40d41307583daba56e89d56a1dedab3d6eab572c
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 fprintf(stderr, "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 fprintf(stderr, "%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 fprintf(stderr, "%s:\n", first);
213 for (i = 0; i < src_size; i++) {
214 fprintf(stderr, " %d ", i);
215 if (src[i])
216 fprintf(stderr, "%06x %s\n", src[i]->ce_mode, sha1_to_hex(src[i]->sha1));
217 else
218 fprintf(stderr, "\n");
219 }
220#endif
221 ret = o->fn(src, o, remove);
222 if (ret < 0)
223 return ret;
224#if DBRT_DEBUG > 1
226 fprintf(stderr, "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 unpack_trees_options *o)
292{
293 unsigned cnt = 0, total = 0;
294 struct progress *progress = NULL;
295 char last_symlink[PATH_MAX];
296 int i;
297 if (o->update && o->verbose_update) {
299 for (total = cnt = 0; cnt < active_nr; cnt++) {
300 struct cache_entry *ce = active_cache[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 for (i = 0; i < active_nr; i++) {
312 struct cache_entry *ce = active_cache[i];
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 remove_cache_entry_at(i);
320 i--;
321 continue;
322 }
323 if (ce->ce_flags & CE_UPDATE) {
324 ce->ce_flags &= ~CE_UPDATE;
325 if (o->update) {
326 checkout_entry(ce, &state, NULL);
327 *last_symlink = '\0';
328 }
329 }
330 }
331 stop_progress(&progress);
332}
333int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
335{
336 struct tree_entry_list **posns;
337 int i;
338 struct tree_entry_list df_conflict_list;
339 static struct cache_entry *dfc;
340 memset(&df_conflict_list, 0, sizeof(df_conflict_list));
342 df_conflict_list.next = &df_conflict_list;
343 memset(&state, 0, sizeof(state));
344 state.base_dir = "";
345 state.force = 1;
346 state.quiet = 1;
347 state.refresh_cache = 1;
348 o->merge_size = len;
350 if (!dfc)
352 dfc = xcalloc(1, sizeof(struct cache_entry) + 1);
353 o->df_conflict_entry = dfc;
354 if (len) {
356 posns = xmalloc(len * sizeof(struct tree_entry_list *));
357 for (i = 0; i < len; i++)
358 posns[i] = create_tree_entry_list(t+i);
359 if (unpack_trees_rec(posns, len, o->prefix ? o->prefix : "",
361 o, &df_conflict_list)) {
362 if (o->gently) {
363 discard_cache();
364 read_cache();
365 }
366 return -1;
367 }
368 }
369 if (o->trivial_merges_only && o->nontrivial_merge) {
371 if (o->gently) {
372 discard_cache();
373 read_cache();
374 }
375 return o->gently ? -1 :
376 error("Merge requires file-level merging");
377 }
378 check_updates(o);
380 return 0;
381}
382/* Here come the merge functions */
384static int reject_merge(struct cache_entry *ce)
386{
387 return error("Entry '%s' would be overwritten by merge. Cannot merge.",
388 ce->name);
389}
390static int same(struct cache_entry *a, struct cache_entry *b)
392{
393 if (!!a != !!b)
394 return 0;
395 if (!a && !b)
396 return 1;
397 return a->ce_mode == b->ce_mode &&
398 !hashcmp(a->sha1, b->sha1);
399}
400/*
403 * When a CE gets turned into an unmerged entry, we
404 * want it to be up-to-date
405 */
406static int verify_uptodate(struct cache_entry *ce,
407 struct unpack_trees_options *o)
408{
409 struct stat st;
410 if (o->index_only || o->reset)
412 return 0;
413 if (!lstat(ce->name, &st)) {
415 unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID);
416 if (!changed)
417 return 0;
418 /*
419 * NEEDSWORK: the current default policy is to allow
420 * submodule to be out of sync wrt the supermodule
421 * index. This needs to be tightened later for
422 * submodules that are marked to be automatically
423 * checked out.
424 */
425 if (S_ISGITLINK(ce->ce_mode))
426 return 0;
427 errno = 0;
428 }
429 if (errno == ENOENT)
430 return 0;
431 return o->gently ? -1 :
432 error("Entry '%s' not uptodate. Cannot merge.", ce->name);
433}
434static void invalidate_ce_path(struct cache_entry *ce)
436{
437 if (ce)
438 cache_tree_invalidate_path(active_cache_tree, ce->name);
439}
440/*
442 * Check that checking out ce->sha1 in subdir ce->name is not
443 * going to overwrite any working files.
444 *
445 * Currently, git does not checkout subprojects during a superproject
446 * checkout, so it is not going to overwrite anything.
447 */
448static int verify_clean_submodule(struct cache_entry *ce, const char *action,
449 struct unpack_trees_options *o)
450{
451 return 0;
452}
453static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
455 struct unpack_trees_options *o)
456{
457 /*
458 * we are about to extract "ce->name"; we would not want to lose
459 * anything in the existing directory there.
460 */
461 int namelen;
462 int pos, i;
463 struct dir_struct d;
464 char *pathbuf;
465 int cnt = 0;
466 unsigned char sha1[20];
467 if (S_ISGITLINK(ce->ce_mode) &&
469 resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
470 /* If we are not going to update the submodule, then
471 * we don't care.
472 */
473 if (!hashcmp(sha1, ce->sha1))
474 return 0;
475 return verify_clean_submodule(ce, action, o);
476 }
477 /*
479 * First let's make sure we do not have a local modification
480 * in that directory.
481 */
482 namelen = strlen(ce->name);
483 pos = cache_name_pos(ce->name, namelen);
484 if (0 <= pos)
485 return cnt; /* we have it as nondirectory */
486 pos = -pos - 1;
487 for (i = pos; i < active_nr; i++) {
488 struct cache_entry *ce = active_cache[i];
489 int len = ce_namelen(ce);
490 if (len < namelen ||
491 strncmp(ce->name, ce->name, namelen) ||
492 ce->name[namelen] != '/')
493 break;
494 /*
495 * ce->name is an entry in the subdirectory.
496 */
497 if (!ce_stage(ce)) {
498 if (verify_uptodate(ce, o))
499 return -1;
500 ce->ce_flags |= CE_REMOVE;
501 }
502 cnt++;
503 }
504 /*
506 * Then we need to make sure that we do not lose a locally
507 * present file that is not ignored.
508 */
509 pathbuf = xmalloc(namelen + 2);
510 memcpy(pathbuf, ce->name, namelen);
511 strcpy(pathbuf+namelen, "/");
512 memset(&d, 0, sizeof(d));
514 if (o->dir)
515 d.exclude_per_dir = o->dir->exclude_per_dir;
516 i = read_directory(&d, ce->name, pathbuf, namelen+1, NULL);
517 if (i)
518 return o->gently ? -1 :
519 error("Updating '%s' would lose untracked files in it",
520 ce->name);
521 free(pathbuf);
522 return cnt;
523}
524/*
526 * We do not want to remove or overwrite a working tree file that
527 * is not tracked, unless it is ignored.
528 */
529static int verify_absent(struct cache_entry *ce, const char *action,
530 struct unpack_trees_options *o)
531{
532 struct stat st;
533 if (o->index_only || o->reset || !o->update)
535 return 0;
536 if (has_symlink_leading_path(ce->name, NULL))
538 return 0;
539 if (!lstat(ce->name, &st)) {
541 int cnt;
542 if (o->dir && excluded(o->dir, ce->name))
544 /*
545 * ce->name is explicitly excluded, so it is Ok to
546 * overwrite it.
547 */
548 return 0;
549 if (S_ISDIR(st.st_mode)) {
550 /*
551 * We are checking out path "foo" and
552 * found "foo/." in the working tree.
553 * This is tricky -- if we have modified
554 * files that are in "foo/" we would lose
555 * it.
556 */
557 cnt = verify_clean_subdirectory(ce, action, o);
558 /*
560 * If this removed entries from the index,
561 * what that means is:
562 *
563 * (1) the caller unpack_trees_rec() saw path/foo
564 * in the index, and it has not removed it because
565 * it thinks it is handling 'path' as blob with
566 * D/F conflict;
567 * (2) we will return "ok, we placed a merged entry
568 * in the index" which would cause o->pos to be
569 * incremented by one;
570 * (3) however, original o->pos now has 'path/foo'
571 * marked with "to be removed".
572 *
573 * We need to increment it by the number of
574 * deleted entries here.
575 */
576 o->pos += cnt;
577 return 0;
578 }
579 /*
581 * The previous round may already have decided to
582 * delete this path, which is in a subdirectory that
583 * is being replaced with a blob.
584 */
585 cnt = cache_name_pos(ce->name, strlen(ce->name));
586 if (0 <= cnt) {
587 struct cache_entry *ce = active_cache[cnt];
588 if (ce->ce_flags & CE_REMOVE)
589 return 0;
590 }
591 return o->gently ? -1 :
593 error("Untracked working tree file '%s' "
594 "would be %s by merge.", ce->name, action);
595 }
596 return 0;
597}
598static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
600 struct unpack_trees_options *o)
601{
602 merge->ce_flags |= CE_UPDATE;
603 if (old) {
604 /*
605 * See if we can re-use the old CE directly?
606 * That way we get the uptodate stat info.
607 *
608 * This also removes the UPDATE flag on
609 * a match.
610 */
611 if (same(old, merge)) {
612 memcpy(merge, old, offsetof(struct cache_entry, name));
613 } else {
614 if (verify_uptodate(old, o))
615 return -1;
616 invalidate_ce_path(old);
617 }
618 }
619 else {
620 if (verify_absent(merge, "overwritten", o))
621 return -1;
622 invalidate_ce_path(merge);
623 }
624 merge->ce_flags &= ~CE_STAGEMASK;
626 add_cache_entry(merge, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
627 return 1;
628}
629static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
631 struct unpack_trees_options *o)
632{
633 if (old) {
634 if (verify_uptodate(old, o))
635 return -1;
636 } else
637 if (verify_absent(ce, "removed", o))
638 return -1;
639 ce->ce_flags |= CE_REMOVE;
640 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
641 invalidate_ce_path(ce);
642 return 1;
643}
644static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o)
646{
647 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
648 return 1;
649}
650#if DBRT_DEBUG
652static void show_stage_entry(FILE *o,
653 const char *label, const struct cache_entry *ce)
654{
655 if (!ce)
656 fprintf(o, "%s (missing)\n", label);
657 else
658 fprintf(o, "%s%06o %s %d\t%s\n",
659 label,
660 ce->ce_mode,
661 sha1_to_hex(ce->sha1),
662 ce_stage(ce),
663 ce->name);
664}
665#endif
666int threeway_merge(struct cache_entry **stages,
668 struct unpack_trees_options *o,
669 int remove)
670{
671 struct cache_entry *index;
672 struct cache_entry *head;
673 struct cache_entry *remote = stages[o->head_idx + 1];
674 int count;
675 int head_match = 0;
676 int remote_match = 0;
677 int df_conflict_head = 0;
679 int df_conflict_remote = 0;
680 int any_anc_missing = 0;
682 int no_anc_exists = 1;
683 int i;
684 for (i = 1; i < o->head_idx; i++) {
686 if (!stages[i] || stages[i] == o->df_conflict_entry)
687 any_anc_missing = 1;
688 else
689 no_anc_exists = 0;
690 }
691 index = stages[0];
693 head = stages[o->head_idx];
694 if (head == o->df_conflict_entry) {
696 df_conflict_head = 1;
697 head = NULL;
698 }
699 if (remote == o->df_conflict_entry) {
701 df_conflict_remote = 1;
702 remote = NULL;
703 }
704 /* First, if there's a #16 situation, note that to prevent #13
706 * and #14.
707 */
708 if (!same(remote, head)) {
709 for (i = 1; i < o->head_idx; i++) {
710 if (same(stages[i], head)) {
711 head_match = i;
712 }
713 if (same(stages[i], remote)) {
714 remote_match = i;
715 }
716 }
717 }
718 /* We start with cases where the index is allowed to match
720 * something other than the head: #14(ALT) and #2ALT, where it
721 * is permitted to match the result instead.
722 */
723 /* #14, #14ALT, #2ALT */
724 if (remote && !df_conflict_head && head_match && !remote_match) {
725 if (index && !same(index, remote) && !same(index, head))
726 return o->gently ? -1 : reject_merge(index);
727 return merged_entry(remote, index, o);
728 }
729 /*
730 * If we have an entry in the index cache, then we want to
731 * make sure that it matches head.
732 */
733 if (index && !same(index, head)) {
734 return o->gently ? -1 : reject_merge(index);
735 }
736 if (head) {
738 /* #5ALT, #15 */
739 if (same(head, remote))
740 return merged_entry(head, index, o);
741 /* #13, #3ALT */
742 if (!df_conflict_remote && remote_match && !head_match)
743 return merged_entry(head, index, o);
744 }
745 /* #1 */
747 if (!head && !remote && any_anc_missing) {
748 remove_entry(remove);
749 return 0;
750 }
751 /* Under the new "aggressive" rule, we resolve mostly trivial
753 * cases that we historically had git-merge-one-file resolve.
754 */
755 if (o->aggressive) {
756 int head_deleted = !head && !df_conflict_head;
757 int remote_deleted = !remote && !df_conflict_remote;
758 struct cache_entry *ce = NULL;
759 if (index)
761 ce = index;
762 else if (head)
763 ce = head;
764 else if (remote)
765 ce = remote;
766 else {
767 for (i = 1; i < o->head_idx; i++) {
768 if (stages[i] && stages[i] != o->df_conflict_entry) {
769 ce = stages[i];
770 break;
771 }
772 }
773 }
774 /*
776 * Deleted in both.
777 * Deleted in one and unchanged in the other.
778 */
779 if ((head_deleted && remote_deleted) ||
780 (head_deleted && remote && remote_match) ||
781 (remote_deleted && head && head_match)) {
782 remove_entry(remove);
783 if (index)
784 return deleted_entry(index, index, o);
785 else if (ce && !head_deleted) {
786 if (verify_absent(ce, "removed", o))
787 return -1;
788 }
789 return 0;
790 }
791 /*
792 * Added in both, identically.
793 */
794 if (no_anc_exists && head && remote && same(head, remote))
795 return merged_entry(head, index, o);
796 }
798 /* Below are "no merge" cases, which require that the index be
800 * up-to-date to avoid the files getting overwritten with
801 * conflict resolution files.
802 */
803 if (index) {
804 if (verify_uptodate(index, o))
805 return -1;
806 }
807 remove_entry(remove);
809 o->nontrivial_merge = 1;
810 /* #2, #3, #4, #6, #7, #9, #10, #11. */
812 count = 0;
813 if (!head_match || !remote_match) {
814 for (i = 1; i < o->head_idx; i++) {
815 if (stages[i] && stages[i] != o->df_conflict_entry) {
816 keep_entry(stages[i], o);
817 count++;
818 break;
819 }
820 }
821 }
822#if DBRT_DEBUG
823 else {
824 fprintf(stderr, "read-tree: warning #16 detected\n");
825 show_stage_entry(stderr, "head ", stages[head_match]);
826 show_stage_entry(stderr, "remote ", stages[remote_match]);
827 }
828#endif
829 if (head) { count += keep_entry(head, o); }
830 if (remote) { count += keep_entry(remote, o); }
831 return count;
832}
833/*
835 * Two-way merge.
836 *
837 * The rule is to "carry forward" what is in the index without losing
838 * information across a "fast forward", favoring a successful merge
839 * over a merge failure when it makes sense. For details of the
840 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
841 *
842 */
843int twoway_merge(struct cache_entry **src,
844 struct unpack_trees_options *o,
845 int remove)
846{
847 struct cache_entry *current = src[0];
848 struct cache_entry *oldtree = src[1];
849 struct cache_entry *newtree = src[2];
850 if (o->merge_size != 2)
852 return error("Cannot do a twoway merge of %d trees",
853 o->merge_size);
854 if (oldtree == o->df_conflict_entry)
856 oldtree = NULL;
857 if (newtree == o->df_conflict_entry)
858 newtree = NULL;
859 if (current) {
861 if ((!oldtree && !newtree) || /* 4 and 5 */
862 (!oldtree && newtree &&
863 same(current, newtree)) || /* 6 and 7 */
864 (oldtree && newtree &&
865 same(oldtree, newtree)) || /* 14 and 15 */
866 (oldtree && newtree &&
867 !same(oldtree, newtree) && /* 18 and 19 */
868 same(current, newtree))) {
869 return keep_entry(current, o);
870 }
871 else if (oldtree && !newtree && same(current, oldtree)) {
872 /* 10 or 11 */
873 remove_entry(remove);
874 return deleted_entry(oldtree, current, o);
875 }
876 else if (oldtree && newtree &&
877 same(current, oldtree) && !same(current, newtree)) {
878 /* 20 or 21 */
879 return merged_entry(newtree, current, o);
880 }
881 else {
882 /* all other failures */
883 remove_entry(remove);
884 if (oldtree)
885 return o->gently ? -1 : reject_merge(oldtree);
886 if (current)
887 return o->gently ? -1 : reject_merge(current);
888 if (newtree)
889 return o->gently ? -1 : reject_merge(newtree);
890 return -1;
891 }
892 }
893 else if (newtree)
894 return merged_entry(newtree, current, o);
895 remove_entry(remove);
896 return deleted_entry(oldtree, current, o);
897}
898/*
900 * Bind merge.
901 *
902 * Keep the index entries at stage0, collapse stage1 but make sure
903 * stage0 does not have anything there.
904 */
905int bind_merge(struct cache_entry **src,
906 struct unpack_trees_options *o,
907 int remove)
908{
909 struct cache_entry *old = src[0];
910 struct cache_entry *a = src[1];
911 if (o->merge_size != 1)
913 return error("Cannot do a bind merge of %d trees\n",
914 o->merge_size);
915 if (a && old)
916 return o->gently ? -1 :
917 error("Entry '%s' overlaps. Cannot bind.", a->name);
918 if (!a)
919 return keep_entry(old, o);
920 else
921 return merged_entry(a, NULL, o);
922}
923/*
925 * One-way merge.
926 *
927 * The rule is:
928 * - take the stat information from stage0, take the data from stage1
929 */
930int oneway_merge(struct cache_entry **src,
931 struct unpack_trees_options *o,
932 int remove)
933{
934 struct cache_entry *old = src[0];
935 struct cache_entry *a = src[1];
936 if (o->merge_size != 1)
938 return error("Cannot do a oneway merge of %d trees",
939 o->merge_size);
940 if (!a) {
942 remove_entry(remove);
943 return deleted_entry(old, old, o);
944 }
945 if (old && same(old, a)) {
946 if (o->reset) {
947 struct stat st;
948 if (lstat(old->name, &st) ||
949 ce_match_stat(old, &st, CE_MATCH_IGNORE_VALID))
950 old->ce_flags |= CE_UPDATE;
951 }
952 return keep_entry(old, o);
953 }
954 return merged_entry(a, old, o);
955}