GIT 1.6.0
[git/git.git] / unpack-trees.c
CommitLineData
bc052d7f 1#define NO_THE_INDEX_COMPATIBILITY_MACROS
16da134b 2#include "cache.h"
f8a9d428 3#include "dir.h"
16da134b
JS
4#include "tree.h"
5#include "tree-walk.h"
076b0adc 6#include "cache-tree.h"
16da134b 7#include "unpack-trees.h"
96a02f8f 8#include "progress.h"
0cf73755 9#include "refs.h"
16da134b 10
8ccba008
JH
11/*
12 * Error messages expected by scripts out of plumbing commands such as
13 * read-tree. Non-scripted Porcelain is not required to use these messages
14 * and in fact are encouraged to reword them to better suit their particular
15 * situation better. See how "git checkout" replaces not_uptodate_file to
16 * explain why it does not allow switching between branches when you have
17 * local changes, for example.
18 */
19static struct unpack_trees_error_msgs unpack_plumbing_errors = {
20 /* would_overwrite */
21 "Entry '%s' would be overwritten by merge. Cannot merge.",
22
23 /* not_uptodate_file */
24 "Entry '%s' not uptodate. Cannot merge.",
25
26 /* not_uptodate_dir */
27 "Updating '%s' would lose untracked files in it",
28
29 /* would_lose_untracked */
30 "Untracked working tree file '%s' would be %s by merge.",
31
32 /* bind_overlap */
33 "Entry '%s' overlaps with '%s'. Cannot bind.",
34};
35
36#define ERRORMSG(o,fld) \
37 ( ((o) && (o)->msgs.fld) \
38 ? ((o)->msgs.fld) \
39 : (unpack_plumbing_errors.fld) )
40
34110cd4
LT
41static void add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
42 unsigned int set, unsigned int clear)
b48d5a05 43{
34110cd4
LT
44 unsigned int size = ce_size(ce);
45 struct cache_entry *new = xmalloc(size);
46
47 clear |= CE_HASHED | CE_UNHASHED;
48
49 memcpy(new, ce, size);
50 new->next = NULL;
51 new->ce_flags = (new->ce_flags & ~clear) | set;
52 add_index_entry(&o->result, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE|ADD_CACHE_SKIP_DFCHECK);
b48d5a05
LT
53}
54
16da134b
JS
55/* Unlink the last component and attempt to remove leading
56 * directories, in case this unlink is the removal of the
57 * last entry in the directory -- empty directories are removed.
58 */
c40641b7 59static void unlink_entry(struct cache_entry *ce)
16da134b
JS
60{
61 char *cp, *prev;
c40641b7 62 char *name = ce->name;
16da134b 63
c40641b7 64 if (has_symlink_leading_path(ce_namelen(ce), ce->name))
16a4c617 65 return;
16da134b
JS
66 if (unlink(name))
67 return;
68 prev = NULL;
69 while (1) {
70 int status;
71 cp = strrchr(name, '/');
72 if (prev)
73 *prev = '/';
74 if (!cp)
75 break;
76
77 *cp = 0;
78 status = rmdir(name);
79 if (status) {
80 *cp = '/';
81 break;
82 }
83 prev = cp;
84 }
85}
86
16da134b 87static struct checkout state;
c4758d3c 88static int check_updates(struct unpack_trees_options *o)
16da134b 89{
96a02f8f 90 unsigned cnt = 0, total = 0;
dc6a0757 91 struct progress *progress = NULL;
34110cd4 92 struct index_state *index = &o->result;
33ecf7eb 93 int i;
c4758d3c 94 int errs = 0;
16da134b
JS
95
96 if (o->update && o->verbose_update) {
34110cd4
LT
97 for (total = cnt = 0; cnt < index->cache_nr; cnt++) {
98 struct cache_entry *ce = index->cache[cnt];
7a51ed66 99 if (ce->ce_flags & (CE_UPDATE | CE_REMOVE))
16da134b
JS
100 total++;
101 }
102
dc6a0757 103 progress = start_progress_delay("Checking out files",
e8548645 104 total, 50, 1);
16da134b
JS
105 cnt = 0;
106 }
107
34110cd4
LT
108 for (i = 0; i < index->cache_nr; i++) {
109 struct cache_entry *ce = index->cache[i];
16da134b 110
7a51ed66 111 if (ce->ce_flags & CE_REMOVE) {
1fa6ead4 112 display_progress(progress, ++cnt);
16da134b 113 if (o->update)
c40641b7 114 unlink_entry(ce);
34110cd4 115 remove_index_entry_at(&o->result, i);
33ecf7eb 116 i--;
16da134b
JS
117 continue;
118 }
1fa6ead4
LT
119 }
120
121 for (i = 0; i < index->cache_nr; i++) {
122 struct cache_entry *ce = index->cache[i];
123
7a51ed66 124 if (ce->ce_flags & CE_UPDATE) {
1fa6ead4 125 display_progress(progress, ++cnt);
7a51ed66 126 ce->ce_flags &= ~CE_UPDATE;
16a4c617 127 if (o->update) {
c4758d3c 128 errs |= checkout_entry(ce, &state, NULL);
16a4c617 129 }
16da134b
JS
130 }
131 }
4d4fcc54 132 stop_progress(&progress);
c4758d3c 133 return errs != 0;
16da134b
JS
134}
135
34110cd4 136static inline int call_unpack_fn(struct cache_entry **src, struct unpack_trees_options *o)
01904572 137{
34110cd4
LT
138 int ret = o->fn(src, o);
139 if (ret > 0)
01904572 140 ret = 0;
01904572
LT
141 return ret;
142}
143
144static int unpack_index_entry(struct cache_entry *ce, struct unpack_trees_options *o)
145{
146 struct cache_entry *src[5] = { ce, };
34110cd4
LT
147
148 o->pos++;
01904572
LT
149 if (ce_stage(ce)) {
150 if (o->skip_unmerged) {
34110cd4
LT
151 add_entry(o, ce, 0, 0);
152 return 0;
01904572 153 }
01904572 154 }
34110cd4 155 return call_unpack_fn(src, o);
01904572
LT
156}
157
158int traverse_trees_recursive(int n, unsigned long dirmask, unsigned long df_conflicts, struct name_entry *names, struct traverse_info *info)
16da134b 159{
16da134b 160 int i;
ca885a4f 161 struct tree_desc t[MAX_UNPACK_TREES];
01904572
LT
162 struct traverse_info newinfo;
163 struct name_entry *p;
164
165 p = names;
166 while (!p->mode)
167 p++;
168
169 newinfo = *info;
170 newinfo.prev = info;
171 newinfo.name = *p;
172 newinfo.pathlen += tree_entry_len(p->path, p->sha1) + 1;
173 newinfo.conflicts |= df_conflicts;
174
175 for (i = 0; i < n; i++, dirmask >>= 1) {
176 const unsigned char *sha1 = NULL;
177 if (dirmask & 1)
178 sha1 = names[i].sha1;
179 fill_tree_descriptor(t+i, sha1);
180 }
542c264b 181 return traverse_trees(n, t, &newinfo);
01904572
LT
182}
183
184/*
185 * Compare the traverse-path to the cache entry without actually
186 * having to generate the textual representation of the traverse
187 * path.
188 *
189 * NOTE! This *only* compares up to the size of the traverse path
190 * itself - the caller needs to do the final check for the cache
191 * entry having more data at the end!
192 */
193static int do_compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
194{
195 int len, pathlen, ce_len;
196 const char *ce_name;
197
198 if (info->prev) {
199 int cmp = do_compare_entry(ce, info->prev, &info->name);
200 if (cmp)
201 return cmp;
202 }
203 pathlen = info->pathlen;
204 ce_len = ce_namelen(ce);
205
206 /* If ce_len < pathlen then we must have previously hit "name == directory" entry */
207 if (ce_len < pathlen)
208 return -1;
209
210 ce_len -= pathlen;
211 ce_name = ce->name + pathlen;
212
213 len = tree_entry_len(n->path, n->sha1);
214 return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode);
215}
216
217static int compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
218{
219 int cmp = do_compare_entry(ce, info, n);
220 if (cmp)
221 return cmp;
222
223 /*
224 * Even if the beginning compared identically, the ce should
225 * compare as bigger than a directory leading up to it!
226 */
227 return ce_namelen(ce) > traverse_path_len(info, n);
228}
229
230static struct cache_entry *create_ce_entry(const struct traverse_info *info, const struct name_entry *n, int stage)
231{
232 int len = traverse_path_len(info, n);
233 struct cache_entry *ce = xcalloc(1, cache_entry_size(len));
234
235 ce->ce_mode = create_ce_mode(n->mode);
236 ce->ce_flags = create_ce_flags(len, stage);
237 hashcpy(ce->sha1, n->sha1);
238 make_traverse_path(ce->name, info, n);
239
240 return ce;
241}
242
243static int unpack_nondirectories(int n, unsigned long mask, unsigned long dirmask, struct cache_entry *src[5],
34110cd4 244 const struct name_entry *names, const struct traverse_info *info)
01904572
LT
245{
246 int i;
247 struct unpack_trees_options *o = info->data;
248 unsigned long conflicts;
249
250 /* Do we have *only* directories? Nothing to do */
251 if (mask == dirmask && !src[0])
252 return 0;
253
254 conflicts = info->conflicts;
255 if (o->merge)
256 conflicts >>= 1;
257 conflicts |= dirmask;
258
259 /*
260 * Ok, we've filled in up to any potential index entry in src[0],
261 * now do the rest.
262 */
263 for (i = 0; i < n; i++) {
264 int stage;
265 unsigned int bit = 1ul << i;
266 if (conflicts & bit) {
267 src[i + o->merge] = o->df_conflict_entry;
268 continue;
269 }
270 if (!(mask & bit))
271 continue;
272 if (!o->merge)
273 stage = 0;
274 else if (i + 1 < o->head_idx)
275 stage = 1;
276 else if (i + 1 > o->head_idx)
277 stage = 3;
278 else
279 stage = 2;
280 src[i + o->merge] = create_ce_entry(info, names + i, stage);
281 }
282
283 if (o->merge)
34110cd4 284 return call_unpack_fn(src, o);
01904572
LT
285
286 n += o->merge;
01904572 287 for (i = 0; i < n; i++)
34110cd4 288 add_entry(o, src[i], 0, 0);
01904572
LT
289 return 0;
290}
291
292static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *names, struct traverse_info *info)
293{
294 struct cache_entry *src[5] = { NULL, };
295 struct unpack_trees_options *o = info->data;
01904572
LT
296 const struct name_entry *p = names;
297
298 /* Find first entry with a real name (we could use "mask" too) */
299 while (!p->mode)
300 p++;
301
302 /* Are we supposed to look at the index too? */
303 if (o->merge) {
34110cd4
LT
304 while (o->pos < o->src_index->cache_nr) {
305 struct cache_entry *ce = o->src_index->cache[o->pos];
01904572
LT
306 int cmp = compare_entry(ce, info, p);
307 if (cmp < 0) {
308 if (unpack_index_entry(ce, o) < 0)
309 return -1;
310 continue;
311 }
312 if (!cmp) {
34110cd4 313 o->pos++;
01904572
LT
314 if (ce_stage(ce)) {
315 /*
316 * If we skip unmerged index entries, we'll skip this
317 * entry *and* the tree entries associated with it!
318 */
34110cd4
LT
319 if (o->skip_unmerged) {
320 add_entry(o, ce, 0, 0);
01904572 321 return mask;
34110cd4 322 }
01904572
LT
323 }
324 src[0] = ce;
01904572
LT
325 }
326 break;
327 }
328 }
329
34110cd4 330 if (unpack_nondirectories(n, mask, dirmask, src, names, info) < 0)
01904572
LT
331 return -1;
332
333 /* Now handle any directories.. */
334 if (dirmask) {
335 unsigned long conflicts = mask & ~dirmask;
336 if (o->merge) {
337 conflicts <<= 1;
338 if (src[0])
339 conflicts |= 1;
340 }
542c264b
JH
341 if (traverse_trees_recursive(n, dirmask, conflicts,
342 names, info) < 0)
343 return -1;
01904572
LT
344 return mask;
345 }
346
347 return mask;
348}
349
350static int unpack_failed(struct unpack_trees_options *o, const char *message)
351{
1caeacc1 352 discard_index(&o->result);
01904572
LT
353 if (!o->gently) {
354 if (message)
355 return error(message);
356 return -1;
357 }
01904572
LT
358 return -1;
359}
360
2e2b887d
JH
361/*
362 * N-way merge "len" trees. Returns 0 on success, -1 on failure to manipulate the
363 * resulting index, -2 on failure to reflect the changes to the work tree.
364 */
01904572
LT
365int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
366{
2e2b887d 367 int ret;
0fb1eaa8 368 static struct cache_entry *dfc;
16da134b 369
ca885a4f
JH
370 if (len > MAX_UNPACK_TREES)
371 die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
076b0adc 372 memset(&state, 0, sizeof(state));
16da134b
JS
373 state.base_dir = "";
374 state.force = 1;
375 state.quiet = 1;
376 state.refresh_cache = 1;
377
34110cd4 378 memset(&o->result, 0, sizeof(o->result));
fac4b328
LT
379 if (o->src_index)
380 o->result.timestamp = o->src_index->timestamp;
16da134b 381 o->merge_size = len;
0fb1eaa8
JH
382
383 if (!dfc)
384 dfc = xcalloc(1, sizeof(struct cache_entry) + 1);
385 o->df_conflict_entry = dfc;
16da134b
JS
386
387 if (len) {
01904572
LT
388 const char *prefix = o->prefix ? o->prefix : "";
389 struct traverse_info info;
390
391 setup_traverse_info(&info, prefix);
392 info.fn = unpack_callback;
393 info.data = o;
394
395 if (traverse_trees(len, t, &info) < 0)
396 return unpack_failed(o, NULL);
16da134b
JS
397 }
398
01904572
LT
399 /* Any left-over entries in the index? */
400 if (o->merge) {
34110cd4
LT
401 while (o->pos < o->src_index->cache_nr) {
402 struct cache_entry *ce = o->src_index->cache[o->pos];
01904572
LT
403 if (unpack_index_entry(ce, o) < 0)
404 return unpack_failed(o, NULL);
17e46426 405 }
17e46426 406 }
16da134b 407
01904572
LT
408 if (o->trivial_merges_only && o->nontrivial_merge)
409 return unpack_failed(o, "Merge requires file-level merging");
410
34110cd4 411 o->src_index = NULL;
2e2b887d 412 ret = check_updates(o) ? (-2) : 0;
34110cd4
LT
413 if (o->dst_index)
414 *o->dst_index = o->result;
2e2b887d 415 return ret;
16da134b 416}
076b0adc
JS
417
418/* Here come the merge functions */
419
8ccba008 420static int reject_merge(struct cache_entry *ce, struct unpack_trees_options *o)
076b0adc 421{
8ccba008 422 return error(ERRORMSG(o, would_overwrite), ce->name);
076b0adc
JS
423}
424
425static int same(struct cache_entry *a, struct cache_entry *b)
426{
427 if (!!a != !!b)
428 return 0;
429 if (!a && !b)
430 return 1;
431 return a->ce_mode == b->ce_mode &&
a89fccd2 432 !hashcmp(a->sha1, b->sha1);
076b0adc
JS
433}
434
435
436/*
437 * When a CE gets turned into an unmerged entry, we
438 * want it to be up-to-date
439 */
203a2fe1 440static int verify_uptodate(struct cache_entry *ce,
076b0adc
JS
441 struct unpack_trees_options *o)
442{
443 struct stat st;
444
445 if (o->index_only || o->reset)
203a2fe1 446 return 0;
076b0adc
JS
447
448 if (!lstat(ce->name, &st)) {
34110cd4 449 unsigned changed = ie_match_stat(o->src_index, ce, &st, CE_MATCH_IGNORE_VALID);
076b0adc 450 if (!changed)
203a2fe1 451 return 0;
936492d3
JH
452 /*
453 * NEEDSWORK: the current default policy is to allow
454 * submodule to be out of sync wrt the supermodule
455 * index. This needs to be tightened later for
456 * submodules that are marked to be automatically
457 * checked out.
458 */
7a51ed66 459 if (S_ISGITLINK(ce->ce_mode))
203a2fe1 460 return 0;
076b0adc
JS
461 errno = 0;
462 }
076b0adc 463 if (errno == ENOENT)
203a2fe1 464 return 0;
17e46426 465 return o->gently ? -1 :
8ccba008 466 error(ERRORMSG(o, not_uptodate_file), ce->name);
076b0adc
JS
467}
468
bc052d7f 469static void invalidate_ce_path(struct cache_entry *ce, struct unpack_trees_options *o)
076b0adc
JS
470{
471 if (ce)
34110cd4 472 cache_tree_invalidate_path(o->src_index->cache_tree, ce->name);
076b0adc
JS
473}
474
0cf73755
SV
475/*
476 * Check that checking out ce->sha1 in subdir ce->name is not
477 * going to overwrite any working files.
478 *
479 * Currently, git does not checkout subprojects during a superproject
480 * checkout, so it is not going to overwrite anything.
481 */
482static int verify_clean_submodule(struct cache_entry *ce, const char *action,
483 struct unpack_trees_options *o)
484{
485 return 0;
486}
487
488static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
c8193534
JH
489 struct unpack_trees_options *o)
490{
491 /*
0cf73755 492 * we are about to extract "ce->name"; we would not want to lose
c8193534
JH
493 * anything in the existing directory there.
494 */
495 int namelen;
496 int pos, i;
497 struct dir_struct d;
498 char *pathbuf;
499 int cnt = 0;
0cf73755
SV
500 unsigned char sha1[20];
501
7a51ed66 502 if (S_ISGITLINK(ce->ce_mode) &&
0cf73755
SV
503 resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
504 /* If we are not going to update the submodule, then
505 * we don't care.
506 */
507 if (!hashcmp(sha1, ce->sha1))
508 return 0;
509 return verify_clean_submodule(ce, action, o);
510 }
c8193534
JH
511
512 /*
513 * First let's make sure we do not have a local modification
514 * in that directory.
515 */
0cf73755 516 namelen = strlen(ce->name);
34110cd4 517 pos = index_name_pos(o->src_index, ce->name, namelen);
c8193534
JH
518 if (0 <= pos)
519 return cnt; /* we have it as nondirectory */
520 pos = -pos - 1;
34110cd4
LT
521 for (i = pos; i < o->src_index->cache_nr; i++) {
522 struct cache_entry *ce = o->src_index->cache[i];
c8193534
JH
523 int len = ce_namelen(ce);
524 if (len < namelen ||
0cf73755 525 strncmp(ce->name, ce->name, namelen) ||
c8193534
JH
526 ce->name[namelen] != '/')
527 break;
528 /*
529 * ce->name is an entry in the subdirectory.
530 */
531 if (!ce_stage(ce)) {
203a2fe1
DB
532 if (verify_uptodate(ce, o))
533 return -1;
34110cd4 534 add_entry(o, ce, CE_REMOVE, 0);
c8193534
JH
535 }
536 cnt++;
537 }
538
539 /*
540 * Then we need to make sure that we do not lose a locally
541 * present file that is not ignored.
542 */
543 pathbuf = xmalloc(namelen + 2);
0cf73755 544 memcpy(pathbuf, ce->name, namelen);
c8193534
JH
545 strcpy(pathbuf+namelen, "/");
546
547 memset(&d, 0, sizeof(d));
548 if (o->dir)
549 d.exclude_per_dir = o->dir->exclude_per_dir;
0cf73755 550 i = read_directory(&d, ce->name, pathbuf, namelen+1, NULL);
c8193534 551 if (i)
17e46426 552 return o->gently ? -1 :
8ccba008 553 error(ERRORMSG(o, not_uptodate_dir), ce->name);
c8193534
JH
554 free(pathbuf);
555 return cnt;
556}
557
32260ad5
LT
558/*
559 * This gets called when there was no index entry for the tree entry 'dst',
560 * but we found a file in the working tree that 'lstat()' said was fine,
561 * and we're on a case-insensitive filesystem.
562 *
563 * See if we can find a case-insensitive match in the index that also
564 * matches the stat information, and assume it's that other file!
565 */
566static int icase_exists(struct unpack_trees_options *o, struct cache_entry *dst, struct stat *st)
567{
568 struct cache_entry *src;
569
570 src = index_name_exists(o->src_index, dst->name, ce_namelen(dst), 1);
571 return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID);
572}
573
076b0adc
JS
574/*
575 * We do not want to remove or overwrite a working tree file that
f8a9d428 576 * is not tracked, unless it is ignored.
076b0adc 577 */
203a2fe1
DB
578static int verify_absent(struct cache_entry *ce, const char *action,
579 struct unpack_trees_options *o)
076b0adc
JS
580{
581 struct stat st;
582
583 if (o->index_only || o->reset || !o->update)
203a2fe1 584 return 0;
c8193534 585
c40641b7 586 if (has_symlink_leading_path(ce_namelen(ce), ce->name))
203a2fe1 587 return 0;
ec0603e1 588
0cf73755 589 if (!lstat(ce->name, &st)) {
c8193534 590 int cnt;
6831a88a 591 int dtype = ce_to_dtype(ce);
df292c79 592 struct cache_entry *result;
c8193534 593
32260ad5
LT
594 /*
595 * It may be that the 'lstat()' succeeded even though
596 * target 'ce' was absent, because there is an old
597 * entry that is different only in case..
598 *
599 * Ignore that lstat() if it matches.
600 */
601 if (ignore_case && icase_exists(o, ce, &st))
602 return 0;
603
6831a88a 604 if (o->dir && excluded(o->dir, ce->name, &dtype))
c8193534 605 /*
0cf73755 606 * ce->name is explicitly excluded, so it is Ok to
c8193534
JH
607 * overwrite it.
608 */
203a2fe1 609 return 0;
c8193534
JH
610 if (S_ISDIR(st.st_mode)) {
611 /*
612 * We are checking out path "foo" and
613 * found "foo/." in the working tree.
614 * This is tricky -- if we have modified
615 * files that are in "foo/" we would lose
616 * it.
617 */
0cf73755 618 cnt = verify_clean_subdirectory(ce, action, o);
c8193534
JH
619
620 /*
621 * If this removed entries from the index,
622 * what that means is:
623 *
624 * (1) the caller unpack_trees_rec() saw path/foo
625 * in the index, and it has not removed it because
626 * it thinks it is handling 'path' as blob with
627 * D/F conflict;
628 * (2) we will return "ok, we placed a merged entry
629 * in the index" which would cause o->pos to be
630 * incremented by one;
631 * (3) however, original o->pos now has 'path/foo'
632 * marked with "to be removed".
633 *
634 * We need to increment it by the number of
635 * deleted entries here.
636 */
637 o->pos += cnt;
203a2fe1 638 return 0;
c8193534
JH
639 }
640
641 /*
642 * The previous round may already have decided to
643 * delete this path, which is in a subdirectory that
644 * is being replaced with a blob.
645 */
cd2fef59 646 result = index_name_exists(&o->result, ce->name, ce_namelen(ce), 0);
df292c79
LT
647 if (result) {
648 if (result->ce_flags & CE_REMOVE)
203a2fe1 649 return 0;
c8193534
JH
650 }
651
17e46426 652 return o->gently ? -1 :
8ccba008 653 error(ERRORMSG(o, would_lose_untracked), ce->name, action);
c8193534 654 }
203a2fe1 655 return 0;
076b0adc
JS
656}
657
658static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
659 struct unpack_trees_options *o)
660{
7f8ab8dc
LT
661 int update = CE_UPDATE;
662
076b0adc
JS
663 if (old) {
664 /*
665 * See if we can re-use the old CE directly?
666 * That way we get the uptodate stat info.
667 *
7f8ab8dc
LT
668 * This also removes the UPDATE flag on a match; otherwise
669 * we will end up overwriting local changes in the work tree.
076b0adc
JS
670 */
671 if (same(old, merge)) {
eb7a2f1d 672 copy_cache_entry(merge, old);
7f8ab8dc 673 update = 0;
076b0adc 674 } else {
203a2fe1
DB
675 if (verify_uptodate(old, o))
676 return -1;
bc052d7f 677 invalidate_ce_path(old, o);
076b0adc
JS
678 }
679 }
680 else {
203a2fe1
DB
681 if (verify_absent(merge, "overwritten", o))
682 return -1;
bc052d7f 683 invalidate_ce_path(merge, o);
076b0adc
JS
684 }
685
7f8ab8dc 686 add_entry(o, merge, update, CE_STAGEMASK);
076b0adc
JS
687 return 1;
688}
689
690static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
691 struct unpack_trees_options *o)
692{
34110cd4
LT
693 /* Did it exist in the index? */
694 if (!old) {
203a2fe1
DB
695 if (verify_absent(ce, "removed", o))
696 return -1;
34110cd4
LT
697 return 0;
698 }
699 if (verify_uptodate(old, o))
700 return -1;
701 add_entry(o, ce, CE_REMOVE, 0);
bc052d7f 702 invalidate_ce_path(ce, o);
076b0adc
JS
703 return 1;
704}
705
7f7932ab 706static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o)
076b0adc 707{
34110cd4 708 add_entry(o, ce, 0, 0);
076b0adc
JS
709 return 1;
710}
711
712#if DBRT_DEBUG
713static void show_stage_entry(FILE *o,
714 const char *label, const struct cache_entry *ce)
715{
716 if (!ce)
717 fprintf(o, "%s (missing)\n", label);
718 else
719 fprintf(o, "%s%06o %s %d\t%s\n",
720 label,
7a51ed66 721 ce->ce_mode,
076b0adc
JS
722 sha1_to_hex(ce->sha1),
723 ce_stage(ce),
724 ce->name);
725}
726#endif
727
34110cd4 728int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o)
076b0adc
JS
729{
730 struct cache_entry *index;
731 struct cache_entry *head;
732 struct cache_entry *remote = stages[o->head_idx + 1];
733 int count;
734 int head_match = 0;
735 int remote_match = 0;
076b0adc
JS
736
737 int df_conflict_head = 0;
738 int df_conflict_remote = 0;
739
740 int any_anc_missing = 0;
741 int no_anc_exists = 1;
742 int i;
743
744 for (i = 1; i < o->head_idx; i++) {
4c4caafc 745 if (!stages[i] || stages[i] == o->df_conflict_entry)
076b0adc 746 any_anc_missing = 1;
4c4caafc 747 else
076b0adc 748 no_anc_exists = 0;
076b0adc
JS
749 }
750
751 index = stages[0];
752 head = stages[o->head_idx];
753
754 if (head == o->df_conflict_entry) {
755 df_conflict_head = 1;
756 head = NULL;
757 }
758
759 if (remote == o->df_conflict_entry) {
760 df_conflict_remote = 1;
761 remote = NULL;
762 }
763
076b0adc
JS
764 /* First, if there's a #16 situation, note that to prevent #13
765 * and #14.
766 */
767 if (!same(remote, head)) {
768 for (i = 1; i < o->head_idx; i++) {
769 if (same(stages[i], head)) {
770 head_match = i;
771 }
772 if (same(stages[i], remote)) {
773 remote_match = i;
774 }
775 }
776 }
777
778 /* We start with cases where the index is allowed to match
779 * something other than the head: #14(ALT) and #2ALT, where it
780 * is permitted to match the result instead.
781 */
782 /* #14, #14ALT, #2ALT */
783 if (remote && !df_conflict_head && head_match && !remote_match) {
784 if (index && !same(index, remote) && !same(index, head))
8ccba008 785 return o->gently ? -1 : reject_merge(index, o);
076b0adc
JS
786 return merged_entry(remote, index, o);
787 }
788 /*
789 * If we have an entry in the index cache, then we want to
790 * make sure that it matches head.
791 */
4e7c4571 792 if (index && !same(index, head))
8ccba008 793 return o->gently ? -1 : reject_merge(index, o);
076b0adc
JS
794
795 if (head) {
796 /* #5ALT, #15 */
797 if (same(head, remote))
798 return merged_entry(head, index, o);
799 /* #13, #3ALT */
800 if (!df_conflict_remote && remote_match && !head_match)
801 return merged_entry(head, index, o);
802 }
803
804 /* #1 */
34110cd4 805 if (!head && !remote && any_anc_missing)
076b0adc
JS
806 return 0;
807
808 /* Under the new "aggressive" rule, we resolve mostly trivial
809 * cases that we historically had git-merge-one-file resolve.
810 */
811 if (o->aggressive) {
812 int head_deleted = !head && !df_conflict_head;
813 int remote_deleted = !remote && !df_conflict_remote;
0cf73755 814 struct cache_entry *ce = NULL;
4c4caafc
JH
815
816 if (index)
0cf73755 817 ce = index;
4c4caafc 818 else if (head)
0cf73755 819 ce = head;
4c4caafc 820 else if (remote)
0cf73755 821 ce = remote;
4c4caafc
JH
822 else {
823 for (i = 1; i < o->head_idx; i++) {
824 if (stages[i] && stages[i] != o->df_conflict_entry) {
0cf73755 825 ce = stages[i];
4c4caafc
JH
826 break;
827 }
828 }
829 }
830
076b0adc
JS
831 /*
832 * Deleted in both.
833 * Deleted in one and unchanged in the other.
834 */
835 if ((head_deleted && remote_deleted) ||
836 (head_deleted && remote && remote_match) ||
837 (remote_deleted && head && head_match)) {
838 if (index)
839 return deleted_entry(index, index, o);
34110cd4 840 if (ce && !head_deleted) {
203a2fe1
DB
841 if (verify_absent(ce, "removed", o))
842 return -1;
843 }
076b0adc
JS
844 return 0;
845 }
846 /*
847 * Added in both, identically.
848 */
849 if (no_anc_exists && head && remote && same(head, remote))
850 return merged_entry(head, index, o);
851
852 }
853
854 /* Below are "no merge" cases, which require that the index be
855 * up-to-date to avoid the files getting overwritten with
856 * conflict resolution files.
857 */
858 if (index) {
203a2fe1
DB
859 if (verify_uptodate(index, o))
860 return -1;
076b0adc 861 }
076b0adc
JS
862
863 o->nontrivial_merge = 1;
864
ea4b52a8 865 /* #2, #3, #4, #6, #7, #9, #10, #11. */
076b0adc
JS
866 count = 0;
867 if (!head_match || !remote_match) {
868 for (i = 1; i < o->head_idx; i++) {
4c4caafc 869 if (stages[i] && stages[i] != o->df_conflict_entry) {
7f7932ab 870 keep_entry(stages[i], o);
076b0adc
JS
871 count++;
872 break;
873 }
874 }
875 }
876#if DBRT_DEBUG
877 else {
878 fprintf(stderr, "read-tree: warning #16 detected\n");
879 show_stage_entry(stderr, "head ", stages[head_match]);
880 show_stage_entry(stderr, "remote ", stages[remote_match]);
881 }
882#endif
7f7932ab
JH
883 if (head) { count += keep_entry(head, o); }
884 if (remote) { count += keep_entry(remote, o); }
076b0adc
JS
885 return count;
886}
887
888/*
889 * Two-way merge.
890 *
891 * The rule is to "carry forward" what is in the index without losing
892 * information across a "fast forward", favoring a successful merge
893 * over a merge failure when it makes sense. For details of the
894 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
895 *
896 */
34110cd4 897int twoway_merge(struct cache_entry **src, struct unpack_trees_options *o)
076b0adc
JS
898{
899 struct cache_entry *current = src[0];
b8ba1535
JH
900 struct cache_entry *oldtree = src[1];
901 struct cache_entry *newtree = src[2];
076b0adc
JS
902
903 if (o->merge_size != 2)
904 return error("Cannot do a twoway merge of %d trees",
905 o->merge_size);
906
b8ba1535
JH
907 if (oldtree == o->df_conflict_entry)
908 oldtree = NULL;
909 if (newtree == o->df_conflict_entry)
910 newtree = NULL;
911
076b0adc
JS
912 if (current) {
913 if ((!oldtree && !newtree) || /* 4 and 5 */
914 (!oldtree && newtree &&
915 same(current, newtree)) || /* 6 and 7 */
916 (oldtree && newtree &&
917 same(oldtree, newtree)) || /* 14 and 15 */
918 (oldtree && newtree &&
b8ba1535 919 !same(oldtree, newtree) && /* 18 and 19 */
076b0adc 920 same(current, newtree))) {
7f7932ab 921 return keep_entry(current, o);
076b0adc
JS
922 }
923 else if (oldtree && !newtree && same(current, oldtree)) {
924 /* 10 or 11 */
925 return deleted_entry(oldtree, current, o);
926 }
927 else if (oldtree && newtree &&
928 same(current, oldtree) && !same(current, newtree)) {
929 /* 20 or 21 */
930 return merged_entry(newtree, current, o);
931 }
932 else {
933 /* all other failures */
934 if (oldtree)
8ccba008 935 return o->gently ? -1 : reject_merge(oldtree, o);
076b0adc 936 if (current)
8ccba008 937 return o->gently ? -1 : reject_merge(current, o);
076b0adc 938 if (newtree)
8ccba008 939 return o->gently ? -1 : reject_merge(newtree, o);
076b0adc
JS
940 return -1;
941 }
942 }
943 else if (newtree)
944 return merged_entry(newtree, current, o);
d699676d 945 return deleted_entry(oldtree, current, o);
076b0adc
JS
946}
947
948/*
949 * Bind merge.
950 *
951 * Keep the index entries at stage0, collapse stage1 but make sure
952 * stage0 does not have anything there.
953 */
954int bind_merge(struct cache_entry **src,
34110cd4 955 struct unpack_trees_options *o)
076b0adc
JS
956{
957 struct cache_entry *old = src[0];
958 struct cache_entry *a = src[1];
959
960 if (o->merge_size != 1)
961 return error("Cannot do a bind merge of %d trees\n",
962 o->merge_size);
963 if (a && old)
17e46426 964 return o->gently ? -1 :
8ccba008 965 error(ERRORMSG(o, bind_overlap), a->name, old->name);
076b0adc 966 if (!a)
7f7932ab 967 return keep_entry(old, o);
076b0adc
JS
968 else
969 return merged_entry(a, NULL, o);
970}
971
972/*
973 * One-way merge.
974 *
975 * The rule is:
976 * - take the stat information from stage0, take the data from stage1
977 */
34110cd4 978int oneway_merge(struct cache_entry **src, struct unpack_trees_options *o)
076b0adc
JS
979{
980 struct cache_entry *old = src[0];
981 struct cache_entry *a = src[1];
982
983 if (o->merge_size != 1)
984 return error("Cannot do a oneway merge of %d trees",
985 o->merge_size);
986
34110cd4 987 if (!a)
076b0adc 988 return deleted_entry(old, old, o);
34110cd4 989
076b0adc 990 if (old && same(old, a)) {
34110cd4 991 int update = 0;
076b0adc
JS
992 if (o->reset) {
993 struct stat st;
994 if (lstat(old->name, &st) ||
34110cd4
LT
995 ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID))
996 update |= CE_UPDATE;
076b0adc 997 }
34110cd4
LT
998 add_entry(o, old, update, 0);
999 return 0;
076b0adc
JS
1000 }
1001 return merged_entry(a, old, o);
1002}