unpack-trees: only clear CE_UPDATE|CE_REMOVE when skip-worktree is always set
[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.",
e800ec9d
NTND
35
36 /* sparse_not_uptodate_file */
37 "Entry '%s' not uptodate. Cannot update sparse checkout.",
38
39 /* would_lose_orphaned */
40 "Working tree file '%s' would be %s by sparse checkout update.",
8ccba008
JH
41};
42
43#define ERRORMSG(o,fld) \
44 ( ((o) && (o)->msgs.fld) \
45 ? ((o)->msgs.fld) \
46 : (unpack_plumbing_errors.fld) )
47
34110cd4
LT
48static void add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
49 unsigned int set, unsigned int clear)
b48d5a05 50{
34110cd4
LT
51 unsigned int size = ce_size(ce);
52 struct cache_entry *new = xmalloc(size);
53
54 clear |= CE_HASHED | CE_UNHASHED;
55
56 memcpy(new, ce, size);
57 new->next = NULL;
58 new->ce_flags = (new->ce_flags & ~clear) | set;
aab3b9a1 59 add_index_entry(&o->result, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
b48d5a05
LT
60}
61
78478927
KB
62/*
63 * Unlink the last component and schedule the leading directories for
64 * removal, such that empty directories get removed.
16da134b 65 */
c40641b7 66static void unlink_entry(struct cache_entry *ce)
16da134b 67{
57199892 68 if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
16a4c617 69 return;
c5e558a8
PC
70 if (S_ISGITLINK(ce->ce_mode)) {
71 if (rmdir(ce->name)) {
72 warning("unable to rmdir %s: %s",
73 ce->name, strerror(errno));
74 return;
75 }
76 }
77 else
78 if (unlink_or_warn(ce->name))
79 return;
78478927 80 schedule_dir_for_removal(ce->name, ce_namelen(ce));
16da134b
JS
81}
82
16da134b 83static struct checkout state;
c4758d3c 84static int check_updates(struct unpack_trees_options *o)
16da134b 85{
96a02f8f 86 unsigned cnt = 0, total = 0;
dc6a0757 87 struct progress *progress = NULL;
34110cd4 88 struct index_state *index = &o->result;
33ecf7eb 89 int i;
c4758d3c 90 int errs = 0;
16da134b
JS
91
92 if (o->update && o->verbose_update) {
34110cd4
LT
93 for (total = cnt = 0; cnt < index->cache_nr; cnt++) {
94 struct cache_entry *ce = index->cache[cnt];
e663db2f 95 if (ce->ce_flags & (CE_UPDATE | CE_REMOVE | CE_WT_REMOVE))
16da134b
JS
96 total++;
97 }
98
dc6a0757 99 progress = start_progress_delay("Checking out files",
e8548645 100 total, 50, 1);
16da134b
JS
101 cnt = 0;
102 }
103
66985e66
JH
104 if (o->update)
105 git_attr_set_direction(GIT_ATTR_CHECKOUT, &o->result);
34110cd4
LT
106 for (i = 0; i < index->cache_nr; i++) {
107 struct cache_entry *ce = index->cache[i];
16da134b 108
e663db2f
NTND
109 if (ce->ce_flags & CE_WT_REMOVE) {
110 display_progress(progress, ++cnt);
111 if (o->update)
112 unlink_entry(ce);
113 continue;
114 }
115
7a51ed66 116 if (ce->ce_flags & CE_REMOVE) {
1fa6ead4 117 display_progress(progress, ++cnt);
16da134b 118 if (o->update)
c40641b7 119 unlink_entry(ce);
16da134b 120 }
1fa6ead4 121 }
36419c8e 122 remove_marked_cache_entries(&o->result);
78478927 123 remove_scheduled_dirs();
1fa6ead4
LT
124
125 for (i = 0; i < index->cache_nr; i++) {
126 struct cache_entry *ce = index->cache[i];
127
7a51ed66 128 if (ce->ce_flags & CE_UPDATE) {
1fa6ead4 129 display_progress(progress, ++cnt);
7a51ed66 130 ce->ce_flags &= ~CE_UPDATE;
16a4c617 131 if (o->update) {
c4758d3c 132 errs |= checkout_entry(ce, &state, NULL);
16a4c617 133 }
16da134b
JS
134 }
135 }
4d4fcc54 136 stop_progress(&progress);
66985e66
JH
137 if (o->update)
138 git_attr_set_direction(GIT_ATTR_CHECKIN, NULL);
c4758d3c 139 return errs != 0;
16da134b
JS
140}
141
e800ec9d
NTND
142static int verify_uptodate_sparse(struct cache_entry *ce, struct unpack_trees_options *o);
143static int verify_absent_sparse(struct cache_entry *ce, const char *action, struct unpack_trees_options *o);
144
145static int will_have_skip_worktree(const struct cache_entry *ce, struct unpack_trees_options *o)
146{
147 const char *basename;
148
149 if (ce_stage(ce))
150 return 0;
151
152 basename = strrchr(ce->name, '/');
153 basename = basename ? basename+1 : ce->name;
154 return excluded_from_list(ce->name, ce_namelen(ce), basename, NULL, o->el) <= 0;
155}
156
157static int apply_sparse_checkout(struct cache_entry *ce, struct unpack_trees_options *o)
158{
159 int was_skip_worktree = ce_skip_worktree(ce);
160
161 if (will_have_skip_worktree(ce, o))
162 ce->ce_flags |= CE_SKIP_WORKTREE;
163 else
164 ce->ce_flags &= ~CE_SKIP_WORKTREE;
165
166 /*
eec3fc03
NTND
167 * if (!was_skip_worktree && !ce_skip_worktree()) {
168 * This is perfectly normal. Move on;
169 * }
e800ec9d 170 */
eec3fc03
NTND
171
172 /*
173 * Merge strategies may set CE_UPDATE|CE_REMOVE outside checkout
174 * area as a result of ce_skip_worktree() shortcuts in
175 * verify_absent() and verify_uptodate(). Clear them.
176 */
177 if (was_skip_worktree && ce_skip_worktree(ce))
178 ce->ce_flags &= ~(CE_UPDATE | CE_REMOVE);
e800ec9d
NTND
179
180 if (!was_skip_worktree && ce_skip_worktree(ce)) {
181 /*
182 * If CE_UPDATE is set, verify_uptodate() must be called already
183 * also stat info may have lost after merged_entry() so calling
184 * verify_uptodate() again may fail
185 */
186 if (!(ce->ce_flags & CE_UPDATE) && verify_uptodate_sparse(ce, o))
187 return -1;
188 ce->ce_flags |= CE_WT_REMOVE;
189 }
190 if (was_skip_worktree && !ce_skip_worktree(ce)) {
191 if (verify_absent_sparse(ce, "overwritten", o))
192 return -1;
193 ce->ce_flags |= CE_UPDATE;
194 }
195 return 0;
196}
197
34110cd4 198static inline int call_unpack_fn(struct cache_entry **src, struct unpack_trees_options *o)
01904572 199{
34110cd4
LT
200 int ret = o->fn(src, o);
201 if (ret > 0)
01904572 202 ret = 0;
01904572
LT
203 return ret;
204}
205
da165f47
JH
206static void mark_ce_used(struct cache_entry *ce, struct unpack_trees_options *o)
207{
208 ce->ce_flags |= CE_UNPACKED;
209
210 if (o->cache_bottom < o->src_index->cache_nr &&
211 o->src_index->cache[o->cache_bottom] == ce) {
212 int bottom = o->cache_bottom;
213 while (bottom < o->src_index->cache_nr &&
214 o->src_index->cache[bottom]->ce_flags & CE_UNPACKED)
215 bottom++;
216 o->cache_bottom = bottom;
217 }
218}
219
220static void mark_all_ce_unused(struct index_state *index)
221{
222 int i;
223 for (i = 0; i < index->cache_nr; i++)
224 index->cache[i]->ce_flags &= ~CE_UNPACKED;
225}
226
227static int locate_in_src_index(struct cache_entry *ce,
228 struct unpack_trees_options *o)
229{
230 struct index_state *index = o->src_index;
231 int len = ce_namelen(ce);
232 int pos = index_name_pos(index, ce->name, len);
233 if (pos < 0)
234 pos = -1 - pos;
235 return pos;
236}
237
238/*
239 * We call unpack_index_entry() with an unmerged cache entry
240 * only in diff-index, and it wants a single callback. Skip
241 * the other unmerged entry with the same name.
242 */
243static void mark_ce_used_same_name(struct cache_entry *ce,
244 struct unpack_trees_options *o)
245{
246 struct index_state *index = o->src_index;
247 int len = ce_namelen(ce);
248 int pos;
249
250 for (pos = locate_in_src_index(ce, o); pos < index->cache_nr; pos++) {
251 struct cache_entry *next = index->cache[pos];
252 if (len != ce_namelen(next) ||
253 memcmp(ce->name, next->name, len))
254 break;
255 mark_ce_used(next, o);
256 }
257}
258
259static struct cache_entry *next_cache_entry(struct unpack_trees_options *o)
260{
261 const struct index_state *index = o->src_index;
262 int pos = o->cache_bottom;
263
264 while (pos < index->cache_nr) {
265 struct cache_entry *ce = index->cache[pos];
266 if (!(ce->ce_flags & CE_UNPACKED))
267 return ce;
268 pos++;
269 }
270 return NULL;
271}
272
273static void add_same_unmerged(struct cache_entry *ce,
274 struct unpack_trees_options *o)
275{
276 struct index_state *index = o->src_index;
277 int len = ce_namelen(ce);
278 int pos = index_name_pos(index, ce->name, len);
279
280 if (0 <= pos)
281 die("programming error in a caller of mark_ce_used_same_name");
282 for (pos = -pos - 1; pos < index->cache_nr; pos++) {
283 struct cache_entry *next = index->cache[pos];
284 if (len != ce_namelen(next) ||
285 memcmp(ce->name, next->name, len))
286 break;
287 add_entry(o, next, 0, 0);
288 mark_ce_used(next, o);
289 }
290}
291
292static int unpack_index_entry(struct cache_entry *ce,
293 struct unpack_trees_options *o)
01904572 294{
0039ba7e 295 struct cache_entry *src[5] = { ce, NULL, };
da165f47 296 int ret;
34110cd4 297
da165f47 298 mark_ce_used(ce, o);
01904572
LT
299 if (ce_stage(ce)) {
300 if (o->skip_unmerged) {
34110cd4
LT
301 add_entry(o, ce, 0, 0);
302 return 0;
01904572 303 }
01904572 304 }
da165f47
JH
305 ret = call_unpack_fn(src, o);
306 if (ce_stage(ce))
307 mark_ce_used_same_name(ce, o);
308 return ret;
01904572
LT
309}
310
730f7284
JH
311static int find_cache_pos(struct traverse_info *, const struct name_entry *);
312
313static void restore_cache_bottom(struct traverse_info *info, int bottom)
314{
315 struct unpack_trees_options *o = info->data;
316
317 if (o->diff_index_cached)
318 return;
319 o->cache_bottom = bottom;
320}
321
322static int switch_cache_bottom(struct traverse_info *info)
323{
324 struct unpack_trees_options *o = info->data;
325 int ret, pos;
326
327 if (o->diff_index_cached)
328 return 0;
329 ret = o->cache_bottom;
330 pos = find_cache_pos(info->prev, &info->name);
331
332 if (pos < -1)
333 o->cache_bottom = -2 - pos;
334 else if (pos < 0)
335 o->cache_bottom = o->src_index->cache_nr;
336 return ret;
01904572
LT
337}
338
2af202be 339static int traverse_trees_recursive(int n, unsigned long dirmask, unsigned long df_conflicts, struct name_entry *names, struct traverse_info *info)
16da134b 340{
730f7284 341 int i, ret, bottom;
ca885a4f 342 struct tree_desc t[MAX_UNPACK_TREES];
01904572
LT
343 struct traverse_info newinfo;
344 struct name_entry *p;
345
346 p = names;
347 while (!p->mode)
348 p++;
349
350 newinfo = *info;
351 newinfo.prev = info;
352 newinfo.name = *p;
353 newinfo.pathlen += tree_entry_len(p->path, p->sha1) + 1;
354 newinfo.conflicts |= df_conflicts;
355
356 for (i = 0; i < n; i++, dirmask >>= 1) {
357 const unsigned char *sha1 = NULL;
358 if (dirmask & 1)
359 sha1 = names[i].sha1;
360 fill_tree_descriptor(t+i, sha1);
361 }
730f7284
JH
362
363 bottom = switch_cache_bottom(&newinfo);
364 ret = traverse_trees(n, t, &newinfo);
365 restore_cache_bottom(&newinfo, bottom);
366 return ret;
01904572
LT
367}
368
369/*
370 * Compare the traverse-path to the cache entry without actually
371 * having to generate the textual representation of the traverse
372 * path.
373 *
374 * NOTE! This *only* compares up to the size of the traverse path
375 * itself - the caller needs to do the final check for the cache
376 * entry having more data at the end!
377 */
378static int do_compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
379{
380 int len, pathlen, ce_len;
381 const char *ce_name;
382
383 if (info->prev) {
384 int cmp = do_compare_entry(ce, info->prev, &info->name);
385 if (cmp)
386 return cmp;
387 }
388 pathlen = info->pathlen;
389 ce_len = ce_namelen(ce);
390
391 /* If ce_len < pathlen then we must have previously hit "name == directory" entry */
392 if (ce_len < pathlen)
393 return -1;
394
395 ce_len -= pathlen;
396 ce_name = ce->name + pathlen;
397
398 len = tree_entry_len(n->path, n->sha1);
399 return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode);
400}
401
402static int compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
403{
404 int cmp = do_compare_entry(ce, info, n);
405 if (cmp)
406 return cmp;
407
408 /*
409 * Even if the beginning compared identically, the ce should
410 * compare as bigger than a directory leading up to it!
411 */
412 return ce_namelen(ce) > traverse_path_len(info, n);
413}
414
da165f47
JH
415static int ce_in_traverse_path(const struct cache_entry *ce,
416 const struct traverse_info *info)
417{
418 if (!info->prev)
419 return 1;
420 if (do_compare_entry(ce, info->prev, &info->name))
421 return 0;
422 /*
423 * If ce (blob) is the same name as the path (which is a tree
424 * we will be descending into), it won't be inside it.
425 */
426 return (info->pathlen < ce_namelen(ce));
427}
428
01904572
LT
429static struct cache_entry *create_ce_entry(const struct traverse_info *info, const struct name_entry *n, int stage)
430{
431 int len = traverse_path_len(info, n);
432 struct cache_entry *ce = xcalloc(1, cache_entry_size(len));
433
434 ce->ce_mode = create_ce_mode(n->mode);
435 ce->ce_flags = create_ce_flags(len, stage);
436 hashcpy(ce->sha1, n->sha1);
437 make_traverse_path(ce->name, info, n);
438
439 return ce;
440}
441
c7cddc1a
RS
442static int unpack_nondirectories(int n, unsigned long mask,
443 unsigned long dirmask,
444 struct cache_entry **src,
445 const struct name_entry *names,
446 const struct traverse_info *info)
01904572
LT
447{
448 int i;
449 struct unpack_trees_options *o = info->data;
450 unsigned long conflicts;
451
452 /* Do we have *only* directories? Nothing to do */
453 if (mask == dirmask && !src[0])
454 return 0;
455
456 conflicts = info->conflicts;
457 if (o->merge)
458 conflicts >>= 1;
459 conflicts |= dirmask;
460
461 /*
462 * Ok, we've filled in up to any potential index entry in src[0],
463 * now do the rest.
464 */
465 for (i = 0; i < n; i++) {
466 int stage;
467 unsigned int bit = 1ul << i;
468 if (conflicts & bit) {
469 src[i + o->merge] = o->df_conflict_entry;
470 continue;
471 }
472 if (!(mask & bit))
473 continue;
474 if (!o->merge)
475 stage = 0;
476 else if (i + 1 < o->head_idx)
477 stage = 1;
478 else if (i + 1 > o->head_idx)
479 stage = 3;
480 else
481 stage = 2;
482 src[i + o->merge] = create_ce_entry(info, names + i, stage);
483 }
484
485 if (o->merge)
34110cd4 486 return call_unpack_fn(src, o);
01904572 487
01904572 488 for (i = 0; i < n; i++)
aab3b9a1
JH
489 if (src[i] && src[i] != o->df_conflict_entry)
490 add_entry(o, src[i], 0, 0);
01904572
LT
491 return 0;
492}
493
353c5eeb
JH
494static int unpack_failed(struct unpack_trees_options *o, const char *message)
495{
496 discard_index(&o->result);
497 if (!o->gently) {
498 if (message)
499 return error("%s", message);
500 return -1;
501 }
502 return -1;
503}
504
730f7284
JH
505/* NEEDSWORK: give this a better name and share with tree-walk.c */
506static int name_compare(const char *a, int a_len,
507 const char *b, int b_len)
508{
509 int len = (a_len < b_len) ? a_len : b_len;
510 int cmp = memcmp(a, b, len);
511 if (cmp)
512 return cmp;
513 return (a_len - b_len);
514}
515
516/*
517 * The tree traversal is looking at name p. If we have a matching entry,
518 * return it. If name p is a directory in the index, do not return
519 * anything, as we will want to match it when the traversal descends into
520 * the directory.
521 */
522static int find_cache_pos(struct traverse_info *info,
523 const struct name_entry *p)
524{
525 int pos;
526 struct unpack_trees_options *o = info->data;
527 struct index_state *index = o->src_index;
528 int pfxlen = info->pathlen;
529 int p_len = tree_entry_len(p->path, p->sha1);
530
531 for (pos = o->cache_bottom; pos < index->cache_nr; pos++) {
532 struct cache_entry *ce = index->cache[pos];
533 const char *ce_name, *ce_slash;
534 int cmp, ce_len;
535
536 if (!ce_in_traverse_path(ce, info))
537 continue;
538 if (ce->ce_flags & CE_UNPACKED)
539 continue;
540 ce_name = ce->name + pfxlen;
541 ce_slash = strchr(ce_name, '/');
542 if (ce_slash)
543 ce_len = ce_slash - ce_name;
544 else
545 ce_len = ce_namelen(ce) - pfxlen;
546 cmp = name_compare(p->path, p_len, ce_name, ce_len);
547 /*
548 * Exact match; if we have a directory we need to
549 * delay returning it.
550 */
551 if (!cmp)
552 return ce_slash ? -2 - pos : pos;
553 if (0 < cmp)
554 continue; /* keep looking */
555 /*
556 * ce_name sorts after p->path; could it be that we
557 * have files under p->path directory in the index?
558 * E.g. ce_name == "t-i", and p->path == "t"; we may
559 * have "t/a" in the index.
560 */
561 if (p_len < ce_len && !memcmp(ce_name, p->path, p_len) &&
562 ce_name[p_len] < '/')
563 continue; /* keep looking */
564 break;
565 }
566 return -1;
567}
568
569static struct cache_entry *find_cache_entry(struct traverse_info *info,
570 const struct name_entry *p)
571{
572 int pos = find_cache_pos(info, p);
573 struct unpack_trees_options *o = info->data;
574
575 if (0 <= pos)
576 return o->src_index->cache[pos];
577 else
578 return NULL;
579}
580
ba655da5
JH
581static void debug_path(struct traverse_info *info)
582{
583 if (info->prev) {
584 debug_path(info->prev);
585 if (*info->prev->name.path)
586 putchar('/');
587 }
588 printf("%s", info->name.path);
589}
590
591static void debug_name_entry(int i, struct name_entry *n)
592{
593 printf("ent#%d %06o %s\n", i,
594 n->path ? n->mode : 0,
595 n->path ? n->path : "(missing)");
596}
597
598static void debug_unpack_callback(int n,
599 unsigned long mask,
600 unsigned long dirmask,
601 struct name_entry *names,
602 struct traverse_info *info)
603{
604 int i;
605 printf("* unpack mask %lu, dirmask %lu, cnt %d ",
606 mask, dirmask, n);
607 debug_path(info);
608 putchar('\n');
609 for (i = 0; i < n; i++)
610 debug_name_entry(i, names + i);
611}
612
01904572
LT
613static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *names, struct traverse_info *info)
614{
c7cddc1a 615 struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
01904572 616 struct unpack_trees_options *o = info->data;
01904572
LT
617 const struct name_entry *p = names;
618
619 /* Find first entry with a real name (we could use "mask" too) */
620 while (!p->mode)
621 p++;
622
ba655da5
JH
623 if (o->debug_unpack)
624 debug_unpack_callback(n, mask, dirmask, names, info);
625
01904572
LT
626 /* Are we supposed to look at the index too? */
627 if (o->merge) {
da165f47 628 while (1) {
da165f47 629 int cmp;
730f7284
JH
630 struct cache_entry *ce;
631
632 if (o->diff_index_cached)
633 ce = next_cache_entry(o);
634 else
635 ce = find_cache_entry(info, p);
636
da165f47
JH
637 if (!ce)
638 break;
639 cmp = compare_entry(ce, info, p);
01904572
LT
640 if (cmp < 0) {
641 if (unpack_index_entry(ce, o) < 0)
353c5eeb 642 return unpack_failed(o, NULL);
01904572
LT
643 continue;
644 }
645 if (!cmp) {
646 if (ce_stage(ce)) {
647 /*
da165f47
JH
648 * If we skip unmerged index
649 * entries, we'll skip this
650 * entry *and* the tree
651 * entries associated with it!
01904572 652 */
34110cd4 653 if (o->skip_unmerged) {
da165f47 654 add_same_unmerged(ce, o);
01904572 655 return mask;
34110cd4 656 }
01904572
LT
657 }
658 src[0] = ce;
01904572
LT
659 }
660 break;
661 }
662 }
663
34110cd4 664 if (unpack_nondirectories(n, mask, dirmask, src, names, info) < 0)
01904572
LT
665 return -1;
666
da165f47
JH
667 if (src[0]) {
668 if (ce_stage(src[0]))
669 mark_ce_used_same_name(src[0], o);
670 else
671 mark_ce_used(src[0], o);
672 }
673
01904572
LT
674 /* Now handle any directories.. */
675 if (dirmask) {
676 unsigned long conflicts = mask & ~dirmask;
677 if (o->merge) {
678 conflicts <<= 1;
679 if (src[0])
680 conflicts |= 1;
681 }
b65982b6
JH
682
683 /* special case: "diff-index --cached" looking at a tree */
684 if (o->diff_index_cached &&
685 n == 1 && dirmask == 1 && S_ISDIR(names->mode)) {
686 int matches;
687 matches = cache_tree_matches_traversal(o->src_index->cache_tree,
688 names, info);
689 /*
da165f47
JH
690 * Everything under the name matches; skip the
691 * entire hierarchy. diff_index_cached codepath
692 * special cases D/F conflicts in such a way that
693 * it does not do any look-ahead, so this is safe.
b65982b6
JH
694 */
695 if (matches) {
da165f47 696 o->cache_bottom += matches;
b65982b6
JH
697 return mask;
698 }
699 }
700
542c264b
JH
701 if (traverse_trees_recursive(n, dirmask, conflicts,
702 names, info) < 0)
703 return -1;
01904572
LT
704 return mask;
705 }
706
707 return mask;
708}
709
2e2b887d
JH
710/*
711 * N-way merge "len" trees. Returns 0 on success, -1 on failure to manipulate the
712 * resulting index, -2 on failure to reflect the changes to the work tree.
713 */
01904572
LT
714int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
715{
e800ec9d 716 int i, ret;
0fb1eaa8 717 static struct cache_entry *dfc;
08aefc9e 718 struct exclude_list el;
16da134b 719
ca885a4f
JH
720 if (len > MAX_UNPACK_TREES)
721 die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
076b0adc 722 memset(&state, 0, sizeof(state));
16da134b
JS
723 state.base_dir = "";
724 state.force = 1;
725 state.quiet = 1;
726 state.refresh_cache = 1;
727
08aefc9e
NTND
728 memset(&el, 0, sizeof(el));
729 if (!core_apply_sparse_checkout || !o->update)
730 o->skip_sparse_checkout = 1;
731 if (!o->skip_sparse_checkout) {
732 if (add_excludes_from_file_to_list(git_path("info/sparse-checkout"), "", 0, NULL, &el, 0) < 0)
733 o->skip_sparse_checkout = 1;
734 else
735 o->el = &el;
736 }
737
34110cd4 738 memset(&o->result, 0, sizeof(o->result));
913e0e99 739 o->result.initialized = 1;
da165f47
JH
740 o->result.timestamp.sec = o->src_index->timestamp.sec;
741 o->result.timestamp.nsec = o->src_index->timestamp.nsec;
16da134b 742 o->merge_size = len;
da165f47 743 mark_all_ce_unused(o->src_index);
0fb1eaa8
JH
744
745 if (!dfc)
13494ed1 746 dfc = xcalloc(1, cache_entry_size(0));
0fb1eaa8 747 o->df_conflict_entry = dfc;
16da134b
JS
748
749 if (len) {
01904572
LT
750 const char *prefix = o->prefix ? o->prefix : "";
751 struct traverse_info info;
752
753 setup_traverse_info(&info, prefix);
754 info.fn = unpack_callback;
755 info.data = o;
756
da165f47
JH
757 if (o->prefix) {
758 /*
759 * Unpack existing index entries that sort before the
760 * prefix the tree is spliced into. Note that o->merge
761 * is always true in this case.
762 */
763 while (1) {
764 struct cache_entry *ce = next_cache_entry(o);
765 if (!ce)
766 break;
767 if (ce_in_traverse_path(ce, &info))
768 break;
769 if (unpack_index_entry(ce, o) < 0)
770 goto return_failed;
771 }
08aefc9e 772 }
da165f47 773
01904572 774 if (traverse_trees(len, t, &info) < 0)
da165f47 775 goto return_failed;
16da134b
JS
776 }
777
01904572
LT
778 /* Any left-over entries in the index? */
779 if (o->merge) {
da165f47
JH
780 while (1) {
781 struct cache_entry *ce = next_cache_entry(o);
782 if (!ce)
783 break;
01904572 784 if (unpack_index_entry(ce, o) < 0)
da165f47 785 goto return_failed;
17e46426 786 }
17e46426 787 }
da165f47 788 mark_all_ce_unused(o->src_index);
16da134b 789
08aefc9e
NTND
790 if (o->trivial_merges_only && o->nontrivial_merge) {
791 ret = unpack_failed(o, "Merge requires file-level merging");
792 goto done;
793 }
01904572 794
e800ec9d 795 if (!o->skip_sparse_checkout) {
9e1afb16 796 int empty_worktree = 1;
e800ec9d
NTND
797 for (i = 0;i < o->result.cache_nr;i++) {
798 struct cache_entry *ce = o->result.cache[i];
799
800 if (apply_sparse_checkout(ce, o)) {
801 ret = -1;
802 goto done;
803 }
eec3fc03 804 if (!ce_skip_worktree(ce))
9e1afb16 805 empty_worktree = 0;
f1f523ea 806
e800ec9d 807 }
9e1afb16
NTND
808 if (o->result.cache_nr && empty_worktree) {
809 ret = unpack_failed(o, "Sparse checkout leaves no entry on working directory");
810 goto done;
811 }
e800ec9d 812 }
01904572 813
34110cd4 814 o->src_index = NULL;
2e2b887d 815 ret = check_updates(o) ? (-2) : 0;
34110cd4
LT
816 if (o->dst_index)
817 *o->dst_index = o->result;
08aefc9e
NTND
818
819done:
820 for (i = 0;i < el.nr;i++)
821 free(el.excludes[i]);
822 if (el.excludes)
823 free(el.excludes);
824
2e2b887d 825 return ret;
da165f47
JH
826
827return_failed:
828 mark_all_ce_unused(o->src_index);
026680f8
JH
829 ret = unpack_failed(o, NULL);
830 goto done;
16da134b 831}
076b0adc
JS
832
833/* Here come the merge functions */
834
8ccba008 835static int reject_merge(struct cache_entry *ce, struct unpack_trees_options *o)
076b0adc 836{
8ccba008 837 return error(ERRORMSG(o, would_overwrite), ce->name);
076b0adc
JS
838}
839
840static int same(struct cache_entry *a, struct cache_entry *b)
841{
842 if (!!a != !!b)
843 return 0;
844 if (!a && !b)
845 return 1;
e11d7b59
JH
846 if ((a->ce_flags | b->ce_flags) & CE_CONFLICTED)
847 return 0;
076b0adc 848 return a->ce_mode == b->ce_mode &&
a89fccd2 849 !hashcmp(a->sha1, b->sha1);
076b0adc
JS
850}
851
852
853/*
854 * When a CE gets turned into an unmerged entry, we
855 * want it to be up-to-date
856 */
35a5aa79
NTND
857static int verify_uptodate_1(struct cache_entry *ce,
858 struct unpack_trees_options *o,
859 const char *error_msg)
076b0adc
JS
860{
861 struct stat st;
862
52030836 863 if (o->index_only || (!ce_skip_worktree(ce) && (o->reset || ce_uptodate(ce))))
203a2fe1 864 return 0;
076b0adc
JS
865
866 if (!lstat(ce->name, &st)) {
56cac48c 867 unsigned changed = ie_match_stat(o->src_index, ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
076b0adc 868 if (!changed)
203a2fe1 869 return 0;
936492d3
JH
870 /*
871 * NEEDSWORK: the current default policy is to allow
872 * submodule to be out of sync wrt the supermodule
873 * index. This needs to be tightened later for
874 * submodules that are marked to be automatically
875 * checked out.
876 */
7a51ed66 877 if (S_ISGITLINK(ce->ce_mode))
203a2fe1 878 return 0;
076b0adc
JS
879 errno = 0;
880 }
076b0adc 881 if (errno == ENOENT)
203a2fe1 882 return 0;
17e46426 883 return o->gently ? -1 :
35a5aa79
NTND
884 error(error_msg, ce->name);
885}
886
887static int verify_uptodate(struct cache_entry *ce,
888 struct unpack_trees_options *o)
889{
f1f523ea
NTND
890 if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
891 return 0;
35a5aa79 892 return verify_uptodate_1(ce, o, ERRORMSG(o, not_uptodate_file));
076b0adc
JS
893}
894
e800ec9d
NTND
895static int verify_uptodate_sparse(struct cache_entry *ce,
896 struct unpack_trees_options *o)
897{
898 return verify_uptodate_1(ce, o, ERRORMSG(o, sparse_not_uptodate_file));
076b0adc
JS
899}
900
bc052d7f 901static void invalidate_ce_path(struct cache_entry *ce, struct unpack_trees_options *o)
076b0adc
JS
902{
903 if (ce)
34110cd4 904 cache_tree_invalidate_path(o->src_index->cache_tree, ce->name);
076b0adc
JS
905}
906
0cf73755
SV
907/*
908 * Check that checking out ce->sha1 in subdir ce->name is not
909 * going to overwrite any working files.
910 *
911 * Currently, git does not checkout subprojects during a superproject
912 * checkout, so it is not going to overwrite anything.
913 */
914static int verify_clean_submodule(struct cache_entry *ce, const char *action,
915 struct unpack_trees_options *o)
916{
917 return 0;
918}
919
920static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
c8193534
JH
921 struct unpack_trees_options *o)
922{
923 /*
0cf73755 924 * we are about to extract "ce->name"; we would not want to lose
c8193534
JH
925 * anything in the existing directory there.
926 */
927 int namelen;
7b9e3ce0 928 int i;
c8193534
JH
929 struct dir_struct d;
930 char *pathbuf;
931 int cnt = 0;
0cf73755
SV
932 unsigned char sha1[20];
933
7a51ed66 934 if (S_ISGITLINK(ce->ce_mode) &&
0cf73755
SV
935 resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
936 /* If we are not going to update the submodule, then
937 * we don't care.
938 */
939 if (!hashcmp(sha1, ce->sha1))
940 return 0;
941 return verify_clean_submodule(ce, action, o);
942 }
c8193534
JH
943
944 /*
945 * First let's make sure we do not have a local modification
946 * in that directory.
947 */
0cf73755 948 namelen = strlen(ce->name);
da165f47
JH
949 for (i = locate_in_src_index(ce, o);
950 i < o->src_index->cache_nr;
951 i++) {
837e5fe9
CB
952 struct cache_entry *ce2 = o->src_index->cache[i];
953 int len = ce_namelen(ce2);
c8193534 954 if (len < namelen ||
837e5fe9
CB
955 strncmp(ce->name, ce2->name, namelen) ||
956 ce2->name[namelen] != '/')
c8193534
JH
957 break;
958 /*
da165f47
JH
959 * ce2->name is an entry in the subdirectory to be
960 * removed.
c8193534 961 */
837e5fe9
CB
962 if (!ce_stage(ce2)) {
963 if (verify_uptodate(ce2, o))
203a2fe1 964 return -1;
837e5fe9 965 add_entry(o, ce2, CE_REMOVE, 0);
da165f47 966 mark_ce_used(ce2, o);
c8193534
JH
967 }
968 cnt++;
969 }
970
971 /*
972 * Then we need to make sure that we do not lose a locally
973 * present file that is not ignored.
974 */
975 pathbuf = xmalloc(namelen + 2);
0cf73755 976 memcpy(pathbuf, ce->name, namelen);
c8193534
JH
977 strcpy(pathbuf+namelen, "/");
978
979 memset(&d, 0, sizeof(d));
980 if (o->dir)
981 d.exclude_per_dir = o->dir->exclude_per_dir;
dba2e203 982 i = read_directory(&d, pathbuf, namelen+1, NULL);
c8193534 983 if (i)
17e46426 984 return o->gently ? -1 :
8ccba008 985 error(ERRORMSG(o, not_uptodate_dir), ce->name);
c8193534
JH
986 free(pathbuf);
987 return cnt;
988}
989
32260ad5
LT
990/*
991 * This gets called when there was no index entry for the tree entry 'dst',
992 * but we found a file in the working tree that 'lstat()' said was fine,
993 * and we're on a case-insensitive filesystem.
994 *
995 * See if we can find a case-insensitive match in the index that also
996 * matches the stat information, and assume it's that other file!
997 */
998static int icase_exists(struct unpack_trees_options *o, struct cache_entry *dst, struct stat *st)
999{
1000 struct cache_entry *src;
1001
1002 src = index_name_exists(o->src_index, dst->name, ce_namelen(dst), 1);
56cac48c 1003 return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
32260ad5
LT
1004}
1005
076b0adc
JS
1006/*
1007 * We do not want to remove or overwrite a working tree file that
f8a9d428 1008 * is not tracked, unless it is ignored.
076b0adc 1009 */
35a5aa79
NTND
1010static int verify_absent_1(struct cache_entry *ce, const char *action,
1011 struct unpack_trees_options *o,
1012 const char *error_msg)
076b0adc
JS
1013{
1014 struct stat st;
1015
1016 if (o->index_only || o->reset || !o->update)
203a2fe1 1017 return 0;
c8193534 1018
57199892 1019 if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
203a2fe1 1020 return 0;
ec0603e1 1021
0cf73755 1022 if (!lstat(ce->name, &st)) {
6831a88a 1023 int dtype = ce_to_dtype(ce);
df292c79 1024 struct cache_entry *result;
c8193534 1025
32260ad5
LT
1026 /*
1027 * It may be that the 'lstat()' succeeded even though
1028 * target 'ce' was absent, because there is an old
1029 * entry that is different only in case..
1030 *
1031 * Ignore that lstat() if it matches.
1032 */
1033 if (ignore_case && icase_exists(o, ce, &st))
1034 return 0;
1035
6831a88a 1036 if (o->dir && excluded(o->dir, ce->name, &dtype))
c8193534 1037 /*
0cf73755 1038 * ce->name is explicitly excluded, so it is Ok to
c8193534
JH
1039 * overwrite it.
1040 */
203a2fe1 1041 return 0;
c8193534
JH
1042 if (S_ISDIR(st.st_mode)) {
1043 /*
1044 * We are checking out path "foo" and
1045 * found "foo/." in the working tree.
1046 * This is tricky -- if we have modified
1047 * files that are in "foo/" we would lose
6caa7b55 1048 * them.
c8193534 1049 */
da165f47
JH
1050 if (verify_clean_subdirectory(ce, action, o) < 0)
1051 return -1;
203a2fe1 1052 return 0;
c8193534
JH
1053 }
1054
1055 /*
1056 * The previous round may already have decided to
1057 * delete this path, which is in a subdirectory that
1058 * is being replaced with a blob.
1059 */
cd2fef59 1060 result = index_name_exists(&o->result, ce->name, ce_namelen(ce), 0);
df292c79
LT
1061 if (result) {
1062 if (result->ce_flags & CE_REMOVE)
203a2fe1 1063 return 0;
c8193534
JH
1064 }
1065
17e46426 1066 return o->gently ? -1 :
8ccba008 1067 error(ERRORMSG(o, would_lose_untracked), ce->name, action);
c8193534 1068 }
203a2fe1 1069 return 0;
076b0adc 1070}
35a5aa79
NTND
1071static int verify_absent(struct cache_entry *ce, const char *action,
1072 struct unpack_trees_options *o)
1073{
f1f523ea
NTND
1074 if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
1075 return 0;
35a5aa79
NTND
1076 return verify_absent_1(ce, action, o, ERRORMSG(o, would_lose_untracked));
1077}
076b0adc 1078
e800ec9d
NTND
1079static int verify_absent_sparse(struct cache_entry *ce, const char *action,
1080 struct unpack_trees_options *o)
1081{
1082 return verify_absent_1(ce, action, o, ERRORMSG(o, would_lose_orphaned));
1083}
076b0adc
JS
1084
1085static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
1086 struct unpack_trees_options *o)
1087{
7f8ab8dc
LT
1088 int update = CE_UPDATE;
1089
e11d7b59
JH
1090 if (!old) {
1091 if (verify_absent(merge, "overwritten", o))
1092 return -1;
1093 invalidate_ce_path(merge, o);
1094 } else if (!(old->ce_flags & CE_CONFLICTED)) {
076b0adc
JS
1095 /*
1096 * See if we can re-use the old CE directly?
1097 * That way we get the uptodate stat info.
1098 *
7f8ab8dc
LT
1099 * This also removes the UPDATE flag on a match; otherwise
1100 * we will end up overwriting local changes in the work tree.
076b0adc
JS
1101 */
1102 if (same(old, merge)) {
eb7a2f1d 1103 copy_cache_entry(merge, old);
7f8ab8dc 1104 update = 0;
076b0adc 1105 } else {
203a2fe1
DB
1106 if (verify_uptodate(old, o))
1107 return -1;
32f54ca3
NTND
1108 if (ce_skip_worktree(old))
1109 update |= CE_SKIP_WORKTREE;
bc052d7f 1110 invalidate_ce_path(old, o);
076b0adc 1111 }
e11d7b59
JH
1112 } else {
1113 /*
1114 * Previously unmerged entry left as an existence
1115 * marker by read_index_unmerged();
1116 */
1117 invalidate_ce_path(old, o);
076b0adc
JS
1118 }
1119
7f8ab8dc 1120 add_entry(o, merge, update, CE_STAGEMASK);
076b0adc
JS
1121 return 1;
1122}
1123
1124static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
1125 struct unpack_trees_options *o)
1126{
34110cd4
LT
1127 /* Did it exist in the index? */
1128 if (!old) {
203a2fe1
DB
1129 if (verify_absent(ce, "removed", o))
1130 return -1;
34110cd4
LT
1131 return 0;
1132 }
e11d7b59 1133 if (!(old->ce_flags & CE_CONFLICTED) && verify_uptodate(old, o))
34110cd4
LT
1134 return -1;
1135 add_entry(o, ce, CE_REMOVE, 0);
bc052d7f 1136 invalidate_ce_path(ce, o);
076b0adc
JS
1137 return 1;
1138}
1139
7f7932ab 1140static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o)
076b0adc 1141{
34110cd4 1142 add_entry(o, ce, 0, 0);
076b0adc
JS
1143 return 1;
1144}
1145
1146#if DBRT_DEBUG
1147static void show_stage_entry(FILE *o,
1148 const char *label, const struct cache_entry *ce)
1149{
1150 if (!ce)
1151 fprintf(o, "%s (missing)\n", label);
1152 else
1153 fprintf(o, "%s%06o %s %d\t%s\n",
1154 label,
7a51ed66 1155 ce->ce_mode,
076b0adc
JS
1156 sha1_to_hex(ce->sha1),
1157 ce_stage(ce),
1158 ce->name);
1159}
1160#endif
1161
34110cd4 1162int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o)
076b0adc
JS
1163{
1164 struct cache_entry *index;
1165 struct cache_entry *head;
1166 struct cache_entry *remote = stages[o->head_idx + 1];
1167 int count;
1168 int head_match = 0;
1169 int remote_match = 0;
076b0adc
JS
1170
1171 int df_conflict_head = 0;
1172 int df_conflict_remote = 0;
1173
1174 int any_anc_missing = 0;
1175 int no_anc_exists = 1;
1176 int i;
1177
1178 for (i = 1; i < o->head_idx; i++) {
4c4caafc 1179 if (!stages[i] || stages[i] == o->df_conflict_entry)
076b0adc 1180 any_anc_missing = 1;
4c4caafc 1181 else
076b0adc 1182 no_anc_exists = 0;
076b0adc
JS
1183 }
1184
1185 index = stages[0];
1186 head = stages[o->head_idx];
1187
1188 if (head == o->df_conflict_entry) {
1189 df_conflict_head = 1;
1190 head = NULL;
1191 }
1192
1193 if (remote == o->df_conflict_entry) {
1194 df_conflict_remote = 1;
1195 remote = NULL;
1196 }
1197
cee2d6ae
JH
1198 /*
1199 * First, if there's a #16 situation, note that to prevent #13
076b0adc
JS
1200 * and #14.
1201 */
1202 if (!same(remote, head)) {
1203 for (i = 1; i < o->head_idx; i++) {
1204 if (same(stages[i], head)) {
1205 head_match = i;
1206 }
1207 if (same(stages[i], remote)) {
1208 remote_match = i;
1209 }
1210 }
1211 }
1212
cee2d6ae
JH
1213 /*
1214 * We start with cases where the index is allowed to match
076b0adc
JS
1215 * something other than the head: #14(ALT) and #2ALT, where it
1216 * is permitted to match the result instead.
1217 */
1218 /* #14, #14ALT, #2ALT */
1219 if (remote && !df_conflict_head && head_match && !remote_match) {
1220 if (index && !same(index, remote) && !same(index, head))
8ccba008 1221 return o->gently ? -1 : reject_merge(index, o);
076b0adc
JS
1222 return merged_entry(remote, index, o);
1223 }
1224 /*
1225 * If we have an entry in the index cache, then we want to
1226 * make sure that it matches head.
1227 */
4e7c4571 1228 if (index && !same(index, head))
8ccba008 1229 return o->gently ? -1 : reject_merge(index, o);
076b0adc
JS
1230
1231 if (head) {
1232 /* #5ALT, #15 */
1233 if (same(head, remote))
1234 return merged_entry(head, index, o);
1235 /* #13, #3ALT */
1236 if (!df_conflict_remote && remote_match && !head_match)
1237 return merged_entry(head, index, o);
1238 }
1239
1240 /* #1 */
34110cd4 1241 if (!head && !remote && any_anc_missing)
076b0adc
JS
1242 return 0;
1243
cee2d6ae
JH
1244 /*
1245 * Under the "aggressive" rule, we resolve mostly trivial
076b0adc
JS
1246 * cases that we historically had git-merge-one-file resolve.
1247 */
1248 if (o->aggressive) {
cee2d6ae
JH
1249 int head_deleted = !head;
1250 int remote_deleted = !remote;
0cf73755 1251 struct cache_entry *ce = NULL;
4c4caafc
JH
1252
1253 if (index)
0cf73755 1254 ce = index;
4c4caafc 1255 else if (head)
0cf73755 1256 ce = head;
4c4caafc 1257 else if (remote)
0cf73755 1258 ce = remote;
4c4caafc
JH
1259 else {
1260 for (i = 1; i < o->head_idx; i++) {
1261 if (stages[i] && stages[i] != o->df_conflict_entry) {
0cf73755 1262 ce = stages[i];
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JH
1263 break;
1264 }
1265 }
1266 }
1267
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JS
1268 /*
1269 * Deleted in both.
1270 * Deleted in one and unchanged in the other.
1271 */
1272 if ((head_deleted && remote_deleted) ||
1273 (head_deleted && remote && remote_match) ||
1274 (remote_deleted && head && head_match)) {
1275 if (index)
1276 return deleted_entry(index, index, o);
34110cd4 1277 if (ce && !head_deleted) {
203a2fe1
DB
1278 if (verify_absent(ce, "removed", o))
1279 return -1;
1280 }
076b0adc
JS
1281 return 0;
1282 }
1283 /*
1284 * Added in both, identically.
1285 */
1286 if (no_anc_exists && head && remote && same(head, remote))
1287 return merged_entry(head, index, o);
1288
1289 }
1290
1291 /* Below are "no merge" cases, which require that the index be
1292 * up-to-date to avoid the files getting overwritten with
1293 * conflict resolution files.
1294 */
1295 if (index) {
203a2fe1
DB
1296 if (verify_uptodate(index, o))
1297 return -1;
076b0adc 1298 }
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JS
1299
1300 o->nontrivial_merge = 1;
1301
ea4b52a8 1302 /* #2, #3, #4, #6, #7, #9, #10, #11. */
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JS
1303 count = 0;
1304 if (!head_match || !remote_match) {
1305 for (i = 1; i < o->head_idx; i++) {
4c4caafc 1306 if (stages[i] && stages[i] != o->df_conflict_entry) {
7f7932ab 1307 keep_entry(stages[i], o);
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JS
1308 count++;
1309 break;
1310 }
1311 }
1312 }
1313#if DBRT_DEBUG
1314 else {
1315 fprintf(stderr, "read-tree: warning #16 detected\n");
1316 show_stage_entry(stderr, "head ", stages[head_match]);
1317 show_stage_entry(stderr, "remote ", stages[remote_match]);
1318 }
1319#endif
7f7932ab
JH
1320 if (head) { count += keep_entry(head, o); }
1321 if (remote) { count += keep_entry(remote, o); }
076b0adc
JS
1322 return count;
1323}
1324
1325/*
1326 * Two-way merge.
1327 *
1328 * The rule is to "carry forward" what is in the index without losing
a75d7b54 1329 * information across a "fast-forward", favoring a successful merge
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JS
1330 * over a merge failure when it makes sense. For details of the
1331 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
1332 *
1333 */
34110cd4 1334int twoway_merge(struct cache_entry **src, struct unpack_trees_options *o)
076b0adc
JS
1335{
1336 struct cache_entry *current = src[0];
b8ba1535
JH
1337 struct cache_entry *oldtree = src[1];
1338 struct cache_entry *newtree = src[2];
076b0adc
JS
1339
1340 if (o->merge_size != 2)
1341 return error("Cannot do a twoway merge of %d trees",
1342 o->merge_size);
1343
b8ba1535
JH
1344 if (oldtree == o->df_conflict_entry)
1345 oldtree = NULL;
1346 if (newtree == o->df_conflict_entry)
1347 newtree = NULL;
1348
076b0adc
JS
1349 if (current) {
1350 if ((!oldtree && !newtree) || /* 4 and 5 */
1351 (!oldtree && newtree &&
1352 same(current, newtree)) || /* 6 and 7 */
1353 (oldtree && newtree &&
1354 same(oldtree, newtree)) || /* 14 and 15 */
1355 (oldtree && newtree &&
b8ba1535 1356 !same(oldtree, newtree) && /* 18 and 19 */
076b0adc 1357 same(current, newtree))) {
7f7932ab 1358 return keep_entry(current, o);
076b0adc
JS
1359 }
1360 else if (oldtree && !newtree && same(current, oldtree)) {
1361 /* 10 or 11 */
1362 return deleted_entry(oldtree, current, o);
1363 }
1364 else if (oldtree && newtree &&
1365 same(current, oldtree) && !same(current, newtree)) {
1366 /* 20 or 21 */
1367 return merged_entry(newtree, current, o);
1368 }
1369 else {
1370 /* all other failures */
1371 if (oldtree)
8ccba008 1372 return o->gently ? -1 : reject_merge(oldtree, o);
076b0adc 1373 if (current)
8ccba008 1374 return o->gently ? -1 : reject_merge(current, o);
076b0adc 1375 if (newtree)
8ccba008 1376 return o->gently ? -1 : reject_merge(newtree, o);
076b0adc
JS
1377 return -1;
1378 }
1379 }
55218834
JH
1380 else if (newtree) {
1381 if (oldtree && !o->initial_checkout) {
1382 /*
1383 * deletion of the path was staged;
1384 */
1385 if (same(oldtree, newtree))
1386 return 1;
1387 return reject_merge(oldtree, o);
1388 }
076b0adc 1389 return merged_entry(newtree, current, o);
55218834 1390 }
d699676d 1391 return deleted_entry(oldtree, current, o);
076b0adc
JS
1392}
1393
1394/*
1395 * Bind merge.
1396 *
1397 * Keep the index entries at stage0, collapse stage1 but make sure
1398 * stage0 does not have anything there.
1399 */
1400int bind_merge(struct cache_entry **src,
34110cd4 1401 struct unpack_trees_options *o)
076b0adc
JS
1402{
1403 struct cache_entry *old = src[0];
1404 struct cache_entry *a = src[1];
1405
1406 if (o->merge_size != 1)
1407 return error("Cannot do a bind merge of %d trees\n",
1408 o->merge_size);
1409 if (a && old)
17e46426 1410 return o->gently ? -1 :
8ccba008 1411 error(ERRORMSG(o, bind_overlap), a->name, old->name);
076b0adc 1412 if (!a)
7f7932ab 1413 return keep_entry(old, o);
076b0adc
JS
1414 else
1415 return merged_entry(a, NULL, o);
1416}
1417
1418/*
1419 * One-way merge.
1420 *
1421 * The rule is:
1422 * - take the stat information from stage0, take the data from stage1
1423 */
34110cd4 1424int oneway_merge(struct cache_entry **src, struct unpack_trees_options *o)
076b0adc
JS
1425{
1426 struct cache_entry *old = src[0];
1427 struct cache_entry *a = src[1];
1428
1429 if (o->merge_size != 1)
1430 return error("Cannot do a oneway merge of %d trees",
1431 o->merge_size);
1432
78d3b06e 1433 if (!a || a == o->df_conflict_entry)
076b0adc 1434 return deleted_entry(old, old, o);
34110cd4 1435
076b0adc 1436 if (old && same(old, a)) {
34110cd4 1437 int update = 0;
52030836 1438 if (o->reset && !ce_uptodate(old) && !ce_skip_worktree(old)) {
076b0adc
JS
1439 struct stat st;
1440 if (lstat(old->name, &st) ||
56cac48c 1441 ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE))
34110cd4 1442 update |= CE_UPDATE;
076b0adc 1443 }
34110cd4
LT
1444 add_entry(o, old, update, 0);
1445 return 0;
076b0adc
JS
1446 }
1447 return merged_entry(a, old, o);
1448}