Windows: boost startup by avoiding a static dependency on shell32.dll
[git/dscho.git] / unpack-trees.c
blobacdd3117370e596716a0bdb751d6255690e6c700
1 #define NO_THE_INDEX_COMPATIBILITY_MACROS
2 #include "cache.h"
3 #include "dir.h"
4 #include "tree.h"
5 #include "tree-walk.h"
6 #include "cache-tree.h"
7 #include "unpack-trees.h"
8 #include "progress.h"
9 #include "refs.h"
10 #include "attr.h"
13 * Error messages expected by scripts out of plumbing commands such as
14 * read-tree. Non-scripted Porcelain is not required to use these messages
15 * and in fact are encouraged to reword them to better suit their particular
16 * situation better. See how "git checkout" replaces not_uptodate_file to
17 * explain why it does not allow switching between branches when you have
18 * local changes, for example.
20 static struct unpack_trees_error_msgs unpack_plumbing_errors = {
21 /* would_overwrite */
22 "Entry '%s' would be overwritten by merge. Cannot merge.",
24 /* not_uptodate_file */
25 "Entry '%s' not uptodate. Cannot merge.",
27 /* not_uptodate_dir */
28 "Updating '%s' would lose untracked files in it",
30 /* would_lose_untracked */
31 "Untracked working tree file '%s' would be %s by merge.",
33 /* bind_overlap */
34 "Entry '%s' overlaps with '%s'. Cannot bind.",
36 /* sparse_not_uptodate_file */
37 "Entry '%s' not uptodate. Cannot update sparse checkout.",
39 /* would_lose_orphaned */
40 "Working tree file '%s' would be %s by sparse checkout update.",
43 #define ERRORMSG(o,fld) \
44 ( ((o) && (o)->msgs.fld) \
45 ? ((o)->msgs.fld) \
46 : (unpack_plumbing_errors.fld) )
48 static void add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
49 unsigned int set, unsigned int clear)
51 unsigned int size = ce_size(ce);
52 struct cache_entry *new = xmalloc(size);
54 clear |= CE_HASHED | CE_UNHASHED;
56 memcpy(new, ce, size);
57 new->next = NULL;
58 new->ce_flags = (new->ce_flags & ~clear) | set;
59 add_index_entry(&o->result, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
63 * Unlink the last component and schedule the leading directories for
64 * removal, such that empty directories get removed.
66 static void unlink_entry(struct cache_entry *ce)
68 if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
69 return;
70 if (unlink_or_warn(ce->name))
71 return;
72 schedule_dir_for_removal(ce->name, ce_namelen(ce));
75 static struct checkout state;
76 static int check_updates(struct unpack_trees_options *o)
78 unsigned cnt = 0, total = 0;
79 struct progress *progress = NULL;
80 struct index_state *index = &o->result;
81 int i;
82 int errs = 0;
84 if (o->update && o->verbose_update) {
85 for (total = cnt = 0; cnt < index->cache_nr; cnt++) {
86 struct cache_entry *ce = index->cache[cnt];
87 if (ce->ce_flags & (CE_UPDATE | CE_REMOVE | CE_WT_REMOVE))
88 total++;
91 progress = start_progress_delay("Checking out files",
92 total, 50, 1);
93 cnt = 0;
96 if (o->update)
97 git_attr_set_direction(GIT_ATTR_CHECKOUT, &o->result);
98 for (i = 0; i < index->cache_nr; i++) {
99 struct cache_entry *ce = index->cache[i];
101 if (ce->ce_flags & CE_WT_REMOVE) {
102 display_progress(progress, ++cnt);
103 if (o->update)
104 unlink_entry(ce);
105 continue;
108 if (ce->ce_flags & CE_REMOVE) {
109 display_progress(progress, ++cnt);
110 if (o->update)
111 unlink_entry(ce);
114 remove_marked_cache_entries(&o->result);
115 remove_scheduled_dirs();
117 for (i = 0; i < index->cache_nr; i++) {
118 struct cache_entry *ce = index->cache[i];
120 if (ce->ce_flags & CE_UPDATE) {
121 display_progress(progress, ++cnt);
122 ce->ce_flags &= ~CE_UPDATE;
123 if (o->update) {
124 errs |= checkout_entry(ce, &state, NULL);
128 stop_progress(&progress);
129 if (o->update)
130 git_attr_set_direction(GIT_ATTR_CHECKIN, NULL);
131 return errs != 0;
134 static int verify_uptodate_sparse(struct cache_entry *ce, struct unpack_trees_options *o);
135 static int verify_absent_sparse(struct cache_entry *ce, const char *action, struct unpack_trees_options *o);
137 static int will_have_skip_worktree(const struct cache_entry *ce, struct unpack_trees_options *o)
139 const char *basename;
141 if (ce_stage(ce))
142 return 0;
144 basename = strrchr(ce->name, '/');
145 basename = basename ? basename+1 : ce->name;
146 return excluded_from_list(ce->name, ce_namelen(ce), basename, NULL, o->el) <= 0;
149 static int apply_sparse_checkout(struct cache_entry *ce, struct unpack_trees_options *o)
151 int was_skip_worktree = ce_skip_worktree(ce);
153 if (will_have_skip_worktree(ce, o))
154 ce->ce_flags |= CE_SKIP_WORKTREE;
155 else
156 ce->ce_flags &= ~CE_SKIP_WORKTREE;
159 * We only care about files getting into the checkout area
160 * If merge strategies want to remove some, go ahead, this
161 * flag will be removed eventually in unpack_trees() if it's
162 * outside checkout area.
164 if (ce->ce_flags & CE_REMOVE)
165 return 0;
167 if (!was_skip_worktree && ce_skip_worktree(ce)) {
169 * If CE_UPDATE is set, verify_uptodate() must be called already
170 * also stat info may have lost after merged_entry() so calling
171 * verify_uptodate() again may fail
173 if (!(ce->ce_flags & CE_UPDATE) && verify_uptodate_sparse(ce, o))
174 return -1;
175 ce->ce_flags |= CE_WT_REMOVE;
177 if (was_skip_worktree && !ce_skip_worktree(ce)) {
178 if (verify_absent_sparse(ce, "overwritten", o))
179 return -1;
180 ce->ce_flags |= CE_UPDATE;
182 return 0;
185 static inline int call_unpack_fn(struct cache_entry **src, struct unpack_trees_options *o)
187 int ret = o->fn(src, o);
188 if (ret > 0)
189 ret = 0;
190 return ret;
193 static int unpack_index_entry(struct cache_entry *ce, struct unpack_trees_options *o)
195 struct cache_entry *src[5] = { ce, NULL, };
197 o->pos++;
198 if (ce_stage(ce)) {
199 if (o->skip_unmerged) {
200 add_entry(o, ce, 0, 0);
201 return 0;
204 return call_unpack_fn(src, o);
207 static int traverse_trees_recursive(int n, unsigned long dirmask, unsigned long df_conflicts, struct name_entry *names, struct traverse_info *info)
209 int i;
210 struct tree_desc t[MAX_UNPACK_TREES];
211 struct traverse_info newinfo;
212 struct name_entry *p;
214 p = names;
215 while (!p->mode)
216 p++;
218 newinfo = *info;
219 newinfo.prev = info;
220 newinfo.name = *p;
221 newinfo.pathlen += tree_entry_len(p->path, p->sha1) + 1;
222 newinfo.conflicts |= df_conflicts;
224 for (i = 0; i < n; i++, dirmask >>= 1) {
225 const unsigned char *sha1 = NULL;
226 if (dirmask & 1)
227 sha1 = names[i].sha1;
228 fill_tree_descriptor(t+i, sha1);
230 return traverse_trees(n, t, &newinfo);
234 * Compare the traverse-path to the cache entry without actually
235 * having to generate the textual representation of the traverse
236 * path.
238 * NOTE! This *only* compares up to the size of the traverse path
239 * itself - the caller needs to do the final check for the cache
240 * entry having more data at the end!
242 static int do_compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
244 int len, pathlen, ce_len;
245 const char *ce_name;
247 if (info->prev) {
248 int cmp = do_compare_entry(ce, info->prev, &info->name);
249 if (cmp)
250 return cmp;
252 pathlen = info->pathlen;
253 ce_len = ce_namelen(ce);
255 /* If ce_len < pathlen then we must have previously hit "name == directory" entry */
256 if (ce_len < pathlen)
257 return -1;
259 ce_len -= pathlen;
260 ce_name = ce->name + pathlen;
262 len = tree_entry_len(n->path, n->sha1);
263 return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode);
266 static int compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
268 int cmp = do_compare_entry(ce, info, n);
269 if (cmp)
270 return cmp;
273 * Even if the beginning compared identically, the ce should
274 * compare as bigger than a directory leading up to it!
276 return ce_namelen(ce) > traverse_path_len(info, n);
279 static struct cache_entry *create_ce_entry(const struct traverse_info *info, const struct name_entry *n, int stage)
281 int len = traverse_path_len(info, n);
282 struct cache_entry *ce = xcalloc(1, cache_entry_size(len));
284 ce->ce_mode = create_ce_mode(n->mode);
285 ce->ce_flags = create_ce_flags(len, stage);
286 hashcpy(ce->sha1, n->sha1);
287 make_traverse_path(ce->name, info, n);
289 return ce;
292 static int unpack_nondirectories(int n, unsigned long mask,
293 unsigned long dirmask,
294 struct cache_entry **src,
295 const struct name_entry *names,
296 const struct traverse_info *info)
298 int i;
299 struct unpack_trees_options *o = info->data;
300 unsigned long conflicts;
302 /* Do we have *only* directories? Nothing to do */
303 if (mask == dirmask && !src[0])
304 return 0;
306 conflicts = info->conflicts;
307 if (o->merge)
308 conflicts >>= 1;
309 conflicts |= dirmask;
312 * Ok, we've filled in up to any potential index entry in src[0],
313 * now do the rest.
315 for (i = 0; i < n; i++) {
316 int stage;
317 unsigned int bit = 1ul << i;
318 if (conflicts & bit) {
319 src[i + o->merge] = o->df_conflict_entry;
320 continue;
322 if (!(mask & bit))
323 continue;
324 if (!o->merge)
325 stage = 0;
326 else if (i + 1 < o->head_idx)
327 stage = 1;
328 else if (i + 1 > o->head_idx)
329 stage = 3;
330 else
331 stage = 2;
332 src[i + o->merge] = create_ce_entry(info, names + i, stage);
335 if (o->merge)
336 return call_unpack_fn(src, o);
338 for (i = 0; i < n; i++)
339 if (src[i] && src[i] != o->df_conflict_entry)
340 add_entry(o, src[i], 0, 0);
341 return 0;
344 static int unpack_failed(struct unpack_trees_options *o, const char *message)
346 discard_index(&o->result);
347 if (!o->gently) {
348 if (message)
349 return error("%s", message);
350 return -1;
352 return -1;
355 static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *names, struct traverse_info *info)
357 struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
358 struct unpack_trees_options *o = info->data;
359 const struct name_entry *p = names;
361 /* Find first entry with a real name (we could use "mask" too) */
362 while (!p->mode)
363 p++;
365 /* Are we supposed to look at the index too? */
366 if (o->merge) {
367 while (o->pos < o->src_index->cache_nr) {
368 struct cache_entry *ce = o->src_index->cache[o->pos];
369 int cmp = compare_entry(ce, info, p);
370 if (cmp < 0) {
371 if (unpack_index_entry(ce, o) < 0)
372 return unpack_failed(o, NULL);
373 continue;
375 if (!cmp) {
376 o->pos++;
377 if (ce_stage(ce)) {
379 * If we skip unmerged index entries, we'll skip this
380 * entry *and* the tree entries associated with it!
382 if (o->skip_unmerged) {
383 add_entry(o, ce, 0, 0);
384 return mask;
387 src[0] = ce;
389 break;
393 if (unpack_nondirectories(n, mask, dirmask, src, names, info) < 0)
394 return -1;
396 /* Now handle any directories.. */
397 if (dirmask) {
398 unsigned long conflicts = mask & ~dirmask;
399 if (o->merge) {
400 conflicts <<= 1;
401 if (src[0])
402 conflicts |= 1;
405 /* special case: "diff-index --cached" looking at a tree */
406 if (o->diff_index_cached &&
407 n == 1 && dirmask == 1 && S_ISDIR(names->mode)) {
408 int matches;
409 matches = cache_tree_matches_traversal(o->src_index->cache_tree,
410 names, info);
412 * Everything under the name matches. Adjust o->pos to
413 * skip the entire hierarchy.
415 if (matches) {
416 o->pos += matches;
417 return mask;
421 if (traverse_trees_recursive(n, dirmask, conflicts,
422 names, info) < 0)
423 return -1;
424 return mask;
427 return mask;
431 * N-way merge "len" trees. Returns 0 on success, -1 on failure to manipulate the
432 * resulting index, -2 on failure to reflect the changes to the work tree.
434 int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
436 int i, ret;
437 static struct cache_entry *dfc;
438 struct exclude_list el;
440 if (len > MAX_UNPACK_TREES)
441 die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
442 memset(&state, 0, sizeof(state));
443 state.base_dir = "";
444 state.force = 1;
445 state.quiet = 1;
446 state.refresh_cache = 1;
448 memset(&el, 0, sizeof(el));
449 if (!core_apply_sparse_checkout || !o->update)
450 o->skip_sparse_checkout = 1;
451 if (!o->skip_sparse_checkout) {
452 if (add_excludes_from_file_to_list(git_path("info/sparse-checkout"), "", 0, NULL, &el, 0) < 0)
453 o->skip_sparse_checkout = 1;
454 else
455 o->el = &el;
458 memset(&o->result, 0, sizeof(o->result));
459 o->result.initialized = 1;
460 if (o->src_index) {
461 o->result.timestamp.sec = o->src_index->timestamp.sec;
462 o->result.timestamp.nsec = o->src_index->timestamp.nsec;
464 o->merge_size = len;
466 if (!dfc)
467 dfc = xcalloc(1, cache_entry_size(0));
468 o->df_conflict_entry = dfc;
470 if (len) {
471 const char *prefix = o->prefix ? o->prefix : "";
472 struct traverse_info info;
474 setup_traverse_info(&info, prefix);
475 info.fn = unpack_callback;
476 info.data = o;
478 if (traverse_trees(len, t, &info) < 0) {
479 ret = unpack_failed(o, NULL);
480 goto done;
484 /* Any left-over entries in the index? */
485 if (o->merge) {
486 while (o->pos < o->src_index->cache_nr) {
487 struct cache_entry *ce = o->src_index->cache[o->pos];
488 if (unpack_index_entry(ce, o) < 0) {
489 ret = unpack_failed(o, NULL);
490 goto done;
495 if (o->trivial_merges_only && o->nontrivial_merge) {
496 ret = unpack_failed(o, "Merge requires file-level merging");
497 goto done;
500 if (!o->skip_sparse_checkout) {
501 int empty_worktree = 1;
502 for (i = 0;i < o->result.cache_nr;i++) {
503 struct cache_entry *ce = o->result.cache[i];
505 if (apply_sparse_checkout(ce, o)) {
506 ret = -1;
507 goto done;
510 * Merge strategies may set CE_UPDATE|CE_REMOVE outside checkout
511 * area as a result of ce_skip_worktree() shortcuts in
512 * verify_absent() and verify_uptodate(). Clear them.
514 if (ce_skip_worktree(ce))
515 ce->ce_flags &= ~(CE_UPDATE | CE_REMOVE);
516 else
517 empty_worktree = 0;
520 if (o->result.cache_nr && empty_worktree) {
521 ret = unpack_failed(o, "Sparse checkout leaves no entry on working directory");
522 goto done;
526 o->src_index = NULL;
527 ret = check_updates(o) ? (-2) : 0;
528 if (o->dst_index)
529 *o->dst_index = o->result;
531 done:
532 for (i = 0;i < el.nr;i++)
533 free(el.excludes[i]);
534 if (el.excludes)
535 free(el.excludes);
537 return ret;
540 /* Here come the merge functions */
542 static int reject_merge(struct cache_entry *ce, struct unpack_trees_options *o)
544 return error(ERRORMSG(o, would_overwrite), ce->name);
547 static int same(struct cache_entry *a, struct cache_entry *b)
549 if (!!a != !!b)
550 return 0;
551 if (!a && !b)
552 return 1;
553 if ((a->ce_flags | b->ce_flags) & CE_CONFLICTED)
554 return 0;
555 return a->ce_mode == b->ce_mode &&
556 !hashcmp(a->sha1, b->sha1);
561 * When a CE gets turned into an unmerged entry, we
562 * want it to be up-to-date
564 static int verify_uptodate_1(struct cache_entry *ce,
565 struct unpack_trees_options *o,
566 const char *error_msg)
568 struct stat st;
570 if (o->index_only || (!ce_skip_worktree(ce) && (o->reset || ce_uptodate(ce))))
571 return 0;
573 if (!lstat(ce->name, &st)) {
574 unsigned changed = ie_match_stat(o->src_index, ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
575 if (!changed)
576 return 0;
578 * NEEDSWORK: the current default policy is to allow
579 * submodule to be out of sync wrt the supermodule
580 * index. This needs to be tightened later for
581 * submodules that are marked to be automatically
582 * checked out.
584 if (S_ISGITLINK(ce->ce_mode))
585 return 0;
586 errno = 0;
588 if (errno == ENOENT)
589 return 0;
590 return o->gently ? -1 :
591 error(error_msg, ce->name);
594 static int verify_uptodate(struct cache_entry *ce,
595 struct unpack_trees_options *o)
597 if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
598 return 0;
599 return verify_uptodate_1(ce, o, ERRORMSG(o, not_uptodate_file));
602 static int verify_uptodate_sparse(struct cache_entry *ce,
603 struct unpack_trees_options *o)
605 return verify_uptodate_1(ce, o, ERRORMSG(o, sparse_not_uptodate_file));
608 static void invalidate_ce_path(struct cache_entry *ce, struct unpack_trees_options *o)
610 if (ce)
611 cache_tree_invalidate_path(o->src_index->cache_tree, ce->name);
615 * Check that checking out ce->sha1 in subdir ce->name is not
616 * going to overwrite any working files.
618 * Currently, git does not checkout subprojects during a superproject
619 * checkout, so it is not going to overwrite anything.
621 static int verify_clean_submodule(struct cache_entry *ce, const char *action,
622 struct unpack_trees_options *o)
624 return 0;
627 static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
628 struct unpack_trees_options *o)
631 * we are about to extract "ce->name"; we would not want to lose
632 * anything in the existing directory there.
634 int namelen;
635 int i;
636 struct dir_struct d;
637 char *pathbuf;
638 int cnt = 0;
639 unsigned char sha1[20];
641 if (S_ISGITLINK(ce->ce_mode) &&
642 resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
643 /* If we are not going to update the submodule, then
644 * we don't care.
646 if (!hashcmp(sha1, ce->sha1))
647 return 0;
648 return verify_clean_submodule(ce, action, o);
652 * First let's make sure we do not have a local modification
653 * in that directory.
655 namelen = strlen(ce->name);
656 for (i = o->pos; i < o->src_index->cache_nr; i++) {
657 struct cache_entry *ce2 = o->src_index->cache[i];
658 int len = ce_namelen(ce2);
659 if (len < namelen ||
660 strncmp(ce->name, ce2->name, namelen) ||
661 ce2->name[namelen] != '/')
662 break;
664 * ce2->name is an entry in the subdirectory.
666 if (!ce_stage(ce2)) {
667 if (verify_uptodate(ce2, o))
668 return -1;
669 add_entry(o, ce2, CE_REMOVE, 0);
671 cnt++;
675 * Then we need to make sure that we do not lose a locally
676 * present file that is not ignored.
678 pathbuf = xmalloc(namelen + 2);
679 memcpy(pathbuf, ce->name, namelen);
680 strcpy(pathbuf+namelen, "/");
682 memset(&d, 0, sizeof(d));
683 if (o->dir)
684 d.exclude_per_dir = o->dir->exclude_per_dir;
685 i = read_directory(&d, pathbuf, namelen+1, NULL);
686 if (i)
687 return o->gently ? -1 :
688 error(ERRORMSG(o, not_uptodate_dir), ce->name);
689 free(pathbuf);
690 return cnt;
694 * This gets called when there was no index entry for the tree entry 'dst',
695 * but we found a file in the working tree that 'lstat()' said was fine,
696 * and we're on a case-insensitive filesystem.
698 * See if we can find a case-insensitive match in the index that also
699 * matches the stat information, and assume it's that other file!
701 static int icase_exists(struct unpack_trees_options *o, struct cache_entry *dst, struct stat *st)
703 struct cache_entry *src;
705 src = index_name_exists(o->src_index, dst->name, ce_namelen(dst), 1);
706 return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
710 * We do not want to remove or overwrite a working tree file that
711 * is not tracked, unless it is ignored.
713 static int verify_absent_1(struct cache_entry *ce, const char *action,
714 struct unpack_trees_options *o,
715 const char *error_msg)
717 struct stat st;
719 if (o->index_only || o->reset || !o->update)
720 return 0;
722 if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
723 return 0;
725 if (!lstat(ce->name, &st)) {
726 int ret;
727 int dtype = ce_to_dtype(ce);
728 struct cache_entry *result;
731 * It may be that the 'lstat()' succeeded even though
732 * target 'ce' was absent, because there is an old
733 * entry that is different only in case..
735 * Ignore that lstat() if it matches.
737 if (ignore_case && icase_exists(o, ce, &st))
738 return 0;
740 if (o->dir && excluded(o->dir, ce->name, &dtype))
742 * ce->name is explicitly excluded, so it is Ok to
743 * overwrite it.
745 return 0;
746 if (S_ISDIR(st.st_mode)) {
748 * We are checking out path "foo" and
749 * found "foo/." in the working tree.
750 * This is tricky -- if we have modified
751 * files that are in "foo/" we would lose
752 * them.
754 ret = verify_clean_subdirectory(ce, action, o);
755 if (ret < 0)
756 return ret;
759 * If this removed entries from the index,
760 * what that means is:
762 * (1) the caller unpack_callback() saw path/foo
763 * in the index, and it has not removed it because
764 * it thinks it is handling 'path' as blob with
765 * D/F conflict;
766 * (2) we will return "ok, we placed a merged entry
767 * in the index" which would cause o->pos to be
768 * incremented by one;
769 * (3) however, original o->pos now has 'path/foo'
770 * marked with "to be removed".
772 * We need to increment it by the number of
773 * deleted entries here.
775 o->pos += ret;
776 return 0;
780 * The previous round may already have decided to
781 * delete this path, which is in a subdirectory that
782 * is being replaced with a blob.
784 result = index_name_exists(&o->result, ce->name, ce_namelen(ce), 0);
785 if (result) {
786 if (result->ce_flags & CE_REMOVE)
787 return 0;
790 return o->gently ? -1 :
791 error(ERRORMSG(o, would_lose_untracked), ce->name, action);
793 return 0;
795 static int verify_absent(struct cache_entry *ce, const char *action,
796 struct unpack_trees_options *o)
798 if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
799 return 0;
800 return verify_absent_1(ce, action, o, ERRORMSG(o, would_lose_untracked));
803 static int verify_absent_sparse(struct cache_entry *ce, const char *action,
804 struct unpack_trees_options *o)
806 return verify_absent_1(ce, action, o, ERRORMSG(o, would_lose_orphaned));
809 static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
810 struct unpack_trees_options *o)
812 int update = CE_UPDATE;
814 if (!old) {
815 if (verify_absent(merge, "overwritten", o))
816 return -1;
817 invalidate_ce_path(merge, o);
818 } else if (!(old->ce_flags & CE_CONFLICTED)) {
820 * See if we can re-use the old CE directly?
821 * That way we get the uptodate stat info.
823 * This also removes the UPDATE flag on a match; otherwise
824 * we will end up overwriting local changes in the work tree.
826 if (same(old, merge)) {
827 copy_cache_entry(merge, old);
828 update = 0;
829 } else {
830 if (verify_uptodate(old, o))
831 return -1;
832 if (ce_skip_worktree(old))
833 update |= CE_SKIP_WORKTREE;
834 invalidate_ce_path(old, o);
836 } else {
838 * Previously unmerged entry left as an existence
839 * marker by read_index_unmerged();
841 invalidate_ce_path(old, o);
844 add_entry(o, merge, update, CE_STAGEMASK);
845 return 1;
848 static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
849 struct unpack_trees_options *o)
851 /* Did it exist in the index? */
852 if (!old) {
853 if (verify_absent(ce, "removed", o))
854 return -1;
855 return 0;
857 if (!(old->ce_flags & CE_CONFLICTED) && verify_uptodate(old, o))
858 return -1;
859 add_entry(o, ce, CE_REMOVE, 0);
860 invalidate_ce_path(ce, o);
861 return 1;
864 static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o)
866 add_entry(o, ce, 0, 0);
867 return 1;
870 #if DBRT_DEBUG
871 static void show_stage_entry(FILE *o,
872 const char *label, const struct cache_entry *ce)
874 if (!ce)
875 fprintf(o, "%s (missing)\n", label);
876 else
877 fprintf(o, "%s%06o %s %d\t%s\n",
878 label,
879 ce->ce_mode,
880 sha1_to_hex(ce->sha1),
881 ce_stage(ce),
882 ce->name);
884 #endif
886 int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o)
888 struct cache_entry *index;
889 struct cache_entry *head;
890 struct cache_entry *remote = stages[o->head_idx + 1];
891 int count;
892 int head_match = 0;
893 int remote_match = 0;
895 int df_conflict_head = 0;
896 int df_conflict_remote = 0;
898 int any_anc_missing = 0;
899 int no_anc_exists = 1;
900 int i;
902 for (i = 1; i < o->head_idx; i++) {
903 if (!stages[i] || stages[i] == o->df_conflict_entry)
904 any_anc_missing = 1;
905 else
906 no_anc_exists = 0;
909 index = stages[0];
910 head = stages[o->head_idx];
912 if (head == o->df_conflict_entry) {
913 df_conflict_head = 1;
914 head = NULL;
917 if (remote == o->df_conflict_entry) {
918 df_conflict_remote = 1;
919 remote = NULL;
922 /* First, if there's a #16 situation, note that to prevent #13
923 * and #14.
925 if (!same(remote, head)) {
926 for (i = 1; i < o->head_idx; i++) {
927 if (same(stages[i], head)) {
928 head_match = i;
930 if (same(stages[i], remote)) {
931 remote_match = i;
936 /* We start with cases where the index is allowed to match
937 * something other than the head: #14(ALT) and #2ALT, where it
938 * is permitted to match the result instead.
940 /* #14, #14ALT, #2ALT */
941 if (remote && !df_conflict_head && head_match && !remote_match) {
942 if (index && !same(index, remote) && !same(index, head))
943 return o->gently ? -1 : reject_merge(index, o);
944 return merged_entry(remote, index, o);
947 * If we have an entry in the index cache, then we want to
948 * make sure that it matches head.
950 if (index && !same(index, head))
951 return o->gently ? -1 : reject_merge(index, o);
953 if (head) {
954 /* #5ALT, #15 */
955 if (same(head, remote))
956 return merged_entry(head, index, o);
957 /* #13, #3ALT */
958 if (!df_conflict_remote && remote_match && !head_match)
959 return merged_entry(head, index, o);
962 /* #1 */
963 if (!head && !remote && any_anc_missing)
964 return 0;
966 /* Under the new "aggressive" rule, we resolve mostly trivial
967 * cases that we historically had git-merge-one-file resolve.
969 if (o->aggressive) {
970 int head_deleted = !head && !df_conflict_head;
971 int remote_deleted = !remote && !df_conflict_remote;
972 struct cache_entry *ce = NULL;
974 if (index)
975 ce = index;
976 else if (head)
977 ce = head;
978 else if (remote)
979 ce = remote;
980 else {
981 for (i = 1; i < o->head_idx; i++) {
982 if (stages[i] && stages[i] != o->df_conflict_entry) {
983 ce = stages[i];
984 break;
990 * Deleted in both.
991 * Deleted in one and unchanged in the other.
993 if ((head_deleted && remote_deleted) ||
994 (head_deleted && remote && remote_match) ||
995 (remote_deleted && head && head_match)) {
996 if (index)
997 return deleted_entry(index, index, o);
998 if (ce && !head_deleted) {
999 if (verify_absent(ce, "removed", o))
1000 return -1;
1002 return 0;
1005 * Added in both, identically.
1007 if (no_anc_exists && head && remote && same(head, remote))
1008 return merged_entry(head, index, o);
1012 /* Below are "no merge" cases, which require that the index be
1013 * up-to-date to avoid the files getting overwritten with
1014 * conflict resolution files.
1016 if (index) {
1017 if (verify_uptodate(index, o))
1018 return -1;
1021 o->nontrivial_merge = 1;
1023 /* #2, #3, #4, #6, #7, #9, #10, #11. */
1024 count = 0;
1025 if (!head_match || !remote_match) {
1026 for (i = 1; i < o->head_idx; i++) {
1027 if (stages[i] && stages[i] != o->df_conflict_entry) {
1028 keep_entry(stages[i], o);
1029 count++;
1030 break;
1034 #if DBRT_DEBUG
1035 else {
1036 fprintf(stderr, "read-tree: warning #16 detected\n");
1037 show_stage_entry(stderr, "head ", stages[head_match]);
1038 show_stage_entry(stderr, "remote ", stages[remote_match]);
1040 #endif
1041 if (head) { count += keep_entry(head, o); }
1042 if (remote) { count += keep_entry(remote, o); }
1043 return count;
1047 * Two-way merge.
1049 * The rule is to "carry forward" what is in the index without losing
1050 * information across a "fast-forward", favoring a successful merge
1051 * over a merge failure when it makes sense. For details of the
1052 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
1055 int twoway_merge(struct cache_entry **src, struct unpack_trees_options *o)
1057 struct cache_entry *current = src[0];
1058 struct cache_entry *oldtree = src[1];
1059 struct cache_entry *newtree = src[2];
1061 if (o->merge_size != 2)
1062 return error("Cannot do a twoway merge of %d trees",
1063 o->merge_size);
1065 if (oldtree == o->df_conflict_entry)
1066 oldtree = NULL;
1067 if (newtree == o->df_conflict_entry)
1068 newtree = NULL;
1070 if (current) {
1071 if ((!oldtree && !newtree) || /* 4 and 5 */
1072 (!oldtree && newtree &&
1073 same(current, newtree)) || /* 6 and 7 */
1074 (oldtree && newtree &&
1075 same(oldtree, newtree)) || /* 14 and 15 */
1076 (oldtree && newtree &&
1077 !same(oldtree, newtree) && /* 18 and 19 */
1078 same(current, newtree))) {
1079 return keep_entry(current, o);
1081 else if (oldtree && !newtree && same(current, oldtree)) {
1082 /* 10 or 11 */
1083 return deleted_entry(oldtree, current, o);
1085 else if (oldtree && newtree &&
1086 same(current, oldtree) && !same(current, newtree)) {
1087 /* 20 or 21 */
1088 return merged_entry(newtree, current, o);
1090 else {
1091 /* all other failures */
1092 if (oldtree)
1093 return o->gently ? -1 : reject_merge(oldtree, o);
1094 if (current)
1095 return o->gently ? -1 : reject_merge(current, o);
1096 if (newtree)
1097 return o->gently ? -1 : reject_merge(newtree, o);
1098 return -1;
1101 else if (newtree) {
1102 if (oldtree && !o->initial_checkout) {
1104 * deletion of the path was staged;
1106 if (same(oldtree, newtree))
1107 return 1;
1108 return reject_merge(oldtree, o);
1110 return merged_entry(newtree, current, o);
1112 return deleted_entry(oldtree, current, o);
1116 * Bind merge.
1118 * Keep the index entries at stage0, collapse stage1 but make sure
1119 * stage0 does not have anything there.
1121 int bind_merge(struct cache_entry **src,
1122 struct unpack_trees_options *o)
1124 struct cache_entry *old = src[0];
1125 struct cache_entry *a = src[1];
1127 if (o->merge_size != 1)
1128 return error("Cannot do a bind merge of %d trees\n",
1129 o->merge_size);
1130 if (a && old)
1131 return o->gently ? -1 :
1132 error(ERRORMSG(o, bind_overlap), a->name, old->name);
1133 if (!a)
1134 return keep_entry(old, o);
1135 else
1136 return merged_entry(a, NULL, o);
1140 * One-way merge.
1142 * The rule is:
1143 * - take the stat information from stage0, take the data from stage1
1145 int oneway_merge(struct cache_entry **src, struct unpack_trees_options *o)
1147 struct cache_entry *old = src[0];
1148 struct cache_entry *a = src[1];
1150 if (o->merge_size != 1)
1151 return error("Cannot do a oneway merge of %d trees",
1152 o->merge_size);
1154 if (!a || a == o->df_conflict_entry)
1155 return deleted_entry(old, old, o);
1157 if (old && same(old, a)) {
1158 int update = 0;
1159 if (o->reset && !ce_uptodate(old) && !ce_skip_worktree(old)) {
1160 struct stat st;
1161 if (lstat(old->name, &st) ||
1162 ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE))
1163 update |= CE_UPDATE;
1165 add_entry(o, old, update, 0);
1166 return 0;
1168 return merged_entry(a, old, o);