gitignore(5): Allow "foo/" in ignore list to match directory "foo"
[git/git.git] / unpack-trees.c
CommitLineData
16da134b 1#include "cache.h"
f8a9d428 2#include "dir.h"
16da134b
JS
3#include "tree.h"
4#include "tree-walk.h"
076b0adc 5#include "cache-tree.h"
16da134b 6#include "unpack-trees.h"
96a02f8f 7#include "progress.h"
0cf73755 8#include "refs.h"
16da134b 9
076b0adc
JS
10#define DBRT_DEBUG 1
11
16da134b
JS
12struct tree_entry_list {
13 struct tree_entry_list *next;
16da134b
JS
14 unsigned int mode;
15 const char *name;
16 const unsigned char *sha1;
17};
18
933bf40a 19static struct tree_entry_list *create_tree_entry_list(struct tree_desc *desc)
16da134b 20{
16da134b
JS
21 struct name_entry one;
22 struct tree_entry_list *ret = NULL;
23 struct tree_entry_list **list_p = &ret;
24
933bf40a 25 while (tree_entry(desc, &one)) {
16da134b
JS
26 struct tree_entry_list *entry;
27
28 entry = xmalloc(sizeof(struct tree_entry_list));
29 entry->name = one.path;
30 entry->sha1 = one.sha1;
31 entry->mode = one.mode;
16da134b
JS
32 entry->next = NULL;
33
34 *list_p = entry;
35 list_p = &entry->next;
36 }
37 return ret;
38}
39
40static 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}
60
b48d5a05
LT
61static inline void remove_entry(int remove)
62{
63 if (remove >= 0)
64 remove_cache_entry_at(remove);
65}
66
16da134b
JS
67static int unpack_trees_rec(struct tree_entry_list **posns, int len,
68 const char *base, struct unpack_trees_options *o,
16da134b
JS
69 struct tree_entry_list *df_conflict_list)
70{
b48d5a05 71 int remove;
16da134b
JS
72 int baselen = strlen(base);
73 int src_size = len + 1;
f8a9d428
JH
74 int retval = 0;
75
16da134b
JS
76 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
89 /* Find the first name in the input. */
90
91 first = NULL;
92 cache_name = NULL;
93
94 /* Check the cache */
9a4d8fdc 95 if (o->merge && o->pos < active_nr) {
16da134b
JS
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
9a4d8fdc 113 cache_name = active_cache[o->pos]->name;
16da134b
JS
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
123#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,
1843d8d5 135 S_ISDIR(posns[i]->mode)) > 0) {
16da134b 136 first = posns[i]->name;
1843d8d5 137 firstdir = S_ISDIR(posns[i]->mode);
16da134b
JS
138 }
139 }
140 /* No name means we're done */
141 if (!first)
f8a9d428 142 goto leave_directory;
16da134b
JS
143
144 pathlen = strlen(first);
145 ce_size = cache_entry_size(baselen + pathlen);
146
147 src = xcalloc(src_size, sizeof(struct cache_entry *));
148
149 subposns = xcalloc(len, sizeof(struct tree_list_entry *));
150
b48d5a05 151 remove = -1;
16da134b
JS
152 if (cache_name && !strcmp(cache_name, first)) {
153 any_files = 1;
9a4d8fdc 154 src[0] = active_cache[o->pos];
b48d5a05 155 remove = o->pos;
16da134b
JS
156 }
157
158 for (i = 0; i < len; i++) {
159 struct cache_entry *ce;
160
161 if (!posns[i] ||
162 (posns[i] != df_conflict_list &&
163 strcmp(first, posns[i]->name))) {
164 continue;
165 }
166
167 if (posns[i] == df_conflict_list) {
168 src[i + o->merge] = o->df_conflict_entry;
169 continue;
170 }
171
1843d8d5 172 if (S_ISDIR(posns[i]->mode)) {
16da134b 173 struct tree *tree = lookup_tree(posns[i]->sha1);
933bf40a 174 struct tree_desc t;
16da134b
JS
175 any_dirs = 1;
176 parse_tree(tree);
933bf40a
LT
177 init_tree_desc(&t, tree->buffer, tree->size);
178 subposns[i] = create_tree_entry_list(&t);
16da134b
JS
179 posns[i] = posns[i]->next;
180 src[i + o->merge] = o->df_conflict_entry;
181 continue;
182 }
183
184 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
193 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
200 any_files = 1;
201
e702496e 202 hashcpy(ce->sha1, posns[i]->sha1);
16da134b
JS
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
211#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
b48d5a05 221 ret = o->fn(src, o, remove);
16da134b
JS
222
223#if DBRT_DEBUG > 1
224 printf("Added %d entries\n", ret);
225#endif
9a4d8fdc 226 o->pos += ret;
16da134b 227 } else {
b48d5a05 228 remove_entry(remove);
16da134b
JS
229 for (i = 0; i < src_size; i++) {
230 if (src[i]) {
231 add_cache_entry(src[i], ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
232 }
233 }
234 }
235 }
236 if (any_dirs) {
237 char *newbase = xmalloc(baselen + 2 + pathlen);
238 memcpy(newbase, base, baselen);
239 memcpy(newbase + baselen, first, pathlen);
240 newbase[baselen + pathlen] = '/';
241 newbase[baselen + pathlen + 1] = '\0';
242 if (unpack_trees_rec(subposns, len, newbase, o,
9a4d8fdc 243 df_conflict_list)) {
f8a9d428
JH
244 retval = -1;
245 goto leave_directory;
246 }
16da134b
JS
247 free(newbase);
248 }
249 free(subposns);
250 free(src);
251 } while (1);
f8a9d428
JH
252
253 leave_directory:
f8a9d428 254 return retval;
16da134b
JS
255}
256
257/* Unlink the last component and attempt to remove leading
258 * directories, in case this unlink is the removal of the
259 * last entry in the directory -- empty directories are removed.
260 */
16a4c617 261static void unlink_entry(char *name, char *last_symlink)
16da134b
JS
262{
263 char *cp, *prev;
264
16a4c617
JH
265 if (has_symlink_leading_path(name, last_symlink))
266 return;
16da134b
JS
267 if (unlink(name))
268 return;
269 prev = NULL;
270 while (1) {
271 int status;
272 cp = strrchr(name, '/');
273 if (prev)
274 *prev = '/';
275 if (!cp)
276 break;
277
278 *cp = 0;
279 status = rmdir(name);
280 if (status) {
281 *cp = '/';
282 break;
283 }
284 prev = cp;
285 }
286}
287
16da134b
JS
288static struct checkout state;
289static void check_updates(struct cache_entry **src, int nr,
16a4c617 290 struct unpack_trees_options *o)
16da134b
JS
291{
292 unsigned short mask = htons(CE_UPDATE);
96a02f8f 293 unsigned cnt = 0, total = 0;
dc6a0757 294 struct progress *progress = NULL;
16a4c617 295 char last_symlink[PATH_MAX];
16da134b
JS
296
297 if (o->update && o->verbose_update) {
298 for (total = cnt = 0; cnt < nr; cnt++) {
299 struct cache_entry *ce = src[cnt];
300 if (!ce->ce_mode || ce->ce_flags & mask)
301 total++;
302 }
303
dc6a0757
NP
304 progress = start_progress_delay("Checking out files",
305 total, 50, 2);
16da134b
JS
306 cnt = 0;
307 }
308
16a4c617 309 *last_symlink = '\0';
16da134b
JS
310 while (nr--) {
311 struct cache_entry *ce = *src++;
312
4d4fcc54
NP
313 if (!ce->ce_mode || ce->ce_flags & mask)
314 display_progress(progress, ++cnt);
16da134b
JS
315 if (!ce->ce_mode) {
316 if (o->update)
16a4c617 317 unlink_entry(ce->name, last_symlink);
16da134b
JS
318 continue;
319 }
320 if (ce->ce_flags & mask) {
321 ce->ce_flags &= ~mask;
16a4c617 322 if (o->update) {
16da134b 323 checkout_entry(ce, &state, NULL);
16a4c617
JH
324 *last_symlink = '\0';
325 }
16da134b
JS
326 }
327 }
4d4fcc54 328 stop_progress(&progress);
16da134b
JS
329}
330
933bf40a 331int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
16da134b 332{
16da134b
JS
333 struct tree_entry_list **posns;
334 int i;
16da134b 335 struct tree_entry_list df_conflict_list;
0fb1eaa8 336 static struct cache_entry *dfc;
16da134b
JS
337
338 memset(&df_conflict_list, 0, sizeof(df_conflict_list));
339 df_conflict_list.next = &df_conflict_list;
076b0adc 340 memset(&state, 0, sizeof(state));
16da134b
JS
341 state.base_dir = "";
342 state.force = 1;
343 state.quiet = 1;
344 state.refresh_cache = 1;
345
346 o->merge_size = len;
0fb1eaa8
JH
347
348 if (!dfc)
349 dfc = xcalloc(1, sizeof(struct cache_entry) + 1);
350 o->df_conflict_entry = dfc;
16da134b
JS
351
352 if (len) {
353 posns = xmalloc(len * sizeof(struct tree_entry_list *));
933bf40a
LT
354 for (i = 0; i < len; i++)
355 posns[i] = create_tree_entry_list(t+i);
356
16da134b 357 if (unpack_trees_rec(posns, len, o->prefix ? o->prefix : "",
9a4d8fdc 358 o, &df_conflict_list))
16da134b
JS
359 return -1;
360 }
361
362 if (o->trivial_merges_only && o->nontrivial_merge)
363 die("Merge requires file-level merging");
364
365 check_updates(active_cache, active_nr, o);
366 return 0;
367}
076b0adc
JS
368
369/* Here come the merge functions */
370
371static void reject_merge(struct cache_entry *ce)
372{
373 die("Entry '%s' would be overwritten by merge. Cannot merge.",
374 ce->name);
375}
376
377static int same(struct cache_entry *a, struct cache_entry *b)
378{
379 if (!!a != !!b)
380 return 0;
381 if (!a && !b)
382 return 1;
383 return a->ce_mode == b->ce_mode &&
a89fccd2 384 !hashcmp(a->sha1, b->sha1);
076b0adc
JS
385}
386
387
388/*
389 * When a CE gets turned into an unmerged entry, we
390 * want it to be up-to-date
391 */
392static void verify_uptodate(struct cache_entry *ce,
393 struct unpack_trees_options *o)
394{
395 struct stat st;
396
397 if (o->index_only || o->reset)
398 return;
399
400 if (!lstat(ce->name, &st)) {
4bd5b7da 401 unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID);
076b0adc
JS
402 if (!changed)
403 return;
936492d3
JH
404 /*
405 * NEEDSWORK: the current default policy is to allow
406 * submodule to be out of sync wrt the supermodule
407 * index. This needs to be tightened later for
408 * submodules that are marked to be automatically
409 * checked out.
410 */
411 if (S_ISGITLINK(ntohl(ce->ce_mode)))
412 return;
076b0adc
JS
413 errno = 0;
414 }
076b0adc
JS
415 if (errno == ENOENT)
416 return;
417 die("Entry '%s' not uptodate. Cannot merge.", ce->name);
418}
419
420static void invalidate_ce_path(struct cache_entry *ce)
421{
422 if (ce)
423 cache_tree_invalidate_path(active_cache_tree, ce->name);
424}
425
0cf73755
SV
426/*
427 * Check that checking out ce->sha1 in subdir ce->name is not
428 * going to overwrite any working files.
429 *
430 * Currently, git does not checkout subprojects during a superproject
431 * checkout, so it is not going to overwrite anything.
432 */
433static int verify_clean_submodule(struct cache_entry *ce, const char *action,
434 struct unpack_trees_options *o)
435{
436 return 0;
437}
438
439static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
c8193534
JH
440 struct unpack_trees_options *o)
441{
442 /*
0cf73755 443 * we are about to extract "ce->name"; we would not want to lose
c8193534
JH
444 * anything in the existing directory there.
445 */
446 int namelen;
447 int pos, i;
448 struct dir_struct d;
449 char *pathbuf;
450 int cnt = 0;
0cf73755
SV
451 unsigned char sha1[20];
452
453 if (S_ISGITLINK(ntohl(ce->ce_mode)) &&
454 resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
455 /* If we are not going to update the submodule, then
456 * we don't care.
457 */
458 if (!hashcmp(sha1, ce->sha1))
459 return 0;
460 return verify_clean_submodule(ce, action, o);
461 }
c8193534
JH
462
463 /*
464 * First let's make sure we do not have a local modification
465 * in that directory.
466 */
0cf73755
SV
467 namelen = strlen(ce->name);
468 pos = cache_name_pos(ce->name, namelen);
c8193534
JH
469 if (0 <= pos)
470 return cnt; /* we have it as nondirectory */
471 pos = -pos - 1;
472 for (i = pos; i < active_nr; i++) {
473 struct cache_entry *ce = active_cache[i];
474 int len = ce_namelen(ce);
475 if (len < namelen ||
0cf73755 476 strncmp(ce->name, ce->name, namelen) ||
c8193534
JH
477 ce->name[namelen] != '/')
478 break;
479 /*
480 * ce->name is an entry in the subdirectory.
481 */
482 if (!ce_stage(ce)) {
483 verify_uptodate(ce, o);
484 ce->ce_mode = 0;
485 }
486 cnt++;
487 }
488
489 /*
490 * Then we need to make sure that we do not lose a locally
491 * present file that is not ignored.
492 */
493 pathbuf = xmalloc(namelen + 2);
0cf73755 494 memcpy(pathbuf, ce->name, namelen);
c8193534
JH
495 strcpy(pathbuf+namelen, "/");
496
497 memset(&d, 0, sizeof(d));
498 if (o->dir)
499 d.exclude_per_dir = o->dir->exclude_per_dir;
0cf73755 500 i = read_directory(&d, ce->name, pathbuf, namelen+1, NULL);
c8193534
JH
501 if (i)
502 die("Updating '%s' would lose untracked files in it",
0cf73755 503 ce->name);
c8193534
JH
504 free(pathbuf);
505 return cnt;
506}
507
076b0adc
JS
508/*
509 * We do not want to remove or overwrite a working tree file that
f8a9d428 510 * is not tracked, unless it is ignored.
076b0adc 511 */
0cf73755 512static void verify_absent(struct cache_entry *ce, const char *action,
076b0adc
JS
513 struct unpack_trees_options *o)
514{
515 struct stat st;
516
517 if (o->index_only || o->reset || !o->update)
518 return;
c8193534 519
0cf73755 520 if (has_symlink_leading_path(ce->name, NULL))
ec0603e1
JH
521 return;
522
0cf73755 523 if (!lstat(ce->name, &st)) {
c8193534
JH
524 int cnt;
525
d6b8fc30 526 if (o->dir && excluded(o->dir, ce->name, ce_to_dtype(ce)))
c8193534 527 /*
0cf73755 528 * ce->name is explicitly excluded, so it is Ok to
c8193534
JH
529 * overwrite it.
530 */
531 return;
532 if (S_ISDIR(st.st_mode)) {
533 /*
534 * We are checking out path "foo" and
535 * found "foo/." in the working tree.
536 * This is tricky -- if we have modified
537 * files that are in "foo/" we would lose
538 * it.
539 */
0cf73755 540 cnt = verify_clean_subdirectory(ce, action, o);
c8193534
JH
541
542 /*
543 * If this removed entries from the index,
544 * what that means is:
545 *
546 * (1) the caller unpack_trees_rec() saw path/foo
547 * in the index, and it has not removed it because
548 * it thinks it is handling 'path' as blob with
549 * D/F conflict;
550 * (2) we will return "ok, we placed a merged entry
551 * in the index" which would cause o->pos to be
552 * incremented by one;
553 * (3) however, original o->pos now has 'path/foo'
554 * marked with "to be removed".
555 *
556 * We need to increment it by the number of
557 * deleted entries here.
558 */
559 o->pos += cnt;
560 return;
561 }
562
563 /*
564 * The previous round may already have decided to
565 * delete this path, which is in a subdirectory that
566 * is being replaced with a blob.
567 */
0cf73755 568 cnt = cache_name_pos(ce->name, strlen(ce->name));
c8193534
JH
569 if (0 <= cnt) {
570 struct cache_entry *ce = active_cache[cnt];
571 if (!ce_stage(ce) && !ce->ce_mode)
572 return;
573 }
574
076b0adc 575 die("Untracked working tree file '%s' "
0cf73755 576 "would be %s by merge.", ce->name, action);
c8193534 577 }
076b0adc
JS
578}
579
580static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
581 struct unpack_trees_options *o)
582{
583 merge->ce_flags |= htons(CE_UPDATE);
584 if (old) {
585 /*
586 * See if we can re-use the old CE directly?
587 * That way we get the uptodate stat info.
588 *
589 * This also removes the UPDATE flag on
590 * a match.
591 */
592 if (same(old, merge)) {
f2fdd10a 593 memcpy(merge, old, offsetof(struct cache_entry, name));
076b0adc
JS
594 } else {
595 verify_uptodate(old, o);
596 invalidate_ce_path(old);
597 }
598 }
599 else {
0cf73755 600 verify_absent(merge, "overwritten", o);
076b0adc
JS
601 invalidate_ce_path(merge);
602 }
603
604 merge->ce_flags &= ~htons(CE_STAGEMASK);
605 add_cache_entry(merge, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
606 return 1;
607}
608
609static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
610 struct unpack_trees_options *o)
611{
612 if (old)
613 verify_uptodate(old, o);
614 else
0cf73755 615 verify_absent(ce, "removed", o);
076b0adc
JS
616 ce->ce_mode = 0;
617 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
618 invalidate_ce_path(ce);
619 return 1;
620}
621
7f7932ab 622static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o)
076b0adc
JS
623{
624 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
625 return 1;
626}
627
628#if DBRT_DEBUG
629static void show_stage_entry(FILE *o,
630 const char *label, const struct cache_entry *ce)
631{
632 if (!ce)
633 fprintf(o, "%s (missing)\n", label);
634 else
635 fprintf(o, "%s%06o %s %d\t%s\n",
636 label,
637 ntohl(ce->ce_mode),
638 sha1_to_hex(ce->sha1),
639 ce_stage(ce),
640 ce->name);
641}
642#endif
643
644int threeway_merge(struct cache_entry **stages,
b48d5a05
LT
645 struct unpack_trees_options *o,
646 int remove)
076b0adc
JS
647{
648 struct cache_entry *index;
649 struct cache_entry *head;
650 struct cache_entry *remote = stages[o->head_idx + 1];
651 int count;
652 int head_match = 0;
653 int remote_match = 0;
076b0adc
JS
654
655 int df_conflict_head = 0;
656 int df_conflict_remote = 0;
657
658 int any_anc_missing = 0;
659 int no_anc_exists = 1;
660 int i;
661
662 for (i = 1; i < o->head_idx; i++) {
4c4caafc 663 if (!stages[i] || stages[i] == o->df_conflict_entry)
076b0adc 664 any_anc_missing = 1;
4c4caafc 665 else
076b0adc 666 no_anc_exists = 0;
076b0adc
JS
667 }
668
669 index = stages[0];
670 head = stages[o->head_idx];
671
672 if (head == o->df_conflict_entry) {
673 df_conflict_head = 1;
674 head = NULL;
675 }
676
677 if (remote == o->df_conflict_entry) {
678 df_conflict_remote = 1;
679 remote = NULL;
680 }
681
076b0adc
JS
682 /* First, if there's a #16 situation, note that to prevent #13
683 * and #14.
684 */
685 if (!same(remote, head)) {
686 for (i = 1; i < o->head_idx; i++) {
687 if (same(stages[i], head)) {
688 head_match = i;
689 }
690 if (same(stages[i], remote)) {
691 remote_match = i;
692 }
693 }
694 }
695
696 /* We start with cases where the index is allowed to match
697 * something other than the head: #14(ALT) and #2ALT, where it
698 * is permitted to match the result instead.
699 */
700 /* #14, #14ALT, #2ALT */
701 if (remote && !df_conflict_head && head_match && !remote_match) {
702 if (index && !same(index, remote) && !same(index, head))
703 reject_merge(index);
704 return merged_entry(remote, index, o);
705 }
706 /*
707 * If we have an entry in the index cache, then we want to
708 * make sure that it matches head.
709 */
710 if (index && !same(index, head)) {
711 reject_merge(index);
712 }
713
714 if (head) {
715 /* #5ALT, #15 */
716 if (same(head, remote))
717 return merged_entry(head, index, o);
718 /* #13, #3ALT */
719 if (!df_conflict_remote && remote_match && !head_match)
720 return merged_entry(head, index, o);
721 }
722
723 /* #1 */
566b5c05
LT
724 if (!head && !remote && any_anc_missing) {
725 remove_entry(remove);
076b0adc 726 return 0;
566b5c05 727 }
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JS
728
729 /* Under the new "aggressive" rule, we resolve mostly trivial
730 * cases that we historically had git-merge-one-file resolve.
731 */
732 if (o->aggressive) {
733 int head_deleted = !head && !df_conflict_head;
734 int remote_deleted = !remote && !df_conflict_remote;
0cf73755 735 struct cache_entry *ce = NULL;
4c4caafc
JH
736
737 if (index)
0cf73755 738 ce = index;
4c4caafc 739 else if (head)
0cf73755 740 ce = head;
4c4caafc 741 else if (remote)
0cf73755 742 ce = remote;
4c4caafc
JH
743 else {
744 for (i = 1; i < o->head_idx; i++) {
745 if (stages[i] && stages[i] != o->df_conflict_entry) {
0cf73755 746 ce = stages[i];
4c4caafc
JH
747 break;
748 }
749 }
750 }
751
076b0adc
JS
752 /*
753 * Deleted in both.
754 * Deleted in one and unchanged in the other.
755 */
756 if ((head_deleted && remote_deleted) ||
757 (head_deleted && remote && remote_match) ||
758 (remote_deleted && head && head_match)) {
566b5c05 759 remove_entry(remove);
076b0adc
JS
760 if (index)
761 return deleted_entry(index, index, o);
0cf73755
SV
762 else if (ce && !head_deleted)
763 verify_absent(ce, "removed", o);
076b0adc
JS
764 return 0;
765 }
766 /*
767 * Added in both, identically.
768 */
769 if (no_anc_exists && head && remote && same(head, remote))
770 return merged_entry(head, index, o);
771
772 }
773
774 /* Below are "no merge" cases, which require that the index be
775 * up-to-date to avoid the files getting overwritten with
776 * conflict resolution files.
777 */
778 if (index) {
779 verify_uptodate(index, o);
780 }
076b0adc 781
566b5c05 782 remove_entry(remove);
076b0adc
JS
783 o->nontrivial_merge = 1;
784
ea4b52a8 785 /* #2, #3, #4, #6, #7, #9, #10, #11. */
076b0adc
JS
786 count = 0;
787 if (!head_match || !remote_match) {
788 for (i = 1; i < o->head_idx; i++) {
4c4caafc 789 if (stages[i] && stages[i] != o->df_conflict_entry) {
7f7932ab 790 keep_entry(stages[i], o);
076b0adc
JS
791 count++;
792 break;
793 }
794 }
795 }
796#if DBRT_DEBUG
797 else {
798 fprintf(stderr, "read-tree: warning #16 detected\n");
799 show_stage_entry(stderr, "head ", stages[head_match]);
800 show_stage_entry(stderr, "remote ", stages[remote_match]);
801 }
802#endif
7f7932ab
JH
803 if (head) { count += keep_entry(head, o); }
804 if (remote) { count += keep_entry(remote, o); }
076b0adc
JS
805 return count;
806}
807
808/*
809 * Two-way merge.
810 *
811 * The rule is to "carry forward" what is in the index without losing
812 * information across a "fast forward", favoring a successful merge
813 * over a merge failure when it makes sense. For details of the
814 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
815 *
816 */
817int twoway_merge(struct cache_entry **src,
b48d5a05
LT
818 struct unpack_trees_options *o,
819 int remove)
076b0adc
JS
820{
821 struct cache_entry *current = src[0];
b8ba1535
JH
822 struct cache_entry *oldtree = src[1];
823 struct cache_entry *newtree = src[2];
076b0adc
JS
824
825 if (o->merge_size != 2)
826 return error("Cannot do a twoway merge of %d trees",
827 o->merge_size);
828
b8ba1535
JH
829 if (oldtree == o->df_conflict_entry)
830 oldtree = NULL;
831 if (newtree == o->df_conflict_entry)
832 newtree = NULL;
833
076b0adc
JS
834 if (current) {
835 if ((!oldtree && !newtree) || /* 4 and 5 */
836 (!oldtree && newtree &&
837 same(current, newtree)) || /* 6 and 7 */
838 (oldtree && newtree &&
839 same(oldtree, newtree)) || /* 14 and 15 */
840 (oldtree && newtree &&
b8ba1535 841 !same(oldtree, newtree) && /* 18 and 19 */
076b0adc 842 same(current, newtree))) {
7f7932ab 843 return keep_entry(current, o);
076b0adc
JS
844 }
845 else if (oldtree && !newtree && same(current, oldtree)) {
846 /* 10 or 11 */
d699676d 847 remove_entry(remove);
076b0adc
JS
848 return deleted_entry(oldtree, current, o);
849 }
850 else if (oldtree && newtree &&
851 same(current, oldtree) && !same(current, newtree)) {
852 /* 20 or 21 */
853 return merged_entry(newtree, current, o);
854 }
855 else {
856 /* all other failures */
d699676d 857 remove_entry(remove);
076b0adc
JS
858 if (oldtree)
859 reject_merge(oldtree);
860 if (current)
861 reject_merge(current);
862 if (newtree)
863 reject_merge(newtree);
864 return -1;
865 }
866 }
867 else if (newtree)
868 return merged_entry(newtree, current, o);
d699676d
LT
869 remove_entry(remove);
870 return deleted_entry(oldtree, current, o);
076b0adc
JS
871}
872
873/*
874 * Bind merge.
875 *
876 * Keep the index entries at stage0, collapse stage1 but make sure
877 * stage0 does not have anything there.
878 */
879int bind_merge(struct cache_entry **src,
b48d5a05
LT
880 struct unpack_trees_options *o,
881 int remove)
076b0adc
JS
882{
883 struct cache_entry *old = src[0];
884 struct cache_entry *a = src[1];
885
886 if (o->merge_size != 1)
887 return error("Cannot do a bind merge of %d trees\n",
888 o->merge_size);
889 if (a && old)
890 die("Entry '%s' overlaps. Cannot bind.", a->name);
891 if (!a)
7f7932ab 892 return keep_entry(old, o);
076b0adc
JS
893 else
894 return merged_entry(a, NULL, o);
895}
896
897/*
898 * One-way merge.
899 *
900 * The rule is:
901 * - take the stat information from stage0, take the data from stage1
902 */
903int oneway_merge(struct cache_entry **src,
b48d5a05
LT
904 struct unpack_trees_options *o,
905 int remove)
076b0adc
JS
906{
907 struct cache_entry *old = src[0];
908 struct cache_entry *a = src[1];
909
910 if (o->merge_size != 1)
911 return error("Cannot do a oneway merge of %d trees",
912 o->merge_size);
913
288f072e
LT
914 if (!a) {
915 remove_entry(remove);
076b0adc 916 return deleted_entry(old, old, o);
288f072e 917 }
076b0adc
JS
918 if (old && same(old, a)) {
919 if (o->reset) {
920 struct stat st;
921 if (lstat(old->name, &st) ||
4bd5b7da 922 ce_match_stat(old, &st, CE_MATCH_IGNORE_VALID))
076b0adc
JS
923 old->ce_flags |= htons(CE_UPDATE);
924 }
7f7932ab 925 return keep_entry(old, o);
076b0adc
JS
926 }
927 return merged_entry(a, old, o);
928}