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#define DBRT_DEBUG 1
9struct tree_entry_list {
11 struct tree_entry_list *next;
12 unsigned directory : 1;
13 unsigned executable : 1;
14 unsigned symlink : 1;
15 unsigned int mode;
16 const char *name;
17 const unsigned char *sha1;
18};
19static struct tree_entry_list *create_tree_entry_list(struct tree *tree)
21{
22 struct tree_desc desc;
23 struct name_entry one;
24 struct tree_entry_list *ret = NULL;
25 struct tree_entry_list **list_p = &ret;
26 if (!tree->object.parsed)
28 parse_tree(tree);
29 init_tree_desc(&desc, tree->buffer, tree->size);
31 while (tree_entry(&desc, &one)) {
33 struct tree_entry_list *entry;
34 entry = xmalloc(sizeof(struct tree_entry_list));
36 entry->name = one.path;
37 entry->sha1 = one.sha1;
38 entry->mode = one.mode;
39 entry->directory = S_ISDIR(one.mode) != 0;
40 entry->executable = (one.mode & S_IXUSR) != 0;
41 entry->symlink = S_ISLNK(one.mode) != 0;
42 entry->next = NULL;
43 *list_p = entry;
45 list_p = &entry->next;
46 }
47 return ret;
48}
49static int entcmp(const char *name1, int dir1, const char *name2, int dir2)
51{
52 int len1 = strlen(name1);
53 int len2 = strlen(name2);
54 int len = len1 < len2 ? len1 : len2;
55 int ret = memcmp(name1, name2, len);
56 unsigned char c1, c2;
57 if (ret)
58 return ret;
59 c1 = name1[len];
60 c2 = name2[len];
61 if (!c1 && dir1)
62 c1 = '/';
63 if (!c2 && dir2)
64 c2 = '/';
65 ret = (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
66 if (c1 && c2 && !ret)
67 ret = len1 - len2;
68 return ret;
69}
70static int unpack_trees_rec(struct tree_entry_list **posns, int len,
72 const char *base, struct unpack_trees_options *o,
73 struct tree_entry_list *df_conflict_list)
74{
75 int baselen = strlen(base);
76 int src_size = len + 1;
77 int i_stk = i_stk;
78 int retval = 0;
79 if (o->dir)
81 i_stk = push_exclude_per_directory(o->dir, base, strlen(base));
82 do {
84 int i;
85 const char *first;
86 int firstdir = 0;
87 int pathlen;
88 unsigned ce_size;
89 struct tree_entry_list **subposns;
90 struct cache_entry **src;
91 int any_files = 0;
92 int any_dirs = 0;
93 char *cache_name;
94 int ce_stage;
95 /* Find the first name in the input. */
97 first = NULL;
99 cache_name = NULL;
100 /* Check the cache */
102 if (o->merge && o->pos < active_nr) {
103 /* This is a bit tricky: */
104 /* If the index has a subdirectory (with
105 * contents) as the first name, it'll get a
106 * filename like "foo/bar". But that's after
107 * "foo", so the entry in trees will get
108 * handled first, at which point we'll go into
109 * "foo", and deal with "bar" from the index,
110 * because the base will be "foo/". The only
111 * way we can actually have "foo/bar" first of
112 * all the things is if the trees don't
113 * contain "foo" at all, in which case we'll
114 * handle "foo/bar" without going into the
115 * directory, but that's fine (and will return
116 * an error anyway, with the added unknown
117 * file case.
118 */
119 cache_name = active_cache[o->pos]->name;
121 if (strlen(cache_name) > baselen &&
122 !memcmp(cache_name, base, baselen)) {
123 cache_name += baselen;
124 first = cache_name;
125 } else {
126 cache_name = NULL;
127 }
128 }
129#if DBRT_DEBUG > 1
131 if (first)
132 printf("index %s\n", first);
133#endif
134 for (i = 0; i < len; i++) {
135 if (!posns[i] || posns[i] == df_conflict_list)
136 continue;
137#if DBRT_DEBUG > 1
138 printf("%d %s\n", i + 1, posns[i]->name);
139#endif
140 if (!first || entcmp(first, firstdir,
141 posns[i]->name,
142 posns[i]->directory) > 0) {
143 first = posns[i]->name;
144 firstdir = posns[i]->directory;
145 }
146 }
147 /* No name means we're done */
148 if (!first)
149 goto leave_directory;
150 pathlen = strlen(first);
152 ce_size = cache_entry_size(baselen + pathlen);
153 src = xcalloc(src_size, sizeof(struct cache_entry *));
155 subposns = xcalloc(len, sizeof(struct tree_list_entry *));
157 if (cache_name && !strcmp(cache_name, first)) {
159 any_files = 1;
160 src[0] = active_cache[o->pos];
161 remove_cache_entry_at(o->pos);
162 }
163 for (i = 0; i < len; i++) {
165 struct cache_entry *ce;
166 if (!posns[i] ||
168 (posns[i] != df_conflict_list &&
169 strcmp(first, posns[i]->name))) {
170 continue;
171 }
172 if (posns[i] == df_conflict_list) {
174 src[i + o->merge] = o->df_conflict_entry;
175 continue;
176 }
177 if (posns[i]->directory) {
179 struct tree *tree = lookup_tree(posns[i]->sha1);
180 any_dirs = 1;
181 parse_tree(tree);
182 subposns[i] = create_tree_entry_list(tree);
183 posns[i] = posns[i]->next;
184 src[i + o->merge] = o->df_conflict_entry;
185 continue;
186 }
187 if (!o->merge)
189 ce_stage = 0;
190 else if (i + 1 < o->head_idx)
191 ce_stage = 1;
192 else if (i + 1 > o->head_idx)
193 ce_stage = 3;
194 else
195 ce_stage = 2;
196 ce = xcalloc(1, ce_size);
198 ce->ce_mode = create_ce_mode(posns[i]->mode);
199 ce->ce_flags = create_ce_flags(baselen + pathlen,
200 ce_stage);
201 memcpy(ce->name, base, baselen);
202 memcpy(ce->name + baselen, first, pathlen + 1);
203 any_files = 1;
205 hashcpy(ce->sha1, posns[i]->sha1);
207 src[i + o->merge] = ce;
208 subposns[i] = df_conflict_list;
209 posns[i] = posns[i]->next;
210 }
211 if (any_files) {
212 if (o->merge) {
213 int ret;
214#if DBRT_DEBUG > 1
216 printf("%s:\n", first);
217 for (i = 0; i < src_size; i++) {
218 printf(" %d ", i);
219 if (src[i])
220 printf("%s\n", sha1_to_hex(src[i]->sha1));
221 else
222 printf("\n");
223 }
224#endif
225 ret = o->fn(src, o);
226#if DBRT_DEBUG > 1
228 printf("Added %d entries\n", ret);
229#endif
230 o->pos += ret;
231 } else {
232 for (i = 0; i < src_size; i++) {
233 if (src[i]) {
234 add_cache_entry(src[i], ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
235 }
236 }
237 }
238 }
239 if (any_dirs) {
240 char *newbase = xmalloc(baselen + 2 + pathlen);
241 memcpy(newbase, base, baselen);
242 memcpy(newbase + baselen, first, pathlen);
243 newbase[baselen + pathlen] = '/';
244 newbase[baselen + pathlen + 1] = '\0';
245 if (unpack_trees_rec(subposns, len, newbase, o,
246 df_conflict_list)) {
247 retval = -1;
248 goto leave_directory;
249 }
250 free(newbase);
251 }
252 free(subposns);
253 free(src);
254 } while (1);
255 leave_directory:
257 if (o->dir)
258 pop_exclude_per_directory(o->dir, i_stk);
259 return retval;
260}
261/* Unlink the last component and attempt to remove leading
263 * directories, in case this unlink is the removal of the
264 * last entry in the directory -- empty directories are removed.
265 */
266static void unlink_entry(char *name)
267{
268 char *cp, *prev;
269 if (unlink(name))
271 return;
272 prev = NULL;
273 while (1) {
274 int status;
275 cp = strrchr(name, '/');
276 if (prev)
277 *prev = '/';
278 if (!cp)
279 break;
280 *cp = 0;
282 status = rmdir(name);
283 if (status) {
284 *cp = '/';
285 break;
286 }
287 prev = cp;
288 }
289}
290static volatile sig_atomic_t progress_update;
292static void progress_interval(int signum)
294{
295 progress_update = 1;
296}
297static void setup_progress_signal(void)
299{
300 struct sigaction sa;
301 struct itimerval v;
302 memset(&sa, 0, sizeof(sa));
304 sa.sa_handler = progress_interval;
305 sigemptyset(&sa.sa_mask);
306 sa.sa_flags = SA_RESTART;
307 sigaction(SIGALRM, &sa, NULL);
308 v.it_interval.tv_sec = 1;
310 v.it_interval.tv_usec = 0;
311 v.it_value = v.it_interval;
312 setitimer(ITIMER_REAL, &v, NULL);
313}
314static struct checkout state;
316static void check_updates(struct cache_entry **src, int nr,
317 struct unpack_trees_options *o)
318{
319 unsigned short mask = htons(CE_UPDATE);
320 unsigned last_percent = 200, cnt = 0, total = 0;
321 if (o->update && o->verbose_update) {
323 for (total = cnt = 0; cnt < nr; cnt++) {
324 struct cache_entry *ce = src[cnt];
325 if (!ce->ce_mode || ce->ce_flags & mask)
326 total++;
327 }
328 /* Don't bother doing this for very small updates */
330 if (total < 250)
331 total = 0;
332 if (total) {
334 fprintf(stderr, "Checking files out...\n");
335 setup_progress_signal();
336 progress_update = 1;
337 }
338 cnt = 0;
339 }
340 while (nr--) {
342 struct cache_entry *ce = *src++;
343 if (total) {
345 if (!ce->ce_mode || ce->ce_flags & mask) {
346 unsigned percent;
347 cnt++;
348 percent = (cnt * 100) / total;
349 if (percent != last_percent ||
350 progress_update) {
351 fprintf(stderr, "%4u%% (%u/%u) done\r",
352 percent, cnt, total);
353 last_percent = percent;
354 progress_update = 0;
355 }
356 }
357 }
358 if (!ce->ce_mode) {
359 if (o->update)
360 unlink_entry(ce->name);
361 continue;
362 }
363 if (ce->ce_flags & mask) {
364 ce->ce_flags &= ~mask;
365 if (o->update)
366 checkout_entry(ce, &state, NULL);
367 }
368 }
369 if (total) {
370 signal(SIGALRM, SIG_IGN);
371 fputc('\n', stderr);
372 }
373}
374int unpack_trees(struct object_list *trees, struct unpack_trees_options *o)
376{
377 unsigned len = object_list_length(trees);
378 struct tree_entry_list **posns;
379 int i;
380 struct object_list *posn = trees;
381 struct tree_entry_list df_conflict_list;
382 static struct cache_entry *dfc;
383 memset(&df_conflict_list, 0, sizeof(df_conflict_list));
385 df_conflict_list.next = &df_conflict_list;
386 memset(&state, 0, sizeof(state));
387 state.base_dir = "";
388 state.force = 1;
389 state.quiet = 1;
390 state.refresh_cache = 1;
391 o->merge_size = len;
393 if (!dfc)
395 dfc = xcalloc(1, sizeof(struct cache_entry) + 1);
396 o->df_conflict_entry = dfc;
397 if (len) {
399 posns = xmalloc(len * sizeof(struct tree_entry_list *));
400 for (i = 0; i < len; i++) {
401 posns[i] = create_tree_entry_list((struct tree *) posn->item);
402 posn = posn->next;
403 }
404 if (unpack_trees_rec(posns, len, o->prefix ? o->prefix : "",
405 o, &df_conflict_list))
406 return -1;
407 }
408 if (o->trivial_merges_only && o->nontrivial_merge)
410 die("Merge requires file-level merging");
411 check_updates(active_cache, active_nr, o);
413 return 0;
414}
415/* Here come the merge functions */
417static void reject_merge(struct cache_entry *ce)
419{
420 die("Entry '%s' would be overwritten by merge. Cannot merge.",
421 ce->name);
422}
423static int same(struct cache_entry *a, struct cache_entry *b)
425{
426 if (!!a != !!b)
427 return 0;
428 if (!a && !b)
429 return 1;
430 return a->ce_mode == b->ce_mode &&
431 !hashcmp(a->sha1, b->sha1);
432}
433/*
436 * When a CE gets turned into an unmerged entry, we
437 * want it to be up-to-date
438 */
439static void verify_uptodate(struct cache_entry *ce,
440 struct unpack_trees_options *o)
441{
442 struct stat st;
443 if (o->index_only || o->reset)
445 return;
446 if (!lstat(ce->name, &st)) {
448 unsigned changed = ce_match_stat(ce, &st, 1);
449 if (!changed)
450 return;
451 errno = 0;
452 }
453 if (o->reset) {
454 ce->ce_flags |= htons(CE_UPDATE);
455 return;
456 }
457 if (errno == ENOENT)
458 return;
459 die("Entry '%s' not uptodate. Cannot merge.", ce->name);
460}
461static void invalidate_ce_path(struct cache_entry *ce)
463{
464 if (ce)
465 cache_tree_invalidate_path(active_cache_tree, ce->name);
466}
467static int verify_clean_subdirectory(const char *path, const char *action,
469 struct unpack_trees_options *o)
470{
471 /*
472 * we are about to extract "path"; we would not want to lose
473 * anything in the existing directory there.
474 */
475 int namelen;
476 int pos, i;
477 struct dir_struct d;
478 char *pathbuf;
479 int cnt = 0;
480 /*
482 * First let's make sure we do not have a local modification
483 * in that directory.
484 */
485 namelen = strlen(path);
486 pos = cache_name_pos(path, namelen);
487 if (0 <= pos)
488 return cnt; /* we have it as nondirectory */
489 pos = -pos - 1;
490 for (i = pos; i < active_nr; i++) {
491 struct cache_entry *ce = active_cache[i];
492 int len = ce_namelen(ce);
493 if (len < namelen ||
494 strncmp(path, ce->name, namelen) ||
495 ce->name[namelen] != '/')
496 break;
497 /*
498 * ce->name is an entry in the subdirectory.
499 */
500 if (!ce_stage(ce)) {
501 verify_uptodate(ce, o);
502 ce->ce_mode = 0;
503 }
504 cnt++;
505 }
506 /*
508 * Then we need to make sure that we do not lose a locally
509 * present file that is not ignored.
510 */
511 pathbuf = xmalloc(namelen + 2);
512 memcpy(pathbuf, path, namelen);
513 strcpy(pathbuf+namelen, "/");
514 memset(&d, 0, sizeof(d));
516 if (o->dir)
517 d.exclude_per_dir = o->dir->exclude_per_dir;
518 i = read_directory(&d, path, pathbuf, namelen+1, NULL);
519 if (i)
520 die("Updating '%s' would lose untracked files in it",
521 path);
522 free(pathbuf);
523 return cnt;
524}
525/*
527 * We do not want to remove or overwrite a working tree file that
528 * is not tracked, unless it is ignored.
529 */
530static void verify_absent(const char *path, const char *action,
531 struct unpack_trees_options *o)
532{
533 struct stat st;
534 if (o->index_only || o->reset || !o->update)
536 return;
537 if (!lstat(path, &st)) {
539 int cnt;
540 if (o->dir && excluded(o->dir, path))
542 /*
543 * path is explicitly excluded, so it is Ok to
544 * overwrite it.
545 */
546 return;
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(path, 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;
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(path, strlen(path));
584 if (0 <= cnt) {
585 struct cache_entry *ce = active_cache[cnt];
586 if (!ce_stage(ce) && !ce->ce_mode)
587 return;
588 }
589 die("Untracked working tree file '%s' "
591 "would be %s by merge.", path, action);
592 }
593}
594static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
596 struct unpack_trees_options *o)
597{
598 merge->ce_flags |= htons(CE_UPDATE);
599 if (old) {
600 /*
601 * See if we can re-use the old CE directly?
602 * That way we get the uptodate stat info.
603 *
604 * This also removes the UPDATE flag on
605 * a match.
606 */
607 if (same(old, merge)) {
608 *merge = *old;
609 } else {
610 verify_uptodate(old, o);
611 invalidate_ce_path(old);
612 }
613 }
614 else {
615 verify_absent(merge->name, "overwritten", o);
616 invalidate_ce_path(merge);
617 }
618 merge->ce_flags &= ~htons(CE_STAGEMASK);
620 add_cache_entry(merge, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
621 return 1;
622}
623static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
625 struct unpack_trees_options *o)
626{
627 if (old)
628 verify_uptodate(old, o);
629 else
630 verify_absent(ce->name, "removed", o);
631 ce->ce_mode = 0;
632 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
633 invalidate_ce_path(ce);
634 return 1;
635}
636static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o)
638{
639 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
640 return 1;
641}
642#if DBRT_DEBUG
644static void show_stage_entry(FILE *o,
645 const char *label, const struct cache_entry *ce)
646{
647 if (!ce)
648 fprintf(o, "%s (missing)\n", label);
649 else
650 fprintf(o, "%s%06o %s %d\t%s\n",
651 label,
652 ntohl(ce->ce_mode),
653 sha1_to_hex(ce->sha1),
654 ce_stage(ce),
655 ce->name);
656}
657#endif
658int threeway_merge(struct cache_entry **stages,
660 struct unpack_trees_options *o)
661{
662 struct cache_entry *index;
663 struct cache_entry *head;
664 struct cache_entry *remote = stages[o->head_idx + 1];
665 int count;
666 int head_match = 0;
667 int remote_match = 0;
668 int df_conflict_head = 0;
670 int df_conflict_remote = 0;
671 int any_anc_missing = 0;
673 int no_anc_exists = 1;
674 int i;
675 for (i = 1; i < o->head_idx; i++) {
677 if (!stages[i] || stages[i] == o->df_conflict_entry)
678 any_anc_missing = 1;
679 else
680 no_anc_exists = 0;
681 }
682 index = stages[0];
684 head = stages[o->head_idx];
685 if (head == o->df_conflict_entry) {
687 df_conflict_head = 1;
688 head = NULL;
689 }
690 if (remote == o->df_conflict_entry) {
692 df_conflict_remote = 1;
693 remote = NULL;
694 }
695 /* First, if there's a #16 situation, note that to prevent #13
697 * and #14.
698 */
699 if (!same(remote, head)) {
700 for (i = 1; i < o->head_idx; i++) {
701 if (same(stages[i], head)) {
702 head_match = i;
703 }
704 if (same(stages[i], remote)) {
705 remote_match = i;
706 }
707 }
708 }
709 /* We start with cases where the index is allowed to match
711 * something other than the head: #14(ALT) and #2ALT, where it
712 * is permitted to match the result instead.
713 */
714 /* #14, #14ALT, #2ALT */
715 if (remote && !df_conflict_head && head_match && !remote_match) {
716 if (index && !same(index, remote) && !same(index, head))
717 reject_merge(index);
718 return merged_entry(remote, index, o);
719 }
720 /*
721 * If we have an entry in the index cache, then we want to
722 * make sure that it matches head.
723 */
724 if (index && !same(index, head)) {
725 reject_merge(index);
726 }
727 if (head) {
729 /* #5ALT, #15 */
730 if (same(head, remote))
731 return merged_entry(head, index, o);
732 /* #13, #3ALT */
733 if (!df_conflict_remote && remote_match && !head_match)
734 return merged_entry(head, index, o);
735 }
736 /* #1 */
738 if (!head && !remote && any_anc_missing)
739 return 0;
740 /* Under the new "aggressive" rule, we resolve mostly trivial
742 * cases that we historically had git-merge-one-file resolve.
743 */
744 if (o->aggressive) {
745 int head_deleted = !head && !df_conflict_head;
746 int remote_deleted = !remote && !df_conflict_remote;
747 const char *path = NULL;
748 if (index)
750 path = index->name;
751 else if (head)
752 path = head->name;
753 else if (remote)
754 path = remote->name;
755 else {
756 for (i = 1; i < o->head_idx; i++) {
757 if (stages[i] && stages[i] != o->df_conflict_entry) {
758 path = stages[i]->name;
759 break;
760 }
761 }
762 }
763 /*
765 * Deleted in both.
766 * Deleted in one and unchanged in the other.
767 */
768 if ((head_deleted && remote_deleted) ||
769 (head_deleted && remote && remote_match) ||
770 (remote_deleted && head && head_match)) {
771 if (index)
772 return deleted_entry(index, index, o);
773 else if (path && !head_deleted)
774 verify_absent(path, "removed", o);
775 return 0;
776 }
777 /*
778 * Added in both, identically.
779 */
780 if (no_anc_exists && head && remote && same(head, remote))
781 return merged_entry(head, index, o);
782 }
784 /* Below are "no merge" cases, which require that the index be
786 * up-to-date to avoid the files getting overwritten with
787 * conflict resolution files.
788 */
789 if (index) {
790 verify_uptodate(index, o);
791 }
792 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{
830 struct cache_entry *current = src[0];
831 struct cache_entry *oldtree = src[1];
832 struct cache_entry *newtree = src[2];
833 if (o->merge_size != 2)
835 return error("Cannot do a twoway merge of %d trees",
836 o->merge_size);
837 if (oldtree == o->df_conflict_entry)
839 oldtree = NULL;
840 if (newtree == o->df_conflict_entry)
841 newtree = NULL;
842 if (current) {
844 if ((!oldtree && !newtree) || /* 4 and 5 */
845 (!oldtree && newtree &&
846 same(current, newtree)) || /* 6 and 7 */
847 (oldtree && newtree &&
848 same(oldtree, newtree)) || /* 14 and 15 */
849 (oldtree && newtree &&
850 !same(oldtree, newtree) && /* 18 and 19 */
851 same(current, newtree))) {
852 return keep_entry(current, o);
853 }
854 else if (oldtree && !newtree && same(current, oldtree)) {
855 /* 10 or 11 */
856 return deleted_entry(oldtree, current, o);
857 }
858 else if (oldtree && newtree &&
859 same(current, oldtree) && !same(current, newtree)) {
860 /* 20 or 21 */
861 return merged_entry(newtree, current, o);
862 }
863 else {
864 /* all other failures */
865 if (oldtree)
866 reject_merge(oldtree);
867 if (current)
868 reject_merge(current);
869 if (newtree)
870 reject_merge(newtree);
871 return -1;
872 }
873 }
874 else if (newtree)
875 return merged_entry(newtree, current, o);
876 else
877 return deleted_entry(oldtree, current, o);
878}
879/*
881 * Bind merge.
882 *
883 * Keep the index entries at stage0, collapse stage1 but make sure
884 * stage0 does not have anything there.
885 */
886int bind_merge(struct cache_entry **src,
887 struct unpack_trees_options *o)
888{
889 struct cache_entry *old = src[0];
890 struct cache_entry *a = src[1];
891 if (o->merge_size != 1)
893 return error("Cannot do a bind merge of %d trees\n",
894 o->merge_size);
895 if (a && old)
896 die("Entry '%s' overlaps. Cannot bind.", a->name);
897 if (!a)
898 return keep_entry(old, o);
899 else
900 return merged_entry(a, NULL, o);
901}
902/*
904 * One-way merge.
905 *
906 * The rule is:
907 * - take the stat information from stage0, take the data from stage1
908 */
909int oneway_merge(struct cache_entry **src,
910 struct unpack_trees_options *o)
911{
912 struct cache_entry *old = src[0];
913 struct cache_entry *a = src[1];
914 if (o->merge_size != 1)
916 return error("Cannot do a oneway merge of %d trees",
917 o->merge_size);
918 if (!a)
920 return deleted_entry(old, old, o);
921 if (old && same(old, a)) {
922 if (o->reset) {
923 struct stat st;
924 if (lstat(old->name, &st) ||
925 ce_match_stat(old, &st, 1))
926 old->ce_flags |= htons(CE_UPDATE);
927 }
928 return keep_entry(old, o);
929 }
930 return merged_entry(a, old, o);
931}