t4007: modernize the style
[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"
06f33c17 10#include "attr.h"
16da134b 11
8ccba008
JH
12/*
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.
19 */
20static struct unpack_trees_error_msgs unpack_plumbing_errors = {
21 /* would_overwrite */
22 "Entry '%s' would be overwritten by merge. Cannot merge.",
23
24 /* not_uptodate_file */
25 "Entry '%s' not uptodate. Cannot merge.",
26
27 /* not_uptodate_dir */
28 "Updating '%s' would lose untracked files in it",
29
30 /* would_lose_untracked */
31 "Untracked working tree file '%s' would be %s by merge.",
32
33 /* bind_overlap */
34 "Entry '%s' overlaps with '%s'. Cannot bind.",
35};
36
37#define ERRORMSG(o,fld) \
38 ( ((o) && (o)->msgs.fld) \
39 ? ((o)->msgs.fld) \
40 : (unpack_plumbing_errors.fld) )
41
34110cd4
LT
42static void add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
43 unsigned int set, unsigned int clear)
b48d5a05 44{
34110cd4
LT
45 unsigned int size = ce_size(ce);
46 struct cache_entry *new = xmalloc(size);
47
48 clear |= CE_HASHED | CE_UNHASHED;
49
50 memcpy(new, ce, size);
51 new->next = NULL;
52 new->ce_flags = (new->ce_flags & ~clear) | set;
aab3b9a1 53 add_index_entry(&o->result, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
b48d5a05
LT
54}
55
78478927
KB
56/*
57 * Unlink the last component and schedule the leading directories for
58 * removal, such that empty directories get removed.
16da134b 59 */
c40641b7 60static void unlink_entry(struct cache_entry *ce)
16da134b 61{
57199892 62 if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
16a4c617 63 return;
691f1a28 64 if (unlink_or_warn(ce->name))
16da134b 65 return;
78478927 66 schedule_dir_for_removal(ce->name, ce_namelen(ce));
16da134b
JS
67}
68
16da134b 69static struct checkout state;
c4758d3c 70static int check_updates(struct unpack_trees_options *o)
16da134b 71{
96a02f8f 72 unsigned cnt = 0, total = 0;
dc6a0757 73 struct progress *progress = NULL;
34110cd4 74 struct index_state *index = &o->result;
33ecf7eb 75 int i;
c4758d3c 76 int errs = 0;
16da134b
JS
77
78 if (o->update && o->verbose_update) {
34110cd4
LT
79 for (total = cnt = 0; cnt < index->cache_nr; cnt++) {
80 struct cache_entry *ce = index->cache[cnt];
7a51ed66 81 if (ce->ce_flags & (CE_UPDATE | CE_REMOVE))
16da134b
JS
82 total++;
83 }
84
dc6a0757 85 progress = start_progress_delay("Checking out files",
e8548645 86 total, 50, 1);
16da134b
JS
87 cnt = 0;
88 }
89
66985e66
JH
90 if (o->update)
91 git_attr_set_direction(GIT_ATTR_CHECKOUT, &o->result);
34110cd4
LT
92 for (i = 0; i < index->cache_nr; i++) {
93 struct cache_entry *ce = index->cache[i];
16da134b 94
7a51ed66 95 if (ce->ce_flags & CE_REMOVE) {
1fa6ead4 96 display_progress(progress, ++cnt);
16da134b 97 if (o->update)
c40641b7 98 unlink_entry(ce);
16da134b 99 }
1fa6ead4 100 }
36419c8e 101 remove_marked_cache_entries(&o->result);
78478927 102 remove_scheduled_dirs();
1fa6ead4
LT
103
104 for (i = 0; i < index->cache_nr; i++) {
105 struct cache_entry *ce = index->cache[i];
106
7a51ed66 107 if (ce->ce_flags & CE_UPDATE) {
1fa6ead4 108 display_progress(progress, ++cnt);
7a51ed66 109 ce->ce_flags &= ~CE_UPDATE;
16a4c617 110 if (o->update) {
c4758d3c 111 errs |= checkout_entry(ce, &state, NULL);
16a4c617 112 }
16da134b
JS
113 }
114 }
4d4fcc54 115 stop_progress(&progress);
66985e66
JH
116 if (o->update)
117 git_attr_set_direction(GIT_ATTR_CHECKIN, NULL);
c4758d3c 118 return errs != 0;
16da134b
JS
119}
120
34110cd4 121static inline int call_unpack_fn(struct cache_entry **src, struct unpack_trees_options *o)
01904572 122{
34110cd4
LT
123 int ret = o->fn(src, o);
124 if (ret > 0)
01904572 125 ret = 0;
01904572
LT
126 return ret;
127}
128
129static int unpack_index_entry(struct cache_entry *ce, struct unpack_trees_options *o)
130{
131 struct cache_entry *src[5] = { ce, };
34110cd4
LT
132
133 o->pos++;
01904572
LT
134 if (ce_stage(ce)) {
135 if (o->skip_unmerged) {
34110cd4
LT
136 add_entry(o, ce, 0, 0);
137 return 0;
01904572 138 }
01904572 139 }
34110cd4 140 return call_unpack_fn(src, o);
01904572
LT
141}
142
143int traverse_trees_recursive(int n, unsigned long dirmask, unsigned long df_conflicts, struct name_entry *names, struct traverse_info *info)
16da134b 144{
16da134b 145 int i;
ca885a4f 146 struct tree_desc t[MAX_UNPACK_TREES];
01904572
LT
147 struct traverse_info newinfo;
148 struct name_entry *p;
149
150 p = names;
151 while (!p->mode)
152 p++;
153
154 newinfo = *info;
155 newinfo.prev = info;
156 newinfo.name = *p;
157 newinfo.pathlen += tree_entry_len(p->path, p->sha1) + 1;
158 newinfo.conflicts |= df_conflicts;
159
160 for (i = 0; i < n; i++, dirmask >>= 1) {
161 const unsigned char *sha1 = NULL;
162 if (dirmask & 1)
163 sha1 = names[i].sha1;
164 fill_tree_descriptor(t+i, sha1);
165 }
542c264b 166 return traverse_trees(n, t, &newinfo);
01904572
LT
167}
168
169/*
170 * Compare the traverse-path to the cache entry without actually
171 * having to generate the textual representation of the traverse
172 * path.
173 *
174 * NOTE! This *only* compares up to the size of the traverse path
175 * itself - the caller needs to do the final check for the cache
176 * entry having more data at the end!
177 */
178static int do_compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
179{
180 int len, pathlen, ce_len;
181 const char *ce_name;
182
183 if (info->prev) {
184 int cmp = do_compare_entry(ce, info->prev, &info->name);
185 if (cmp)
186 return cmp;
187 }
188 pathlen = info->pathlen;
189 ce_len = ce_namelen(ce);
190
191 /* If ce_len < pathlen then we must have previously hit "name == directory" entry */
192 if (ce_len < pathlen)
193 return -1;
194
195 ce_len -= pathlen;
196 ce_name = ce->name + pathlen;
197
198 len = tree_entry_len(n->path, n->sha1);
199 return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode);
200}
201
202static int compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
203{
204 int cmp = do_compare_entry(ce, info, n);
205 if (cmp)
206 return cmp;
207
208 /*
209 * Even if the beginning compared identically, the ce should
210 * compare as bigger than a directory leading up to it!
211 */
212 return ce_namelen(ce) > traverse_path_len(info, n);
213}
214
215static struct cache_entry *create_ce_entry(const struct traverse_info *info, const struct name_entry *n, int stage)
216{
217 int len = traverse_path_len(info, n);
218 struct cache_entry *ce = xcalloc(1, cache_entry_size(len));
219
220 ce->ce_mode = create_ce_mode(n->mode);
221 ce->ce_flags = create_ce_flags(len, stage);
222 hashcpy(ce->sha1, n->sha1);
223 make_traverse_path(ce->name, info, n);
224
225 return ce;
226}
227
c7cddc1a
RS
228static int unpack_nondirectories(int n, unsigned long mask,
229 unsigned long dirmask,
230 struct cache_entry **src,
231 const struct name_entry *names,
232 const struct traverse_info *info)
01904572
LT
233{
234 int i;
235 struct unpack_trees_options *o = info->data;
236 unsigned long conflicts;
237
238 /* Do we have *only* directories? Nothing to do */
239 if (mask == dirmask && !src[0])
240 return 0;
241
242 conflicts = info->conflicts;
243 if (o->merge)
244 conflicts >>= 1;
245 conflicts |= dirmask;
246
247 /*
248 * Ok, we've filled in up to any potential index entry in src[0],
249 * now do the rest.
250 */
251 for (i = 0; i < n; i++) {
252 int stage;
253 unsigned int bit = 1ul << i;
254 if (conflicts & bit) {
255 src[i + o->merge] = o->df_conflict_entry;
256 continue;
257 }
258 if (!(mask & bit))
259 continue;
260 if (!o->merge)
261 stage = 0;
262 else if (i + 1 < o->head_idx)
263 stage = 1;
264 else if (i + 1 > o->head_idx)
265 stage = 3;
266 else
267 stage = 2;
268 src[i + o->merge] = create_ce_entry(info, names + i, stage);
269 }
270
271 if (o->merge)
34110cd4 272 return call_unpack_fn(src, o);
01904572 273
01904572 274 for (i = 0; i < n; i++)
aab3b9a1
JH
275 if (src[i] && src[i] != o->df_conflict_entry)
276 add_entry(o, src[i], 0, 0);
01904572
LT
277 return 0;
278}
279
280static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *names, struct traverse_info *info)
281{
c7cddc1a 282 struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
01904572 283 struct unpack_trees_options *o = info->data;
01904572
LT
284 const struct name_entry *p = names;
285
286 /* Find first entry with a real name (we could use "mask" too) */
287 while (!p->mode)
288 p++;
289
290 /* Are we supposed to look at the index too? */
291 if (o->merge) {
34110cd4
LT
292 while (o->pos < o->src_index->cache_nr) {
293 struct cache_entry *ce = o->src_index->cache[o->pos];
01904572
LT
294 int cmp = compare_entry(ce, info, p);
295 if (cmp < 0) {
296 if (unpack_index_entry(ce, o) < 0)
297 return -1;
298 continue;
299 }
300 if (!cmp) {
34110cd4 301 o->pos++;
01904572
LT
302 if (ce_stage(ce)) {
303 /*
304 * If we skip unmerged index entries, we'll skip this
305 * entry *and* the tree entries associated with it!
306 */
34110cd4
LT
307 if (o->skip_unmerged) {
308 add_entry(o, ce, 0, 0);
01904572 309 return mask;
34110cd4 310 }
01904572
LT
311 }
312 src[0] = ce;
01904572
LT
313 }
314 break;
315 }
316 }
317
34110cd4 318 if (unpack_nondirectories(n, mask, dirmask, src, names, info) < 0)
01904572
LT
319 return -1;
320
321 /* Now handle any directories.. */
322 if (dirmask) {
323 unsigned long conflicts = mask & ~dirmask;
324 if (o->merge) {
325 conflicts <<= 1;
326 if (src[0])
327 conflicts |= 1;
328 }
542c264b
JH
329 if (traverse_trees_recursive(n, dirmask, conflicts,
330 names, info) < 0)
331 return -1;
01904572
LT
332 return mask;
333 }
334
335 return mask;
336}
337
338static int unpack_failed(struct unpack_trees_options *o, const char *message)
339{
1caeacc1 340 discard_index(&o->result);
01904572
LT
341 if (!o->gently) {
342 if (message)
9db56f71 343 return error("%s", message);
01904572
LT
344 return -1;
345 }
01904572
LT
346 return -1;
347}
348
2e2b887d
JH
349/*
350 * N-way merge "len" trees. Returns 0 on success, -1 on failure to manipulate the
351 * resulting index, -2 on failure to reflect the changes to the work tree.
352 */
01904572
LT
353int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
354{
2e2b887d 355 int ret;
0fb1eaa8 356 static struct cache_entry *dfc;
16da134b 357
ca885a4f
JH
358 if (len > MAX_UNPACK_TREES)
359 die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
076b0adc 360 memset(&state, 0, sizeof(state));
16da134b
JS
361 state.base_dir = "";
362 state.force = 1;
363 state.quiet = 1;
364 state.refresh_cache = 1;
365
34110cd4 366 memset(&o->result, 0, sizeof(o->result));
913e0e99 367 o->result.initialized = 1;
fba2f38a
KB
368 if (o->src_index) {
369 o->result.timestamp.sec = o->src_index->timestamp.sec;
fba2f38a 370 o->result.timestamp.nsec = o->src_index->timestamp.nsec;
fba2f38a 371 }
16da134b 372 o->merge_size = len;
0fb1eaa8
JH
373
374 if (!dfc)
13494ed1 375 dfc = xcalloc(1, cache_entry_size(0));
0fb1eaa8 376 o->df_conflict_entry = dfc;
16da134b
JS
377
378 if (len) {
01904572
LT
379 const char *prefix = o->prefix ? o->prefix : "";
380 struct traverse_info info;
381
382 setup_traverse_info(&info, prefix);
383 info.fn = unpack_callback;
384 info.data = o;
385
386 if (traverse_trees(len, t, &info) < 0)
387 return unpack_failed(o, NULL);
16da134b
JS
388 }
389
01904572
LT
390 /* Any left-over entries in the index? */
391 if (o->merge) {
34110cd4
LT
392 while (o->pos < o->src_index->cache_nr) {
393 struct cache_entry *ce = o->src_index->cache[o->pos];
01904572
LT
394 if (unpack_index_entry(ce, o) < 0)
395 return unpack_failed(o, NULL);
17e46426 396 }
17e46426 397 }
16da134b 398
01904572
LT
399 if (o->trivial_merges_only && o->nontrivial_merge)
400 return unpack_failed(o, "Merge requires file-level merging");
401
34110cd4 402 o->src_index = NULL;
2e2b887d 403 ret = check_updates(o) ? (-2) : 0;
34110cd4
LT
404 if (o->dst_index)
405 *o->dst_index = o->result;
2e2b887d 406 return ret;
16da134b 407}
076b0adc
JS
408
409/* Here come the merge functions */
410
8ccba008 411static int reject_merge(struct cache_entry *ce, struct unpack_trees_options *o)
076b0adc 412{
8ccba008 413 return error(ERRORMSG(o, would_overwrite), ce->name);
076b0adc
JS
414}
415
416static int same(struct cache_entry *a, struct cache_entry *b)
417{
418 if (!!a != !!b)
419 return 0;
420 if (!a && !b)
421 return 1;
422 return a->ce_mode == b->ce_mode &&
a89fccd2 423 !hashcmp(a->sha1, b->sha1);
076b0adc
JS
424}
425
426
427/*
428 * When a CE gets turned into an unmerged entry, we
429 * want it to be up-to-date
430 */
203a2fe1 431static int verify_uptodate(struct cache_entry *ce,
076b0adc
JS
432 struct unpack_trees_options *o)
433{
434 struct stat st;
435
1dcafcc0 436 if (o->index_only || o->reset || ce_uptodate(ce))
203a2fe1 437 return 0;
076b0adc
JS
438
439 if (!lstat(ce->name, &st)) {
34110cd4 440 unsigned changed = ie_match_stat(o->src_index, ce, &st, CE_MATCH_IGNORE_VALID);
076b0adc 441 if (!changed)
203a2fe1 442 return 0;
936492d3
JH
443 /*
444 * NEEDSWORK: the current default policy is to allow
445 * submodule to be out of sync wrt the supermodule
446 * index. This needs to be tightened later for
447 * submodules that are marked to be automatically
448 * checked out.
449 */
7a51ed66 450 if (S_ISGITLINK(ce->ce_mode))
203a2fe1 451 return 0;
076b0adc
JS
452 errno = 0;
453 }
076b0adc 454 if (errno == ENOENT)
203a2fe1 455 return 0;
17e46426 456 return o->gently ? -1 :
8ccba008 457 error(ERRORMSG(o, not_uptodate_file), ce->name);
076b0adc
JS
458}
459
bc052d7f 460static void invalidate_ce_path(struct cache_entry *ce, struct unpack_trees_options *o)
076b0adc
JS
461{
462 if (ce)
34110cd4 463 cache_tree_invalidate_path(o->src_index->cache_tree, ce->name);
076b0adc
JS
464}
465
0cf73755
SV
466/*
467 * Check that checking out ce->sha1 in subdir ce->name is not
468 * going to overwrite any working files.
469 *
470 * Currently, git does not checkout subprojects during a superproject
471 * checkout, so it is not going to overwrite anything.
472 */
473static int verify_clean_submodule(struct cache_entry *ce, const char *action,
474 struct unpack_trees_options *o)
475{
476 return 0;
477}
478
479static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
c8193534
JH
480 struct unpack_trees_options *o)
481{
482 /*
0cf73755 483 * we are about to extract "ce->name"; we would not want to lose
c8193534
JH
484 * anything in the existing directory there.
485 */
486 int namelen;
7b9e3ce0 487 int i;
c8193534
JH
488 struct dir_struct d;
489 char *pathbuf;
490 int cnt = 0;
0cf73755
SV
491 unsigned char sha1[20];
492
7a51ed66 493 if (S_ISGITLINK(ce->ce_mode) &&
0cf73755
SV
494 resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
495 /* If we are not going to update the submodule, then
496 * we don't care.
497 */
498 if (!hashcmp(sha1, ce->sha1))
499 return 0;
500 return verify_clean_submodule(ce, action, o);
501 }
c8193534
JH
502
503 /*
504 * First let's make sure we do not have a local modification
505 * in that directory.
506 */
0cf73755 507 namelen = strlen(ce->name);
7b9e3ce0 508 for (i = o->pos; i < o->src_index->cache_nr; i++) {
837e5fe9
CB
509 struct cache_entry *ce2 = o->src_index->cache[i];
510 int len = ce_namelen(ce2);
c8193534 511 if (len < namelen ||
837e5fe9
CB
512 strncmp(ce->name, ce2->name, namelen) ||
513 ce2->name[namelen] != '/')
c8193534
JH
514 break;
515 /*
837e5fe9 516 * ce2->name is an entry in the subdirectory.
c8193534 517 */
837e5fe9
CB
518 if (!ce_stage(ce2)) {
519 if (verify_uptodate(ce2, o))
203a2fe1 520 return -1;
837e5fe9 521 add_entry(o, ce2, CE_REMOVE, 0);
c8193534
JH
522 }
523 cnt++;
524 }
525
526 /*
527 * Then we need to make sure that we do not lose a locally
528 * present file that is not ignored.
529 */
530 pathbuf = xmalloc(namelen + 2);
0cf73755 531 memcpy(pathbuf, ce->name, namelen);
c8193534
JH
532 strcpy(pathbuf+namelen, "/");
533
534 memset(&d, 0, sizeof(d));
535 if (o->dir)
536 d.exclude_per_dir = o->dir->exclude_per_dir;
0cf73755 537 i = read_directory(&d, ce->name, pathbuf, namelen+1, NULL);
c8193534 538 if (i)
17e46426 539 return o->gently ? -1 :
8ccba008 540 error(ERRORMSG(o, not_uptodate_dir), ce->name);
c8193534
JH
541 free(pathbuf);
542 return cnt;
543}
544
32260ad5
LT
545/*
546 * This gets called when there was no index entry for the tree entry 'dst',
547 * but we found a file in the working tree that 'lstat()' said was fine,
548 * and we're on a case-insensitive filesystem.
549 *
550 * See if we can find a case-insensitive match in the index that also
551 * matches the stat information, and assume it's that other file!
552 */
553static int icase_exists(struct unpack_trees_options *o, struct cache_entry *dst, struct stat *st)
554{
555 struct cache_entry *src;
556
557 src = index_name_exists(o->src_index, dst->name, ce_namelen(dst), 1);
558 return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID);
559}
560
076b0adc
JS
561/*
562 * We do not want to remove or overwrite a working tree file that
f8a9d428 563 * is not tracked, unless it is ignored.
076b0adc 564 */
203a2fe1
DB
565static int verify_absent(struct cache_entry *ce, const char *action,
566 struct unpack_trees_options *o)
076b0adc
JS
567{
568 struct stat st;
569
570 if (o->index_only || o->reset || !o->update)
203a2fe1 571 return 0;
c8193534 572
57199892 573 if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
203a2fe1 574 return 0;
ec0603e1 575
0cf73755 576 if (!lstat(ce->name, &st)) {
6b9315d5 577 int ret;
6831a88a 578 int dtype = ce_to_dtype(ce);
df292c79 579 struct cache_entry *result;
c8193534 580
32260ad5
LT
581 /*
582 * It may be that the 'lstat()' succeeded even though
583 * target 'ce' was absent, because there is an old
584 * entry that is different only in case..
585 *
586 * Ignore that lstat() if it matches.
587 */
588 if (ignore_case && icase_exists(o, ce, &st))
589 return 0;
590
6831a88a 591 if (o->dir && excluded(o->dir, ce->name, &dtype))
c8193534 592 /*
0cf73755 593 * ce->name is explicitly excluded, so it is Ok to
c8193534
JH
594 * overwrite it.
595 */
203a2fe1 596 return 0;
c8193534
JH
597 if (S_ISDIR(st.st_mode)) {
598 /*
599 * We are checking out path "foo" and
600 * found "foo/." in the working tree.
601 * This is tricky -- if we have modified
602 * files that are in "foo/" we would lose
603 * it.
604 */
6b9315d5
CB
605 ret = verify_clean_subdirectory(ce, action, o);
606 if (ret < 0)
607 return ret;
c8193534
JH
608
609 /*
610 * If this removed entries from the index,
611 * what that means is:
612 *
837e5fe9 613 * (1) the caller unpack_callback() saw path/foo
c8193534
JH
614 * in the index, and it has not removed it because
615 * it thinks it is handling 'path' as blob with
616 * D/F conflict;
617 * (2) we will return "ok, we placed a merged entry
618 * in the index" which would cause o->pos to be
619 * incremented by one;
620 * (3) however, original o->pos now has 'path/foo'
621 * marked with "to be removed".
622 *
623 * We need to increment it by the number of
624 * deleted entries here.
625 */
6b9315d5 626 o->pos += ret;
203a2fe1 627 return 0;
c8193534
JH
628 }
629
630 /*
631 * The previous round may already have decided to
632 * delete this path, which is in a subdirectory that
633 * is being replaced with a blob.
634 */
cd2fef59 635 result = index_name_exists(&o->result, ce->name, ce_namelen(ce), 0);
df292c79
LT
636 if (result) {
637 if (result->ce_flags & CE_REMOVE)
203a2fe1 638 return 0;
c8193534
JH
639 }
640
17e46426 641 return o->gently ? -1 :
8ccba008 642 error(ERRORMSG(o, would_lose_untracked), ce->name, action);
c8193534 643 }
203a2fe1 644 return 0;
076b0adc
JS
645}
646
647static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
648 struct unpack_trees_options *o)
649{
7f8ab8dc
LT
650 int update = CE_UPDATE;
651
076b0adc
JS
652 if (old) {
653 /*
654 * See if we can re-use the old CE directly?
655 * That way we get the uptodate stat info.
656 *
7f8ab8dc
LT
657 * This also removes the UPDATE flag on a match; otherwise
658 * we will end up overwriting local changes in the work tree.
076b0adc
JS
659 */
660 if (same(old, merge)) {
eb7a2f1d 661 copy_cache_entry(merge, old);
7f8ab8dc 662 update = 0;
076b0adc 663 } else {
203a2fe1
DB
664 if (verify_uptodate(old, o))
665 return -1;
bc052d7f 666 invalidate_ce_path(old, o);
076b0adc
JS
667 }
668 }
669 else {
203a2fe1
DB
670 if (verify_absent(merge, "overwritten", o))
671 return -1;
bc052d7f 672 invalidate_ce_path(merge, o);
076b0adc
JS
673 }
674
7f8ab8dc 675 add_entry(o, merge, update, CE_STAGEMASK);
076b0adc
JS
676 return 1;
677}
678
679static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
680 struct unpack_trees_options *o)
681{
34110cd4
LT
682 /* Did it exist in the index? */
683 if (!old) {
203a2fe1
DB
684 if (verify_absent(ce, "removed", o))
685 return -1;
34110cd4
LT
686 return 0;
687 }
688 if (verify_uptodate(old, o))
689 return -1;
690 add_entry(o, ce, CE_REMOVE, 0);
bc052d7f 691 invalidate_ce_path(ce, o);
076b0adc
JS
692 return 1;
693}
694
7f7932ab 695static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o)
076b0adc 696{
34110cd4 697 add_entry(o, ce, 0, 0);
076b0adc
JS
698 return 1;
699}
700
701#if DBRT_DEBUG
702static void show_stage_entry(FILE *o,
703 const char *label, const struct cache_entry *ce)
704{
705 if (!ce)
706 fprintf(o, "%s (missing)\n", label);
707 else
708 fprintf(o, "%s%06o %s %d\t%s\n",
709 label,
7a51ed66 710 ce->ce_mode,
076b0adc
JS
711 sha1_to_hex(ce->sha1),
712 ce_stage(ce),
713 ce->name);
714}
715#endif
716
34110cd4 717int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o)
076b0adc
JS
718{
719 struct cache_entry *index;
720 struct cache_entry *head;
721 struct cache_entry *remote = stages[o->head_idx + 1];
722 int count;
723 int head_match = 0;
724 int remote_match = 0;
076b0adc
JS
725
726 int df_conflict_head = 0;
727 int df_conflict_remote = 0;
728
729 int any_anc_missing = 0;
730 int no_anc_exists = 1;
731 int i;
732
733 for (i = 1; i < o->head_idx; i++) {
4c4caafc 734 if (!stages[i] || stages[i] == o->df_conflict_entry)
076b0adc 735 any_anc_missing = 1;
4c4caafc 736 else
076b0adc 737 no_anc_exists = 0;
076b0adc
JS
738 }
739
740 index = stages[0];
741 head = stages[o->head_idx];
742
743 if (head == o->df_conflict_entry) {
744 df_conflict_head = 1;
745 head = NULL;
746 }
747
748 if (remote == o->df_conflict_entry) {
749 df_conflict_remote = 1;
750 remote = NULL;
751 }
752
076b0adc
JS
753 /* First, if there's a #16 situation, note that to prevent #13
754 * and #14.
755 */
756 if (!same(remote, head)) {
757 for (i = 1; i < o->head_idx; i++) {
758 if (same(stages[i], head)) {
759 head_match = i;
760 }
761 if (same(stages[i], remote)) {
762 remote_match = i;
763 }
764 }
765 }
766
767 /* We start with cases where the index is allowed to match
768 * something other than the head: #14(ALT) and #2ALT, where it
769 * is permitted to match the result instead.
770 */
771 /* #14, #14ALT, #2ALT */
772 if (remote && !df_conflict_head && head_match && !remote_match) {
773 if (index && !same(index, remote) && !same(index, head))
8ccba008 774 return o->gently ? -1 : reject_merge(index, o);
076b0adc
JS
775 return merged_entry(remote, index, o);
776 }
777 /*
778 * If we have an entry in the index cache, then we want to
779 * make sure that it matches head.
780 */
4e7c4571 781 if (index && !same(index, head))
8ccba008 782 return o->gently ? -1 : reject_merge(index, o);
076b0adc
JS
783
784 if (head) {
785 /* #5ALT, #15 */
786 if (same(head, remote))
787 return merged_entry(head, index, o);
788 /* #13, #3ALT */
789 if (!df_conflict_remote && remote_match && !head_match)
790 return merged_entry(head, index, o);
791 }
792
793 /* #1 */
34110cd4 794 if (!head && !remote && any_anc_missing)
076b0adc
JS
795 return 0;
796
797 /* Under the new "aggressive" rule, we resolve mostly trivial
798 * cases that we historically had git-merge-one-file resolve.
799 */
800 if (o->aggressive) {
801 int head_deleted = !head && !df_conflict_head;
802 int remote_deleted = !remote && !df_conflict_remote;
0cf73755 803 struct cache_entry *ce = NULL;
4c4caafc
JH
804
805 if (index)
0cf73755 806 ce = index;
4c4caafc 807 else if (head)
0cf73755 808 ce = head;
4c4caafc 809 else if (remote)
0cf73755 810 ce = remote;
4c4caafc
JH
811 else {
812 for (i = 1; i < o->head_idx; i++) {
813 if (stages[i] && stages[i] != o->df_conflict_entry) {
0cf73755 814 ce = stages[i];
4c4caafc
JH
815 break;
816 }
817 }
818 }
819
076b0adc
JS
820 /*
821 * Deleted in both.
822 * Deleted in one and unchanged in the other.
823 */
824 if ((head_deleted && remote_deleted) ||
825 (head_deleted && remote && remote_match) ||
826 (remote_deleted && head && head_match)) {
827 if (index)
828 return deleted_entry(index, index, o);
34110cd4 829 if (ce && !head_deleted) {
203a2fe1
DB
830 if (verify_absent(ce, "removed", o))
831 return -1;
832 }
076b0adc
JS
833 return 0;
834 }
835 /*
836 * Added in both, identically.
837 */
838 if (no_anc_exists && head && remote && same(head, remote))
839 return merged_entry(head, index, o);
840
841 }
842
843 /* Below are "no merge" cases, which require that the index be
844 * up-to-date to avoid the files getting overwritten with
845 * conflict resolution files.
846 */
847 if (index) {
203a2fe1
DB
848 if (verify_uptodate(index, o))
849 return -1;
076b0adc 850 }
076b0adc
JS
851
852 o->nontrivial_merge = 1;
853
ea4b52a8 854 /* #2, #3, #4, #6, #7, #9, #10, #11. */
076b0adc
JS
855 count = 0;
856 if (!head_match || !remote_match) {
857 for (i = 1; i < o->head_idx; i++) {
4c4caafc 858 if (stages[i] && stages[i] != o->df_conflict_entry) {
7f7932ab 859 keep_entry(stages[i], o);
076b0adc
JS
860 count++;
861 break;
862 }
863 }
864 }
865#if DBRT_DEBUG
866 else {
867 fprintf(stderr, "read-tree: warning #16 detected\n");
868 show_stage_entry(stderr, "head ", stages[head_match]);
869 show_stage_entry(stderr, "remote ", stages[remote_match]);
870 }
871#endif
7f7932ab
JH
872 if (head) { count += keep_entry(head, o); }
873 if (remote) { count += keep_entry(remote, o); }
076b0adc
JS
874 return count;
875}
876
877/*
878 * Two-way merge.
879 *
880 * The rule is to "carry forward" what is in the index without losing
881 * information across a "fast forward", favoring a successful merge
882 * over a merge failure when it makes sense. For details of the
883 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
884 *
885 */
34110cd4 886int twoway_merge(struct cache_entry **src, struct unpack_trees_options *o)
076b0adc
JS
887{
888 struct cache_entry *current = src[0];
b8ba1535
JH
889 struct cache_entry *oldtree = src[1];
890 struct cache_entry *newtree = src[2];
076b0adc
JS
891
892 if (o->merge_size != 2)
893 return error("Cannot do a twoway merge of %d trees",
894 o->merge_size);
895
b8ba1535
JH
896 if (oldtree == o->df_conflict_entry)
897 oldtree = NULL;
898 if (newtree == o->df_conflict_entry)
899 newtree = NULL;
900
076b0adc
JS
901 if (current) {
902 if ((!oldtree && !newtree) || /* 4 and 5 */
903 (!oldtree && newtree &&
904 same(current, newtree)) || /* 6 and 7 */
905 (oldtree && newtree &&
906 same(oldtree, newtree)) || /* 14 and 15 */
907 (oldtree && newtree &&
b8ba1535 908 !same(oldtree, newtree) && /* 18 and 19 */
076b0adc 909 same(current, newtree))) {
7f7932ab 910 return keep_entry(current, o);
076b0adc
JS
911 }
912 else if (oldtree && !newtree && same(current, oldtree)) {
913 /* 10 or 11 */
914 return deleted_entry(oldtree, current, o);
915 }
916 else if (oldtree && newtree &&
917 same(current, oldtree) && !same(current, newtree)) {
918 /* 20 or 21 */
919 return merged_entry(newtree, current, o);
920 }
921 else {
922 /* all other failures */
923 if (oldtree)
8ccba008 924 return o->gently ? -1 : reject_merge(oldtree, o);
076b0adc 925 if (current)
8ccba008 926 return o->gently ? -1 : reject_merge(current, o);
076b0adc 927 if (newtree)
8ccba008 928 return o->gently ? -1 : reject_merge(newtree, o);
076b0adc
JS
929 return -1;
930 }
931 }
55218834
JH
932 else if (newtree) {
933 if (oldtree && !o->initial_checkout) {
934 /*
935 * deletion of the path was staged;
936 */
937 if (same(oldtree, newtree))
938 return 1;
939 return reject_merge(oldtree, o);
940 }
076b0adc 941 return merged_entry(newtree, current, o);
55218834 942 }
d699676d 943 return deleted_entry(oldtree, current, o);
076b0adc
JS
944}
945
946/*
947 * Bind merge.
948 *
949 * Keep the index entries at stage0, collapse stage1 but make sure
950 * stage0 does not have anything there.
951 */
952int bind_merge(struct cache_entry **src,
34110cd4 953 struct unpack_trees_options *o)
076b0adc
JS
954{
955 struct cache_entry *old = src[0];
956 struct cache_entry *a = src[1];
957
958 if (o->merge_size != 1)
959 return error("Cannot do a bind merge of %d trees\n",
960 o->merge_size);
961 if (a && old)
17e46426 962 return o->gently ? -1 :
8ccba008 963 error(ERRORMSG(o, bind_overlap), a->name, old->name);
076b0adc 964 if (!a)
7f7932ab 965 return keep_entry(old, o);
076b0adc
JS
966 else
967 return merged_entry(a, NULL, o);
968}
969
970/*
971 * One-way merge.
972 *
973 * The rule is:
974 * - take the stat information from stage0, take the data from stage1
975 */
34110cd4 976int oneway_merge(struct cache_entry **src, struct unpack_trees_options *o)
076b0adc
JS
977{
978 struct cache_entry *old = src[0];
979 struct cache_entry *a = src[1];
980
981 if (o->merge_size != 1)
982 return error("Cannot do a oneway merge of %d trees",
983 o->merge_size);
984
34110cd4 985 if (!a)
076b0adc 986 return deleted_entry(old, old, o);
34110cd4 987
076b0adc 988 if (old && same(old, a)) {
34110cd4 989 int update = 0;
076b0adc
JS
990 if (o->reset) {
991 struct stat st;
992 if (lstat(old->name, &st) ||
34110cd4
LT
993 ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID))
994 update |= CE_UPDATE;
076b0adc 995 }
34110cd4
LT
996 add_entry(o, old, update, 0);
997 return 0;
076b0adc
JS
998 }
999 return merged_entry(a, old, o);
1000}