
669 }
670 index = stages[0];
672 head = stages[o->head_idx];
673 if (head == o->df_conflict_entry) {
675 df_conflict_head = 1;
676 head = NULL;
677 }
678 if (remote == o->df_conflict_entry) {
680 df_conflict_remote = 1;
681 remote = NULL;
682 }
683 /* First, if there's a #16 situation, note that to prevent #13
685 * and #14.
686 */
687 if (!same(remote, head)) {
688 for (i = 1; i < o->head_idx; i++) {
689 if (same(stages[i], head)) {
690 head_match = i;
691 }
692 if (same(stages[i], remote)) {
693 remote_match = i;
694 }
695 }
696 }
697 /* We start with cases where the index is allowed to match
699 * something other than the head: #14(ALT) and #2ALT, where it
700 * is permitted to match the result instead.
701 */
702 /* #14, #14ALT, #2ALT */
703 if (remote && !df_conflict_head && head_match && !remote_match) {
704 if (index && !same(index, remote) && !same(index, head))
705 reject_merge(index);
706 return merged_entry(remote, index, o);
707 }
708 /*
709 * If we have an entry in the index cache, then we want to
710 * make sure that it matches head.
711 */
712 if (index && !same(index, head)) {
713 reject_merge(index);
714 }
715 if (head) {
717 /* #5ALT, #15 */
718 if (same(head, remote))
719 return merged_entry(head, index, o);
720 /* #13, #3ALT */
721 if (!df_conflict_remote && remote_match && !head_match)
722 return merged_entry(head, index, o);
723 }
724 /* #1 */
726 if (!head && !remote && any_anc_missing)
727 return 0;
728 /* Under the new "aggressive" rule, we resolve mostly trivial
730 * cases that we historically had git-merge-one-file resolve.
731 */
732 if (o->aggressive) {
733 int head_deleted = !head && !df_conflict_head;
734 int remote_deleted = !remote && !df_conflict_remote;
735 struct cache_entry *ce = NULL;
736 if (index)
738 ce = index;
739 else if (head)
740 ce = head;
741 else if (remote)
742 ce = remote;
743 else {
744 for (i = 1; i < o->head_idx; i++) {
745 if (stages[i] && stages[i] != o->df_conflict_entry) {
746 ce = stages[i];
747 break;
748 }
749 }
750 }
751 /*
753 * Deleted in both.
754 * Deleted in one and unchanged in the other.
755 */
756 if ((head_deleted && remote_deleted) ||
757 (head_deleted && remote && remote_match) ||
758 (remote_deleted && head && head_match)) {
759 if (index)
760 return deleted_entry(index, index, o);
761 else if (ce && !head_deleted)
762 verify_absent(ce, "removed", o);
763 return 0;
764 }
765 /*
766 * Added in both, identically.
767 */
768 if (no_anc_exists && head && remote && same(head, remote))
769 return merged_entry(head, index, o);
770 }
772 /* Below are "no merge" cases, which require that the index be
774 * up-to-date to avoid the files getting overwritten with
775 * conflict resolution files.
776 */
777 if (index) {
778 verify_uptodate(index, o);
779 }
780 o->nontrivial_merge = 1;
782 /* #2, #3, #4, #6, #7, #9, #10, #11. */
784 count = 0;
785 if (!head_match || !remote_match) {
786 for (i = 1; i < o->head_idx; i++) {
787 if (stages[i] && stages[i] != o->df_conflict_entry) {
788 keep_entry(stages[i], o);
789 count++;
790 break;
791 }
792 }
793 }
794#if DBRT_DEBUG
795 else {
796 fprintf(stderr, "read-tree: warning #16 detected\n");
797 show_stage_entry(stderr, "head ", stages[head_match]);
798 show_stage_entry(stderr, "remote ", stages[remote_match]);
799 }
800#endif
801 if (head) { count += keep_entry(head, o); }
802 if (remote) { count += keep_entry(remote, o); }
803 return count;
804}
805/*
807 * Two-way merge.
808 *
809 * The rule is to "carry forward" what is in the index without losing
810 * information across a "fast forward", favoring a successful merge
811 * over a merge failure when it makes sense. For details of the
812 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
813 *
814 */
815int twoway_merge(struct cache_entry **src,
816 struct unpack_trees_options *o)
817{
818 struct cache_entry *current = src[0];
819 struct cache_entry *oldtree = src[1];
820 struct cache_entry *newtree = src[2];
821 if (o->merge_size != 2)
823 return error("Cannot do a twoway merge of %d trees",
824 o->merge_size);
825 if (oldtree == o->df_conflict_entry)
827 oldtree = NULL;
828 if (newtree == o->df_conflict_entry)
829 newtree = NULL;
830 if (current) {
832 if ((!oldtree && !newtree) || /* 4 and 5 */
833 (!oldtree && newtree &&
834 same(current, newtree)) || /* 6 and 7 */
835 (oldtree && newtree &&
836 same(oldtree, newtree)) || /* 14 and 15 */
837 (oldtree && newtree &&
838 !same(oldtree, newtree) && /* 18 and 19 */
839 same(current, newtree))) {
840 return keep_entry(current, o);
841 }
842 else if (oldtree && !newtree && same(current, oldtree)) {
843 /* 10 or 11 */
844 return deleted_entry(oldtree, current, o);
845 }
846 else if (oldtree && newtree &&
847 same(current, oldtree) && !same(current, newtree)) {
848 /* 20 or 21 */
849 return merged_entry(newtree, current, o);
850 }
851 else {
852 /* all other failures */
853 if (oldtree)
854 reject_merge(oldtree);
855 if (current)
856 reject_merge(current);
857 if (newtree)
858 reject_merge(newtree);
859 return -1;
860 }
861 }
862 else if (newtree)
863 return merged_entry(newtree, current, o);
864 else
865 return deleted_entry(oldtree, current, o);
866}
867/*
869 * Bind merge.
870 *
871 * Keep the index entries at stage0, collapse stage1 but make sure
872 * stage0 does not have anything there.
873 */
874int bind_merge(struct cache_entry **src,
875 struct unpack_trees_options *o)
876{
877 struct cache_entry *old = src[0];
878 struct cache_entry *a = src[1];
879 if (o->merge_size != 1)
881 return error("Cannot do a bind merge of %d trees\n",
882 o->merge_size);
883 if (a && old)
884 die("Entry '%s' overlaps. Cannot bind.", a->name);
885 if (!a)
886 return keep_entry(old, o);
887 else
888 return merged_entry(a, NULL, o);
889}
890/*
892 * One-way merge.
893 *
894 * The rule is:
895 * - take the stat information from stage0, take the data from stage1
896 */
897int oneway_merge(struct cache_entry **src,
898 struct unpack_trees_options *o)
899{
900 struct cache_entry *old = src[0];
901 struct cache_entry *a = src[1];
902 if (o->merge_size != 1)
904 return error("Cannot do a oneway merge of %d trees",
905 o->merge_size);
906 if (!a)
908 return deleted_entry(old, old, o);
909 if (old && same(old, a)) {
910 if (o->reset) {
911 struct stat st;
912 if (lstat(old->name, &st) ||
913 ce_match_stat(old, &st, 1))
914 old->ce_flags |= htons(CE_UPDATE);
915 }
916 return keep_entry(old, o);
917 }
918 return merged_entry(a, old, o);
919}