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 if (o->gently) {
361 discard_cache();
362 read_cache();
363 }
364 return -1;
365 }
366 }
367 if (o->trivial_merges_only && o->nontrivial_merge) {
369 if (o->gently) {
370 discard_cache();
371 read_cache();
372 }
373 return o->gently ? -1 :
374 error("Merge requires file-level merging");
375 }
376 check_updates(active_cache, active_nr, o);
378 return 0;
379}
380/* Here come the merge functions */
382static int reject_merge(struct cache_entry *ce)
384{
385 return error("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 int 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 0;
411 if (!lstat(ce->name, &st)) {
413 unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID);
414 if (!changed)
415 return 0;
416 /*
417 * NEEDSWORK: the current default policy is to allow
418 * submodule to be out of sync wrt the supermodule
419 * index. This needs to be tightened later for
420 * submodules that are marked to be automatically
421 * checked out.
422 */
423 if (S_ISGITLINK(ce->ce_mode))
424 return 0;
425 errno = 0;
426 }
427 if (errno == ENOENT)
428 return 0;
429 return o->gently ? -1 :
430 error("Entry '%s' not uptodate. Cannot merge.", ce->name);
431}
432static void invalidate_ce_path(struct cache_entry *ce)
434{
435 if (ce)
436 cache_tree_invalidate_path(active_cache_tree, ce->name);
437}
438/*
440 * Check that checking out ce->sha1 in subdir ce->name is not
441 * going to overwrite any working files.
442 *
443 * Currently, git does not checkout subprojects during a superproject
444 * checkout, so it is not going to overwrite anything.
445 */
446static int verify_clean_submodule(struct cache_entry *ce, const char *action,
447 struct unpack_trees_options *o)
448{
449 return 0;
450}
451static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
453 struct unpack_trees_options *o)
454{
455 /*
456 * we are about to extract "ce->name"; we would not want to lose
457 * anything in the existing directory there.
458 */
459 int namelen;
460 int pos, i;
461 struct dir_struct d;
462 char *pathbuf;
463 int cnt = 0;
464 unsigned char sha1[20];
465 if (S_ISGITLINK(ce->ce_mode) &&
467 resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
468 /* If we are not going to update the submodule, then
469 * we don't care.
470 */
471 if (!hashcmp(sha1, ce->sha1))
472 return 0;
473 return verify_clean_submodule(ce, action, o);
474 }
475 /*
477 * First let's make sure we do not have a local modification
478 * in that directory.
479 */
480 namelen = strlen(ce->name);
481 pos = cache_name_pos(ce->name, namelen);
482 if (0 <= pos)
483 return cnt; /* we have it as nondirectory */
484 pos = -pos - 1;
485 for (i = pos; i < active_nr; i++) {
486 struct cache_entry *ce = active_cache[i];
487 int len = ce_namelen(ce);
488 if (len < namelen ||
489 strncmp(ce->name, ce->name, namelen) ||
490 ce->name[namelen] != '/')
491 break;
492 /*
493 * ce->name is an entry in the subdirectory.
494 */
495 if (!ce_stage(ce)) {
496 if (verify_uptodate(ce, o))
497 return -1;
498 ce->ce_flags |= CE_REMOVE;
499 }
500 cnt++;
501 }
502 /*
504 * Then we need to make sure that we do not lose a locally
505 * present file that is not ignored.
506 */
507 pathbuf = xmalloc(namelen + 2);
508 memcpy(pathbuf, ce->name, namelen);
509 strcpy(pathbuf+namelen, "/");
510 memset(&d, 0, sizeof(d));
512 if (o->dir)
513 d.exclude_per_dir = o->dir->exclude_per_dir;
514 i = read_directory(&d, ce->name, pathbuf, namelen+1, NULL);
515 if (i)
516 return o->gently ? -1 :
517 error("Updating '%s' would lose untracked files in it",
518 ce->name);
519 free(pathbuf);
520 return cnt;
521}
522/*
524 * We do not want to remove or overwrite a working tree file that
525 * is not tracked, unless it is ignored.
526 */
527static int verify_absent(struct cache_entry *ce, const char *action,
528 struct unpack_trees_options *o)
529{
530 struct stat st;
531 if (o->index_only || o->reset || !o->update)
533 return 0;
534 if (has_symlink_leading_path(ce->name, NULL))
536 return 0;
537 if (!lstat(ce->name, &st)) {
539 int cnt;
540 if (o->dir && excluded(o->dir, ce->name))
542 /*
543 * ce->name is explicitly excluded, so it is Ok to
544 * overwrite it.
545 */
546 return 0;
547 if (S_ISDIR(st.st_mode)) {
548 /*
549 * We are checking out path "foo" and
550 * found "foo/." in the working tree.
551 * This is tricky -- if we have modified
552 * files that are in "foo/" we would lose
553 * it.
554 */
555 cnt = verify_clean_subdirectory(ce, action, o);
556 /*
558 * If this removed entries from the index,
559 * what that means is:
560 *
561 * (1) the caller unpack_trees_rec() saw path/foo
562 * in the index, and it has not removed it because
563 * it thinks it is handling 'path' as blob with
564 * D/F conflict;
565 * (2) we will return "ok, we placed a merged entry
566 * in the index" which would cause o->pos to be
567 * incremented by one;
568 * (3) however, original o->pos now has 'path/foo'
569 * marked with "to be removed".
570 *
571 * We need to increment it by the number of
572 * deleted entries here.
573 */
574 o->pos += cnt;
575 return 0;
576 }
577 /*
579 * The previous round may already have decided to
580 * delete this path, which is in a subdirectory that
581 * is being replaced with a blob.
582 */
583 cnt = cache_name_pos(ce->name, strlen(ce->name));
584 if (0 <= cnt) {
585 struct cache_entry *ce = active_cache[cnt];
586 if (ce->ce_flags & CE_REMOVE)
587 return 0;
588 }
589 return o->gently ? -1 :
591 error("Untracked working tree file '%s' "
592 "would be %s by merge.", ce->name, action);
593 }
594 return 0;
595}
596static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
598 struct unpack_trees_options *o)
599{
600 merge->ce_flags |= CE_UPDATE;
601 if (old) {
602 /*
603 * See if we can re-use the old CE directly?
604 * That way we get the uptodate stat info.
605 *
606 * This also removes the UPDATE flag on
607 * a match.
608 */
609 if (same(old, merge)) {
610 memcpy(merge, old, offsetof(struct cache_entry, name));
611 } else {
612 if (verify_uptodate(old, o))
613 return -1;
614 invalidate_ce_path(old);
615 }
616 }
617 else {
618 if (verify_absent(merge, "overwritten", o))
619 return -1;
620 invalidate_ce_path(merge);
621 }
622 merge->ce_flags &= ~CE_STAGEMASK;
624 add_cache_entry(merge, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
625 return 1;
626}
627static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
629 struct unpack_trees_options *o)
630{
631 if (old) {
632 if (verify_uptodate(old, o))
633 return -1;
634 } else
635 if (verify_absent(ce, "removed", o))
636 return -1;
637 ce->ce_flags |= CE_REMOVE;
638 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
639 invalidate_ce_path(ce);
640 return 1;
641}
642static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o)
644{
645 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
646 return 1;
647}
648#if DBRT_DEBUG
650static void show_stage_entry(FILE *o,
651 const char *label, const struct cache_entry *ce)
652{
653 if (!ce)
654 fprintf(o, "%s (missing)\n", label);
655 else
656 fprintf(o, "%s%06o %s %d\t%s\n",
657 label,
658 ce->ce_mode,
659 sha1_to_hex(ce->sha1),
660 ce_stage(ce),
661 ce->name);
662}
663#endif
664int threeway_merge(struct cache_entry **stages,
666 struct unpack_trees_options *o,
667 int remove)
668{
669 struct cache_entry *index;
670 struct cache_entry *head;
671 struct cache_entry *remote = stages[o->head_idx + 1];
672 int count;
673 int head_match = 0;
674 int remote_match = 0;
675 int df_conflict_head = 0;
677 int df_conflict_remote = 0;
678 int any_anc_missing = 0;
680 int no_anc_exists = 1;
681 int i;
682 for (i = 1; i < o->head_idx; i++) {
684 if (!stages[i] || stages[i] == o->df_conflict_entry)
685 any_anc_missing = 1;
686 else
687 no_anc_exists = 0;
688 }
689 index = stages[0];
691 head = stages[o->head_idx];
692 if (head == o->df_conflict_entry) {
694 df_conflict_head = 1;
695 head = NULL;
696 }
697 if (remote == o->df_conflict_entry) {
699 df_conflict_remote = 1;
700 remote = NULL;
701 }
702 /* First, if there's a #16 situation, note that to prevent #13
704 * and #14.
705 */
706 if (!same(remote, head)) {
707 for (i = 1; i < o->head_idx; i++) {
708 if (same(stages[i], head)) {
709 head_match = i;
710 }
711 if (same(stages[i], remote)) {
712 remote_match = i;
713 }
714 }
715 }
716 /* We start with cases where the index is allowed to match
718 * something other than the head: #14(ALT) and #2ALT, where it
719 * is permitted to match the result instead.
720 */
721 /* #14, #14ALT, #2ALT */
722 if (remote && !df_conflict_head && head_match && !remote_match) {
723 if (index && !same(index, remote) && !same(index, head))
724 return o->gently ? -1 : reject_merge(index);
725 return merged_entry(remote, index, o);
726 }
727 /*
728 * If we have an entry in the index cache, then we want to
729 * make sure that it matches head.
730 */
731 if (index && !same(index, head)) {
732 return o->gently ? -1 : reject_merge(index);
733 }
734 if (head) {
736 /* #5ALT, #15 */
737 if (same(head, remote))
738 return merged_entry(head, index, o);
739 /* #13, #3ALT */
740 if (!df_conflict_remote && remote_match && !head_match)
741 return merged_entry(head, index, o);
742 }
743 /* #1 */
745 if (!head && !remote && any_anc_missing) {
746 remove_entry(remove);
747 return 0;
748 }
749 /* Under the new "aggressive" rule, we resolve mostly trivial
751 * cases that we historically had git-merge-one-file resolve.
752 */
753 if (o->aggressive) {
754 int head_deleted = !head && !df_conflict_head;
755 int remote_deleted = !remote && !df_conflict_remote;
756 struct cache_entry *ce = NULL;
757 if (index)
759 ce = index;
760 else if (head)
761 ce = head;
762 else if (remote)
763 ce = remote;
764 else {
765 for (i = 1; i < o->head_idx; i++) {
766 if (stages[i] && stages[i] != o->df_conflict_entry) {
767 ce = stages[i];
768 break;
769 }
770 }
771 }
772 /*
774 * Deleted in both.
775 * Deleted in one and unchanged in the other.
776 */
777 if ((head_deleted && remote_deleted) ||
778 (head_deleted && remote && remote_match) ||
779 (remote_deleted && head && head_match)) {
780 remove_entry(remove);
781 if (index)
782 return deleted_entry(index, index, o);
783 else if (ce && !head_deleted) {
784 if (verify_absent(ce, "removed", o))
785 return -1;
786 }
787 return 0;
788 }
789 /*
790 * Added in both, identically.
791 */
792 if (no_anc_exists && head && remote && same(head, remote))
793 return merged_entry(head, index, o);
794 }
796 /* Below are "no merge" cases, which require that the index be
798 * up-to-date to avoid the files getting overwritten with
799 * conflict resolution files.
800 */
801 if (index) {
802 if (verify_uptodate(index, o))
803 return -1;
804 }
805 remove_entry(remove);
807 o->nontrivial_merge = 1;
808 /* #2, #3, #4, #6, #7, #9, #10, #11. */
810 count = 0;
811 if (!head_match || !remote_match) {
812 for (i = 1; i < o->head_idx; i++) {
813 if (stages[i] && stages[i] != o->df_conflict_entry) {
814 keep_entry(stages[i], o);
815 count++;
816 break;
817 }
818 }
819 }
820#if DBRT_DEBUG
821 else {
822 fprintf(stderr, "read-tree: warning #16 detected\n");
823 show_stage_entry(stderr, "head ", stages[head_match]);
824 show_stage_entry(stderr, "remote ", stages[remote_match]);
825 }
826#endif
827 if (head) { count += keep_entry(head, o); }
828 if (remote) { count += keep_entry(remote, o); }
829 return count;
830}
831/*
833 * Two-way merge.
834 *
835 * The rule is to "carry forward" what is in the index without losing
836 * information across a "fast forward", favoring a successful merge
837 * over a merge failure when it makes sense. For details of the
838 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
839 *
840 */
841int twoway_merge(struct cache_entry **src,
842 struct unpack_trees_options *o,
843 int remove)
844{
845 struct cache_entry *current = src[0];
846 struct cache_entry *oldtree = src[1];
847 struct cache_entry *newtree = src[2];
848 if (o->merge_size != 2)
850 return error("Cannot do a twoway merge of %d trees",
851 o->merge_size);
852 if (oldtree == o->df_conflict_entry)
854 oldtree = NULL;
855 if (newtree == o->df_conflict_entry)
856 newtree = NULL;
857 if (current) {
859 if ((!oldtree && !newtree) || /* 4 and 5 */
860 (!oldtree && newtree &&
861 same(current, newtree)) || /* 6 and 7 */
862 (oldtree && newtree &&
863 same(oldtree, newtree)) || /* 14 and 15 */
864 (oldtree && newtree &&
865 !same(oldtree, newtree) && /* 18 and 19 */
866 same(current, newtree))) {
867 return keep_entry(current, o);
868 }
869 else if (oldtree && !newtree && same(current, oldtree)) {
870 /* 10 or 11 */
871 remove_entry(remove);
872 return deleted_entry(oldtree, current, o);
873 }
874 else if (oldtree && newtree &&
875 same(current, oldtree) && !same(current, newtree)) {
876 /* 20 or 21 */
877 return merged_entry(newtree, current, o);
878 }
879 else {
880 /* all other failures */
881 remove_entry(remove);
882 if (oldtree)
883 return o->gently ? -1 : reject_merge(oldtree);
884 if (current)
885 return o->gently ? -1 : reject_merge(current);
886 if (newtree)
887 return o->gently ? -1 : reject_merge(newtree);
888 return -1;
889 }
890 }
891 else if (newtree)
892 return merged_entry(newtree, current, o);
893 remove_entry(remove);
894 return deleted_entry(oldtree, current, o);
895}
896/*
898 * Bind merge.
899 *
900 * Keep the index entries at stage0, collapse stage1 but make sure
901 * stage0 does not have anything there.
902 */
903int bind_merge(struct cache_entry **src,
904 struct unpack_trees_options *o,
905 int remove)
906{
907 struct cache_entry *old = src[0];
908 struct cache_entry *a = src[1];
909 if (o->merge_size != 1)
911 return error("Cannot do a bind merge of %d trees\n",
912 o->merge_size);
913 if (a && old)
914 return o->gently ? -1 :
915 error("Entry '%s' overlaps. Cannot bind.", a->name);
916 if (!a)
917 return keep_entry(old, o);
918 else
919 return merged_entry(a, NULL, o);
920}
921/*
923 * One-way merge.
924 *
925 * The rule is:
926 * - take the stat information from stage0, take the data from stage1
927 */
928int oneway_merge(struct cache_entry **src,
929 struct unpack_trees_options *o,
930 int remove)
931{
932 struct cache_entry *old = src[0];
933 struct cache_entry *a = src[1];
934 if (o->merge_size != 1)
936 return error("Cannot do a oneway merge of %d trees",
937 o->merge_size);
938 if (!a) {
940 remove_entry(remove);
941 return deleted_entry(old, old, o);
942 }
943 if (old && same(old, a)) {
944 if (o->reset) {
945 struct stat st;
946 if (lstat(old->name, &st) ||
947 ce_match_stat(old, &st, CE_MATCH_IGNORE_VALID))
948 old->ce_flags |= CE_UPDATE;
949 }
950 return keep_entry(old, o);
951 }
952 return merged_entry(a, old, o);
953}