Git 1.7.2
[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;
80d706af
PC
70 if (remove_or_warn(ce->ce_mode, ce->name))
71 return;
78478927 72 schedule_dir_for_removal(ce->name, ce_namelen(ce));
16da134b
JS
73}
74
16da134b 75static struct checkout state;
c4758d3c 76static int check_updates(struct unpack_trees_options *o)
16da134b 77{
96a02f8f 78 unsigned cnt = 0, total = 0;
dc6a0757 79 struct progress *progress = NULL;
34110cd4 80 struct index_state *index = &o->result;
33ecf7eb 81 int i;
c4758d3c 82 int errs = 0;
16da134b
JS
83
84 if (o->update && o->verbose_update) {
34110cd4
LT
85 for (total = cnt = 0; cnt < index->cache_nr; cnt++) {
86 struct cache_entry *ce = index->cache[cnt];
e663db2f 87 if (ce->ce_flags & (CE_UPDATE | CE_REMOVE | CE_WT_REMOVE))
16da134b
JS
88 total++;
89 }
90
dc6a0757 91 progress = start_progress_delay("Checking out files",
e8548645 92 total, 50, 1);
16da134b
JS
93 cnt = 0;
94 }
95
66985e66
JH
96 if (o->update)
97 git_attr_set_direction(GIT_ATTR_CHECKOUT, &o->result);
34110cd4
LT
98 for (i = 0; i < index->cache_nr; i++) {
99 struct cache_entry *ce = index->cache[i];
16da134b 100
e663db2f
NTND
101 if (ce->ce_flags & CE_WT_REMOVE) {
102 display_progress(progress, ++cnt);
103 if (o->update)
104 unlink_entry(ce);
105 continue;
106 }
107
7a51ed66 108 if (ce->ce_flags & CE_REMOVE) {
1fa6ead4 109 display_progress(progress, ++cnt);
16da134b 110 if (o->update)
c40641b7 111 unlink_entry(ce);
16da134b 112 }
1fa6ead4 113 }
36419c8e 114 remove_marked_cache_entries(&o->result);
78478927 115 remove_scheduled_dirs();
1fa6ead4
LT
116
117 for (i = 0; i < index->cache_nr; i++) {
118 struct cache_entry *ce = index->cache[i];
119
7a51ed66 120 if (ce->ce_flags & CE_UPDATE) {
1fa6ead4 121 display_progress(progress, ++cnt);
7a51ed66 122 ce->ce_flags &= ~CE_UPDATE;
16a4c617 123 if (o->update) {
c4758d3c 124 errs |= checkout_entry(ce, &state, NULL);
16a4c617 125 }
16da134b
JS
126 }
127 }
4d4fcc54 128 stop_progress(&progress);
66985e66
JH
129 if (o->update)
130 git_attr_set_direction(GIT_ATTR_CHECKIN, NULL);
c4758d3c 131 return errs != 0;
16da134b
JS
132}
133
e800ec9d
NTND
134static int verify_uptodate_sparse(struct cache_entry *ce, struct unpack_trees_options *o);
135static int verify_absent_sparse(struct cache_entry *ce, const char *action, struct unpack_trees_options *o);
136
137static int will_have_skip_worktree(const struct cache_entry *ce, struct unpack_trees_options *o)
138{
139 const char *basename;
140
141 if (ce_stage(ce))
142 return 0;
143
144 basename = strrchr(ce->name, '/');
145 basename = basename ? basename+1 : ce->name;
146 return excluded_from_list(ce->name, ce_namelen(ce), basename, NULL, o->el) <= 0;
147}
148
149static int apply_sparse_checkout(struct cache_entry *ce, struct unpack_trees_options *o)
150{
151 int was_skip_worktree = ce_skip_worktree(ce);
152
153 if (will_have_skip_worktree(ce, o))
154 ce->ce_flags |= CE_SKIP_WORKTREE;
155 else
156 ce->ce_flags &= ~CE_SKIP_WORKTREE;
157
158 /*
159 * We only care about files getting into the checkout area
160 * If merge strategies want to remove some, go ahead, this
161 * flag will be removed eventually in unpack_trees() if it's
162 * outside checkout area.
163 */
164 if (ce->ce_flags & CE_REMOVE)
165 return 0;
166
167 if (!was_skip_worktree && ce_skip_worktree(ce)) {
168 /*
169 * If CE_UPDATE is set, verify_uptodate() must be called already
170 * also stat info may have lost after merged_entry() so calling
171 * verify_uptodate() again may fail
172 */
173 if (!(ce->ce_flags & CE_UPDATE) && verify_uptodate_sparse(ce, o))
174 return -1;
175 ce->ce_flags |= CE_WT_REMOVE;
176 }
177 if (was_skip_worktree && !ce_skip_worktree(ce)) {
178 if (verify_absent_sparse(ce, "overwritten", o))
179 return -1;
180 ce->ce_flags |= CE_UPDATE;
181 }
182 return 0;
183}
184
34110cd4 185static inline int call_unpack_fn(struct cache_entry **src, struct unpack_trees_options *o)
01904572 186{
34110cd4
LT
187 int ret = o->fn(src, o);
188 if (ret > 0)
01904572 189 ret = 0;
01904572
LT
190 return ret;
191}
192
da165f47
JH
193static void mark_ce_used(struct cache_entry *ce, struct unpack_trees_options *o)
194{
195 ce->ce_flags |= CE_UNPACKED;
196
197 if (o->cache_bottom < o->src_index->cache_nr &&
198 o->src_index->cache[o->cache_bottom] == ce) {
199 int bottom = o->cache_bottom;
200 while (bottom < o->src_index->cache_nr &&
201 o->src_index->cache[bottom]->ce_flags & CE_UNPACKED)
202 bottom++;
203 o->cache_bottom = bottom;
204 }
205}
206
207static void mark_all_ce_unused(struct index_state *index)
208{
209 int i;
210 for (i = 0; i < index->cache_nr; i++)
211 index->cache[i]->ce_flags &= ~CE_UNPACKED;
212}
213
214static int locate_in_src_index(struct cache_entry *ce,
215 struct unpack_trees_options *o)
216{
217 struct index_state *index = o->src_index;
218 int len = ce_namelen(ce);
219 int pos = index_name_pos(index, ce->name, len);
220 if (pos < 0)
221 pos = -1 - pos;
222 return pos;
223}
224
225/*
226 * We call unpack_index_entry() with an unmerged cache entry
227 * only in diff-index, and it wants a single callback. Skip
228 * the other unmerged entry with the same name.
229 */
230static void mark_ce_used_same_name(struct cache_entry *ce,
231 struct unpack_trees_options *o)
232{
233 struct index_state *index = o->src_index;
234 int len = ce_namelen(ce);
235 int pos;
236
237 for (pos = locate_in_src_index(ce, o); pos < index->cache_nr; pos++) {
238 struct cache_entry *next = index->cache[pos];
239 if (len != ce_namelen(next) ||
240 memcmp(ce->name, next->name, len))
241 break;
242 mark_ce_used(next, o);
243 }
244}
245
246static struct cache_entry *next_cache_entry(struct unpack_trees_options *o)
247{
248 const struct index_state *index = o->src_index;
249 int pos = o->cache_bottom;
250
251 while (pos < index->cache_nr) {
252 struct cache_entry *ce = index->cache[pos];
253 if (!(ce->ce_flags & CE_UNPACKED))
254 return ce;
255 pos++;
256 }
257 return NULL;
258}
259
260static void add_same_unmerged(struct cache_entry *ce,
261 struct unpack_trees_options *o)
262{
263 struct index_state *index = o->src_index;
264 int len = ce_namelen(ce);
265 int pos = index_name_pos(index, ce->name, len);
266
267 if (0 <= pos)
268 die("programming error in a caller of mark_ce_used_same_name");
269 for (pos = -pos - 1; pos < index->cache_nr; pos++) {
270 struct cache_entry *next = index->cache[pos];
271 if (len != ce_namelen(next) ||
272 memcmp(ce->name, next->name, len))
273 break;
274 add_entry(o, next, 0, 0);
275 mark_ce_used(next, o);
276 }
277}
278
279static int unpack_index_entry(struct cache_entry *ce,
280 struct unpack_trees_options *o)
01904572 281{
66dbfd55 282 struct cache_entry *src[5] = { NULL };
da165f47 283 int ret;
34110cd4 284
66dbfd55
GV
285 src[0] = ce;
286
da165f47 287 mark_ce_used(ce, o);
01904572
LT
288 if (ce_stage(ce)) {
289 if (o->skip_unmerged) {
34110cd4
LT
290 add_entry(o, ce, 0, 0);
291 return 0;
01904572 292 }
01904572 293 }
da165f47
JH
294 ret = call_unpack_fn(src, o);
295 if (ce_stage(ce))
296 mark_ce_used_same_name(ce, o);
297 return ret;
01904572
LT
298}
299
730f7284
JH
300static int find_cache_pos(struct traverse_info *, const struct name_entry *);
301
302static void restore_cache_bottom(struct traverse_info *info, int bottom)
303{
304 struct unpack_trees_options *o = info->data;
305
306 if (o->diff_index_cached)
307 return;
308 o->cache_bottom = bottom;
309}
310
311static int switch_cache_bottom(struct traverse_info *info)
312{
313 struct unpack_trees_options *o = info->data;
314 int ret, pos;
315
316 if (o->diff_index_cached)
317 return 0;
318 ret = o->cache_bottom;
319 pos = find_cache_pos(info->prev, &info->name);
320
321 if (pos < -1)
322 o->cache_bottom = -2 - pos;
323 else if (pos < 0)
324 o->cache_bottom = o->src_index->cache_nr;
325 return ret;
01904572
LT
326}
327
2af202be 328static int traverse_trees_recursive(int n, unsigned long dirmask, unsigned long df_conflicts, struct name_entry *names, struct traverse_info *info)
16da134b 329{
730f7284 330 int i, ret, bottom;
ca885a4f 331 struct tree_desc t[MAX_UNPACK_TREES];
01904572
LT
332 struct traverse_info newinfo;
333 struct name_entry *p;
334
335 p = names;
336 while (!p->mode)
337 p++;
338
339 newinfo = *info;
340 newinfo.prev = info;
341 newinfo.name = *p;
342 newinfo.pathlen += tree_entry_len(p->path, p->sha1) + 1;
343 newinfo.conflicts |= df_conflicts;
344
345 for (i = 0; i < n; i++, dirmask >>= 1) {
346 const unsigned char *sha1 = NULL;
347 if (dirmask & 1)
348 sha1 = names[i].sha1;
349 fill_tree_descriptor(t+i, sha1);
350 }
730f7284
JH
351
352 bottom = switch_cache_bottom(&newinfo);
353 ret = traverse_trees(n, t, &newinfo);
354 restore_cache_bottom(&newinfo, bottom);
355 return ret;
01904572
LT
356}
357
358/*
359 * Compare the traverse-path to the cache entry without actually
360 * having to generate the textual representation of the traverse
361 * path.
362 *
363 * NOTE! This *only* compares up to the size of the traverse path
364 * itself - the caller needs to do the final check for the cache
365 * entry having more data at the end!
366 */
367static int do_compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
368{
369 int len, pathlen, ce_len;
370 const char *ce_name;
371
372 if (info->prev) {
373 int cmp = do_compare_entry(ce, info->prev, &info->name);
374 if (cmp)
375 return cmp;
376 }
377 pathlen = info->pathlen;
378 ce_len = ce_namelen(ce);
379
380 /* If ce_len < pathlen then we must have previously hit "name == directory" entry */
381 if (ce_len < pathlen)
382 return -1;
383
384 ce_len -= pathlen;
385 ce_name = ce->name + pathlen;
386
387 len = tree_entry_len(n->path, n->sha1);
388 return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode);
389}
390
391static int compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
392{
393 int cmp = do_compare_entry(ce, info, n);
394 if (cmp)
395 return cmp;
396
397 /*
398 * Even if the beginning compared identically, the ce should
399 * compare as bigger than a directory leading up to it!
400 */
401 return ce_namelen(ce) > traverse_path_len(info, n);
402}
403
da165f47
JH
404static int ce_in_traverse_path(const struct cache_entry *ce,
405 const struct traverse_info *info)
406{
407 if (!info->prev)
408 return 1;
409 if (do_compare_entry(ce, info->prev, &info->name))
410 return 0;
411 /*
412 * If ce (blob) is the same name as the path (which is a tree
413 * we will be descending into), it won't be inside it.
414 */
415 return (info->pathlen < ce_namelen(ce));
416}
417
01904572
LT
418static struct cache_entry *create_ce_entry(const struct traverse_info *info, const struct name_entry *n, int stage)
419{
420 int len = traverse_path_len(info, n);
421 struct cache_entry *ce = xcalloc(1, cache_entry_size(len));
422
423 ce->ce_mode = create_ce_mode(n->mode);
424 ce->ce_flags = create_ce_flags(len, stage);
425 hashcpy(ce->sha1, n->sha1);
426 make_traverse_path(ce->name, info, n);
427
428 return ce;
429}
430
c7cddc1a
RS
431static int unpack_nondirectories(int n, unsigned long mask,
432 unsigned long dirmask,
433 struct cache_entry **src,
434 const struct name_entry *names,
435 const struct traverse_info *info)
01904572
LT
436{
437 int i;
438 struct unpack_trees_options *o = info->data;
439 unsigned long conflicts;
440
441 /* Do we have *only* directories? Nothing to do */
442 if (mask == dirmask && !src[0])
443 return 0;
444
445 conflicts = info->conflicts;
446 if (o->merge)
447 conflicts >>= 1;
448 conflicts |= dirmask;
449
450 /*
451 * Ok, we've filled in up to any potential index entry in src[0],
452 * now do the rest.
453 */
454 for (i = 0; i < n; i++) {
455 int stage;
456 unsigned int bit = 1ul << i;
457 if (conflicts & bit) {
458 src[i + o->merge] = o->df_conflict_entry;
459 continue;
460 }
461 if (!(mask & bit))
462 continue;
463 if (!o->merge)
464 stage = 0;
465 else if (i + 1 < o->head_idx)
466 stage = 1;
467 else if (i + 1 > o->head_idx)
468 stage = 3;
469 else
470 stage = 2;
471 src[i + o->merge] = create_ce_entry(info, names + i, stage);
472 }
473
474 if (o->merge)
34110cd4 475 return call_unpack_fn(src, o);
01904572 476
01904572 477 for (i = 0; i < n; i++)
aab3b9a1
JH
478 if (src[i] && src[i] != o->df_conflict_entry)
479 add_entry(o, src[i], 0, 0);
01904572
LT
480 return 0;
481}
482
353c5eeb
JH
483static int unpack_failed(struct unpack_trees_options *o, const char *message)
484{
485 discard_index(&o->result);
486 if (!o->gently) {
487 if (message)
488 return error("%s", message);
489 return -1;
490 }
491 return -1;
492}
493
730f7284
JH
494/* NEEDSWORK: give this a better name and share with tree-walk.c */
495static int name_compare(const char *a, int a_len,
496 const char *b, int b_len)
497{
498 int len = (a_len < b_len) ? a_len : b_len;
499 int cmp = memcmp(a, b, len);
500 if (cmp)
501 return cmp;
502 return (a_len - b_len);
503}
504
505/*
506 * The tree traversal is looking at name p. If we have a matching entry,
507 * return it. If name p is a directory in the index, do not return
508 * anything, as we will want to match it when the traversal descends into
509 * the directory.
510 */
511static int find_cache_pos(struct traverse_info *info,
512 const struct name_entry *p)
513{
514 int pos;
515 struct unpack_trees_options *o = info->data;
516 struct index_state *index = o->src_index;
517 int pfxlen = info->pathlen;
518 int p_len = tree_entry_len(p->path, p->sha1);
519
520 for (pos = o->cache_bottom; pos < index->cache_nr; pos++) {
521 struct cache_entry *ce = index->cache[pos];
522 const char *ce_name, *ce_slash;
523 int cmp, ce_len;
524
e53e6b44
BD
525 if (ce->ce_flags & CE_UNPACKED) {
526 /*
527 * cache_bottom entry is already unpacked, so
528 * we can never match it; don't check it
529 * again.
530 */
531 if (pos == o->cache_bottom)
532 ++o->cache_bottom;
730f7284 533 continue;
e53e6b44
BD
534 }
535 if (!ce_in_traverse_path(ce, info))
730f7284
JH
536 continue;
537 ce_name = ce->name + pfxlen;
538 ce_slash = strchr(ce_name, '/');
539 if (ce_slash)
540 ce_len = ce_slash - ce_name;
541 else
542 ce_len = ce_namelen(ce) - pfxlen;
543 cmp = name_compare(p->path, p_len, ce_name, ce_len);
544 /*
545 * Exact match; if we have a directory we need to
546 * delay returning it.
547 */
548 if (!cmp)
549 return ce_slash ? -2 - pos : pos;
550 if (0 < cmp)
551 continue; /* keep looking */
552 /*
553 * ce_name sorts after p->path; could it be that we
554 * have files under p->path directory in the index?
555 * E.g. ce_name == "t-i", and p->path == "t"; we may
556 * have "t/a" in the index.
557 */
558 if (p_len < ce_len && !memcmp(ce_name, p->path, p_len) &&
559 ce_name[p_len] < '/')
560 continue; /* keep looking */
561 break;
562 }
563 return -1;
564}
565
566static struct cache_entry *find_cache_entry(struct traverse_info *info,
567 const struct name_entry *p)
568{
569 int pos = find_cache_pos(info, p);
570 struct unpack_trees_options *o = info->data;
571
572 if (0 <= pos)
573 return o->src_index->cache[pos];
574 else
575 return NULL;
576}
577
ba655da5
JH
578static void debug_path(struct traverse_info *info)
579{
580 if (info->prev) {
581 debug_path(info->prev);
582 if (*info->prev->name.path)
583 putchar('/');
584 }
585 printf("%s", info->name.path);
586}
587
588static void debug_name_entry(int i, struct name_entry *n)
589{
590 printf("ent#%d %06o %s\n", i,
591 n->path ? n->mode : 0,
592 n->path ? n->path : "(missing)");
593}
594
595static void debug_unpack_callback(int n,
596 unsigned long mask,
597 unsigned long dirmask,
598 struct name_entry *names,
599 struct traverse_info *info)
600{
601 int i;
602 printf("* unpack mask %lu, dirmask %lu, cnt %d ",
603 mask, dirmask, n);
604 debug_path(info);
605 putchar('\n');
606 for (i = 0; i < n; i++)
607 debug_name_entry(i, names + i);
608}
609
01904572
LT
610static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *names, struct traverse_info *info)
611{
c7cddc1a 612 struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
01904572 613 struct unpack_trees_options *o = info->data;
01904572
LT
614 const struct name_entry *p = names;
615
616 /* Find first entry with a real name (we could use "mask" too) */
617 while (!p->mode)
618 p++;
619
ba655da5
JH
620 if (o->debug_unpack)
621 debug_unpack_callback(n, mask, dirmask, names, info);
622
01904572
LT
623 /* Are we supposed to look at the index too? */
624 if (o->merge) {
da165f47 625 while (1) {
da165f47 626 int cmp;
730f7284
JH
627 struct cache_entry *ce;
628
629 if (o->diff_index_cached)
630 ce = next_cache_entry(o);
631 else
632 ce = find_cache_entry(info, p);
633
da165f47
JH
634 if (!ce)
635 break;
636 cmp = compare_entry(ce, info, p);
01904572
LT
637 if (cmp < 0) {
638 if (unpack_index_entry(ce, o) < 0)
353c5eeb 639 return unpack_failed(o, NULL);
01904572
LT
640 continue;
641 }
642 if (!cmp) {
643 if (ce_stage(ce)) {
644 /*
da165f47
JH
645 * If we skip unmerged index
646 * entries, we'll skip this
647 * entry *and* the tree
648 * entries associated with it!
01904572 649 */
34110cd4 650 if (o->skip_unmerged) {
da165f47 651 add_same_unmerged(ce, o);
01904572 652 return mask;
34110cd4 653 }
01904572
LT
654 }
655 src[0] = ce;
01904572
LT
656 }
657 break;
658 }
659 }
660
34110cd4 661 if (unpack_nondirectories(n, mask, dirmask, src, names, info) < 0)
01904572
LT
662 return -1;
663
da165f47
JH
664 if (src[0]) {
665 if (ce_stage(src[0]))
666 mark_ce_used_same_name(src[0], o);
667 else
668 mark_ce_used(src[0], o);
669 }
670
01904572
LT
671 /* Now handle any directories.. */
672 if (dirmask) {
673 unsigned long conflicts = mask & ~dirmask;
674 if (o->merge) {
675 conflicts <<= 1;
676 if (src[0])
677 conflicts |= 1;
678 }
b65982b6
JH
679
680 /* special case: "diff-index --cached" looking at a tree */
681 if (o->diff_index_cached &&
682 n == 1 && dirmask == 1 && S_ISDIR(names->mode)) {
683 int matches;
684 matches = cache_tree_matches_traversal(o->src_index->cache_tree,
685 names, info);
686 /*
da165f47
JH
687 * Everything under the name matches; skip the
688 * entire hierarchy. diff_index_cached codepath
689 * special cases D/F conflicts in such a way that
690 * it does not do any look-ahead, so this is safe.
b65982b6
JH
691 */
692 if (matches) {
da165f47 693 o->cache_bottom += matches;
b65982b6
JH
694 return mask;
695 }
696 }
697
542c264b
JH
698 if (traverse_trees_recursive(n, dirmask, conflicts,
699 names, info) < 0)
700 return -1;
01904572
LT
701 return mask;
702 }
703
704 return mask;
705}
706
2e2b887d
JH
707/*
708 * N-way merge "len" trees. Returns 0 on success, -1 on failure to manipulate the
709 * resulting index, -2 on failure to reflect the changes to the work tree.
710 */
01904572
LT
711int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
712{
e800ec9d 713 int i, ret;
0fb1eaa8 714 static struct cache_entry *dfc;
08aefc9e 715 struct exclude_list el;
16da134b 716
ca885a4f
JH
717 if (len > MAX_UNPACK_TREES)
718 die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
076b0adc 719 memset(&state, 0, sizeof(state));
16da134b
JS
720 state.base_dir = "";
721 state.force = 1;
722 state.quiet = 1;
723 state.refresh_cache = 1;
724
08aefc9e
NTND
725 memset(&el, 0, sizeof(el));
726 if (!core_apply_sparse_checkout || !o->update)
727 o->skip_sparse_checkout = 1;
728 if (!o->skip_sparse_checkout) {
729 if (add_excludes_from_file_to_list(git_path("info/sparse-checkout"), "", 0, NULL, &el, 0) < 0)
730 o->skip_sparse_checkout = 1;
731 else
732 o->el = &el;
733 }
734
34110cd4 735 memset(&o->result, 0, sizeof(o->result));
913e0e99 736 o->result.initialized = 1;
da165f47
JH
737 o->result.timestamp.sec = o->src_index->timestamp.sec;
738 o->result.timestamp.nsec = o->src_index->timestamp.nsec;
16da134b 739 o->merge_size = len;
da165f47 740 mark_all_ce_unused(o->src_index);
0fb1eaa8
JH
741
742 if (!dfc)
13494ed1 743 dfc = xcalloc(1, cache_entry_size(0));
0fb1eaa8 744 o->df_conflict_entry = dfc;
16da134b
JS
745
746 if (len) {
01904572
LT
747 const char *prefix = o->prefix ? o->prefix : "";
748 struct traverse_info info;
749
750 setup_traverse_info(&info, prefix);
751 info.fn = unpack_callback;
752 info.data = o;
753
da165f47
JH
754 if (o->prefix) {
755 /*
756 * Unpack existing index entries that sort before the
757 * prefix the tree is spliced into. Note that o->merge
758 * is always true in this case.
759 */
760 while (1) {
761 struct cache_entry *ce = next_cache_entry(o);
762 if (!ce)
763 break;
764 if (ce_in_traverse_path(ce, &info))
765 break;
766 if (unpack_index_entry(ce, o) < 0)
767 goto return_failed;
768 }
08aefc9e 769 }
da165f47 770
01904572 771 if (traverse_trees(len, t, &info) < 0)
da165f47 772 goto return_failed;
16da134b
JS
773 }
774
01904572
LT
775 /* Any left-over entries in the index? */
776 if (o->merge) {
da165f47
JH
777 while (1) {
778 struct cache_entry *ce = next_cache_entry(o);
779 if (!ce)
780 break;
01904572 781 if (unpack_index_entry(ce, o) < 0)
da165f47 782 goto return_failed;
17e46426 783 }
17e46426 784 }
da165f47 785 mark_all_ce_unused(o->src_index);
16da134b 786
08aefc9e
NTND
787 if (o->trivial_merges_only && o->nontrivial_merge) {
788 ret = unpack_failed(o, "Merge requires file-level merging");
789 goto done;
790 }
01904572 791
e800ec9d 792 if (!o->skip_sparse_checkout) {
9e1afb16 793 int empty_worktree = 1;
e800ec9d
NTND
794 for (i = 0;i < o->result.cache_nr;i++) {
795 struct cache_entry *ce = o->result.cache[i];
796
797 if (apply_sparse_checkout(ce, o)) {
798 ret = -1;
799 goto done;
800 }
f1f523ea
NTND
801 /*
802 * Merge strategies may set CE_UPDATE|CE_REMOVE outside checkout
803 * area as a result of ce_skip_worktree() shortcuts in
804 * verify_absent() and verify_uptodate(). Clear them.
805 */
806 if (ce_skip_worktree(ce))
807 ce->ce_flags &= ~(CE_UPDATE | CE_REMOVE);
9e1afb16
NTND
808 else
809 empty_worktree = 0;
f1f523ea 810
e800ec9d 811 }
9e1afb16
NTND
812 if (o->result.cache_nr && empty_worktree) {
813 ret = unpack_failed(o, "Sparse checkout leaves no entry on working directory");
814 goto done;
815 }
e800ec9d 816 }
01904572 817
34110cd4 818 o->src_index = NULL;
2e2b887d 819 ret = check_updates(o) ? (-2) : 0;
34110cd4
LT
820 if (o->dst_index)
821 *o->dst_index = o->result;
08aefc9e
NTND
822
823done:
824 for (i = 0;i < el.nr;i++)
825 free(el.excludes[i]);
826 if (el.excludes)
827 free(el.excludes);
828
2e2b887d 829 return ret;
da165f47
JH
830
831return_failed:
832 mark_all_ce_unused(o->src_index);
026680f8
JH
833 ret = unpack_failed(o, NULL);
834 goto done;
16da134b 835}
076b0adc
JS
836
837/* Here come the merge functions */
838
8ccba008 839static int reject_merge(struct cache_entry *ce, struct unpack_trees_options *o)
076b0adc 840{
8ccba008 841 return error(ERRORMSG(o, would_overwrite), ce->name);
076b0adc
JS
842}
843
844static int same(struct cache_entry *a, struct cache_entry *b)
845{
846 if (!!a != !!b)
847 return 0;
848 if (!a && !b)
849 return 1;
e11d7b59
JH
850 if ((a->ce_flags | b->ce_flags) & CE_CONFLICTED)
851 return 0;
076b0adc 852 return a->ce_mode == b->ce_mode &&
a89fccd2 853 !hashcmp(a->sha1, b->sha1);
076b0adc
JS
854}
855
856
857/*
858 * When a CE gets turned into an unmerged entry, we
859 * want it to be up-to-date
860 */
35a5aa79
NTND
861static int verify_uptodate_1(struct cache_entry *ce,
862 struct unpack_trees_options *o,
863 const char *error_msg)
076b0adc
JS
864{
865 struct stat st;
866
aecda37c 867 if (o->index_only || (!((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) && (o->reset || ce_uptodate(ce))))
203a2fe1 868 return 0;
076b0adc
JS
869
870 if (!lstat(ce->name, &st)) {
56cac48c 871 unsigned changed = ie_match_stat(o->src_index, ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
076b0adc 872 if (!changed)
203a2fe1 873 return 0;
936492d3
JH
874 /*
875 * NEEDSWORK: the current default policy is to allow
876 * submodule to be out of sync wrt the supermodule
877 * index. This needs to be tightened later for
878 * submodules that are marked to be automatically
879 * checked out.
880 */
7a51ed66 881 if (S_ISGITLINK(ce->ce_mode))
203a2fe1 882 return 0;
076b0adc
JS
883 errno = 0;
884 }
076b0adc 885 if (errno == ENOENT)
203a2fe1 886 return 0;
17e46426 887 return o->gently ? -1 :
35a5aa79
NTND
888 error(error_msg, ce->name);
889}
890
891static int verify_uptodate(struct cache_entry *ce,
892 struct unpack_trees_options *o)
893{
f1f523ea
NTND
894 if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
895 return 0;
35a5aa79 896 return verify_uptodate_1(ce, o, ERRORMSG(o, not_uptodate_file));
076b0adc
JS
897}
898
e800ec9d
NTND
899static int verify_uptodate_sparse(struct cache_entry *ce,
900 struct unpack_trees_options *o)
901{
902 return verify_uptodate_1(ce, o, ERRORMSG(o, sparse_not_uptodate_file));
076b0adc
JS
903}
904
bc052d7f 905static void invalidate_ce_path(struct cache_entry *ce, struct unpack_trees_options *o)
076b0adc
JS
906{
907 if (ce)
34110cd4 908 cache_tree_invalidate_path(o->src_index->cache_tree, ce->name);
076b0adc
JS
909}
910
0cf73755
SV
911/*
912 * Check that checking out ce->sha1 in subdir ce->name is not
913 * going to overwrite any working files.
914 *
915 * Currently, git does not checkout subprojects during a superproject
916 * checkout, so it is not going to overwrite anything.
917 */
918static int verify_clean_submodule(struct cache_entry *ce, const char *action,
919 struct unpack_trees_options *o)
920{
921 return 0;
922}
923
924static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
c8193534
JH
925 struct unpack_trees_options *o)
926{
927 /*
0cf73755 928 * we are about to extract "ce->name"; we would not want to lose
c8193534
JH
929 * anything in the existing directory there.
930 */
931 int namelen;
7b9e3ce0 932 int i;
c8193534
JH
933 struct dir_struct d;
934 char *pathbuf;
935 int cnt = 0;
0cf73755
SV
936 unsigned char sha1[20];
937
7a51ed66 938 if (S_ISGITLINK(ce->ce_mode) &&
0cf73755
SV
939 resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
940 /* If we are not going to update the submodule, then
941 * we don't care.
942 */
943 if (!hashcmp(sha1, ce->sha1))
944 return 0;
945 return verify_clean_submodule(ce, action, o);
946 }
c8193534
JH
947
948 /*
949 * First let's make sure we do not have a local modification
950 * in that directory.
951 */
0cf73755 952 namelen = strlen(ce->name);
da165f47
JH
953 for (i = locate_in_src_index(ce, o);
954 i < o->src_index->cache_nr;
955 i++) {
837e5fe9
CB
956 struct cache_entry *ce2 = o->src_index->cache[i];
957 int len = ce_namelen(ce2);
c8193534 958 if (len < namelen ||
837e5fe9
CB
959 strncmp(ce->name, ce2->name, namelen) ||
960 ce2->name[namelen] != '/')
c8193534
JH
961 break;
962 /*
da165f47
JH
963 * ce2->name is an entry in the subdirectory to be
964 * removed.
c8193534 965 */
837e5fe9
CB
966 if (!ce_stage(ce2)) {
967 if (verify_uptodate(ce2, o))
203a2fe1 968 return -1;
837e5fe9 969 add_entry(o, ce2, CE_REMOVE, 0);
da165f47 970 mark_ce_used(ce2, o);
c8193534
JH
971 }
972 cnt++;
973 }
974
975 /*
976 * Then we need to make sure that we do not lose a locally
977 * present file that is not ignored.
978 */
979 pathbuf = xmalloc(namelen + 2);
0cf73755 980 memcpy(pathbuf, ce->name, namelen);
c8193534
JH
981 strcpy(pathbuf+namelen, "/");
982
983 memset(&d, 0, sizeof(d));
984 if (o->dir)
985 d.exclude_per_dir = o->dir->exclude_per_dir;
dba2e203 986 i = read_directory(&d, pathbuf, namelen+1, NULL);
c8193534 987 if (i)
17e46426 988 return o->gently ? -1 :
8ccba008 989 error(ERRORMSG(o, not_uptodate_dir), ce->name);
c8193534
JH
990 free(pathbuf);
991 return cnt;
992}
993
32260ad5
LT
994/*
995 * This gets called when there was no index entry for the tree entry 'dst',
996 * but we found a file in the working tree that 'lstat()' said was fine,
997 * and we're on a case-insensitive filesystem.
998 *
999 * See if we can find a case-insensitive match in the index that also
1000 * matches the stat information, and assume it's that other file!
1001 */
1002static int icase_exists(struct unpack_trees_options *o, struct cache_entry *dst, struct stat *st)
1003{
1004 struct cache_entry *src;
1005
1006 src = index_name_exists(o->src_index, dst->name, ce_namelen(dst), 1);
56cac48c 1007 return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
32260ad5
LT
1008}
1009
076b0adc
JS
1010/*
1011 * We do not want to remove or overwrite a working tree file that
f8a9d428 1012 * is not tracked, unless it is ignored.
076b0adc 1013 */
35a5aa79
NTND
1014static int verify_absent_1(struct cache_entry *ce, const char *action,
1015 struct unpack_trees_options *o,
1016 const char *error_msg)
076b0adc
JS
1017{
1018 struct stat st;
1019
1020 if (o->index_only || o->reset || !o->update)
203a2fe1 1021 return 0;
c8193534 1022
57199892 1023 if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
203a2fe1 1024 return 0;
ec0603e1 1025
0cf73755 1026 if (!lstat(ce->name, &st)) {
6831a88a 1027 int dtype = ce_to_dtype(ce);
df292c79 1028 struct cache_entry *result;
c8193534 1029
32260ad5
LT
1030 /*
1031 * It may be that the 'lstat()' succeeded even though
1032 * target 'ce' was absent, because there is an old
1033 * entry that is different only in case..
1034 *
1035 * Ignore that lstat() if it matches.
1036 */
1037 if (ignore_case && icase_exists(o, ce, &st))
1038 return 0;
1039
6831a88a 1040 if (o->dir && excluded(o->dir, ce->name, &dtype))
c8193534 1041 /*
0cf73755 1042 * ce->name is explicitly excluded, so it is Ok to
c8193534
JH
1043 * overwrite it.
1044 */
203a2fe1 1045 return 0;
c8193534
JH
1046 if (S_ISDIR(st.st_mode)) {
1047 /*
1048 * We are checking out path "foo" and
1049 * found "foo/." in the working tree.
1050 * This is tricky -- if we have modified
1051 * files that are in "foo/" we would lose
6caa7b55 1052 * them.
c8193534 1053 */
da165f47
JH
1054 if (verify_clean_subdirectory(ce, action, o) < 0)
1055 return -1;
203a2fe1 1056 return 0;
c8193534
JH
1057 }
1058
1059 /*
1060 * The previous round may already have decided to
1061 * delete this path, which is in a subdirectory that
1062 * is being replaced with a blob.
1063 */
cd2fef59 1064 result = index_name_exists(&o->result, ce->name, ce_namelen(ce), 0);
df292c79
LT
1065 if (result) {
1066 if (result->ce_flags & CE_REMOVE)
203a2fe1 1067 return 0;
c8193534
JH
1068 }
1069
17e46426 1070 return o->gently ? -1 :
8ccba008 1071 error(ERRORMSG(o, would_lose_untracked), ce->name, action);
c8193534 1072 }
203a2fe1 1073 return 0;
076b0adc 1074}
35a5aa79
NTND
1075static int verify_absent(struct cache_entry *ce, const char *action,
1076 struct unpack_trees_options *o)
1077{
f1f523ea
NTND
1078 if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
1079 return 0;
35a5aa79
NTND
1080 return verify_absent_1(ce, action, o, ERRORMSG(o, would_lose_untracked));
1081}
076b0adc 1082
e800ec9d
NTND
1083static int verify_absent_sparse(struct cache_entry *ce, const char *action,
1084 struct unpack_trees_options *o)
1085{
1086 return verify_absent_1(ce, action, o, ERRORMSG(o, would_lose_orphaned));
1087}
076b0adc
JS
1088
1089static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
1090 struct unpack_trees_options *o)
1091{
7f8ab8dc
LT
1092 int update = CE_UPDATE;
1093
e11d7b59
JH
1094 if (!old) {
1095 if (verify_absent(merge, "overwritten", o))
1096 return -1;
1097 invalidate_ce_path(merge, o);
1098 } else if (!(old->ce_flags & CE_CONFLICTED)) {
076b0adc
JS
1099 /*
1100 * See if we can re-use the old CE directly?
1101 * That way we get the uptodate stat info.
1102 *
7f8ab8dc
LT
1103 * This also removes the UPDATE flag on a match; otherwise
1104 * we will end up overwriting local changes in the work tree.
076b0adc
JS
1105 */
1106 if (same(old, merge)) {
eb7a2f1d 1107 copy_cache_entry(merge, old);
7f8ab8dc 1108 update = 0;
076b0adc 1109 } else {
203a2fe1
DB
1110 if (verify_uptodate(old, o))
1111 return -1;
32f54ca3
NTND
1112 if (ce_skip_worktree(old))
1113 update |= CE_SKIP_WORKTREE;
bc052d7f 1114 invalidate_ce_path(old, o);
076b0adc 1115 }
e11d7b59
JH
1116 } else {
1117 /*
1118 * Previously unmerged entry left as an existence
1119 * marker by read_index_unmerged();
1120 */
1121 invalidate_ce_path(old, o);
076b0adc
JS
1122 }
1123
7f8ab8dc 1124 add_entry(o, merge, update, CE_STAGEMASK);
076b0adc
JS
1125 return 1;
1126}
1127
1128static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
1129 struct unpack_trees_options *o)
1130{
34110cd4
LT
1131 /* Did it exist in the index? */
1132 if (!old) {
203a2fe1
DB
1133 if (verify_absent(ce, "removed", o))
1134 return -1;
34110cd4
LT
1135 return 0;
1136 }
e11d7b59 1137 if (!(old->ce_flags & CE_CONFLICTED) && verify_uptodate(old, o))
34110cd4
LT
1138 return -1;
1139 add_entry(o, ce, CE_REMOVE, 0);
bc052d7f 1140 invalidate_ce_path(ce, o);
076b0adc
JS
1141 return 1;
1142}
1143
7f7932ab 1144static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o)
076b0adc 1145{
34110cd4 1146 add_entry(o, ce, 0, 0);
076b0adc
JS
1147 return 1;
1148}
1149
1150#if DBRT_DEBUG
1151static void show_stage_entry(FILE *o,
1152 const char *label, const struct cache_entry *ce)
1153{
1154 if (!ce)
1155 fprintf(o, "%s (missing)\n", label);
1156 else
1157 fprintf(o, "%s%06o %s %d\t%s\n",
1158 label,
7a51ed66 1159 ce->ce_mode,
076b0adc
JS
1160 sha1_to_hex(ce->sha1),
1161 ce_stage(ce),
1162 ce->name);
1163}
1164#endif
1165
34110cd4 1166int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o)
076b0adc
JS
1167{
1168 struct cache_entry *index;
1169 struct cache_entry *head;
1170 struct cache_entry *remote = stages[o->head_idx + 1];
1171 int count;
1172 int head_match = 0;
1173 int remote_match = 0;
076b0adc
JS
1174
1175 int df_conflict_head = 0;
1176 int df_conflict_remote = 0;
1177
1178 int any_anc_missing = 0;
1179 int no_anc_exists = 1;
1180 int i;
1181
1182 for (i = 1; i < o->head_idx; i++) {
4c4caafc 1183 if (!stages[i] || stages[i] == o->df_conflict_entry)
076b0adc 1184 any_anc_missing = 1;
4c4caafc 1185 else
076b0adc 1186 no_anc_exists = 0;
076b0adc
JS
1187 }
1188
1189 index = stages[0];
1190 head = stages[o->head_idx];
1191
1192 if (head == o->df_conflict_entry) {
1193 df_conflict_head = 1;
1194 head = NULL;
1195 }
1196
1197 if (remote == o->df_conflict_entry) {
1198 df_conflict_remote = 1;
1199 remote = NULL;
1200 }
1201
cee2d6ae
JH
1202 /*
1203 * First, if there's a #16 situation, note that to prevent #13
076b0adc
JS
1204 * and #14.
1205 */
1206 if (!same(remote, head)) {
1207 for (i = 1; i < o->head_idx; i++) {
1208 if (same(stages[i], head)) {
1209 head_match = i;
1210 }
1211 if (same(stages[i], remote)) {
1212 remote_match = i;
1213 }
1214 }
1215 }
1216
cee2d6ae
JH
1217 /*
1218 * We start with cases where the index is allowed to match
076b0adc
JS
1219 * something other than the head: #14(ALT) and #2ALT, where it
1220 * is permitted to match the result instead.
1221 */
1222 /* #14, #14ALT, #2ALT */
1223 if (remote && !df_conflict_head && head_match && !remote_match) {
1224 if (index && !same(index, remote) && !same(index, head))
8ccba008 1225 return o->gently ? -1 : reject_merge(index, o);
076b0adc
JS
1226 return merged_entry(remote, index, o);
1227 }
1228 /*
1229 * If we have an entry in the index cache, then we want to
1230 * make sure that it matches head.
1231 */
4e7c4571 1232 if (index && !same(index, head))
8ccba008 1233 return o->gently ? -1 : reject_merge(index, o);
076b0adc
JS
1234
1235 if (head) {
1236 /* #5ALT, #15 */
1237 if (same(head, remote))
1238 return merged_entry(head, index, o);
1239 /* #13, #3ALT */
1240 if (!df_conflict_remote && remote_match && !head_match)
1241 return merged_entry(head, index, o);
1242 }
1243
1244 /* #1 */
34110cd4 1245 if (!head && !remote && any_anc_missing)
076b0adc
JS
1246 return 0;
1247
cee2d6ae
JH
1248 /*
1249 * Under the "aggressive" rule, we resolve mostly trivial
076b0adc
JS
1250 * cases that we historically had git-merge-one-file resolve.
1251 */
1252 if (o->aggressive) {
cee2d6ae
JH
1253 int head_deleted = !head;
1254 int remote_deleted = !remote;
0cf73755 1255 struct cache_entry *ce = NULL;
4c4caafc
JH
1256
1257 if (index)
0cf73755 1258 ce = index;
4c4caafc 1259 else if (head)
0cf73755 1260 ce = head;
4c4caafc 1261 else if (remote)
0cf73755 1262 ce = remote;
4c4caafc
JH
1263 else {
1264 for (i = 1; i < o->head_idx; i++) {
1265 if (stages[i] && stages[i] != o->df_conflict_entry) {
0cf73755 1266 ce = stages[i];
4c4caafc
JH
1267 break;
1268 }
1269 }
1270 }
1271
076b0adc
JS
1272 /*
1273 * Deleted in both.
1274 * Deleted in one and unchanged in the other.
1275 */
1276 if ((head_deleted && remote_deleted) ||
1277 (head_deleted && remote && remote_match) ||
1278 (remote_deleted && head && head_match)) {
1279 if (index)
1280 return deleted_entry(index, index, o);
34110cd4 1281 if (ce && !head_deleted) {
203a2fe1
DB
1282 if (verify_absent(ce, "removed", o))
1283 return -1;
1284 }
076b0adc
JS
1285 return 0;
1286 }
1287 /*
1288 * Added in both, identically.
1289 */
1290 if (no_anc_exists && head && remote && same(head, remote))
1291 return merged_entry(head, index, o);
1292
1293 }
1294
1295 /* Below are "no merge" cases, which require that the index be
1296 * up-to-date to avoid the files getting overwritten with
1297 * conflict resolution files.
1298 */
1299 if (index) {
203a2fe1
DB
1300 if (verify_uptodate(index, o))
1301 return -1;
076b0adc 1302 }
076b0adc
JS
1303
1304 o->nontrivial_merge = 1;
1305
ea4b52a8 1306 /* #2, #3, #4, #6, #7, #9, #10, #11. */
076b0adc
JS
1307 count = 0;
1308 if (!head_match || !remote_match) {
1309 for (i = 1; i < o->head_idx; i++) {
4c4caafc 1310 if (stages[i] && stages[i] != o->df_conflict_entry) {
7f7932ab 1311 keep_entry(stages[i], o);
076b0adc
JS
1312 count++;
1313 break;
1314 }
1315 }
1316 }
1317#if DBRT_DEBUG
1318 else {
1319 fprintf(stderr, "read-tree: warning #16 detected\n");
1320 show_stage_entry(stderr, "head ", stages[head_match]);
1321 show_stage_entry(stderr, "remote ", stages[remote_match]);
1322 }
1323#endif
7f7932ab
JH
1324 if (head) { count += keep_entry(head, o); }
1325 if (remote) { count += keep_entry(remote, o); }
076b0adc
JS
1326 return count;
1327}
1328
1329/*
1330 * Two-way merge.
1331 *
1332 * The rule is to "carry forward" what is in the index without losing
a75d7b54 1333 * information across a "fast-forward", favoring a successful merge
076b0adc
JS
1334 * over a merge failure when it makes sense. For details of the
1335 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
1336 *
1337 */
34110cd4 1338int twoway_merge(struct cache_entry **src, struct unpack_trees_options *o)
076b0adc
JS
1339{
1340 struct cache_entry *current = src[0];
b8ba1535
JH
1341 struct cache_entry *oldtree = src[1];
1342 struct cache_entry *newtree = src[2];
076b0adc
JS
1343
1344 if (o->merge_size != 2)
1345 return error("Cannot do a twoway merge of %d trees",
1346 o->merge_size);
1347
b8ba1535
JH
1348 if (oldtree == o->df_conflict_entry)
1349 oldtree = NULL;
1350 if (newtree == o->df_conflict_entry)
1351 newtree = NULL;
1352
076b0adc
JS
1353 if (current) {
1354 if ((!oldtree && !newtree) || /* 4 and 5 */
1355 (!oldtree && newtree &&
1356 same(current, newtree)) || /* 6 and 7 */
1357 (oldtree && newtree &&
1358 same(oldtree, newtree)) || /* 14 and 15 */
1359 (oldtree && newtree &&
b8ba1535 1360 !same(oldtree, newtree) && /* 18 and 19 */
076b0adc 1361 same(current, newtree))) {
7f7932ab 1362 return keep_entry(current, o);
076b0adc
JS
1363 }
1364 else if (oldtree && !newtree && same(current, oldtree)) {
1365 /* 10 or 11 */
1366 return deleted_entry(oldtree, current, o);
1367 }
1368 else if (oldtree && newtree &&
1369 same(current, oldtree) && !same(current, newtree)) {
1370 /* 20 or 21 */
1371 return merged_entry(newtree, current, o);
1372 }
1373 else {
1374 /* all other failures */
1375 if (oldtree)
8ccba008 1376 return o->gently ? -1 : reject_merge(oldtree, o);
076b0adc 1377 if (current)
8ccba008 1378 return o->gently ? -1 : reject_merge(current, o);
076b0adc 1379 if (newtree)
8ccba008 1380 return o->gently ? -1 : reject_merge(newtree, o);
076b0adc
JS
1381 return -1;
1382 }
1383 }
55218834
JH
1384 else if (newtree) {
1385 if (oldtree && !o->initial_checkout) {
1386 /*
1387 * deletion of the path was staged;
1388 */
1389 if (same(oldtree, newtree))
1390 return 1;
1391 return reject_merge(oldtree, o);
1392 }
076b0adc 1393 return merged_entry(newtree, current, o);
55218834 1394 }
d699676d 1395 return deleted_entry(oldtree, current, o);
076b0adc
JS
1396}
1397
1398/*
1399 * Bind merge.
1400 *
1401 * Keep the index entries at stage0, collapse stage1 but make sure
1402 * stage0 does not have anything there.
1403 */
1404int bind_merge(struct cache_entry **src,
34110cd4 1405 struct unpack_trees_options *o)
076b0adc
JS
1406{
1407 struct cache_entry *old = src[0];
1408 struct cache_entry *a = src[1];
1409
1410 if (o->merge_size != 1)
1411 return error("Cannot do a bind merge of %d trees\n",
1412 o->merge_size);
1413 if (a && old)
17e46426 1414 return o->gently ? -1 :
8ccba008 1415 error(ERRORMSG(o, bind_overlap), a->name, old->name);
076b0adc 1416 if (!a)
7f7932ab 1417 return keep_entry(old, o);
076b0adc
JS
1418 else
1419 return merged_entry(a, NULL, o);
1420}
1421
1422/*
1423 * One-way merge.
1424 *
1425 * The rule is:
1426 * - take the stat information from stage0, take the data from stage1
1427 */
34110cd4 1428int oneway_merge(struct cache_entry **src, struct unpack_trees_options *o)
076b0adc
JS
1429{
1430 struct cache_entry *old = src[0];
1431 struct cache_entry *a = src[1];
1432
1433 if (o->merge_size != 1)
1434 return error("Cannot do a oneway merge of %d trees",
1435 o->merge_size);
1436
78d3b06e 1437 if (!a || a == o->df_conflict_entry)
076b0adc 1438 return deleted_entry(old, old, o);
34110cd4 1439
076b0adc 1440 if (old && same(old, a)) {
34110cd4 1441 int update = 0;
52030836 1442 if (o->reset && !ce_uptodate(old) && !ce_skip_worktree(old)) {
076b0adc
JS
1443 struct stat st;
1444 if (lstat(old->name, &st) ||
56cac48c 1445 ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE))
34110cd4 1446 update |= CE_UPDATE;
076b0adc 1447 }
34110cd4
LT
1448 add_entry(o, old, update, 0);
1449 return 0;
076b0adc
JS
1450 }
1451 return merged_entry(a, old, o);
1452}