Change C99 comments to old-style C comments
[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 /*
167 * We only care about files getting into the checkout area
168 * If merge strategies want to remove some, go ahead, this
169 * flag will be removed eventually in unpack_trees() if it's
170 * outside checkout area.
171 */
172 if (ce->ce_flags & CE_REMOVE)
173 return 0;
174
175 if (!was_skip_worktree && ce_skip_worktree(ce)) {
176 /*
177 * If CE_UPDATE is set, verify_uptodate() must be called already
178 * also stat info may have lost after merged_entry() so calling
179 * verify_uptodate() again may fail
180 */
181 if (!(ce->ce_flags & CE_UPDATE) && verify_uptodate_sparse(ce, o))
182 return -1;
183 ce->ce_flags |= CE_WT_REMOVE;
184 }
185 if (was_skip_worktree && !ce_skip_worktree(ce)) {
186 if (verify_absent_sparse(ce, "overwritten", o))
187 return -1;
188 ce->ce_flags |= CE_UPDATE;
189 }
190 return 0;
191}
192
34110cd4 193static inline int call_unpack_fn(struct cache_entry **src, struct unpack_trees_options *o)
01904572 194{
34110cd4
LT
195 int ret = o->fn(src, o);
196 if (ret > 0)
01904572 197 ret = 0;
01904572
LT
198 return ret;
199}
200
da165f47
JH
201static void mark_ce_used(struct cache_entry *ce, struct unpack_trees_options *o)
202{
203 ce->ce_flags |= CE_UNPACKED;
204
205 if (o->cache_bottom < o->src_index->cache_nr &&
206 o->src_index->cache[o->cache_bottom] == ce) {
207 int bottom = o->cache_bottom;
208 while (bottom < o->src_index->cache_nr &&
209 o->src_index->cache[bottom]->ce_flags & CE_UNPACKED)
210 bottom++;
211 o->cache_bottom = bottom;
212 }
213}
214
215static void mark_all_ce_unused(struct index_state *index)
216{
217 int i;
218 for (i = 0; i < index->cache_nr; i++)
219 index->cache[i]->ce_flags &= ~CE_UNPACKED;
220}
221
222static int locate_in_src_index(struct cache_entry *ce,
223 struct unpack_trees_options *o)
224{
225 struct index_state *index = o->src_index;
226 int len = ce_namelen(ce);
227 int pos = index_name_pos(index, ce->name, len);
228 if (pos < 0)
229 pos = -1 - pos;
230 return pos;
231}
232
233/*
234 * We call unpack_index_entry() with an unmerged cache entry
235 * only in diff-index, and it wants a single callback. Skip
236 * the other unmerged entry with the same name.
237 */
238static void mark_ce_used_same_name(struct cache_entry *ce,
239 struct unpack_trees_options *o)
240{
241 struct index_state *index = o->src_index;
242 int len = ce_namelen(ce);
243 int pos;
244
245 for (pos = locate_in_src_index(ce, o); pos < index->cache_nr; pos++) {
246 struct cache_entry *next = index->cache[pos];
247 if (len != ce_namelen(next) ||
248 memcmp(ce->name, next->name, len))
249 break;
250 mark_ce_used(next, o);
251 }
252}
253
254static struct cache_entry *next_cache_entry(struct unpack_trees_options *o)
255{
256 const struct index_state *index = o->src_index;
257 int pos = o->cache_bottom;
258
259 while (pos < index->cache_nr) {
260 struct cache_entry *ce = index->cache[pos];
261 if (!(ce->ce_flags & CE_UNPACKED))
262 return ce;
263 pos++;
264 }
265 return NULL;
266}
267
268static void add_same_unmerged(struct cache_entry *ce,
269 struct unpack_trees_options *o)
270{
271 struct index_state *index = o->src_index;
272 int len = ce_namelen(ce);
273 int pos = index_name_pos(index, ce->name, len);
274
275 if (0 <= pos)
276 die("programming error in a caller of mark_ce_used_same_name");
277 for (pos = -pos - 1; pos < index->cache_nr; pos++) {
278 struct cache_entry *next = index->cache[pos];
279 if (len != ce_namelen(next) ||
280 memcmp(ce->name, next->name, len))
281 break;
282 add_entry(o, next, 0, 0);
283 mark_ce_used(next, o);
284 }
285}
286
287static int unpack_index_entry(struct cache_entry *ce,
288 struct unpack_trees_options *o)
01904572 289{
0039ba7e 290 struct cache_entry *src[5] = { ce, NULL, };
da165f47 291 int ret;
34110cd4 292
da165f47 293 mark_ce_used(ce, o);
01904572
LT
294 if (ce_stage(ce)) {
295 if (o->skip_unmerged) {
34110cd4
LT
296 add_entry(o, ce, 0, 0);
297 return 0;
01904572 298 }
01904572 299 }
da165f47
JH
300 ret = call_unpack_fn(src, o);
301 if (ce_stage(ce))
302 mark_ce_used_same_name(ce, o);
303 return ret;
01904572
LT
304}
305
730f7284
JH
306static int find_cache_pos(struct traverse_info *, const struct name_entry *);
307
308static void restore_cache_bottom(struct traverse_info *info, int bottom)
309{
310 struct unpack_trees_options *o = info->data;
311
312 if (o->diff_index_cached)
313 return;
314 o->cache_bottom = bottom;
315}
316
317static int switch_cache_bottom(struct traverse_info *info)
318{
319 struct unpack_trees_options *o = info->data;
320 int ret, pos;
321
322 if (o->diff_index_cached)
323 return 0;
324 ret = o->cache_bottom;
325 pos = find_cache_pos(info->prev, &info->name);
326
327 if (pos < -1)
328 o->cache_bottom = -2 - pos;
329 else if (pos < 0)
330 o->cache_bottom = o->src_index->cache_nr;
331 return ret;
01904572
LT
332}
333
2af202be 334static int traverse_trees_recursive(int n, unsigned long dirmask, unsigned long df_conflicts, struct name_entry *names, struct traverse_info *info)
16da134b 335{
730f7284 336 int i, ret, bottom;
ca885a4f 337 struct tree_desc t[MAX_UNPACK_TREES];
01904572
LT
338 struct traverse_info newinfo;
339 struct name_entry *p;
340
341 p = names;
342 while (!p->mode)
343 p++;
344
345 newinfo = *info;
346 newinfo.prev = info;
347 newinfo.name = *p;
348 newinfo.pathlen += tree_entry_len(p->path, p->sha1) + 1;
349 newinfo.conflicts |= df_conflicts;
350
351 for (i = 0; i < n; i++, dirmask >>= 1) {
352 const unsigned char *sha1 = NULL;
353 if (dirmask & 1)
354 sha1 = names[i].sha1;
355 fill_tree_descriptor(t+i, sha1);
356 }
730f7284
JH
357
358 bottom = switch_cache_bottom(&newinfo);
359 ret = traverse_trees(n, t, &newinfo);
360 restore_cache_bottom(&newinfo, bottom);
361 return ret;
01904572
LT
362}
363
364/*
365 * Compare the traverse-path to the cache entry without actually
366 * having to generate the textual representation of the traverse
367 * path.
368 *
369 * NOTE! This *only* compares up to the size of the traverse path
370 * itself - the caller needs to do the final check for the cache
371 * entry having more data at the end!
372 */
373static int do_compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
374{
375 int len, pathlen, ce_len;
376 const char *ce_name;
377
378 if (info->prev) {
379 int cmp = do_compare_entry(ce, info->prev, &info->name);
380 if (cmp)
381 return cmp;
382 }
383 pathlen = info->pathlen;
384 ce_len = ce_namelen(ce);
385
386 /* If ce_len < pathlen then we must have previously hit "name == directory" entry */
387 if (ce_len < pathlen)
388 return -1;
389
390 ce_len -= pathlen;
391 ce_name = ce->name + pathlen;
392
393 len = tree_entry_len(n->path, n->sha1);
394 return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode);
395}
396
397static int compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
398{
399 int cmp = do_compare_entry(ce, info, n);
400 if (cmp)
401 return cmp;
402
403 /*
404 * Even if the beginning compared identically, the ce should
405 * compare as bigger than a directory leading up to it!
406 */
407 return ce_namelen(ce) > traverse_path_len(info, n);
408}
409
da165f47
JH
410static int ce_in_traverse_path(const struct cache_entry *ce,
411 const struct traverse_info *info)
412{
413 if (!info->prev)
414 return 1;
415 if (do_compare_entry(ce, info->prev, &info->name))
416 return 0;
417 /*
418 * If ce (blob) is the same name as the path (which is a tree
419 * we will be descending into), it won't be inside it.
420 */
421 return (info->pathlen < ce_namelen(ce));
422}
423
01904572
LT
424static struct cache_entry *create_ce_entry(const struct traverse_info *info, const struct name_entry *n, int stage)
425{
426 int len = traverse_path_len(info, n);
427 struct cache_entry *ce = xcalloc(1, cache_entry_size(len));
428
429 ce->ce_mode = create_ce_mode(n->mode);
430 ce->ce_flags = create_ce_flags(len, stage);
431 hashcpy(ce->sha1, n->sha1);
432 make_traverse_path(ce->name, info, n);
433
434 return ce;
435}
436
c7cddc1a
RS
437static int unpack_nondirectories(int n, unsigned long mask,
438 unsigned long dirmask,
439 struct cache_entry **src,
440 const struct name_entry *names,
441 const struct traverse_info *info)
01904572
LT
442{
443 int i;
444 struct unpack_trees_options *o = info->data;
445 unsigned long conflicts;
446
447 /* Do we have *only* directories? Nothing to do */
448 if (mask == dirmask && !src[0])
449 return 0;
450
451 conflicts = info->conflicts;
452 if (o->merge)
453 conflicts >>= 1;
454 conflicts |= dirmask;
455
456 /*
457 * Ok, we've filled in up to any potential index entry in src[0],
458 * now do the rest.
459 */
460 for (i = 0; i < n; i++) {
461 int stage;
462 unsigned int bit = 1ul << i;
463 if (conflicts & bit) {
464 src[i + o->merge] = o->df_conflict_entry;
465 continue;
466 }
467 if (!(mask & bit))
468 continue;
469 if (!o->merge)
470 stage = 0;
471 else if (i + 1 < o->head_idx)
472 stage = 1;
473 else if (i + 1 > o->head_idx)
474 stage = 3;
475 else
476 stage = 2;
477 src[i + o->merge] = create_ce_entry(info, names + i, stage);
478 }
479
480 if (o->merge)
34110cd4 481 return call_unpack_fn(src, o);
01904572 482
01904572 483 for (i = 0; i < n; i++)
aab3b9a1
JH
484 if (src[i] && src[i] != o->df_conflict_entry)
485 add_entry(o, src[i], 0, 0);
01904572
LT
486 return 0;
487}
488
353c5eeb
JH
489static int unpack_failed(struct unpack_trees_options *o, const char *message)
490{
491 discard_index(&o->result);
492 if (!o->gently) {
493 if (message)
494 return error("%s", message);
495 return -1;
496 }
497 return -1;
498}
499
730f7284
JH
500/* NEEDSWORK: give this a better name and share with tree-walk.c */
501static int name_compare(const char *a, int a_len,
502 const char *b, int b_len)
503{
504 int len = (a_len < b_len) ? a_len : b_len;
505 int cmp = memcmp(a, b, len);
506 if (cmp)
507 return cmp;
508 return (a_len - b_len);
509}
510
511/*
512 * The tree traversal is looking at name p. If we have a matching entry,
513 * return it. If name p is a directory in the index, do not return
514 * anything, as we will want to match it when the traversal descends into
515 * the directory.
516 */
517static int find_cache_pos(struct traverse_info *info,
518 const struct name_entry *p)
519{
520 int pos;
521 struct unpack_trees_options *o = info->data;
522 struct index_state *index = o->src_index;
523 int pfxlen = info->pathlen;
524 int p_len = tree_entry_len(p->path, p->sha1);
525
526 for (pos = o->cache_bottom; pos < index->cache_nr; pos++) {
527 struct cache_entry *ce = index->cache[pos];
528 const char *ce_name, *ce_slash;
529 int cmp, ce_len;
530
531 if (!ce_in_traverse_path(ce, info))
532 continue;
533 if (ce->ce_flags & CE_UNPACKED)
534 continue;
535 ce_name = ce->name + pfxlen;
536 ce_slash = strchr(ce_name, '/');
537 if (ce_slash)
538 ce_len = ce_slash - ce_name;
539 else
540 ce_len = ce_namelen(ce) - pfxlen;
541 cmp = name_compare(p->path, p_len, ce_name, ce_len);
542 /*
543 * Exact match; if we have a directory we need to
544 * delay returning it.
545 */
546 if (!cmp)
547 return ce_slash ? -2 - pos : pos;
548 if (0 < cmp)
549 continue; /* keep looking */
550 /*
551 * ce_name sorts after p->path; could it be that we
552 * have files under p->path directory in the index?
553 * E.g. ce_name == "t-i", and p->path == "t"; we may
554 * have "t/a" in the index.
555 */
556 if (p_len < ce_len && !memcmp(ce_name, p->path, p_len) &&
557 ce_name[p_len] < '/')
558 continue; /* keep looking */
559 break;
560 }
561 return -1;
562}
563
564static struct cache_entry *find_cache_entry(struct traverse_info *info,
565 const struct name_entry *p)
566{
567 int pos = find_cache_pos(info, p);
568 struct unpack_trees_options *o = info->data;
569
570 if (0 <= pos)
571 return o->src_index->cache[pos];
572 else
573 return NULL;
574}
575
ba655da5
JH
576static void debug_path(struct traverse_info *info)
577{
578 if (info->prev) {
579 debug_path(info->prev);
580 if (*info->prev->name.path)
581 putchar('/');
582 }
583 printf("%s", info->name.path);
584}
585
586static void debug_name_entry(int i, struct name_entry *n)
587{
588 printf("ent#%d %06o %s\n", i,
589 n->path ? n->mode : 0,
590 n->path ? n->path : "(missing)");
591}
592
593static void debug_unpack_callback(int n,
594 unsigned long mask,
595 unsigned long dirmask,
596 struct name_entry *names,
597 struct traverse_info *info)
598{
599 int i;
600 printf("* unpack mask %lu, dirmask %lu, cnt %d ",
601 mask, dirmask, n);
602 debug_path(info);
603 putchar('\n');
604 for (i = 0; i < n; i++)
605 debug_name_entry(i, names + i);
606}
607
01904572
LT
608static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *names, struct traverse_info *info)
609{
c7cddc1a 610 struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
01904572 611 struct unpack_trees_options *o = info->data;
01904572
LT
612 const struct name_entry *p = names;
613
614 /* Find first entry with a real name (we could use "mask" too) */
615 while (!p->mode)
616 p++;
617
ba655da5
JH
618 if (o->debug_unpack)
619 debug_unpack_callback(n, mask, dirmask, names, info);
620
01904572
LT
621 /* Are we supposed to look at the index too? */
622 if (o->merge) {
da165f47 623 while (1) {
da165f47 624 int cmp;
730f7284
JH
625 struct cache_entry *ce;
626
627 if (o->diff_index_cached)
628 ce = next_cache_entry(o);
629 else
630 ce = find_cache_entry(info, p);
631
da165f47
JH
632 if (!ce)
633 break;
634 cmp = compare_entry(ce, info, p);
01904572
LT
635 if (cmp < 0) {
636 if (unpack_index_entry(ce, o) < 0)
353c5eeb 637 return unpack_failed(o, NULL);
01904572
LT
638 continue;
639 }
640 if (!cmp) {
641 if (ce_stage(ce)) {
642 /*
da165f47
JH
643 * If we skip unmerged index
644 * entries, we'll skip this
645 * entry *and* the tree
646 * entries associated with it!
01904572 647 */
34110cd4 648 if (o->skip_unmerged) {
da165f47 649 add_same_unmerged(ce, o);
01904572 650 return mask;
34110cd4 651 }
01904572
LT
652 }
653 src[0] = ce;
01904572
LT
654 }
655 break;
656 }
657 }
658
34110cd4 659 if (unpack_nondirectories(n, mask, dirmask, src, names, info) < 0)
01904572
LT
660 return -1;
661
da165f47
JH
662 if (src[0]) {
663 if (ce_stage(src[0]))
664 mark_ce_used_same_name(src[0], o);
665 else
666 mark_ce_used(src[0], o);
667 }
668
01904572
LT
669 /* Now handle any directories.. */
670 if (dirmask) {
671 unsigned long conflicts = mask & ~dirmask;
672 if (o->merge) {
673 conflicts <<= 1;
674 if (src[0])
675 conflicts |= 1;
676 }
b65982b6
JH
677
678 /* special case: "diff-index --cached" looking at a tree */
679 if (o->diff_index_cached &&
680 n == 1 && dirmask == 1 && S_ISDIR(names->mode)) {
681 int matches;
682 matches = cache_tree_matches_traversal(o->src_index->cache_tree,
683 names, info);
684 /*
da165f47
JH
685 * Everything under the name matches; skip the
686 * entire hierarchy. diff_index_cached codepath
687 * special cases D/F conflicts in such a way that
688 * it does not do any look-ahead, so this is safe.
b65982b6
JH
689 */
690 if (matches) {
da165f47 691 o->cache_bottom += matches;
b65982b6
JH
692 return mask;
693 }
694 }
695
542c264b
JH
696 if (traverse_trees_recursive(n, dirmask, conflicts,
697 names, info) < 0)
698 return -1;
01904572
LT
699 return mask;
700 }
701
702 return mask;
703}
704
2e2b887d
JH
705/*
706 * N-way merge "len" trees. Returns 0 on success, -1 on failure to manipulate the
707 * resulting index, -2 on failure to reflect the changes to the work tree.
708 */
01904572
LT
709int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
710{
e800ec9d 711 int i, ret;
0fb1eaa8 712 static struct cache_entry *dfc;
08aefc9e 713 struct exclude_list el;
16da134b 714
ca885a4f
JH
715 if (len > MAX_UNPACK_TREES)
716 die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
076b0adc 717 memset(&state, 0, sizeof(state));
16da134b
JS
718 state.base_dir = "";
719 state.force = 1;
720 state.quiet = 1;
721 state.refresh_cache = 1;
722
08aefc9e
NTND
723 memset(&el, 0, sizeof(el));
724 if (!core_apply_sparse_checkout || !o->update)
725 o->skip_sparse_checkout = 1;
726 if (!o->skip_sparse_checkout) {
727 if (add_excludes_from_file_to_list(git_path("info/sparse-checkout"), "", 0, NULL, &el, 0) < 0)
728 o->skip_sparse_checkout = 1;
729 else
730 o->el = &el;
731 }
732
34110cd4 733 memset(&o->result, 0, sizeof(o->result));
913e0e99 734 o->result.initialized = 1;
da165f47
JH
735 o->result.timestamp.sec = o->src_index->timestamp.sec;
736 o->result.timestamp.nsec = o->src_index->timestamp.nsec;
16da134b 737 o->merge_size = len;
da165f47 738 mark_all_ce_unused(o->src_index);
0fb1eaa8
JH
739
740 if (!dfc)
13494ed1 741 dfc = xcalloc(1, cache_entry_size(0));
0fb1eaa8 742 o->df_conflict_entry = dfc;
16da134b
JS
743
744 if (len) {
01904572
LT
745 const char *prefix = o->prefix ? o->prefix : "";
746 struct traverse_info info;
747
748 setup_traverse_info(&info, prefix);
749 info.fn = unpack_callback;
750 info.data = o;
751
da165f47
JH
752 if (o->prefix) {
753 /*
754 * Unpack existing index entries that sort before the
755 * prefix the tree is spliced into. Note that o->merge
756 * is always true in this case.
757 */
758 while (1) {
759 struct cache_entry *ce = next_cache_entry(o);
760 if (!ce)
761 break;
762 if (ce_in_traverse_path(ce, &info))
763 break;
764 if (unpack_index_entry(ce, o) < 0)
765 goto return_failed;
766 }
08aefc9e 767 }
da165f47 768
01904572 769 if (traverse_trees(len, t, &info) < 0)
da165f47 770 goto return_failed;
16da134b
JS
771 }
772
01904572
LT
773 /* Any left-over entries in the index? */
774 if (o->merge) {
da165f47
JH
775 while (1) {
776 struct cache_entry *ce = next_cache_entry(o);
777 if (!ce)
778 break;
01904572 779 if (unpack_index_entry(ce, o) < 0)
da165f47 780 goto return_failed;
17e46426 781 }
17e46426 782 }
da165f47 783 mark_all_ce_unused(o->src_index);
16da134b 784
08aefc9e
NTND
785 if (o->trivial_merges_only && o->nontrivial_merge) {
786 ret = unpack_failed(o, "Merge requires file-level merging");
787 goto done;
788 }
01904572 789
e800ec9d 790 if (!o->skip_sparse_checkout) {
9e1afb16 791 int empty_worktree = 1;
e800ec9d
NTND
792 for (i = 0;i < o->result.cache_nr;i++) {
793 struct cache_entry *ce = o->result.cache[i];
794
795 if (apply_sparse_checkout(ce, o)) {
796 ret = -1;
797 goto done;
798 }
f1f523ea
NTND
799 /*
800 * Merge strategies may set CE_UPDATE|CE_REMOVE outside checkout
801 * area as a result of ce_skip_worktree() shortcuts in
802 * verify_absent() and verify_uptodate(). Clear them.
803 */
804 if (ce_skip_worktree(ce))
805 ce->ce_flags &= ~(CE_UPDATE | CE_REMOVE);
9e1afb16
NTND
806 else
807 empty_worktree = 0;
f1f523ea 808
e800ec9d 809 }
9e1afb16
NTND
810 if (o->result.cache_nr && empty_worktree) {
811 ret = unpack_failed(o, "Sparse checkout leaves no entry on working directory");
812 goto done;
813 }
e800ec9d 814 }
01904572 815
34110cd4 816 o->src_index = NULL;
2e2b887d 817 ret = check_updates(o) ? (-2) : 0;
34110cd4
LT
818 if (o->dst_index)
819 *o->dst_index = o->result;
08aefc9e
NTND
820
821done:
822 for (i = 0;i < el.nr;i++)
823 free(el.excludes[i]);
824 if (el.excludes)
825 free(el.excludes);
826
2e2b887d 827 return ret;
da165f47
JH
828
829return_failed:
830 mark_all_ce_unused(o->src_index);
026680f8
JH
831 ret = unpack_failed(o, NULL);
832 goto done;
16da134b 833}
076b0adc
JS
834
835/* Here come the merge functions */
836
8ccba008 837static int reject_merge(struct cache_entry *ce, struct unpack_trees_options *o)
076b0adc 838{
8ccba008 839 return error(ERRORMSG(o, would_overwrite), ce->name);
076b0adc
JS
840}
841
842static int same(struct cache_entry *a, struct cache_entry *b)
843{
844 if (!!a != !!b)
845 return 0;
846 if (!a && !b)
847 return 1;
e11d7b59
JH
848 if ((a->ce_flags | b->ce_flags) & CE_CONFLICTED)
849 return 0;
076b0adc 850 return a->ce_mode == b->ce_mode &&
a89fccd2 851 !hashcmp(a->sha1, b->sha1);
076b0adc
JS
852}
853
854
855/*
856 * When a CE gets turned into an unmerged entry, we
857 * want it to be up-to-date
858 */
35a5aa79
NTND
859static int verify_uptodate_1(struct cache_entry *ce,
860 struct unpack_trees_options *o,
861 const char *error_msg)
076b0adc
JS
862{
863 struct stat st;
864
52030836 865 if (o->index_only || (!ce_skip_worktree(ce) && (o->reset || ce_uptodate(ce))))
203a2fe1 866 return 0;
076b0adc
JS
867
868 if (!lstat(ce->name, &st)) {
56cac48c 869 unsigned changed = ie_match_stat(o->src_index, ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
076b0adc 870 if (!changed)
203a2fe1 871 return 0;
936492d3
JH
872 /*
873 * NEEDSWORK: the current default policy is to allow
874 * submodule to be out of sync wrt the supermodule
875 * index. This needs to be tightened later for
876 * submodules that are marked to be automatically
877 * checked out.
878 */
7a51ed66 879 if (S_ISGITLINK(ce->ce_mode))
203a2fe1 880 return 0;
076b0adc
JS
881 errno = 0;
882 }
076b0adc 883 if (errno == ENOENT)
203a2fe1 884 return 0;
17e46426 885 return o->gently ? -1 :
35a5aa79
NTND
886 error(error_msg, ce->name);
887}
888
889static int verify_uptodate(struct cache_entry *ce,
890 struct unpack_trees_options *o)
891{
f1f523ea
NTND
892 if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
893 return 0;
35a5aa79 894 return verify_uptodate_1(ce, o, ERRORMSG(o, not_uptodate_file));
076b0adc
JS
895}
896
e800ec9d
NTND
897static int verify_uptodate_sparse(struct cache_entry *ce,
898 struct unpack_trees_options *o)
899{
900 return verify_uptodate_1(ce, o, ERRORMSG(o, sparse_not_uptodate_file));
076b0adc
JS
901}
902
bc052d7f 903static void invalidate_ce_path(struct cache_entry *ce, struct unpack_trees_options *o)
076b0adc
JS
904{
905 if (ce)
34110cd4 906 cache_tree_invalidate_path(o->src_index->cache_tree, ce->name);
076b0adc
JS
907}
908
0cf73755
SV
909/*
910 * Check that checking out ce->sha1 in subdir ce->name is not
911 * going to overwrite any working files.
912 *
913 * Currently, git does not checkout subprojects during a superproject
914 * checkout, so it is not going to overwrite anything.
915 */
916static int verify_clean_submodule(struct cache_entry *ce, const char *action,
917 struct unpack_trees_options *o)
918{
919 return 0;
920}
921
922static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
c8193534
JH
923 struct unpack_trees_options *o)
924{
925 /*
0cf73755 926 * we are about to extract "ce->name"; we would not want to lose
c8193534
JH
927 * anything in the existing directory there.
928 */
929 int namelen;
7b9e3ce0 930 int i;
c8193534
JH
931 struct dir_struct d;
932 char *pathbuf;
933 int cnt = 0;
0cf73755
SV
934 unsigned char sha1[20];
935
7a51ed66 936 if (S_ISGITLINK(ce->ce_mode) &&
0cf73755
SV
937 resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
938 /* If we are not going to update the submodule, then
939 * we don't care.
940 */
941 if (!hashcmp(sha1, ce->sha1))
942 return 0;
943 return verify_clean_submodule(ce, action, o);
944 }
c8193534
JH
945
946 /*
947 * First let's make sure we do not have a local modification
948 * in that directory.
949 */
0cf73755 950 namelen = strlen(ce->name);
da165f47
JH
951 for (i = locate_in_src_index(ce, o);
952 i < o->src_index->cache_nr;
953 i++) {
837e5fe9
CB
954 struct cache_entry *ce2 = o->src_index->cache[i];
955 int len = ce_namelen(ce2);
c8193534 956 if (len < namelen ||
837e5fe9
CB
957 strncmp(ce->name, ce2->name, namelen) ||
958 ce2->name[namelen] != '/')
c8193534
JH
959 break;
960 /*
da165f47
JH
961 * ce2->name is an entry in the subdirectory to be
962 * removed.
c8193534 963 */
837e5fe9
CB
964 if (!ce_stage(ce2)) {
965 if (verify_uptodate(ce2, o))
203a2fe1 966 return -1;
837e5fe9 967 add_entry(o, ce2, CE_REMOVE, 0);
da165f47 968 mark_ce_used(ce2, o);
c8193534
JH
969 }
970 cnt++;
971 }
972
973 /*
974 * Then we need to make sure that we do not lose a locally
975 * present file that is not ignored.
976 */
977 pathbuf = xmalloc(namelen + 2);
0cf73755 978 memcpy(pathbuf, ce->name, namelen);
c8193534
JH
979 strcpy(pathbuf+namelen, "/");
980
981 memset(&d, 0, sizeof(d));
982 if (o->dir)
983 d.exclude_per_dir = o->dir->exclude_per_dir;
dba2e203 984 i = read_directory(&d, pathbuf, namelen+1, NULL);
c8193534 985 if (i)
17e46426 986 return o->gently ? -1 :
8ccba008 987 error(ERRORMSG(o, not_uptodate_dir), ce->name);
c8193534
JH
988 free(pathbuf);
989 return cnt;
990}
991
32260ad5
LT
992/*
993 * This gets called when there was no index entry for the tree entry 'dst',
994 * but we found a file in the working tree that 'lstat()' said was fine,
995 * and we're on a case-insensitive filesystem.
996 *
997 * See if we can find a case-insensitive match in the index that also
998 * matches the stat information, and assume it's that other file!
999 */
1000static int icase_exists(struct unpack_trees_options *o, struct cache_entry *dst, struct stat *st)
1001{
1002 struct cache_entry *src;
1003
1004 src = index_name_exists(o->src_index, dst->name, ce_namelen(dst), 1);
56cac48c 1005 return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
32260ad5
LT
1006}
1007
076b0adc
JS
1008/*
1009 * We do not want to remove or overwrite a working tree file that
f8a9d428 1010 * is not tracked, unless it is ignored.
076b0adc 1011 */
35a5aa79
NTND
1012static int verify_absent_1(struct cache_entry *ce, const char *action,
1013 struct unpack_trees_options *o,
1014 const char *error_msg)
076b0adc
JS
1015{
1016 struct stat st;
1017
1018 if (o->index_only || o->reset || !o->update)
203a2fe1 1019 return 0;
c8193534 1020
57199892 1021 if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
203a2fe1 1022 return 0;
ec0603e1 1023
0cf73755 1024 if (!lstat(ce->name, &st)) {
6831a88a 1025 int dtype = ce_to_dtype(ce);
df292c79 1026 struct cache_entry *result;
c8193534 1027
32260ad5
LT
1028 /*
1029 * It may be that the 'lstat()' succeeded even though
1030 * target 'ce' was absent, because there is an old
1031 * entry that is different only in case..
1032 *
1033 * Ignore that lstat() if it matches.
1034 */
1035 if (ignore_case && icase_exists(o, ce, &st))
1036 return 0;
1037
6831a88a 1038 if (o->dir && excluded(o->dir, ce->name, &dtype))
c8193534 1039 /*
0cf73755 1040 * ce->name is explicitly excluded, so it is Ok to
c8193534
JH
1041 * overwrite it.
1042 */
203a2fe1 1043 return 0;
c8193534
JH
1044 if (S_ISDIR(st.st_mode)) {
1045 /*
1046 * We are checking out path "foo" and
1047 * found "foo/." in the working tree.
1048 * This is tricky -- if we have modified
1049 * files that are in "foo/" we would lose
6caa7b55 1050 * them.
c8193534 1051 */
da165f47
JH
1052 if (verify_clean_subdirectory(ce, action, o) < 0)
1053 return -1;
203a2fe1 1054 return 0;
c8193534
JH
1055 }
1056
1057 /*
1058 * The previous round may already have decided to
1059 * delete this path, which is in a subdirectory that
1060 * is being replaced with a blob.
1061 */
cd2fef59 1062 result = index_name_exists(&o->result, ce->name, ce_namelen(ce), 0);
df292c79
LT
1063 if (result) {
1064 if (result->ce_flags & CE_REMOVE)
203a2fe1 1065 return 0;
c8193534
JH
1066 }
1067
17e46426 1068 return o->gently ? -1 :
8ccba008 1069 error(ERRORMSG(o, would_lose_untracked), ce->name, action);
c8193534 1070 }
203a2fe1 1071 return 0;
076b0adc 1072}
35a5aa79
NTND
1073static int verify_absent(struct cache_entry *ce, const char *action,
1074 struct unpack_trees_options *o)
1075{
f1f523ea
NTND
1076 if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
1077 return 0;
35a5aa79
NTND
1078 return verify_absent_1(ce, action, o, ERRORMSG(o, would_lose_untracked));
1079}
076b0adc 1080
e800ec9d
NTND
1081static int verify_absent_sparse(struct cache_entry *ce, const char *action,
1082 struct unpack_trees_options *o)
1083{
1084 return verify_absent_1(ce, action, o, ERRORMSG(o, would_lose_orphaned));
1085}
076b0adc
JS
1086
1087static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
1088 struct unpack_trees_options *o)
1089{
7f8ab8dc
LT
1090 int update = CE_UPDATE;
1091
e11d7b59
JH
1092 if (!old) {
1093 if (verify_absent(merge, "overwritten", o))
1094 return -1;
1095 invalidate_ce_path(merge, o);
1096 } else if (!(old->ce_flags & CE_CONFLICTED)) {
076b0adc
JS
1097 /*
1098 * See if we can re-use the old CE directly?
1099 * That way we get the uptodate stat info.
1100 *
7f8ab8dc
LT
1101 * This also removes the UPDATE flag on a match; otherwise
1102 * we will end up overwriting local changes in the work tree.
076b0adc
JS
1103 */
1104 if (same(old, merge)) {
eb7a2f1d 1105 copy_cache_entry(merge, old);
7f8ab8dc 1106 update = 0;
076b0adc 1107 } else {
203a2fe1
DB
1108 if (verify_uptodate(old, o))
1109 return -1;
32f54ca3
NTND
1110 if (ce_skip_worktree(old))
1111 update |= CE_SKIP_WORKTREE;
bc052d7f 1112 invalidate_ce_path(old, o);
076b0adc 1113 }
e11d7b59
JH
1114 } else {
1115 /*
1116 * Previously unmerged entry left as an existence
1117 * marker by read_index_unmerged();
1118 */
1119 invalidate_ce_path(old, o);
076b0adc
JS
1120 }
1121
7f8ab8dc 1122 add_entry(o, merge, update, CE_STAGEMASK);
076b0adc
JS
1123 return 1;
1124}
1125
1126static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
1127 struct unpack_trees_options *o)
1128{
34110cd4
LT
1129 /* Did it exist in the index? */
1130 if (!old) {
203a2fe1
DB
1131 if (verify_absent(ce, "removed", o))
1132 return -1;
34110cd4
LT
1133 return 0;
1134 }
e11d7b59 1135 if (!(old->ce_flags & CE_CONFLICTED) && verify_uptodate(old, o))
34110cd4
LT
1136 return -1;
1137 add_entry(o, ce, CE_REMOVE, 0);
bc052d7f 1138 invalidate_ce_path(ce, o);
076b0adc
JS
1139 return 1;
1140}
1141
7f7932ab 1142static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o)
076b0adc 1143{
34110cd4 1144 add_entry(o, ce, 0, 0);
076b0adc
JS
1145 return 1;
1146}
1147
1148#if DBRT_DEBUG
1149static void show_stage_entry(FILE *o,
1150 const char *label, const struct cache_entry *ce)
1151{
1152 if (!ce)
1153 fprintf(o, "%s (missing)\n", label);
1154 else
1155 fprintf(o, "%s%06o %s %d\t%s\n",
1156 label,
7a51ed66 1157 ce->ce_mode,
076b0adc
JS
1158 sha1_to_hex(ce->sha1),
1159 ce_stage(ce),
1160 ce->name);
1161}
1162#endif
1163
34110cd4 1164int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o)
076b0adc
JS
1165{
1166 struct cache_entry *index;
1167 struct cache_entry *head;
1168 struct cache_entry *remote = stages[o->head_idx + 1];
1169 int count;
1170 int head_match = 0;
1171 int remote_match = 0;
076b0adc
JS
1172
1173 int df_conflict_head = 0;
1174 int df_conflict_remote = 0;
1175
1176 int any_anc_missing = 0;
1177 int no_anc_exists = 1;
1178 int i;
1179
1180 for (i = 1; i < o->head_idx; i++) {
4c4caafc 1181 if (!stages[i] || stages[i] == o->df_conflict_entry)
076b0adc 1182 any_anc_missing = 1;
4c4caafc 1183 else
076b0adc 1184 no_anc_exists = 0;
076b0adc
JS
1185 }
1186
1187 index = stages[0];
1188 head = stages[o->head_idx];
1189
1190 if (head == o->df_conflict_entry) {
1191 df_conflict_head = 1;
1192 head = NULL;
1193 }
1194
1195 if (remote == o->df_conflict_entry) {
1196 df_conflict_remote = 1;
1197 remote = NULL;
1198 }
1199
cee2d6ae
JH
1200 /*
1201 * First, if there's a #16 situation, note that to prevent #13
076b0adc
JS
1202 * and #14.
1203 */
1204 if (!same(remote, head)) {
1205 for (i = 1; i < o->head_idx; i++) {
1206 if (same(stages[i], head)) {
1207 head_match = i;
1208 }
1209 if (same(stages[i], remote)) {
1210 remote_match = i;
1211 }
1212 }
1213 }
1214
cee2d6ae
JH
1215 /*
1216 * We start with cases where the index is allowed to match
076b0adc
JS
1217 * something other than the head: #14(ALT) and #2ALT, where it
1218 * is permitted to match the result instead.
1219 */
1220 /* #14, #14ALT, #2ALT */
1221 if (remote && !df_conflict_head && head_match && !remote_match) {
1222 if (index && !same(index, remote) && !same(index, head))
8ccba008 1223 return o->gently ? -1 : reject_merge(index, o);
076b0adc
JS
1224 return merged_entry(remote, index, o);
1225 }
1226 /*
1227 * If we have an entry in the index cache, then we want to
1228 * make sure that it matches head.
1229 */
4e7c4571 1230 if (index && !same(index, head))
8ccba008 1231 return o->gently ? -1 : reject_merge(index, o);
076b0adc
JS
1232
1233 if (head) {
1234 /* #5ALT, #15 */
1235 if (same(head, remote))
1236 return merged_entry(head, index, o);
1237 /* #13, #3ALT */
1238 if (!df_conflict_remote && remote_match && !head_match)
1239 return merged_entry(head, index, o);
1240 }
1241
1242 /* #1 */
34110cd4 1243 if (!head && !remote && any_anc_missing)
076b0adc
JS
1244 return 0;
1245
cee2d6ae
JH
1246 /*
1247 * Under the "aggressive" rule, we resolve mostly trivial
076b0adc
JS
1248 * cases that we historically had git-merge-one-file resolve.
1249 */
1250 if (o->aggressive) {
cee2d6ae
JH
1251 int head_deleted = !head;
1252 int remote_deleted = !remote;
0cf73755 1253 struct cache_entry *ce = NULL;
4c4caafc
JH
1254
1255 if (index)
0cf73755 1256 ce = index;
4c4caafc 1257 else if (head)
0cf73755 1258 ce = head;
4c4caafc 1259 else if (remote)
0cf73755 1260 ce = remote;
4c4caafc
JH
1261 else {
1262 for (i = 1; i < o->head_idx; i++) {
1263 if (stages[i] && stages[i] != o->df_conflict_entry) {
0cf73755 1264 ce = stages[i];
4c4caafc
JH
1265 break;
1266 }
1267 }
1268 }
1269
076b0adc
JS
1270 /*
1271 * Deleted in both.
1272 * Deleted in one and unchanged in the other.
1273 */
1274 if ((head_deleted && remote_deleted) ||
1275 (head_deleted && remote && remote_match) ||
1276 (remote_deleted && head && head_match)) {
1277 if (index)
1278 return deleted_entry(index, index, o);
34110cd4 1279 if (ce && !head_deleted) {
203a2fe1
DB
1280 if (verify_absent(ce, "removed", o))
1281 return -1;
1282 }
076b0adc
JS
1283 return 0;
1284 }
1285 /*
1286 * Added in both, identically.
1287 */
1288 if (no_anc_exists && head && remote && same(head, remote))
1289 return merged_entry(head, index, o);
1290
1291 }
1292
1293 /* Below are "no merge" cases, which require that the index be
1294 * up-to-date to avoid the files getting overwritten with
1295 * conflict resolution files.
1296 */
1297 if (index) {
203a2fe1
DB
1298 if (verify_uptodate(index, o))
1299 return -1;
076b0adc 1300 }
076b0adc
JS
1301
1302 o->nontrivial_merge = 1;
1303
ea4b52a8 1304 /* #2, #3, #4, #6, #7, #9, #10, #11. */
076b0adc
JS
1305 count = 0;
1306 if (!head_match || !remote_match) {
1307 for (i = 1; i < o->head_idx; i++) {
4c4caafc 1308 if (stages[i] && stages[i] != o->df_conflict_entry) {
7f7932ab 1309 keep_entry(stages[i], o);
076b0adc
JS
1310 count++;
1311 break;
1312 }
1313 }
1314 }
1315#if DBRT_DEBUG
1316 else {
1317 fprintf(stderr, "read-tree: warning #16 detected\n");
1318 show_stage_entry(stderr, "head ", stages[head_match]);
1319 show_stage_entry(stderr, "remote ", stages[remote_match]);
1320 }
1321#endif
7f7932ab
JH
1322 if (head) { count += keep_entry(head, o); }
1323 if (remote) { count += keep_entry(remote, o); }
076b0adc
JS
1324 return count;
1325}
1326
1327/*
1328 * Two-way merge.
1329 *
1330 * The rule is to "carry forward" what is in the index without losing
a75d7b54 1331 * information across a "fast-forward", favoring a successful merge
076b0adc
JS
1332 * over a merge failure when it makes sense. For details of the
1333 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
1334 *
1335 */
34110cd4 1336int twoway_merge(struct cache_entry **src, struct unpack_trees_options *o)
076b0adc
JS
1337{
1338 struct cache_entry *current = src[0];
b8ba1535
JH
1339 struct cache_entry *oldtree = src[1];
1340 struct cache_entry *newtree = src[2];
076b0adc
JS
1341
1342 if (o->merge_size != 2)
1343 return error("Cannot do a twoway merge of %d trees",
1344 o->merge_size);
1345
b8ba1535
JH
1346 if (oldtree == o->df_conflict_entry)
1347 oldtree = NULL;
1348 if (newtree == o->df_conflict_entry)
1349 newtree = NULL;
1350
076b0adc
JS
1351 if (current) {
1352 if ((!oldtree && !newtree) || /* 4 and 5 */
1353 (!oldtree && newtree &&
1354 same(current, newtree)) || /* 6 and 7 */
1355 (oldtree && newtree &&
1356 same(oldtree, newtree)) || /* 14 and 15 */
1357 (oldtree && newtree &&
b8ba1535 1358 !same(oldtree, newtree) && /* 18 and 19 */
076b0adc 1359 same(current, newtree))) {
7f7932ab 1360 return keep_entry(current, o);
076b0adc
JS
1361 }
1362 else if (oldtree && !newtree && same(current, oldtree)) {
1363 /* 10 or 11 */
1364 return deleted_entry(oldtree, current, o);
1365 }
1366 else if (oldtree && newtree &&
1367 same(current, oldtree) && !same(current, newtree)) {
1368 /* 20 or 21 */
1369 return merged_entry(newtree, current, o);
1370 }
1371 else {
1372 /* all other failures */
1373 if (oldtree)
8ccba008 1374 return o->gently ? -1 : reject_merge(oldtree, o);
076b0adc 1375 if (current)
8ccba008 1376 return o->gently ? -1 : reject_merge(current, o);
076b0adc 1377 if (newtree)
8ccba008 1378 return o->gently ? -1 : reject_merge(newtree, o);
076b0adc
JS
1379 return -1;
1380 }
1381 }
55218834
JH
1382 else if (newtree) {
1383 if (oldtree && !o->initial_checkout) {
1384 /*
1385 * deletion of the path was staged;
1386 */
1387 if (same(oldtree, newtree))
1388 return 1;
1389 return reject_merge(oldtree, o);
1390 }
076b0adc 1391 return merged_entry(newtree, current, o);
55218834 1392 }
d699676d 1393 return deleted_entry(oldtree, current, o);
076b0adc
JS
1394}
1395
1396/*
1397 * Bind merge.
1398 *
1399 * Keep the index entries at stage0, collapse stage1 but make sure
1400 * stage0 does not have anything there.
1401 */
1402int bind_merge(struct cache_entry **src,
34110cd4 1403 struct unpack_trees_options *o)
076b0adc
JS
1404{
1405 struct cache_entry *old = src[0];
1406 struct cache_entry *a = src[1];
1407
1408 if (o->merge_size != 1)
1409 return error("Cannot do a bind merge of %d trees\n",
1410 o->merge_size);
1411 if (a && old)
17e46426 1412 return o->gently ? -1 :
8ccba008 1413 error(ERRORMSG(o, bind_overlap), a->name, old->name);
076b0adc 1414 if (!a)
7f7932ab 1415 return keep_entry(old, o);
076b0adc
JS
1416 else
1417 return merged_entry(a, NULL, o);
1418}
1419
1420/*
1421 * One-way merge.
1422 *
1423 * The rule is:
1424 * - take the stat information from stage0, take the data from stage1
1425 */
34110cd4 1426int oneway_merge(struct cache_entry **src, struct unpack_trees_options *o)
076b0adc
JS
1427{
1428 struct cache_entry *old = src[0];
1429 struct cache_entry *a = src[1];
1430
1431 if (o->merge_size != 1)
1432 return error("Cannot do a oneway merge of %d trees",
1433 o->merge_size);
1434
78d3b06e 1435 if (!a || a == o->df_conflict_entry)
076b0adc 1436 return deleted_entry(old, old, o);
34110cd4 1437
076b0adc 1438 if (old && same(old, a)) {
34110cd4 1439 int update = 0;
52030836 1440 if (o->reset && !ce_uptodate(old) && !ce_skip_worktree(old)) {
076b0adc
JS
1441 struct stat st;
1442 if (lstat(old->name, &st) ||
56cac48c 1443 ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE))
34110cd4 1444 update |= CE_UPDATE;
076b0adc 1445 }
34110cd4
LT
1446 add_entry(o, old, update, 0);
1447 return 0;
076b0adc
JS
1448 }
1449 return merged_entry(a, old, o);
1450}