Add 'const' where appropriate to index handling functions
[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
b48d5a05
LT
10static inline void remove_entry(int remove)
11{
12 if (remove >= 0)
13 remove_cache_entry_at(remove);
14}
15
16da134b
JS
16/* Unlink the last component and attempt to remove leading
17 * directories, in case this unlink is the removal of the
18 * last entry in the directory -- empty directories are removed.
19 */
16a4c617 20static void unlink_entry(char *name, char *last_symlink)
16da134b
JS
21{
22 char *cp, *prev;
23
16a4c617
JH
24 if (has_symlink_leading_path(name, last_symlink))
25 return;
16da134b
JS
26 if (unlink(name))
27 return;
28 prev = NULL;
29 while (1) {
30 int status;
31 cp = strrchr(name, '/');
32 if (prev)
33 *prev = '/';
34 if (!cp)
35 break;
36
37 *cp = 0;
38 status = rmdir(name);
39 if (status) {
40 *cp = '/';
41 break;
42 }
43 prev = cp;
44 }
45}
46
16da134b 47static struct checkout state;
33ecf7eb 48static void check_updates(struct unpack_trees_options *o)
16da134b 49{
96a02f8f 50 unsigned cnt = 0, total = 0;
dc6a0757 51 struct progress *progress = NULL;
16a4c617 52 char last_symlink[PATH_MAX];
33ecf7eb 53 int i;
16da134b
JS
54
55 if (o->update && o->verbose_update) {
33ecf7eb
DB
56 for (total = cnt = 0; cnt < active_nr; cnt++) {
57 struct cache_entry *ce = active_cache[cnt];
7a51ed66 58 if (ce->ce_flags & (CE_UPDATE | CE_REMOVE))
16da134b
JS
59 total++;
60 }
61
dc6a0757 62 progress = start_progress_delay("Checking out files",
e8548645 63 total, 50, 1);
16da134b
JS
64 cnt = 0;
65 }
66
16a4c617 67 *last_symlink = '\0';
33ecf7eb
DB
68 for (i = 0; i < active_nr; i++) {
69 struct cache_entry *ce = active_cache[i];
16da134b 70
7a51ed66 71 if (ce->ce_flags & (CE_UPDATE | CE_REMOVE))
4d4fcc54 72 display_progress(progress, ++cnt);
7a51ed66 73 if (ce->ce_flags & CE_REMOVE) {
16da134b 74 if (o->update)
16a4c617 75 unlink_entry(ce->name, last_symlink);
33ecf7eb
DB
76 remove_cache_entry_at(i);
77 i--;
16da134b
JS
78 continue;
79 }
7a51ed66
LT
80 if (ce->ce_flags & CE_UPDATE) {
81 ce->ce_flags &= ~CE_UPDATE;
16a4c617 82 if (o->update) {
16da134b 83 checkout_entry(ce, &state, NULL);
16a4c617
JH
84 *last_symlink = '\0';
85 }
16da134b
JS
86 }
87 }
4d4fcc54 88 stop_progress(&progress);
16da134b
JS
89}
90
01904572
LT
91static inline int call_unpack_fn(struct cache_entry **src, struct unpack_trees_options *o, int remove)
92{
93 int ret = o->fn(src, o, remove);
94 if (ret > 0) {
95 o->pos += ret;
96 ret = 0;
97 }
98 return ret;
99}
100
101static int unpack_index_entry(struct cache_entry *ce, struct unpack_trees_options *o)
102{
103 struct cache_entry *src[5] = { ce, };
104 if (ce_stage(ce)) {
105 if (o->skip_unmerged) {
106 o->pos++;
107 } else {
108 remove_entry(o->pos);
109 }
110 return 0;
111 }
112 return call_unpack_fn(src, o, o->pos);
113}
114
115int traverse_trees_recursive(int n, unsigned long dirmask, unsigned long df_conflicts, struct name_entry *names, struct traverse_info *info)
16da134b 116{
16da134b 117 int i;
01904572
LT
118 struct tree_desc t[3];
119 struct traverse_info newinfo;
120 struct name_entry *p;
121
122 p = names;
123 while (!p->mode)
124 p++;
125
126 newinfo = *info;
127 newinfo.prev = info;
128 newinfo.name = *p;
129 newinfo.pathlen += tree_entry_len(p->path, p->sha1) + 1;
130 newinfo.conflicts |= df_conflicts;
131
132 for (i = 0; i < n; i++, dirmask >>= 1) {
133 const unsigned char *sha1 = NULL;
134 if (dirmask & 1)
135 sha1 = names[i].sha1;
136 fill_tree_descriptor(t+i, sha1);
137 }
138 traverse_trees(n, t, &newinfo);
139 return 0;
140}
141
142/*
143 * Compare the traverse-path to the cache entry without actually
144 * having to generate the textual representation of the traverse
145 * path.
146 *
147 * NOTE! This *only* compares up to the size of the traverse path
148 * itself - the caller needs to do the final check for the cache
149 * entry having more data at the end!
150 */
151static int do_compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
152{
153 int len, pathlen, ce_len;
154 const char *ce_name;
155
156 if (info->prev) {
157 int cmp = do_compare_entry(ce, info->prev, &info->name);
158 if (cmp)
159 return cmp;
160 }
161 pathlen = info->pathlen;
162 ce_len = ce_namelen(ce);
163
164 /* If ce_len < pathlen then we must have previously hit "name == directory" entry */
165 if (ce_len < pathlen)
166 return -1;
167
168 ce_len -= pathlen;
169 ce_name = ce->name + pathlen;
170
171 len = tree_entry_len(n->path, n->sha1);
172 return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode);
173}
174
175static int compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
176{
177 int cmp = do_compare_entry(ce, info, n);
178 if (cmp)
179 return cmp;
180
181 /*
182 * Even if the beginning compared identically, the ce should
183 * compare as bigger than a directory leading up to it!
184 */
185 return ce_namelen(ce) > traverse_path_len(info, n);
186}
187
188static struct cache_entry *create_ce_entry(const struct traverse_info *info, const struct name_entry *n, int stage)
189{
190 int len = traverse_path_len(info, n);
191 struct cache_entry *ce = xcalloc(1, cache_entry_size(len));
192
193 ce->ce_mode = create_ce_mode(n->mode);
194 ce->ce_flags = create_ce_flags(len, stage);
195 hashcpy(ce->sha1, n->sha1);
196 make_traverse_path(ce->name, info, n);
197
198 return ce;
199}
200
201static int unpack_nondirectories(int n, unsigned long mask, unsigned long dirmask, struct cache_entry *src[5],
202 const struct name_entry *names, const struct traverse_info *info, int remove)
203{
204 int i;
205 struct unpack_trees_options *o = info->data;
206 unsigned long conflicts;
207
208 /* Do we have *only* directories? Nothing to do */
209 if (mask == dirmask && !src[0])
210 return 0;
211
212 conflicts = info->conflicts;
213 if (o->merge)
214 conflicts >>= 1;
215 conflicts |= dirmask;
216
217 /*
218 * Ok, we've filled in up to any potential index entry in src[0],
219 * now do the rest.
220 */
221 for (i = 0; i < n; i++) {
222 int stage;
223 unsigned int bit = 1ul << i;
224 if (conflicts & bit) {
225 src[i + o->merge] = o->df_conflict_entry;
226 continue;
227 }
228 if (!(mask & bit))
229 continue;
230 if (!o->merge)
231 stage = 0;
232 else if (i + 1 < o->head_idx)
233 stage = 1;
234 else if (i + 1 > o->head_idx)
235 stage = 3;
236 else
237 stage = 2;
238 src[i + o->merge] = create_ce_entry(info, names + i, stage);
239 }
240
241 if (o->merge)
242 return call_unpack_fn(src, o, remove);
243
244 n += o->merge;
245 remove_entry(remove);
246 for (i = 0; i < n; i++)
247 add_cache_entry(src[i], ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
248 return 0;
249}
250
251static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *names, struct traverse_info *info)
252{
253 struct cache_entry *src[5] = { NULL, };
254 struct unpack_trees_options *o = info->data;
255 int remove = -1;
256 const struct name_entry *p = names;
257
258 /* Find first entry with a real name (we could use "mask" too) */
259 while (!p->mode)
260 p++;
261
262 /* Are we supposed to look at the index too? */
263 if (o->merge) {
264 while (o->pos < active_nr) {
265 struct cache_entry *ce = active_cache[o->pos];
266 int cmp = compare_entry(ce, info, p);
267 if (cmp < 0) {
268 if (unpack_index_entry(ce, o) < 0)
269 return -1;
270 continue;
271 }
272 if (!cmp) {
273 if (ce_stage(ce)) {
274 /*
275 * If we skip unmerged index entries, we'll skip this
276 * entry *and* the tree entries associated with it!
277 */
278 if (o->skip_unmerged)
279 return mask;
280 remove_entry(o->pos);
281 continue;
282 }
283 src[0] = ce;
284 remove = o->pos;
285 }
286 break;
287 }
288 }
289
290 if (unpack_nondirectories(n, mask, dirmask, src, names, info, remove) < 0)
291 return -1;
292
293 /* Now handle any directories.. */
294 if (dirmask) {
295 unsigned long conflicts = mask & ~dirmask;
296 if (o->merge) {
297 conflicts <<= 1;
298 if (src[0])
299 conflicts |= 1;
300 }
301 traverse_trees_recursive(n, dirmask, conflicts, names, info);
302 return mask;
303 }
304
305 return mask;
306}
307
308static int unpack_failed(struct unpack_trees_options *o, const char *message)
309{
310 if (!o->gently) {
311 if (message)
312 return error(message);
313 return -1;
314 }
315 discard_cache();
316 read_cache();
317 return -1;
318}
319
320int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
321{
0fb1eaa8 322 static struct cache_entry *dfc;
16da134b 323
01904572
LT
324 if (len > 4)
325 die("unpack_trees takes at most four trees");
076b0adc 326 memset(&state, 0, sizeof(state));
16da134b
JS
327 state.base_dir = "";
328 state.force = 1;
329 state.quiet = 1;
330 state.refresh_cache = 1;
331
332 o->merge_size = len;
0fb1eaa8
JH
333
334 if (!dfc)
335 dfc = xcalloc(1, sizeof(struct cache_entry) + 1);
336 o->df_conflict_entry = dfc;
16da134b
JS
337
338 if (len) {
01904572
LT
339 const char *prefix = o->prefix ? o->prefix : "";
340 struct traverse_info info;
341
342 setup_traverse_info(&info, prefix);
343 info.fn = unpack_callback;
344 info.data = o;
345
346 if (traverse_trees(len, t, &info) < 0)
347 return unpack_failed(o, NULL);
16da134b
JS
348 }
349
01904572
LT
350 /* Any left-over entries in the index? */
351 if (o->merge) {
352 while (o->pos < active_nr) {
353 struct cache_entry *ce = active_cache[o->pos];
354 if (unpack_index_entry(ce, o) < 0)
355 return unpack_failed(o, NULL);
17e46426 356 }
17e46426 357 }
16da134b 358
01904572
LT
359 if (o->trivial_merges_only && o->nontrivial_merge)
360 return unpack_failed(o, "Merge requires file-level merging");
361
33ecf7eb 362 check_updates(o);
16da134b
JS
363 return 0;
364}
076b0adc
JS
365
366/* Here come the merge functions */
367
203a2fe1 368static int reject_merge(struct cache_entry *ce)
076b0adc 369{
203a2fe1
DB
370 return error("Entry '%s' would be overwritten by merge. Cannot merge.",
371 ce->name);
076b0adc
JS
372}
373
374static int same(struct cache_entry *a, struct cache_entry *b)
375{
376 if (!!a != !!b)
377 return 0;
378 if (!a && !b)
379 return 1;
380 return a->ce_mode == b->ce_mode &&
a89fccd2 381 !hashcmp(a->sha1, b->sha1);
076b0adc
JS
382}
383
384
385/*
386 * When a CE gets turned into an unmerged entry, we
387 * want it to be up-to-date
388 */
203a2fe1 389static int verify_uptodate(struct cache_entry *ce,
076b0adc
JS
390 struct unpack_trees_options *o)
391{
392 struct stat st;
393
394 if (o->index_only || o->reset)
203a2fe1 395 return 0;
076b0adc
JS
396
397 if (!lstat(ce->name, &st)) {
4bd5b7da 398 unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID);
076b0adc 399 if (!changed)
203a2fe1 400 return 0;
936492d3
JH
401 /*
402 * NEEDSWORK: the current default policy is to allow
403 * submodule to be out of sync wrt the supermodule
404 * index. This needs to be tightened later for
405 * submodules that are marked to be automatically
406 * checked out.
407 */
7a51ed66 408 if (S_ISGITLINK(ce->ce_mode))
203a2fe1 409 return 0;
076b0adc
JS
410 errno = 0;
411 }
076b0adc 412 if (errno == ENOENT)
203a2fe1 413 return 0;
17e46426
DB
414 return o->gently ? -1 :
415 error("Entry '%s' not uptodate. Cannot merge.", ce->name);
076b0adc
JS
416}
417
418static void invalidate_ce_path(struct cache_entry *ce)
419{
420 if (ce)
421 cache_tree_invalidate_path(active_cache_tree, ce->name);
422}
423
0cf73755
SV
424/*
425 * Check that checking out ce->sha1 in subdir ce->name is not
426 * going to overwrite any working files.
427 *
428 * Currently, git does not checkout subprojects during a superproject
429 * checkout, so it is not going to overwrite anything.
430 */
431static int verify_clean_submodule(struct cache_entry *ce, const char *action,
432 struct unpack_trees_options *o)
433{
434 return 0;
435}
436
437static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
c8193534
JH
438 struct unpack_trees_options *o)
439{
440 /*
0cf73755 441 * we are about to extract "ce->name"; we would not want to lose
c8193534
JH
442 * anything in the existing directory there.
443 */
444 int namelen;
445 int pos, i;
446 struct dir_struct d;
447 char *pathbuf;
448 int cnt = 0;
0cf73755
SV
449 unsigned char sha1[20];
450
7a51ed66 451 if (S_ISGITLINK(ce->ce_mode) &&
0cf73755
SV
452 resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
453 /* If we are not going to update the submodule, then
454 * we don't care.
455 */
456 if (!hashcmp(sha1, ce->sha1))
457 return 0;
458 return verify_clean_submodule(ce, action, o);
459 }
c8193534
JH
460
461 /*
462 * First let's make sure we do not have a local modification
463 * in that directory.
464 */
0cf73755
SV
465 namelen = strlen(ce->name);
466 pos = cache_name_pos(ce->name, namelen);
c8193534
JH
467 if (0 <= pos)
468 return cnt; /* we have it as nondirectory */
469 pos = -pos - 1;
470 for (i = pos; i < active_nr; i++) {
471 struct cache_entry *ce = active_cache[i];
472 int len = ce_namelen(ce);
473 if (len < namelen ||
0cf73755 474 strncmp(ce->name, ce->name, namelen) ||
c8193534
JH
475 ce->name[namelen] != '/')
476 break;
477 /*
478 * ce->name is an entry in the subdirectory.
479 */
480 if (!ce_stage(ce)) {
203a2fe1
DB
481 if (verify_uptodate(ce, o))
482 return -1;
7a51ed66 483 ce->ce_flags |= CE_REMOVE;
c8193534
JH
484 }
485 cnt++;
486 }
487
488 /*
489 * Then we need to make sure that we do not lose a locally
490 * present file that is not ignored.
491 */
492 pathbuf = xmalloc(namelen + 2);
0cf73755 493 memcpy(pathbuf, ce->name, namelen);
c8193534
JH
494 strcpy(pathbuf+namelen, "/");
495
496 memset(&d, 0, sizeof(d));
497 if (o->dir)
498 d.exclude_per_dir = o->dir->exclude_per_dir;
0cf73755 499 i = read_directory(&d, ce->name, pathbuf, namelen+1, NULL);
c8193534 500 if (i)
17e46426
DB
501 return o->gently ? -1 :
502 error("Updating '%s' would lose untracked files in it",
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 */
203a2fe1
DB
512static int verify_absent(struct cache_entry *ce, const char *action,
513 struct unpack_trees_options *o)
076b0adc
JS
514{
515 struct stat st;
516
517 if (o->index_only || o->reset || !o->update)
203a2fe1 518 return 0;
c8193534 519
0cf73755 520 if (has_symlink_leading_path(ce->name, NULL))
203a2fe1 521 return 0;
ec0603e1 522
0cf73755 523 if (!lstat(ce->name, &st)) {
c8193534 524 int cnt;
6831a88a 525 int dtype = ce_to_dtype(ce);
c8193534 526
6831a88a 527 if (o->dir && excluded(o->dir, ce->name, &dtype))
c8193534 528 /*
0cf73755 529 * ce->name is explicitly excluded, so it is Ok to
c8193534
JH
530 * overwrite it.
531 */
203a2fe1 532 return 0;
c8193534
JH
533 if (S_ISDIR(st.st_mode)) {
534 /*
535 * We are checking out path "foo" and
536 * found "foo/." in the working tree.
537 * This is tricky -- if we have modified
538 * files that are in "foo/" we would lose
539 * it.
540 */
0cf73755 541 cnt = verify_clean_subdirectory(ce, action, o);
c8193534
JH
542
543 /*
544 * If this removed entries from the index,
545 * what that means is:
546 *
547 * (1) the caller unpack_trees_rec() saw path/foo
548 * in the index, and it has not removed it because
549 * it thinks it is handling 'path' as blob with
550 * D/F conflict;
551 * (2) we will return "ok, we placed a merged entry
552 * in the index" which would cause o->pos to be
553 * incremented by one;
554 * (3) however, original o->pos now has 'path/foo'
555 * marked with "to be removed".
556 *
557 * We need to increment it by the number of
558 * deleted entries here.
559 */
560 o->pos += cnt;
203a2fe1 561 return 0;
c8193534
JH
562 }
563
564 /*
565 * The previous round may already have decided to
566 * delete this path, which is in a subdirectory that
567 * is being replaced with a blob.
568 */
0cf73755 569 cnt = cache_name_pos(ce->name, strlen(ce->name));
c8193534
JH
570 if (0 <= cnt) {
571 struct cache_entry *ce = active_cache[cnt];
7a51ed66 572 if (ce->ce_flags & CE_REMOVE)
203a2fe1 573 return 0;
c8193534
JH
574 }
575
17e46426
DB
576 return o->gently ? -1 :
577 error("Untracked working tree file '%s' "
578 "would be %s by merge.", ce->name, action);
c8193534 579 }
203a2fe1 580 return 0;
076b0adc
JS
581}
582
583static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
584 struct unpack_trees_options *o)
585{
7a51ed66 586 merge->ce_flags |= CE_UPDATE;
076b0adc
JS
587 if (old) {
588 /*
589 * See if we can re-use the old CE directly?
590 * That way we get the uptodate stat info.
591 *
592 * This also removes the UPDATE flag on
593 * a match.
594 */
595 if (same(old, merge)) {
eb7a2f1d 596 copy_cache_entry(merge, old);
076b0adc 597 } else {
203a2fe1
DB
598 if (verify_uptodate(old, o))
599 return -1;
076b0adc
JS
600 invalidate_ce_path(old);
601 }
602 }
603 else {
203a2fe1
DB
604 if (verify_absent(merge, "overwritten", o))
605 return -1;
076b0adc
JS
606 invalidate_ce_path(merge);
607 }
608
7a51ed66 609 merge->ce_flags &= ~CE_STAGEMASK;
076b0adc
JS
610 add_cache_entry(merge, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
611 return 1;
612}
613
614static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
615 struct unpack_trees_options *o)
616{
203a2fe1
DB
617 if (old) {
618 if (verify_uptodate(old, o))
619 return -1;
620 } else
621 if (verify_absent(ce, "removed", o))
622 return -1;
7a51ed66 623 ce->ce_flags |= CE_REMOVE;
076b0adc
JS
624 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
625 invalidate_ce_path(ce);
626 return 1;
627}
628
7f7932ab 629static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o)
076b0adc
JS
630{
631 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
632 return 1;
633}
634
635#if DBRT_DEBUG
636static void show_stage_entry(FILE *o,
637 const char *label, const struct cache_entry *ce)
638{
639 if (!ce)
640 fprintf(o, "%s (missing)\n", label);
641 else
642 fprintf(o, "%s%06o %s %d\t%s\n",
643 label,
7a51ed66 644 ce->ce_mode,
076b0adc
JS
645 sha1_to_hex(ce->sha1),
646 ce_stage(ce),
647 ce->name);
648}
649#endif
650
651int threeway_merge(struct cache_entry **stages,
b48d5a05
LT
652 struct unpack_trees_options *o,
653 int remove)
076b0adc
JS
654{
655 struct cache_entry *index;
656 struct cache_entry *head;
657 struct cache_entry *remote = stages[o->head_idx + 1];
658 int count;
659 int head_match = 0;
660 int remote_match = 0;
076b0adc
JS
661
662 int df_conflict_head = 0;
663 int df_conflict_remote = 0;
664
665 int any_anc_missing = 0;
666 int no_anc_exists = 1;
667 int i;
668
669 for (i = 1; i < o->head_idx; i++) {
4c4caafc 670 if (!stages[i] || stages[i] == o->df_conflict_entry)
076b0adc 671 any_anc_missing = 1;
4c4caafc 672 else
076b0adc 673 no_anc_exists = 0;
076b0adc
JS
674 }
675
676 index = stages[0];
677 head = stages[o->head_idx];
678
679 if (head == o->df_conflict_entry) {
680 df_conflict_head = 1;
681 head = NULL;
682 }
683
684 if (remote == o->df_conflict_entry) {
685 df_conflict_remote = 1;
686 remote = NULL;
687 }
688
076b0adc
JS
689 /* First, if there's a #16 situation, note that to prevent #13
690 * and #14.
691 */
692 if (!same(remote, head)) {
693 for (i = 1; i < o->head_idx; i++) {
694 if (same(stages[i], head)) {
695 head_match = i;
696 }
697 if (same(stages[i], remote)) {
698 remote_match = i;
699 }
700 }
701 }
702
703 /* We start with cases where the index is allowed to match
704 * something other than the head: #14(ALT) and #2ALT, where it
705 * is permitted to match the result instead.
706 */
707 /* #14, #14ALT, #2ALT */
708 if (remote && !df_conflict_head && head_match && !remote_match) {
709 if (index && !same(index, remote) && !same(index, head))
17e46426 710 return o->gently ? -1 : reject_merge(index);
076b0adc
JS
711 return merged_entry(remote, index, o);
712 }
713 /*
714 * If we have an entry in the index cache, then we want to
715 * make sure that it matches head.
716 */
4e7c4571 717 if (index && !same(index, head))
17e46426 718 return o->gently ? -1 : reject_merge(index);
076b0adc
JS
719
720 if (head) {
721 /* #5ALT, #15 */
722 if (same(head, remote))
723 return merged_entry(head, index, o);
724 /* #13, #3ALT */
725 if (!df_conflict_remote && remote_match && !head_match)
726 return merged_entry(head, index, o);
727 }
728
729 /* #1 */
566b5c05
LT
730 if (!head && !remote && any_anc_missing) {
731 remove_entry(remove);
076b0adc 732 return 0;
566b5c05 733 }
076b0adc
JS
734
735 /* Under the new "aggressive" rule, we resolve mostly trivial
736 * cases that we historically had git-merge-one-file resolve.
737 */
738 if (o->aggressive) {
739 int head_deleted = !head && !df_conflict_head;
740 int remote_deleted = !remote && !df_conflict_remote;
0cf73755 741 struct cache_entry *ce = NULL;
4c4caafc
JH
742
743 if (index)
0cf73755 744 ce = index;
4c4caafc 745 else if (head)
0cf73755 746 ce = head;
4c4caafc 747 else if (remote)
0cf73755 748 ce = remote;
4c4caafc
JH
749 else {
750 for (i = 1; i < o->head_idx; i++) {
751 if (stages[i] && stages[i] != o->df_conflict_entry) {
0cf73755 752 ce = stages[i];
4c4caafc
JH
753 break;
754 }
755 }
756 }
757
076b0adc
JS
758 /*
759 * Deleted in both.
760 * Deleted in one and unchanged in the other.
761 */
762 if ((head_deleted && remote_deleted) ||
763 (head_deleted && remote && remote_match) ||
764 (remote_deleted && head && head_match)) {
566b5c05 765 remove_entry(remove);
076b0adc
JS
766 if (index)
767 return deleted_entry(index, index, o);
203a2fe1
DB
768 else if (ce && !head_deleted) {
769 if (verify_absent(ce, "removed", o))
770 return -1;
771 }
076b0adc
JS
772 return 0;
773 }
774 /*
775 * Added in both, identically.
776 */
777 if (no_anc_exists && head && remote && same(head, remote))
778 return merged_entry(head, index, o);
779
780 }
781
782 /* Below are "no merge" cases, which require that the index be
783 * up-to-date to avoid the files getting overwritten with
784 * conflict resolution files.
785 */
786 if (index) {
203a2fe1
DB
787 if (verify_uptodate(index, o))
788 return -1;
076b0adc 789 }
076b0adc 790
566b5c05 791 remove_entry(remove);
076b0adc
JS
792 o->nontrivial_merge = 1;
793
ea4b52a8 794 /* #2, #3, #4, #6, #7, #9, #10, #11. */
076b0adc
JS
795 count = 0;
796 if (!head_match || !remote_match) {
797 for (i = 1; i < o->head_idx; i++) {
4c4caafc 798 if (stages[i] && stages[i] != o->df_conflict_entry) {
7f7932ab 799 keep_entry(stages[i], o);
076b0adc
JS
800 count++;
801 break;
802 }
803 }
804 }
805#if DBRT_DEBUG
806 else {
807 fprintf(stderr, "read-tree: warning #16 detected\n");
808 show_stage_entry(stderr, "head ", stages[head_match]);
809 show_stage_entry(stderr, "remote ", stages[remote_match]);
810 }
811#endif
7f7932ab
JH
812 if (head) { count += keep_entry(head, o); }
813 if (remote) { count += keep_entry(remote, o); }
076b0adc
JS
814 return count;
815}
816
817/*
818 * Two-way merge.
819 *
820 * The rule is to "carry forward" what is in the index without losing
821 * information across a "fast forward", favoring a successful merge
822 * over a merge failure when it makes sense. For details of the
823 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
824 *
825 */
826int twoway_merge(struct cache_entry **src,
b48d5a05
LT
827 struct unpack_trees_options *o,
828 int remove)
076b0adc
JS
829{
830 struct cache_entry *current = src[0];
b8ba1535
JH
831 struct cache_entry *oldtree = src[1];
832 struct cache_entry *newtree = src[2];
076b0adc
JS
833
834 if (o->merge_size != 2)
835 return error("Cannot do a twoway merge of %d trees",
836 o->merge_size);
837
b8ba1535
JH
838 if (oldtree == o->df_conflict_entry)
839 oldtree = NULL;
840 if (newtree == o->df_conflict_entry)
841 newtree = NULL;
842
076b0adc
JS
843 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 &&
b8ba1535 850 !same(oldtree, newtree) && /* 18 and 19 */
076b0adc 851 same(current, newtree))) {
7f7932ab 852 return keep_entry(current, o);
076b0adc
JS
853 }
854 else if (oldtree && !newtree && same(current, oldtree)) {
855 /* 10 or 11 */
d699676d 856 remove_entry(remove);
076b0adc
JS
857 return deleted_entry(oldtree, current, o);
858 }
859 else if (oldtree && newtree &&
860 same(current, oldtree) && !same(current, newtree)) {
861 /* 20 or 21 */
862 return merged_entry(newtree, current, o);
863 }
864 else {
865 /* all other failures */
d699676d 866 remove_entry(remove);
076b0adc 867 if (oldtree)
17e46426 868 return o->gently ? -1 : reject_merge(oldtree);
076b0adc 869 if (current)
17e46426 870 return o->gently ? -1 : reject_merge(current);
076b0adc 871 if (newtree)
17e46426 872 return o->gently ? -1 : reject_merge(newtree);
076b0adc
JS
873 return -1;
874 }
875 }
876 else if (newtree)
877 return merged_entry(newtree, current, o);
d699676d
LT
878 remove_entry(remove);
879 return deleted_entry(oldtree, current, o);
076b0adc
JS
880}
881
882/*
883 * Bind merge.
884 *
885 * Keep the index entries at stage0, collapse stage1 but make sure
886 * stage0 does not have anything there.
887 */
888int bind_merge(struct cache_entry **src,
b48d5a05
LT
889 struct unpack_trees_options *o,
890 int remove)
076b0adc
JS
891{
892 struct cache_entry *old = src[0];
893 struct cache_entry *a = src[1];
894
895 if (o->merge_size != 1)
896 return error("Cannot do a bind merge of %d trees\n",
897 o->merge_size);
898 if (a && old)
17e46426
DB
899 return o->gently ? -1 :
900 error("Entry '%s' overlaps. Cannot bind.", a->name);
076b0adc 901 if (!a)
7f7932ab 902 return keep_entry(old, o);
076b0adc
JS
903 else
904 return merged_entry(a, NULL, o);
905}
906
907/*
908 * One-way merge.
909 *
910 * The rule is:
911 * - take the stat information from stage0, take the data from stage1
912 */
913int oneway_merge(struct cache_entry **src,
b48d5a05
LT
914 struct unpack_trees_options *o,
915 int remove)
076b0adc
JS
916{
917 struct cache_entry *old = src[0];
918 struct cache_entry *a = src[1];
919
920 if (o->merge_size != 1)
921 return error("Cannot do a oneway merge of %d trees",
922 o->merge_size);
923
288f072e
LT
924 if (!a) {
925 remove_entry(remove);
076b0adc 926 return deleted_entry(old, old, o);
288f072e 927 }
076b0adc
JS
928 if (old && same(old, a)) {
929 if (o->reset) {
930 struct stat st;
931 if (lstat(old->name, &st) ||
4bd5b7da 932 ce_match_stat(old, &st, CE_MATCH_IGNORE_VALID))
7a51ed66 933 old->ce_flags |= CE_UPDATE;
076b0adc 934 }
7f7932ab 935 return keep_entry(old, o);
076b0adc
JS
936 }
937 return merged_entry(a, old, o);
938}