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 int mode;
15 const char *name;
16 const unsigned char *sha1;
17};
18static struct tree_entry_list *create_tree_entry_list(struct tree_desc *desc)
20{
21 struct name_entry one;
22 struct tree_entry_list *ret = NULL;
23 struct tree_entry_list **list_p = &ret;
24 while (tree_entry(desc, &one)) {
26 struct tree_entry_list *entry;
27 entry = xmalloc(sizeof(struct tree_entry_list));
29 entry->name = one.path;
30 entry->sha1 = one.sha1;
31 entry->mode = one.mode;
32 entry->next = NULL;
33 *list_p = entry;
35 list_p = &entry->next;
36 }
37 return ret;
38}
39static int entcmp(const char *name1, int dir1, const char *name2, int dir2)
41{
42 int len1 = strlen(name1);
43 int len2 = strlen(name2);
44 int len = len1 < len2 ? len1 : len2;
45 int ret = memcmp(name1, name2, len);
46 unsigned char c1, c2;
47 if (ret)
48 return ret;
49 c1 = name1[len];
50 c2 = name2[len];
51 if (!c1 && dir1)
52 c1 = '/';
53 if (!c2 && dir2)
54 c2 = '/';
55 ret = (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
56 if (c1 && c2 && !ret)
57 ret = len1 - len2;
58 return ret;
59}
60static inline void remove_entry(int remove)
62{
63 if (remove >= 0)
64 remove_cache_entry_at(remove);
65}
66static int unpack_trees_rec(struct tree_entry_list **posns, int len,
68 const char *base, struct unpack_trees_options *o,
69 struct tree_entry_list *df_conflict_list)
70{
71 int remove;
72 int baselen = strlen(base);
73 int src_size = len + 1;
74 int retval = 0;
75 do {
77 int i;
78 const char *first;
79 int firstdir = 0;
80 int pathlen;
81 unsigned ce_size;
82 struct tree_entry_list **subposns;
83 struct cache_entry **src;
84 int any_files = 0;
85 int any_dirs = 0;
86 char *cache_name;
87 int ce_stage;
88 /* Find the first name in the input. */
90 first = NULL;
92 cache_name = NULL;
93 /* Check the cache */
95 if (o->merge && o->pos < active_nr) {
96 /* This is a bit tricky: */
97 /* If the index has a subdirectory (with
98 * contents) as the first name, it'll get a
99 * filename like "foo/bar". But that's after
100 * "foo", so the entry in trees will get
101 * handled first, at which point we'll go into
102 * "foo", and deal with "bar" from the index,
103 * because the base will be "foo/". The only
104 * way we can actually have "foo/bar" first of
105 * all the things is if the trees don't
106 * contain "foo" at all, in which case we'll
107 * handle "foo/bar" without going into the
108 * directory, but that's fine (and will return
109 * an error anyway, with the added unknown
110 * file case.
111 */
112 cache_name = active_cache[o->pos]->name;
114 if (strlen(cache_name) > baselen &&
115 !memcmp(cache_name, base, baselen)) {
116 cache_name += baselen;
117 first = cache_name;
118 } else {
119 cache_name = NULL;
120 }
121 }
122#if DBRT_DEBUG > 1
124 if (first)
125 printf("index %s\n", first);
126#endif
127 for (i = 0; i < len; i++) {
128 if (!posns[i] || posns[i] == df_conflict_list)
129 continue;
130#if DBRT_DEBUG > 1
131 printf("%d %s\n", i + 1, posns[i]->name);
132#endif
133 if (!first || entcmp(first, firstdir,
134 posns[i]->name,
135 S_ISDIR(posns[i]->mode)) > 0) {
136 first = posns[i]->name;
137 firstdir = S_ISDIR(posns[i]->mode);
138 }
139 }
140 /* No name means we're done */
141 if (!first)
142 goto leave_directory;
143 pathlen = strlen(first);
145 ce_size = cache_entry_size(baselen + pathlen);
146 src = xcalloc(src_size, sizeof(struct cache_entry *));
148 subposns = xcalloc(len, sizeof(struct tree_list_entry *));
150 remove = -1;
152 if (cache_name && !strcmp(cache_name, first)) {
153 any_files = 1;
154 src[0] = active_cache[o->pos];
155 remove = o->pos;
156 }
157 for (i = 0; i < len; i++) {
159 struct cache_entry *ce;
160 if (!posns[i] ||
162 (posns[i] != df_conflict_list &&
163 strcmp(first, posns[i]->name))) {
164 continue;
165 }
166 if (posns[i] == df_conflict_list) {
168 src[i + o->merge] = o->df_conflict_entry;
169 continue;
170 }
171 if (S_ISDIR(posns[i]->mode)) {
173 struct tree *tree = lookup_tree(posns[i]->sha1);
174 struct tree_desc t;
175 any_dirs = 1;
176 parse_tree(tree);
177 init_tree_desc(&t, tree->buffer, tree->size);
178 subposns[i] = create_tree_entry_list(&t);
179 posns[i] = posns[i]->next;
180 src[i + o->merge] = o->df_conflict_entry;
181 continue;
182 }
183 if (!o->merge)
185 ce_stage = 0;
186 else if (i + 1 < o->head_idx)
187 ce_stage = 1;
188 else if (i + 1 > o->head_idx)
189 ce_stage = 3;
190 else
191 ce_stage = 2;
192 ce = xcalloc(1, ce_size);
194 ce->ce_mode = create_ce_mode(posns[i]->mode);
195 ce->ce_flags = create_ce_flags(baselen + pathlen,
196 ce_stage);
197 memcpy(ce->name, base, baselen);
198 memcpy(ce->name + baselen, first, pathlen + 1);
199 any_files = 1;
201 hashcpy(ce->sha1, posns[i]->sha1);
203 src[i + o->merge] = ce;
204 subposns[i] = df_conflict_list;
205 posns[i] = posns[i]->next;
206 }
207 if (any_files) {
208 if (o->merge) {
209 int ret;
210#if DBRT_DEBUG > 1
212 printf("%s:\n", first);
213 for (i = 0; i < src_size; i++) {
214 printf(" %d ", i);
215 if (src[i])
216 printf("%s\n", sha1_to_hex(src[i]->sha1));
217 else
218 printf("\n");
219 }
220#endif
221 ret = o->fn(src, o, remove);
222 if (ret < 0)
223 return ret;
224#if DBRT_DEBUG > 1
226 printf("Added %d entries\n", ret);
227#endif
228 o->pos += ret;
229 } else {
230 remove_entry(remove);
231 for (i = 0; i < src_size; i++) {
232 if (src[i]) {
233 add_cache_entry(src[i], ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
234 }
235 }
236 }
237 }
238 if (any_dirs) {
239 char *newbase = xmalloc(baselen + 2 + pathlen);
240 memcpy(newbase, base, baselen);
241 memcpy(newbase + baselen, first, pathlen);
242 newbase[baselen + pathlen] = '/';
243 newbase[baselen + pathlen + 1] = '\0';
244 if (unpack_trees_rec(subposns, len, newbase, o,
245 df_conflict_list)) {
246 retval = -1;
247 goto leave_directory;
248 }
249 free(newbase);
250 }
251 free(subposns);
252 free(src);
253 } while (1);
254 leave_directory:
256 return retval;
257}
258/* Unlink the last component and attempt to remove leading
260 * directories, in case this unlink is the removal of the
261 * last entry in the directory -- empty directories are removed.
262 */
263static void unlink_entry(char *name, char *last_symlink)
264{
265 char *cp, *prev;
266 if (has_symlink_leading_path(name, last_symlink))
268 return;
269 if (unlink(name))
270 return;
271 prev = NULL;
272 while (1) {
273 int status;
274 cp = strrchr(name, '/');
275 if (prev)
276 *prev = '/';
277 if (!cp)
278 break;
279 *cp = 0;
281 status = rmdir(name);
282 if (status) {
283 *cp = '/';
284 break;
285 }
286 prev = cp;
287 }
288}
289static struct checkout state;
291static void check_updates(struct cache_entry **src, int nr,
292 struct unpack_trees_options *o)
293{
294 unsigned cnt = 0, total = 0;
295 struct progress *progress = NULL;
296 char last_symlink[PATH_MAX];
297 if (o->update && o->verbose_update) {
299 for (total = cnt = 0; cnt < nr; cnt++) {
300 struct cache_entry *ce = src[cnt];
301 if (ce->ce_flags & (CE_UPDATE | CE_REMOVE))
302 total++;
303 }
304 progress = start_progress_delay("Checking out files",
306 total, 50, 2);
307 cnt = 0;
308 }
309 *last_symlink = '\0';
311 while (nr--) {
312 struct cache_entry *ce = *src++;
313 if (ce->ce_flags & (CE_UPDATE | CE_REMOVE))
315 display_progress(progress, ++cnt);
316 if (ce->ce_flags & CE_REMOVE) {
317 if (o->update)
318 unlink_entry(ce->name, last_symlink);
319 continue;
320 }
321 if (ce->ce_flags & CE_UPDATE) {
322 ce->ce_flags &= ~CE_UPDATE;
323 if (o->update) {
324 checkout_entry(ce, &state, NULL);
325 *last_symlink = '\0';
326 }
327 }
328 }
329 stop_progress(&progress);
330}
331int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
333{
334 struct tree_entry_list **posns;
335 int i;
336 struct tree_entry_list df_conflict_list;
337 static struct cache_entry *dfc;
338 memset(&df_conflict_list, 0, sizeof(df_conflict_list));
340 df_conflict_list.next = &df_conflict_list;
341 memset(&state, 0, sizeof(state));
342 state.base_dir = "";
343 state.force = 1;
344 state.quiet = 1;
345 state.refresh_cache = 1;
346 o->merge_size = len;
348 if (!dfc)
350 dfc = xcalloc(1, sizeof(struct cache_entry) + 1);
351 o->df_conflict_entry = dfc;
352 if (len) {
354 posns = xmalloc(len * sizeof(struct tree_entry_list *));
355 for (i = 0; i < len; i++)
356 posns[i] = create_tree_entry_list(t+i);
357 if (unpack_trees_rec(posns, len, o->prefix ? o->prefix : "",
359 o, &df_conflict_list))
360 return -1;
361 }
362 if (o->trivial_merges_only && o->nontrivial_merge)
364 return error("Merge requires file-level merging");
365 check_updates(active_cache, active_nr, o);
367 return 0;
368}
369/* Here come the merge functions */
371static int reject_merge(struct cache_entry *ce)
373{
374 return error("Entry '%s' would be overwritten by merge. Cannot merge.",
375 ce->name);
376}
377static int same(struct cache_entry *a, struct cache_entry *b)
379{
380 if (!!a != !!b)
381 return 0;
382 if (!a && !b)
383 return 1;
384 return a->ce_mode == b->ce_mode &&
385 !hashcmp(a->sha1, b->sha1);
386}
387/*
390 * When a CE gets turned into an unmerged entry, we
391 * want it to be up-to-date
392 */
393static int verify_uptodate(struct cache_entry *ce,
394 struct unpack_trees_options *o)
395{
396 struct stat st;
397 if (o->index_only || o->reset)
399 return 0;
400 if (!lstat(ce->name, &st)) {
402 unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID);
403 if (!changed)
404 return 0;
405 /*
406 * NEEDSWORK: the current default policy is to allow
407 * submodule to be out of sync wrt the supermodule
408 * index. This needs to be tightened later for
409 * submodules that are marked to be automatically
410 * checked out.
411 */
412 if (S_ISGITLINK(ce->ce_mode))
413 return 0;
414 errno = 0;
415 }
416 if (errno == ENOENT)
417 return 0;
418 return error("Entry '%s' not uptodate. Cannot merge.", ce->name);
419}
420static void invalidate_ce_path(struct cache_entry *ce)
422{
423 if (ce)
424 cache_tree_invalidate_path(active_cache_tree, ce->name);
425}
426/*
428 * Check that checking out ce->sha1 in subdir ce->name is not
429 * going to overwrite any working files.
430 *
431 * Currently, git does not checkout subprojects during a superproject
432 * checkout, so it is not going to overwrite anything.
433 */
434static int verify_clean_submodule(struct cache_entry *ce, const char *action,
435 struct unpack_trees_options *o)
436{
437 return 0;
438}
439static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
441 struct unpack_trees_options *o)
442{
443 /*
444 * we are about to extract "ce->name"; we would not want to lose
445 * anything in the existing directory there.
446 */
447 int namelen;
448 int pos, i;
449 struct dir_struct d;
450 char *pathbuf;
451 int cnt = 0;
452 unsigned char sha1[20];
453 if (S_ISGITLINK(ce->ce_mode) &&
455 resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
456 /* If we are not going to update the submodule, then
457 * we don't care.
458 */
459 if (!hashcmp(sha1, ce->sha1))
460 return 0;
461 return verify_clean_submodule(ce, action, o);
462 }
463 /*
465 * First let's make sure we do not have a local modification
466 * in that directory.
467 */
468 namelen = strlen(ce->name);
469 pos = cache_name_pos(ce->name, namelen);
470 if (0 <= pos)
471 return cnt; /* we have it as nondirectory */
472 pos = -pos - 1;
473 for (i = pos; i < active_nr; i++) {
474 struct cache_entry *ce = active_cache[i];
475 int len = ce_namelen(ce);
476 if (len < namelen ||
477 strncmp(ce->name, ce->name, namelen) ||
478 ce->name[namelen] != '/')
479 break;
480 /*
481 * ce->name is an entry in the subdirectory.
482 */
483 if (!ce_stage(ce)) {
484 if (verify_uptodate(ce, o))
485 return -1;
486 ce->ce_flags |= CE_REMOVE;
487 }
488 cnt++;
489 }
490 /*
492 * Then we need to make sure that we do not lose a locally
493 * present file that is not ignored.
494 */
495 pathbuf = xmalloc(namelen + 2);
496 memcpy(pathbuf, ce->name, namelen);
497 strcpy(pathbuf+namelen, "/");
498 memset(&d, 0, sizeof(d));
500 if (o->dir)
501 d.exclude_per_dir = o->dir->exclude_per_dir;
502 i = read_directory(&d, ce->name, pathbuf, namelen+1, NULL);
503 if (i)
504 return error("Updating '%s' would lose untracked files in it",
505 ce->name);
506 free(pathbuf);
507 return cnt;
508}
509/*
511 * We do not want to remove or overwrite a working tree file that
512 * is not tracked, unless it is ignored.
513 */
514static int verify_absent(struct cache_entry *ce, const char *action,
515 struct unpack_trees_options *o)
516{
517 struct stat st;
518 if (o->index_only || o->reset || !o->update)
520 return 0;
521 if (has_symlink_leading_path(ce->name, NULL))
523 return 0;
524 if (!lstat(ce->name, &st)) {
526 int cnt;
527 if (o->dir && excluded(o->dir, ce->name))
529 /*
530 * ce->name is explicitly excluded, so it is Ok to
531 * overwrite it.
532 */
533 return 0;
534 if (S_ISDIR(st.st_mode)) {
535 /*
536 * We are checking out path "foo" and
537 * found "foo/." in the working tree.
538 * This is tricky -- if we have modified
539 * files that are in "foo/" we would lose
540 * it.
541 */
542 cnt = verify_clean_subdirectory(ce, action, o);
543 /*
545 * If this removed entries from the index,
546 * what that means is:
547 *
548 * (1) the caller unpack_trees_rec() saw path/foo
549 * in the index, and it has not removed it because
550 * it thinks it is handling 'path' as blob with
551 * D/F conflict;
552 * (2) we will return "ok, we placed a merged entry
553 * in the index" which would cause o->pos to be
554 * incremented by one;
555 * (3) however, original o->pos now has 'path/foo'
556 * marked with "to be removed".
557 *
558 * We need to increment it by the number of
559 * deleted entries here.
560 */
561 o->pos += cnt;
562 return 0;
563 }
564 /*
566 * The previous round may already have decided to
567 * delete this path, which is in a subdirectory that
568 * is being replaced with a blob.
569 */
570 cnt = cache_name_pos(ce->name, strlen(ce->name));
571 if (0 <= cnt) {
572 struct cache_entry *ce = active_cache[cnt];
573 if (ce->ce_flags & CE_REMOVE)
574 return 0;
575 }
576 return error("Untracked working tree file '%s' "
578 "would be %s by merge.", ce->name, action);
579 }
580 return 0;
581}
582static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
584 struct unpack_trees_options *o)
585{
586 merge->ce_flags |= 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 memcpy(merge, old, offsetof(struct cache_entry, name));
597 } else {
598 if (verify_uptodate(old, o))
599 return -1;
600 invalidate_ce_path(old);
601 }
602 }
603 else {
604 if (verify_absent(merge, "overwritten", o))
605 return -1;
606 invalidate_ce_path(merge);
607 }
608 merge->ce_flags &= ~CE_STAGEMASK;
610 add_cache_entry(merge, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
611 return 1;
612}
613static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
615 struct unpack_trees_options *o)
616{
617 if (old) {
618 if (verify_uptodate(old, o))
619 return -1;
620 } else
621 if (verify_absent(ce, "removed", o))
622 return -1;
623 ce->ce_flags |= CE_REMOVE;
624 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
625 invalidate_ce_path(ce);
626 return 1;
627}
628static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o)
630{
631 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
632 return 1;
633}
634#if DBRT_DEBUG
636static void show_stage_entry(FILE *o,
637 const char *label, const struct cache_entry *ce)
638{
639 if (!ce)
640 fprintf(o, "%s (missing)\n", label);
641 else
642 fprintf(o, "%s%06o %s %d\t%s\n",
643 label,
644 ce->ce_mode,
645 sha1_to_hex(ce->sha1),
646 ce_stage(ce),
647 ce->name);
648}
649#endif
650int threeway_merge(struct cache_entry **stages,
652 struct unpack_trees_options *o,
653 int remove)
654{
655 struct cache_entry *index;
656 struct cache_entry *head;
657 struct cache_entry *remote = stages[o->head_idx + 1];
658 int count;
659 int head_match = 0;
660 int remote_match = 0;
661 int df_conflict_head = 0;
663 int df_conflict_remote = 0;
664 int any_anc_missing = 0;
666 int no_anc_exists = 1;
667 int i;
668 for (i = 1; i < o->head_idx; i++) {
670 if (!stages[i] || stages[i] == o->df_conflict_entry)
671 any_anc_missing = 1;
672 else
673 no_anc_exists = 0;
674 }
675 index = stages[0];
677 head = stages[o->head_idx];
678 if (head == o->df_conflict_entry) {
680 df_conflict_head = 1;
681 head = NULL;
682 }
683 if (remote == o->df_conflict_entry) {
685 df_conflict_remote = 1;
686 remote = NULL;
687 }
688 /* First, if there's a #16 situation, note that to prevent #13
690 * and #14.
691 */
692 if (!same(remote, head)) {
693 for (i = 1; i < o->head_idx; i++) {
694 if (same(stages[i], head)) {
695 head_match = i;
696 }
697 if (same(stages[i], remote)) {
698 remote_match = i;
699 }
700 }
701 }
702 /* We start with cases where the index is allowed to match
704 * something other than the head: #14(ALT) and #2ALT, where it
705 * is permitted to match the result instead.
706 */
707 /* #14, #14ALT, #2ALT */
708 if (remote && !df_conflict_head && head_match && !remote_match) {
709 if (index && !same(index, remote) && !same(index, head))
710 return reject_merge(index);
711 return merged_entry(remote, index, o);
712 }
713 /*
714 * If we have an entry in the index cache, then we want to
715 * make sure that it matches head.
716 */
717 if (index && !same(index, head)) {
718 return reject_merge(index);
719 }
720 if (head) {
722 /* #5ALT, #15 */
723 if (same(head, remote))
724 return merged_entry(head, index, o);
725 /* #13, #3ALT */
726 if (!df_conflict_remote && remote_match && !head_match)
727 return merged_entry(head, index, o);
728 }
729 /* #1 */
731 if (!head && !remote && any_anc_missing) {
732 remove_entry(remove);
733 return 0;
734 }
735 /* Under the new "aggressive" rule, we resolve mostly trivial
737 * cases that we historically had git-merge-one-file resolve.
738 */
739 if (o->aggressive) {
740 int head_deleted = !head && !df_conflict_head;
741 int remote_deleted = !remote && !df_conflict_remote;
742 struct cache_entry *ce = NULL;
743 if (index)
745 ce = index;
746 else if (head)
747 ce = head;
748 else if (remote)
749 ce = remote;
750 else {
751 for (i = 1; i < o->head_idx; i++) {
752 if (stages[i] && stages[i] != o->df_conflict_entry) {
753 ce = stages[i];
754 break;
755 }
756 }
757 }
758 /*
760 * Deleted in both.
761 * Deleted in one and unchanged in the other.
762 */
763 if ((head_deleted && remote_deleted) ||
764 (head_deleted && remote && remote_match) ||
765 (remote_deleted && head && head_match)) {
766 remove_entry(remove);
767 if (index)
768 return deleted_entry(index, index, o);
769 else if (ce && !head_deleted) {
770 if (verify_absent(ce, "removed", o))
771 return -1;
772 }
773 return 0;
774 }
775 /*
776 * Added in both, identically.
777 */
778 if (no_anc_exists && head && remote && same(head, remote))
779 return merged_entry(head, index, o);
780 }
782 /* Below are "no merge" cases, which require that the index be
784 * up-to-date to avoid the files getting overwritten with
785 * conflict resolution files.
786 */
787 if (index) {
788 if (verify_uptodate(index, o))
789 return -1;
790 }
791 remove_entry(remove);
793 o->nontrivial_merge = 1;
794 /* #2, #3, #4, #6, #7, #9, #10, #11. */
796 count = 0;
797 if (!head_match || !remote_match) {
798 for (i = 1; i < o->head_idx; i++) {
799 if (stages[i] && stages[i] != o->df_conflict_entry) {
800 keep_entry(stages[i], o);
801 count++;
802 break;
803 }
804 }
805 }
806#if DBRT_DEBUG
807 else {
808 fprintf(stderr, "read-tree: warning #16 detected\n");
809 show_stage_entry(stderr, "head ", stages[head_match]);
810 show_stage_entry(stderr, "remote ", stages[remote_match]);
811 }
812#endif
813 if (head) { count += keep_entry(head, o); }
814 if (remote) { count += keep_entry(remote, o); }
815 return count;
816}
817/*
819 * Two-way merge.
820 *
821 * The rule is to "carry forward" what is in the index without losing
822 * information across a "fast forward", favoring a successful merge
823 * over a merge failure when it makes sense. For details of the
824 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
825 *
826 */
827int twoway_merge(struct cache_entry **src,
828 struct unpack_trees_options *o,
829 int remove)
830{
831 struct cache_entry *current = src[0];
832 struct cache_entry *oldtree = src[1];
833 struct cache_entry *newtree = src[2];
834 if (o->merge_size != 2)
836 return error("Cannot do a twoway merge of %d trees",
837 o->merge_size);
838 if (oldtree == o->df_conflict_entry)
840 oldtree = NULL;
841 if (newtree == o->df_conflict_entry)
842 newtree = NULL;
843 if (current) {
845 if ((!oldtree && !newtree) || /* 4 and 5 */
846 (!oldtree && newtree &&
847 same(current, newtree)) || /* 6 and 7 */
848 (oldtree && newtree &&
849 same(oldtree, newtree)) || /* 14 and 15 */
850 (oldtree && newtree &&
851 !same(oldtree, newtree) && /* 18 and 19 */
852 same(current, newtree))) {
853 return keep_entry(current, o);
854 }
855 else if (oldtree && !newtree && same(current, oldtree)) {
856 /* 10 or 11 */
857 remove_entry(remove);
858 return deleted_entry(oldtree, current, o);
859 }
860 else if (oldtree && newtree &&
861 same(current, oldtree) && !same(current, newtree)) {
862 /* 20 or 21 */
863 return merged_entry(newtree, current, o);
864 }
865 else {
866 /* all other failures */
867 remove_entry(remove);
868 if (oldtree)
869 return reject_merge(oldtree);
870 if (current)
871 return reject_merge(current);
872 if (newtree)
873 return reject_merge(newtree);
874 return -1;
875 }
876 }
877 else if (newtree)
878 return merged_entry(newtree, current, o);
879 remove_entry(remove);
880 return deleted_entry(oldtree, current, o);
881}
882/*
884 * Bind merge.
885 *
886 * Keep the index entries at stage0, collapse stage1 but make sure
887 * stage0 does not have anything there.
888 */
889int bind_merge(struct cache_entry **src,
890 struct unpack_trees_options *o,
891 int remove)
892{
893 struct cache_entry *old = src[0];
894 struct cache_entry *a = src[1];
895 if (o->merge_size != 1)
897 return error("Cannot do a bind merge of %d trees\n",
898 o->merge_size);
899 if (a && old)
900 return error("Entry '%s' overlaps. Cannot bind.", a->name);
901 if (!a)
902 return keep_entry(old, o);
903 else
904 return merged_entry(a, NULL, o);
905}
906/*
908 * One-way merge.
909 *
910 * The rule is:
911 * - take the stat information from stage0, take the data from stage1
912 */
913int oneway_merge(struct cache_entry **src,
914 struct unpack_trees_options *o,
915 int remove)
916{
917 struct cache_entry *old = src[0];
918 struct cache_entry *a = src[1];
919 if (o->merge_size != 1)
921 return error("Cannot do a oneway merge of %d trees",
922 o->merge_size);
923 if (!a) {
925 remove_entry(remove);
926 return deleted_entry(old, old, o);
927 }
928 if (old && same(old, a)) {
929 if (o->reset) {
930 struct stat st;
931 if (lstat(old->name, &st) ||
932 ce_match_stat(old, &st, CE_MATCH_IGNORE_VALID))
933 old->ce_flags |= CE_UPDATE;
934 }
935 return keep_entry(old, o);
936 }
937 return merged_entry(a, old, o);
938}