Move "show_all_errors = 1" to setup_unpack_trees_porcelain()
[git/git.git] / unpack-trees.c
1 #define NO_THE_INDEX_COMPATIBILITY_MACROS
2 #include "cache.h"
3 #include "dir.h"
4 #include "tree.h"
5 #include "tree-walk.h"
6 #include "cache-tree.h"
7 #include "unpack-trees.h"
8 #include "progress.h"
9 #include "refs.h"
10 #include "attr.h"
11
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" and "git merge" replaces
17 * them using setup_unpack_trees_porcelain(), for example.
18 */
19 const char *unpack_plumbing_errors[NB_UNPACK_TREES_ERROR_TYPES] = {
20 /* ERROR_WOULD_OVERWRITE */
21 "Entry '%s' would be overwritten by merge. Cannot merge.",
22
23 /* ERROR_NOT_UPTODATE_FILE */
24 "Entry '%s' not uptodate. Cannot merge.",
25
26 /* ERROR_NOT_UPTODATE_DIR */
27 "Updating '%s' would lose untracked files in it",
28
29 /* ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN */
30 "Untracked working tree file '%s' would be overwritten by merge.",
31
32 /* ERROR_WOULD_LOSE_UNTRACKED_REMOVED */
33 "Untracked working tree file '%s' would be removed by merge.",
34
35 /* ERROR_BIND_OVERLAP */
36 "Entry '%s' overlaps with '%s'. Cannot bind.",
37
38 /* ERROR_SPARSE_NOT_UPTODATE_FILE */
39 "Entry '%s' not uptodate. Cannot update sparse checkout.",
40
41 /* ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN */
42 "Working tree file '%s' would be overwritten by sparse checkout update.",
43
44 /* ERROR_WOULD_LOSE_ORPHANED_REMOVED */
45 "Working tree file '%s' would be removed by sparse checkout update.",
46 };
47
48 #define ERRORMSG(o,type) \
49 ( ((o) && (o)->msgs[(type)]) \
50 ? ((o)->msgs[(type)]) \
51 : (unpack_plumbing_errors[(type)]) )
52
53 void setup_unpack_trees_porcelain(struct unpack_trees_options *opts,
54 const char *cmd)
55 {
56 const char **msgs = opts->msgs;
57 const char *msg;
58 char *tmp;
59 const char *cmd2 = strcmp(cmd, "checkout") ? cmd : "switch branches";
60 if (advice_commit_before_merge)
61 msg = "Your local changes to the following files would be overwritten by %s:\n%%s"
62 "Please, commit your changes or stash them before you can %s.";
63 else
64 msg = "Your local changes to the following files would be overwritten by %s:\n%%s";
65 tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen(cmd2) - 2);
66 sprintf(tmp, msg, cmd, cmd2);
67 msgs[ERROR_WOULD_OVERWRITE] = tmp;
68 msgs[ERROR_NOT_UPTODATE_FILE] = tmp;
69
70 msgs[ERROR_NOT_UPTODATE_DIR] =
71 "Updating the following directories would lose untracked files in it:\n%s";
72
73 if (advice_commit_before_merge)
74 msg = "The following untracked working tree files would be %s by %s:\n%%s"
75 "Please move or remove them before you can %s.";
76 else
77 msg = "The following untracked working tree files would be %s by %s:\n%%s";
78 tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen("removed") + strlen(cmd2) - 4);
79 sprintf(tmp, msg, "removed", cmd, cmd2);
80 msgs[ERROR_WOULD_LOSE_UNTRACKED_REMOVED] = tmp;
81 tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen("overwritten") + strlen(cmd2) - 4);
82 sprintf(tmp, msg, "overwritten", cmd, cmd2);
83 msgs[ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN] = tmp;
84
85 /*
86 * Special case: ERROR_BIND_OVERLAP refers to a pair of paths, we
87 * cannot easily display it as a list.
88 */
89 msgs[ERROR_BIND_OVERLAP] = "Entry '%s' overlaps with '%s'. Cannot bind.";
90
91 msgs[ERROR_SPARSE_NOT_UPTODATE_FILE] =
92 "Cannot update sparse checkout: the following entries are not up-to-date:\n%s";
93 msgs[ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN] =
94 "The following Working tree files would be overwritten by sparse checkout update:\n%s";
95 msgs[ERROR_WOULD_LOSE_ORPHANED_REMOVED] =
96 "The following Working tree files would be removed by sparse checkout update:\n%s";
97
98 opts->show_all_errors = 1;
99 }
100
101 static void add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
102 unsigned int set, unsigned int clear)
103 {
104 unsigned int size = ce_size(ce);
105 struct cache_entry *new = xmalloc(size);
106
107 clear |= CE_HASHED | CE_UNHASHED;
108
109 memcpy(new, ce, size);
110 new->next = NULL;
111 new->ce_flags = (new->ce_flags & ~clear) | set;
112 add_index_entry(&o->result, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
113 }
114
115 /*
116 * add error messages on path <path>
117 * corresponding to the type <e> with the message <msg>
118 * indicating if it should be display in porcelain or not
119 */
120 static int add_rejected_path(struct unpack_trees_options *o,
121 enum unpack_trees_error_types e,
122 const char *path)
123 {
124 struct rejected_paths_list *newentry;
125 if (!o->show_all_errors)
126 return error(ERRORMSG(o, e), path);
127
128 /*
129 * Otherwise, insert in a list for future display by
130 * display_error_msgs()
131 */
132 newentry = xmalloc(sizeof(struct rejected_paths_list));
133 newentry->path = (char *)path;
134 newentry->next = o->unpack_rejects[e];
135 o->unpack_rejects[e] = newentry;
136 return -1;
137 }
138
139 /*
140 * free all the structures allocated for the error <e>
141 */
142 static void free_rejected_paths(struct unpack_trees_options *o,
143 enum unpack_trees_error_types e)
144 {
145 while (o->unpack_rejects[e]) {
146 struct rejected_paths_list *del = o->unpack_rejects[e];
147 o->unpack_rejects[e] = o->unpack_rejects[e]->next;
148 free(del);
149 }
150 free(o->unpack_rejects[e]);
151 }
152
153 /*
154 * display all the error messages stored in a nice way
155 */
156 static void display_error_msgs(struct unpack_trees_options *o)
157 {
158 int e;
159 int something_displayed = 0;
160 for (e = 0; e < NB_UNPACK_TREES_ERROR_TYPES; e++) {
161 if (o->unpack_rejects[e]) {
162 struct rejected_paths_list *rp;
163 struct strbuf path = STRBUF_INIT;
164 something_displayed = 1;
165 for (rp = o->unpack_rejects[e]; rp; rp = rp->next)
166 strbuf_addf(&path, "\t%s\n", rp->path);
167 error(ERRORMSG(o, e), path.buf);
168 strbuf_release(&path);
169 free_rejected_paths(o, e);
170 }
171 }
172 if (something_displayed)
173 printf("Aborting\n");
174 }
175
176 /*
177 * Unlink the last component and schedule the leading directories for
178 * removal, such that empty directories get removed.
179 */
180 static void unlink_entry(struct cache_entry *ce)
181 {
182 if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
183 return;
184 if (remove_or_warn(ce->ce_mode, ce->name))
185 return;
186 schedule_dir_for_removal(ce->name, ce_namelen(ce));
187 }
188
189 static struct checkout state;
190 static int check_updates(struct unpack_trees_options *o)
191 {
192 unsigned cnt = 0, total = 0;
193 struct progress *progress = NULL;
194 struct index_state *index = &o->result;
195 int i;
196 int errs = 0;
197
198 if (o->update && o->verbose_update) {
199 for (total = cnt = 0; cnt < index->cache_nr; cnt++) {
200 struct cache_entry *ce = index->cache[cnt];
201 if (ce->ce_flags & (CE_UPDATE | CE_REMOVE | CE_WT_REMOVE))
202 total++;
203 }
204
205 progress = start_progress_delay("Checking out files",
206 total, 50, 1);
207 cnt = 0;
208 }
209
210 if (o->update)
211 git_attr_set_direction(GIT_ATTR_CHECKOUT, &o->result);
212 for (i = 0; i < index->cache_nr; i++) {
213 struct cache_entry *ce = index->cache[i];
214
215 if (ce->ce_flags & CE_WT_REMOVE) {
216 display_progress(progress, ++cnt);
217 if (o->update)
218 unlink_entry(ce);
219 continue;
220 }
221
222 if (ce->ce_flags & CE_REMOVE) {
223 display_progress(progress, ++cnt);
224 if (o->update)
225 unlink_entry(ce);
226 }
227 }
228 remove_marked_cache_entries(&o->result);
229 remove_scheduled_dirs();
230
231 for (i = 0; i < index->cache_nr; i++) {
232 struct cache_entry *ce = index->cache[i];
233
234 if (ce->ce_flags & CE_UPDATE) {
235 display_progress(progress, ++cnt);
236 ce->ce_flags &= ~CE_UPDATE;
237 if (o->update) {
238 errs |= checkout_entry(ce, &state, NULL);
239 }
240 }
241 }
242 stop_progress(&progress);
243 if (o->update)
244 git_attr_set_direction(GIT_ATTR_CHECKIN, NULL);
245 return errs != 0;
246 }
247
248 static int verify_uptodate_sparse(struct cache_entry *ce, struct unpack_trees_options *o);
249 static int verify_absent_sparse(struct cache_entry *ce, enum unpack_trees_error_types, struct unpack_trees_options *o);
250
251 static int will_have_skip_worktree(const struct cache_entry *ce, struct unpack_trees_options *o)
252 {
253 const char *basename;
254
255 if (ce_stage(ce))
256 return 0;
257
258 basename = strrchr(ce->name, '/');
259 basename = basename ? basename+1 : ce->name;
260 return excluded_from_list(ce->name, ce_namelen(ce), basename, NULL, o->el) <= 0;
261 }
262
263 static int apply_sparse_checkout(struct cache_entry *ce, struct unpack_trees_options *o)
264 {
265 int was_skip_worktree = ce_skip_worktree(ce);
266
267 if (will_have_skip_worktree(ce, o))
268 ce->ce_flags |= CE_SKIP_WORKTREE;
269 else
270 ce->ce_flags &= ~CE_SKIP_WORKTREE;
271
272 /*
273 * We only care about files getting into the checkout area
274 * If merge strategies want to remove some, go ahead, this
275 * flag will be removed eventually in unpack_trees() if it's
276 * outside checkout area.
277 */
278 if (ce->ce_flags & CE_REMOVE)
279 return 0;
280
281 if (!was_skip_worktree && ce_skip_worktree(ce)) {
282 /*
283 * If CE_UPDATE is set, verify_uptodate() must be called already
284 * also stat info may have lost after merged_entry() so calling
285 * verify_uptodate() again may fail
286 */
287 if (!(ce->ce_flags & CE_UPDATE) && verify_uptodate_sparse(ce, o))
288 return -1;
289 ce->ce_flags |= CE_WT_REMOVE;
290 }
291 if (was_skip_worktree && !ce_skip_worktree(ce)) {
292 if (verify_absent_sparse(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o))
293 return -1;
294 ce->ce_flags |= CE_UPDATE;
295 }
296 return 0;
297 }
298
299 static inline int call_unpack_fn(struct cache_entry **src, struct unpack_trees_options *o)
300 {
301 int ret = o->fn(src, o);
302 if (ret > 0)
303 ret = 0;
304 return ret;
305 }
306
307 static void mark_ce_used(struct cache_entry *ce, struct unpack_trees_options *o)
308 {
309 ce->ce_flags |= CE_UNPACKED;
310
311 if (o->cache_bottom < o->src_index->cache_nr &&
312 o->src_index->cache[o->cache_bottom] == ce) {
313 int bottom = o->cache_bottom;
314 while (bottom < o->src_index->cache_nr &&
315 o->src_index->cache[bottom]->ce_flags & CE_UNPACKED)
316 bottom++;
317 o->cache_bottom = bottom;
318 }
319 }
320
321 static void mark_all_ce_unused(struct index_state *index)
322 {
323 int i;
324 for (i = 0; i < index->cache_nr; i++)
325 index->cache[i]->ce_flags &= ~CE_UNPACKED;
326 }
327
328 static int locate_in_src_index(struct cache_entry *ce,
329 struct unpack_trees_options *o)
330 {
331 struct index_state *index = o->src_index;
332 int len = ce_namelen(ce);
333 int pos = index_name_pos(index, ce->name, len);
334 if (pos < 0)
335 pos = -1 - pos;
336 return pos;
337 }
338
339 /*
340 * We call unpack_index_entry() with an unmerged cache entry
341 * only in diff-index, and it wants a single callback. Skip
342 * the other unmerged entry with the same name.
343 */
344 static void mark_ce_used_same_name(struct cache_entry *ce,
345 struct unpack_trees_options *o)
346 {
347 struct index_state *index = o->src_index;
348 int len = ce_namelen(ce);
349 int pos;
350
351 for (pos = locate_in_src_index(ce, o); pos < index->cache_nr; pos++) {
352 struct cache_entry *next = index->cache[pos];
353 if (len != ce_namelen(next) ||
354 memcmp(ce->name, next->name, len))
355 break;
356 mark_ce_used(next, o);
357 }
358 }
359
360 static struct cache_entry *next_cache_entry(struct unpack_trees_options *o)
361 {
362 const struct index_state *index = o->src_index;
363 int pos = o->cache_bottom;
364
365 while (pos < index->cache_nr) {
366 struct cache_entry *ce = index->cache[pos];
367 if (!(ce->ce_flags & CE_UNPACKED))
368 return ce;
369 pos++;
370 }
371 return NULL;
372 }
373
374 static void add_same_unmerged(struct cache_entry *ce,
375 struct unpack_trees_options *o)
376 {
377 struct index_state *index = o->src_index;
378 int len = ce_namelen(ce);
379 int pos = index_name_pos(index, ce->name, len);
380
381 if (0 <= pos)
382 die("programming error in a caller of mark_ce_used_same_name");
383 for (pos = -pos - 1; pos < index->cache_nr; pos++) {
384 struct cache_entry *next = index->cache[pos];
385 if (len != ce_namelen(next) ||
386 memcmp(ce->name, next->name, len))
387 break;
388 add_entry(o, next, 0, 0);
389 mark_ce_used(next, o);
390 }
391 }
392
393 static int unpack_index_entry(struct cache_entry *ce,
394 struct unpack_trees_options *o)
395 {
396 struct cache_entry *src[5] = { NULL };
397 int ret;
398
399 src[0] = ce;
400
401 mark_ce_used(ce, o);
402 if (ce_stage(ce)) {
403 if (o->skip_unmerged) {
404 add_entry(o, ce, 0, 0);
405 return 0;
406 }
407 }
408 ret = call_unpack_fn(src, o);
409 if (ce_stage(ce))
410 mark_ce_used_same_name(ce, o);
411 return ret;
412 }
413
414 static int find_cache_pos(struct traverse_info *, const struct name_entry *);
415
416 static void restore_cache_bottom(struct traverse_info *info, int bottom)
417 {
418 struct unpack_trees_options *o = info->data;
419
420 if (o->diff_index_cached)
421 return;
422 o->cache_bottom = bottom;
423 }
424
425 static int switch_cache_bottom(struct traverse_info *info)
426 {
427 struct unpack_trees_options *o = info->data;
428 int ret, pos;
429
430 if (o->diff_index_cached)
431 return 0;
432 ret = o->cache_bottom;
433 pos = find_cache_pos(info->prev, &info->name);
434
435 if (pos < -1)
436 o->cache_bottom = -2 - pos;
437 else if (pos < 0)
438 o->cache_bottom = o->src_index->cache_nr;
439 return ret;
440 }
441
442 static int traverse_trees_recursive(int n, unsigned long dirmask, unsigned long df_conflicts, struct name_entry *names, struct traverse_info *info)
443 {
444 int i, ret, bottom;
445 struct tree_desc t[MAX_UNPACK_TREES];
446 struct traverse_info newinfo;
447 struct name_entry *p;
448
449 p = names;
450 while (!p->mode)
451 p++;
452
453 newinfo = *info;
454 newinfo.prev = info;
455 newinfo.name = *p;
456 newinfo.pathlen += tree_entry_len(p->path, p->sha1) + 1;
457 newinfo.conflicts |= df_conflicts;
458
459 for (i = 0; i < n; i++, dirmask >>= 1) {
460 const unsigned char *sha1 = NULL;
461 if (dirmask & 1)
462 sha1 = names[i].sha1;
463 fill_tree_descriptor(t+i, sha1);
464 }
465
466 bottom = switch_cache_bottom(&newinfo);
467 ret = traverse_trees(n, t, &newinfo);
468 restore_cache_bottom(&newinfo, bottom);
469 return ret;
470 }
471
472 /*
473 * Compare the traverse-path to the cache entry without actually
474 * having to generate the textual representation of the traverse
475 * path.
476 *
477 * NOTE! This *only* compares up to the size of the traverse path
478 * itself - the caller needs to do the final check for the cache
479 * entry having more data at the end!
480 */
481 static int do_compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
482 {
483 int len, pathlen, ce_len;
484 const char *ce_name;
485
486 if (info->prev) {
487 int cmp = do_compare_entry(ce, info->prev, &info->name);
488 if (cmp)
489 return cmp;
490 }
491 pathlen = info->pathlen;
492 ce_len = ce_namelen(ce);
493
494 /* If ce_len < pathlen then we must have previously hit "name == directory" entry */
495 if (ce_len < pathlen)
496 return -1;
497
498 ce_len -= pathlen;
499 ce_name = ce->name + pathlen;
500
501 len = tree_entry_len(n->path, n->sha1);
502 return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode);
503 }
504
505 static int compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
506 {
507 int cmp = do_compare_entry(ce, info, n);
508 if (cmp)
509 return cmp;
510
511 /*
512 * Even if the beginning compared identically, the ce should
513 * compare as bigger than a directory leading up to it!
514 */
515 return ce_namelen(ce) > traverse_path_len(info, n);
516 }
517
518 static int ce_in_traverse_path(const struct cache_entry *ce,
519 const struct traverse_info *info)
520 {
521 if (!info->prev)
522 return 1;
523 if (do_compare_entry(ce, info->prev, &info->name))
524 return 0;
525 /*
526 * If ce (blob) is the same name as the path (which is a tree
527 * we will be descending into), it won't be inside it.
528 */
529 return (info->pathlen < ce_namelen(ce));
530 }
531
532 static struct cache_entry *create_ce_entry(const struct traverse_info *info, const struct name_entry *n, int stage)
533 {
534 int len = traverse_path_len(info, n);
535 struct cache_entry *ce = xcalloc(1, cache_entry_size(len));
536
537 ce->ce_mode = create_ce_mode(n->mode);
538 ce->ce_flags = create_ce_flags(len, stage);
539 hashcpy(ce->sha1, n->sha1);
540 make_traverse_path(ce->name, info, n);
541
542 return ce;
543 }
544
545 static int unpack_nondirectories(int n, unsigned long mask,
546 unsigned long dirmask,
547 struct cache_entry **src,
548 const struct name_entry *names,
549 const struct traverse_info *info)
550 {
551 int i;
552 struct unpack_trees_options *o = info->data;
553 unsigned long conflicts;
554
555 /* Do we have *only* directories? Nothing to do */
556 if (mask == dirmask && !src[0])
557 return 0;
558
559 conflicts = info->conflicts;
560 if (o->merge)
561 conflicts >>= 1;
562 conflicts |= dirmask;
563
564 /*
565 * Ok, we've filled in up to any potential index entry in src[0],
566 * now do the rest.
567 */
568 for (i = 0; i < n; i++) {
569 int stage;
570 unsigned int bit = 1ul << i;
571 if (conflicts & bit) {
572 src[i + o->merge] = o->df_conflict_entry;
573 continue;
574 }
575 if (!(mask & bit))
576 continue;
577 if (!o->merge)
578 stage = 0;
579 else if (i + 1 < o->head_idx)
580 stage = 1;
581 else if (i + 1 > o->head_idx)
582 stage = 3;
583 else
584 stage = 2;
585 src[i + o->merge] = create_ce_entry(info, names + i, stage);
586 }
587
588 if (o->merge)
589 return call_unpack_fn(src, o);
590
591 for (i = 0; i < n; i++)
592 if (src[i] && src[i] != o->df_conflict_entry)
593 add_entry(o, src[i], 0, 0);
594 return 0;
595 }
596
597 static int unpack_failed(struct unpack_trees_options *o, const char *message)
598 {
599 discard_index(&o->result);
600 if (!o->gently) {
601 if (message)
602 return error("%s", message);
603 return -1;
604 }
605 return -1;
606 }
607
608 /* NEEDSWORK: give this a better name and share with tree-walk.c */
609 static int name_compare(const char *a, int a_len,
610 const char *b, int b_len)
611 {
612 int len = (a_len < b_len) ? a_len : b_len;
613 int cmp = memcmp(a, b, len);
614 if (cmp)
615 return cmp;
616 return (a_len - b_len);
617 }
618
619 /*
620 * The tree traversal is looking at name p. If we have a matching entry,
621 * return it. If name p is a directory in the index, do not return
622 * anything, as we will want to match it when the traversal descends into
623 * the directory.
624 */
625 static int find_cache_pos(struct traverse_info *info,
626 const struct name_entry *p)
627 {
628 int pos;
629 struct unpack_trees_options *o = info->data;
630 struct index_state *index = o->src_index;
631 int pfxlen = info->pathlen;
632 int p_len = tree_entry_len(p->path, p->sha1);
633
634 for (pos = o->cache_bottom; pos < index->cache_nr; pos++) {
635 struct cache_entry *ce = index->cache[pos];
636 const char *ce_name, *ce_slash;
637 int cmp, ce_len;
638
639 if (ce->ce_flags & CE_UNPACKED) {
640 /*
641 * cache_bottom entry is already unpacked, so
642 * we can never match it; don't check it
643 * again.
644 */
645 if (pos == o->cache_bottom)
646 ++o->cache_bottom;
647 continue;
648 }
649 if (!ce_in_traverse_path(ce, info))
650 continue;
651 ce_name = ce->name + pfxlen;
652 ce_slash = strchr(ce_name, '/');
653 if (ce_slash)
654 ce_len = ce_slash - ce_name;
655 else
656 ce_len = ce_namelen(ce) - pfxlen;
657 cmp = name_compare(p->path, p_len, ce_name, ce_len);
658 /*
659 * Exact match; if we have a directory we need to
660 * delay returning it.
661 */
662 if (!cmp)
663 return ce_slash ? -2 - pos : pos;
664 if (0 < cmp)
665 continue; /* keep looking */
666 /*
667 * ce_name sorts after p->path; could it be that we
668 * have files under p->path directory in the index?
669 * E.g. ce_name == "t-i", and p->path == "t"; we may
670 * have "t/a" in the index.
671 */
672 if (p_len < ce_len && !memcmp(ce_name, p->path, p_len) &&
673 ce_name[p_len] < '/')
674 continue; /* keep looking */
675 break;
676 }
677 return -1;
678 }
679
680 static struct cache_entry *find_cache_entry(struct traverse_info *info,
681 const struct name_entry *p)
682 {
683 int pos = find_cache_pos(info, p);
684 struct unpack_trees_options *o = info->data;
685
686 if (0 <= pos)
687 return o->src_index->cache[pos];
688 else
689 return NULL;
690 }
691
692 static void debug_path(struct traverse_info *info)
693 {
694 if (info->prev) {
695 debug_path(info->prev);
696 if (*info->prev->name.path)
697 putchar('/');
698 }
699 printf("%s", info->name.path);
700 }
701
702 static void debug_name_entry(int i, struct name_entry *n)
703 {
704 printf("ent#%d %06o %s\n", i,
705 n->path ? n->mode : 0,
706 n->path ? n->path : "(missing)");
707 }
708
709 static void debug_unpack_callback(int n,
710 unsigned long mask,
711 unsigned long dirmask,
712 struct name_entry *names,
713 struct traverse_info *info)
714 {
715 int i;
716 printf("* unpack mask %lu, dirmask %lu, cnt %d ",
717 mask, dirmask, n);
718 debug_path(info);
719 putchar('\n');
720 for (i = 0; i < n; i++)
721 debug_name_entry(i, names + i);
722 }
723
724 static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *names, struct traverse_info *info)
725 {
726 struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
727 struct unpack_trees_options *o = info->data;
728 const struct name_entry *p = names;
729
730 /* Find first entry with a real name (we could use "mask" too) */
731 while (!p->mode)
732 p++;
733
734 if (o->debug_unpack)
735 debug_unpack_callback(n, mask, dirmask, names, info);
736
737 /* Are we supposed to look at the index too? */
738 if (o->merge) {
739 while (1) {
740 int cmp;
741 struct cache_entry *ce;
742
743 if (o->diff_index_cached)
744 ce = next_cache_entry(o);
745 else
746 ce = find_cache_entry(info, p);
747
748 if (!ce)
749 break;
750 cmp = compare_entry(ce, info, p);
751 if (cmp < 0) {
752 if (unpack_index_entry(ce, o) < 0)
753 return unpack_failed(o, NULL);
754 continue;
755 }
756 if (!cmp) {
757 if (ce_stage(ce)) {
758 /*
759 * If we skip unmerged index
760 * entries, we'll skip this
761 * entry *and* the tree
762 * entries associated with it!
763 */
764 if (o->skip_unmerged) {
765 add_same_unmerged(ce, o);
766 return mask;
767 }
768 }
769 src[0] = ce;
770 }
771 break;
772 }
773 }
774
775 if (unpack_nondirectories(n, mask, dirmask, src, names, info) < 0)
776 return -1;
777
778 if (src[0]) {
779 if (ce_stage(src[0]))
780 mark_ce_used_same_name(src[0], o);
781 else
782 mark_ce_used(src[0], o);
783 }
784
785 /* Now handle any directories.. */
786 if (dirmask) {
787 unsigned long conflicts = mask & ~dirmask;
788 if (o->merge) {
789 conflicts <<= 1;
790 if (src[0])
791 conflicts |= 1;
792 }
793
794 /* special case: "diff-index --cached" looking at a tree */
795 if (o->diff_index_cached &&
796 n == 1 && dirmask == 1 && S_ISDIR(names->mode)) {
797 int matches;
798 matches = cache_tree_matches_traversal(o->src_index->cache_tree,
799 names, info);
800 /*
801 * Everything under the name matches; skip the
802 * entire hierarchy. diff_index_cached codepath
803 * special cases D/F conflicts in such a way that
804 * it does not do any look-ahead, so this is safe.
805 */
806 if (matches) {
807 o->cache_bottom += matches;
808 return mask;
809 }
810 }
811
812 if (traverse_trees_recursive(n, dirmask, conflicts,
813 names, info) < 0)
814 return -1;
815 return mask;
816 }
817
818 return mask;
819 }
820
821 /*
822 * N-way merge "len" trees. Returns 0 on success, -1 on failure to manipulate the
823 * resulting index, -2 on failure to reflect the changes to the work tree.
824 */
825 int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
826 {
827 int i, ret;
828 static struct cache_entry *dfc;
829 struct exclude_list el;
830
831 if (len > MAX_UNPACK_TREES)
832 die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
833 memset(&state, 0, sizeof(state));
834 state.base_dir = "";
835 state.force = 1;
836 state.quiet = 1;
837 state.refresh_cache = 1;
838
839 memset(&el, 0, sizeof(el));
840 if (!core_apply_sparse_checkout || !o->update)
841 o->skip_sparse_checkout = 1;
842 if (!o->skip_sparse_checkout) {
843 if (add_excludes_from_file_to_list(git_path("info/sparse-checkout"), "", 0, NULL, &el, 0) < 0)
844 o->skip_sparse_checkout = 1;
845 else
846 o->el = &el;
847 }
848
849 memset(&o->result, 0, sizeof(o->result));
850 o->result.initialized = 1;
851 o->result.timestamp.sec = o->src_index->timestamp.sec;
852 o->result.timestamp.nsec = o->src_index->timestamp.nsec;
853 o->merge_size = len;
854 mark_all_ce_unused(o->src_index);
855
856 if (!dfc)
857 dfc = xcalloc(1, cache_entry_size(0));
858 o->df_conflict_entry = dfc;
859
860 if (len) {
861 const char *prefix = o->prefix ? o->prefix : "";
862 struct traverse_info info;
863
864 setup_traverse_info(&info, prefix);
865 info.fn = unpack_callback;
866 info.data = o;
867 info.show_all_errors = o->show_all_errors;
868
869 if (o->prefix) {
870 /*
871 * Unpack existing index entries that sort before the
872 * prefix the tree is spliced into. Note that o->merge
873 * is always true in this case.
874 */
875 while (1) {
876 struct cache_entry *ce = next_cache_entry(o);
877 if (!ce)
878 break;
879 if (ce_in_traverse_path(ce, &info))
880 break;
881 if (unpack_index_entry(ce, o) < 0)
882 goto return_failed;
883 }
884 }
885
886 if (traverse_trees(len, t, &info) < 0)
887 goto return_failed;
888 }
889
890 /* Any left-over entries in the index? */
891 if (o->merge) {
892 while (1) {
893 struct cache_entry *ce = next_cache_entry(o);
894 if (!ce)
895 break;
896 if (unpack_index_entry(ce, o) < 0)
897 goto return_failed;
898 }
899 }
900 mark_all_ce_unused(o->src_index);
901
902 if (o->trivial_merges_only && o->nontrivial_merge) {
903 ret = unpack_failed(o, "Merge requires file-level merging");
904 goto done;
905 }
906
907 if (!o->skip_sparse_checkout) {
908 int empty_worktree = 1;
909 for (i = 0;i < o->result.cache_nr;i++) {
910 struct cache_entry *ce = o->result.cache[i];
911
912 if (apply_sparse_checkout(ce, o)) {
913 ret = -1;
914 goto done;
915 }
916 /*
917 * Merge strategies may set CE_UPDATE|CE_REMOVE outside checkout
918 * area as a result of ce_skip_worktree() shortcuts in
919 * verify_absent() and verify_uptodate(). Clear them.
920 */
921 if (ce_skip_worktree(ce))
922 ce->ce_flags &= ~(CE_UPDATE | CE_REMOVE);
923 else
924 empty_worktree = 0;
925
926 }
927 if (o->result.cache_nr && empty_worktree) {
928 ret = unpack_failed(o, "Sparse checkout leaves no entry on working directory");
929 goto done;
930 }
931 }
932
933 o->src_index = NULL;
934 ret = check_updates(o) ? (-2) : 0;
935 if (o->dst_index)
936 *o->dst_index = o->result;
937
938 done:
939 for (i = 0;i < el.nr;i++)
940 free(el.excludes[i]);
941 if (el.excludes)
942 free(el.excludes);
943
944 return ret;
945
946 return_failed:
947 if (o->show_all_errors)
948 display_error_msgs(o);
949 mark_all_ce_unused(o->src_index);
950 ret = unpack_failed(o, NULL);
951 goto done;
952 }
953
954 /* Here come the merge functions */
955
956 static int reject_merge(struct cache_entry *ce, struct unpack_trees_options *o)
957 {
958 return add_rejected_path(o, ERROR_WOULD_OVERWRITE, ce->name);
959 }
960
961 static int same(struct cache_entry *a, struct cache_entry *b)
962 {
963 if (!!a != !!b)
964 return 0;
965 if (!a && !b)
966 return 1;
967 if ((a->ce_flags | b->ce_flags) & CE_CONFLICTED)
968 return 0;
969 return a->ce_mode == b->ce_mode &&
970 !hashcmp(a->sha1, b->sha1);
971 }
972
973
974 /*
975 * When a CE gets turned into an unmerged entry, we
976 * want it to be up-to-date
977 */
978 static int verify_uptodate_1(struct cache_entry *ce,
979 struct unpack_trees_options *o,
980 enum unpack_trees_error_types error_type)
981 {
982 struct stat st;
983
984 if (o->index_only || (!((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) && (o->reset || ce_uptodate(ce))))
985 return 0;
986
987 if (!lstat(ce->name, &st)) {
988 unsigned changed = ie_match_stat(o->src_index, ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
989 if (!changed)
990 return 0;
991 /*
992 * NEEDSWORK: the current default policy is to allow
993 * submodule to be out of sync wrt the supermodule
994 * index. This needs to be tightened later for
995 * submodules that are marked to be automatically
996 * checked out.
997 */
998 if (S_ISGITLINK(ce->ce_mode))
999 return 0;
1000 errno = 0;
1001 }
1002 if (errno == ENOENT)
1003 return 0;
1004 return o->gently ? -1 :
1005 add_rejected_path(o, error_type, ce->name);
1006 }
1007
1008 static int verify_uptodate(struct cache_entry *ce,
1009 struct unpack_trees_options *o)
1010 {
1011 if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
1012 return 0;
1013 return verify_uptodate_1(ce, o, ERROR_NOT_UPTODATE_FILE);
1014 }
1015
1016 static int verify_uptodate_sparse(struct cache_entry *ce,
1017 struct unpack_trees_options *o)
1018 {
1019 return verify_uptodate_1(ce, o, ERROR_SPARSE_NOT_UPTODATE_FILE);
1020 }
1021
1022 static void invalidate_ce_path(struct cache_entry *ce, struct unpack_trees_options *o)
1023 {
1024 if (ce)
1025 cache_tree_invalidate_path(o->src_index->cache_tree, ce->name);
1026 }
1027
1028 /*
1029 * Check that checking out ce->sha1 in subdir ce->name is not
1030 * going to overwrite any working files.
1031 *
1032 * Currently, git does not checkout subprojects during a superproject
1033 * checkout, so it is not going to overwrite anything.
1034 */
1035 static int verify_clean_submodule(struct cache_entry *ce,
1036 enum unpack_trees_error_types error_type,
1037 struct unpack_trees_options *o)
1038 {
1039 return 0;
1040 }
1041
1042 static int verify_clean_subdirectory(struct cache_entry *ce,
1043 enum unpack_trees_error_types error_type,
1044 struct unpack_trees_options *o)
1045 {
1046 /*
1047 * we are about to extract "ce->name"; we would not want to lose
1048 * anything in the existing directory there.
1049 */
1050 int namelen;
1051 int i;
1052 struct dir_struct d;
1053 char *pathbuf;
1054 int cnt = 0;
1055 unsigned char sha1[20];
1056
1057 if (S_ISGITLINK(ce->ce_mode) &&
1058 resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
1059 /* If we are not going to update the submodule, then
1060 * we don't care.
1061 */
1062 if (!hashcmp(sha1, ce->sha1))
1063 return 0;
1064 return verify_clean_submodule(ce, error_type, o);
1065 }
1066
1067 /*
1068 * First let's make sure we do not have a local modification
1069 * in that directory.
1070 */
1071 namelen = strlen(ce->name);
1072 for (i = locate_in_src_index(ce, o);
1073 i < o->src_index->cache_nr;
1074 i++) {
1075 struct cache_entry *ce2 = o->src_index->cache[i];
1076 int len = ce_namelen(ce2);
1077 if (len < namelen ||
1078 strncmp(ce->name, ce2->name, namelen) ||
1079 ce2->name[namelen] != '/')
1080 break;
1081 /*
1082 * ce2->name is an entry in the subdirectory to be
1083 * removed.
1084 */
1085 if (!ce_stage(ce2)) {
1086 if (verify_uptodate(ce2, o))
1087 return -1;
1088 add_entry(o, ce2, CE_REMOVE, 0);
1089 mark_ce_used(ce2, o);
1090 }
1091 cnt++;
1092 }
1093
1094 /*
1095 * Then we need to make sure that we do not lose a locally
1096 * present file that is not ignored.
1097 */
1098 pathbuf = xmalloc(namelen + 2);
1099 memcpy(pathbuf, ce->name, namelen);
1100 strcpy(pathbuf+namelen, "/");
1101
1102 memset(&d, 0, sizeof(d));
1103 if (o->dir)
1104 d.exclude_per_dir = o->dir->exclude_per_dir;
1105 i = read_directory(&d, pathbuf, namelen+1, NULL);
1106 if (i)
1107 return o->gently ? -1 :
1108 add_rejected_path(o, ERROR_NOT_UPTODATE_DIR, ce->name);
1109 free(pathbuf);
1110 return cnt;
1111 }
1112
1113 /*
1114 * This gets called when there was no index entry for the tree entry 'dst',
1115 * but we found a file in the working tree that 'lstat()' said was fine,
1116 * and we're on a case-insensitive filesystem.
1117 *
1118 * See if we can find a case-insensitive match in the index that also
1119 * matches the stat information, and assume it's that other file!
1120 */
1121 static int icase_exists(struct unpack_trees_options *o, struct cache_entry *dst, struct stat *st)
1122 {
1123 struct cache_entry *src;
1124
1125 src = index_name_exists(o->src_index, dst->name, ce_namelen(dst), 1);
1126 return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
1127 }
1128
1129 /*
1130 * We do not want to remove or overwrite a working tree file that
1131 * is not tracked, unless it is ignored.
1132 */
1133 static int verify_absent_1(struct cache_entry *ce,
1134 enum unpack_trees_error_types error_type,
1135 struct unpack_trees_options *o)
1136 {
1137 struct stat st;
1138
1139 if (o->index_only || o->reset || !o->update)
1140 return 0;
1141
1142 if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
1143 return 0;
1144
1145 if (!lstat(ce->name, &st)) {
1146 int dtype = ce_to_dtype(ce);
1147 struct cache_entry *result;
1148
1149 /*
1150 * It may be that the 'lstat()' succeeded even though
1151 * target 'ce' was absent, because there is an old
1152 * entry that is different only in case..
1153 *
1154 * Ignore that lstat() if it matches.
1155 */
1156 if (ignore_case && icase_exists(o, ce, &st))
1157 return 0;
1158
1159 if (o->dir && excluded(o->dir, ce->name, &dtype))
1160 /*
1161 * ce->name is explicitly excluded, so it is Ok to
1162 * overwrite it.
1163 */
1164 return 0;
1165 if (S_ISDIR(st.st_mode)) {
1166 /*
1167 * We are checking out path "foo" and
1168 * found "foo/." in the working tree.
1169 * This is tricky -- if we have modified
1170 * files that are in "foo/" we would lose
1171 * them.
1172 */
1173 if (verify_clean_subdirectory(ce, error_type, o) < 0)
1174 return -1;
1175 return 0;
1176 }
1177
1178 /*
1179 * The previous round may already have decided to
1180 * delete this path, which is in a subdirectory that
1181 * is being replaced with a blob.
1182 */
1183 result = index_name_exists(&o->result, ce->name, ce_namelen(ce), 0);
1184 if (result) {
1185 if (result->ce_flags & CE_REMOVE)
1186 return 0;
1187 }
1188
1189 return o->gently ? -1 :
1190 add_rejected_path(o, error_type, ce->name);
1191 }
1192 return 0;
1193 }
1194 static int verify_absent(struct cache_entry *ce,
1195 enum unpack_trees_error_types error_type,
1196 struct unpack_trees_options *o)
1197 {
1198 if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
1199 return 0;
1200 return verify_absent_1(ce, error_type, o);
1201 }
1202
1203 static int verify_absent_sparse(struct cache_entry *ce,
1204 enum unpack_trees_error_types error_type,
1205 struct unpack_trees_options *o)
1206 {
1207 enum unpack_trees_error_types orphaned_error = error_type;
1208 if (orphaned_error == ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN)
1209 orphaned_error = ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN;
1210
1211 return verify_absent_1(ce, orphaned_error, o);
1212 }
1213
1214 static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
1215 struct unpack_trees_options *o)
1216 {
1217 int update = CE_UPDATE;
1218
1219 if (!old) {
1220 if (verify_absent(merge, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o))
1221 return -1;
1222 invalidate_ce_path(merge, o);
1223 } else if (!(old->ce_flags & CE_CONFLICTED)) {
1224 /*
1225 * See if we can re-use the old CE directly?
1226 * That way we get the uptodate stat info.
1227 *
1228 * This also removes the UPDATE flag on a match; otherwise
1229 * we will end up overwriting local changes in the work tree.
1230 */
1231 if (same(old, merge)) {
1232 copy_cache_entry(merge, old);
1233 update = 0;
1234 } else {
1235 if (verify_uptodate(old, o))
1236 return -1;
1237 if (ce_skip_worktree(old))
1238 update |= CE_SKIP_WORKTREE;
1239 invalidate_ce_path(old, o);
1240 }
1241 } else {
1242 /*
1243 * Previously unmerged entry left as an existence
1244 * marker by read_index_unmerged();
1245 */
1246 invalidate_ce_path(old, o);
1247 }
1248
1249 add_entry(o, merge, update, CE_STAGEMASK);
1250 return 1;
1251 }
1252
1253 static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
1254 struct unpack_trees_options *o)
1255 {
1256 /* Did it exist in the index? */
1257 if (!old) {
1258 if (verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_REMOVED, o))
1259 return -1;
1260 return 0;
1261 }
1262 if (!(old->ce_flags & CE_CONFLICTED) && verify_uptodate(old, o))
1263 return -1;
1264 add_entry(o, ce, CE_REMOVE, 0);
1265 invalidate_ce_path(ce, o);
1266 return 1;
1267 }
1268
1269 static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o)
1270 {
1271 add_entry(o, ce, 0, 0);
1272 return 1;
1273 }
1274
1275 #if DBRT_DEBUG
1276 static void show_stage_entry(FILE *o,
1277 const char *label, const struct cache_entry *ce)
1278 {
1279 if (!ce)
1280 fprintf(o, "%s (missing)\n", label);
1281 else
1282 fprintf(o, "%s%06o %s %d\t%s\n",
1283 label,
1284 ce->ce_mode,
1285 sha1_to_hex(ce->sha1),
1286 ce_stage(ce),
1287 ce->name);
1288 }
1289 #endif
1290
1291 int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o)
1292 {
1293 struct cache_entry *index;
1294 struct cache_entry *head;
1295 struct cache_entry *remote = stages[o->head_idx + 1];
1296 int count;
1297 int head_match = 0;
1298 int remote_match = 0;
1299
1300 int df_conflict_head = 0;
1301 int df_conflict_remote = 0;
1302
1303 int any_anc_missing = 0;
1304 int no_anc_exists = 1;
1305 int i;
1306
1307 for (i = 1; i < o->head_idx; i++) {
1308 if (!stages[i] || stages[i] == o->df_conflict_entry)
1309 any_anc_missing = 1;
1310 else
1311 no_anc_exists = 0;
1312 }
1313
1314 index = stages[0];
1315 head = stages[o->head_idx];
1316
1317 if (head == o->df_conflict_entry) {
1318 df_conflict_head = 1;
1319 head = NULL;
1320 }
1321
1322 if (remote == o->df_conflict_entry) {
1323 df_conflict_remote = 1;
1324 remote = NULL;
1325 }
1326
1327 /*
1328 * First, if there's a #16 situation, note that to prevent #13
1329 * and #14.
1330 */
1331 if (!same(remote, head)) {
1332 for (i = 1; i < o->head_idx; i++) {
1333 if (same(stages[i], head)) {
1334 head_match = i;
1335 }
1336 if (same(stages[i], remote)) {
1337 remote_match = i;
1338 }
1339 }
1340 }
1341
1342 /*
1343 * We start with cases where the index is allowed to match
1344 * something other than the head: #14(ALT) and #2ALT, where it
1345 * is permitted to match the result instead.
1346 */
1347 /* #14, #14ALT, #2ALT */
1348 if (remote && !df_conflict_head && head_match && !remote_match) {
1349 if (index && !same(index, remote) && !same(index, head))
1350 return o->gently ? -1 : reject_merge(index, o);
1351 return merged_entry(remote, index, o);
1352 }
1353 /*
1354 * If we have an entry in the index cache, then we want to
1355 * make sure that it matches head.
1356 */
1357 if (index && !same(index, head))
1358 return o->gently ? -1 : reject_merge(index, o);
1359
1360 if (head) {
1361 /* #5ALT, #15 */
1362 if (same(head, remote))
1363 return merged_entry(head, index, o);
1364 /* #13, #3ALT */
1365 if (!df_conflict_remote && remote_match && !head_match)
1366 return merged_entry(head, index, o);
1367 }
1368
1369 /* #1 */
1370 if (!head && !remote && any_anc_missing)
1371 return 0;
1372
1373 /*
1374 * Under the "aggressive" rule, we resolve mostly trivial
1375 * cases that we historically had git-merge-one-file resolve.
1376 */
1377 if (o->aggressive) {
1378 int head_deleted = !head;
1379 int remote_deleted = !remote;
1380 struct cache_entry *ce = NULL;
1381
1382 if (index)
1383 ce = index;
1384 else if (head)
1385 ce = head;
1386 else if (remote)
1387 ce = remote;
1388 else {
1389 for (i = 1; i < o->head_idx; i++) {
1390 if (stages[i] && stages[i] != o->df_conflict_entry) {
1391 ce = stages[i];
1392 break;
1393 }
1394 }
1395 }
1396
1397 /*
1398 * Deleted in both.
1399 * Deleted in one and unchanged in the other.
1400 */
1401 if ((head_deleted && remote_deleted) ||
1402 (head_deleted && remote && remote_match) ||
1403 (remote_deleted && head && head_match)) {
1404 if (index)
1405 return deleted_entry(index, index, o);
1406 if (ce && !head_deleted) {
1407 if (verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_REMOVED, o))
1408 return -1;
1409 }
1410 return 0;
1411 }
1412 /*
1413 * Added in both, identically.
1414 */
1415 if (no_anc_exists && head && remote && same(head, remote))
1416 return merged_entry(head, index, o);
1417
1418 }
1419
1420 /* Below are "no merge" cases, which require that the index be
1421 * up-to-date to avoid the files getting overwritten with
1422 * conflict resolution files.
1423 */
1424 if (index) {
1425 if (verify_uptodate(index, o))
1426 return -1;
1427 }
1428
1429 o->nontrivial_merge = 1;
1430
1431 /* #2, #3, #4, #6, #7, #9, #10, #11. */
1432 count = 0;
1433 if (!head_match || !remote_match) {
1434 for (i = 1; i < o->head_idx; i++) {
1435 if (stages[i] && stages[i] != o->df_conflict_entry) {
1436 keep_entry(stages[i], o);
1437 count++;
1438 break;
1439 }
1440 }
1441 }
1442 #if DBRT_DEBUG
1443 else {
1444 fprintf(stderr, "read-tree: warning #16 detected\n");
1445 show_stage_entry(stderr, "head ", stages[head_match]);
1446 show_stage_entry(stderr, "remote ", stages[remote_match]);
1447 }
1448 #endif
1449 if (head) { count += keep_entry(head, o); }
1450 if (remote) { count += keep_entry(remote, o); }
1451 return count;
1452 }
1453
1454 /*
1455 * Two-way merge.
1456 *
1457 * The rule is to "carry forward" what is in the index without losing
1458 * information across a "fast-forward", favoring a successful merge
1459 * over a merge failure when it makes sense. For details of the
1460 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
1461 *
1462 */
1463 int twoway_merge(struct cache_entry **src, struct unpack_trees_options *o)
1464 {
1465 struct cache_entry *current = src[0];
1466 struct cache_entry *oldtree = src[1];
1467 struct cache_entry *newtree = src[2];
1468
1469 if (o->merge_size != 2)
1470 return error("Cannot do a twoway merge of %d trees",
1471 o->merge_size);
1472
1473 if (oldtree == o->df_conflict_entry)
1474 oldtree = NULL;
1475 if (newtree == o->df_conflict_entry)
1476 newtree = NULL;
1477
1478 if (current) {
1479 if ((!oldtree && !newtree) || /* 4 and 5 */
1480 (!oldtree && newtree &&
1481 same(current, newtree)) || /* 6 and 7 */
1482 (oldtree && newtree &&
1483 same(oldtree, newtree)) || /* 14 and 15 */
1484 (oldtree && newtree &&
1485 !same(oldtree, newtree) && /* 18 and 19 */
1486 same(current, newtree))) {
1487 return keep_entry(current, o);
1488 }
1489 else if (oldtree && !newtree && same(current, oldtree)) {
1490 /* 10 or 11 */
1491 return deleted_entry(oldtree, current, o);
1492 }
1493 else if (oldtree && newtree &&
1494 same(current, oldtree) && !same(current, newtree)) {
1495 /* 20 or 21 */
1496 return merged_entry(newtree, current, o);
1497 }
1498 else {
1499 /* all other failures */
1500 if (oldtree)
1501 return o->gently ? -1 : reject_merge(oldtree, o);
1502 if (current)
1503 return o->gently ? -1 : reject_merge(current, o);
1504 if (newtree)
1505 return o->gently ? -1 : reject_merge(newtree, o);
1506 return -1;
1507 }
1508 }
1509 else if (newtree) {
1510 if (oldtree && !o->initial_checkout) {
1511 /*
1512 * deletion of the path was staged;
1513 */
1514 if (same(oldtree, newtree))
1515 return 1;
1516 return reject_merge(oldtree, o);
1517 }
1518 return merged_entry(newtree, current, o);
1519 }
1520 return deleted_entry(oldtree, current, o);
1521 }
1522
1523 /*
1524 * Bind merge.
1525 *
1526 * Keep the index entries at stage0, collapse stage1 but make sure
1527 * stage0 does not have anything there.
1528 */
1529 int bind_merge(struct cache_entry **src,
1530 struct unpack_trees_options *o)
1531 {
1532 struct cache_entry *old = src[0];
1533 struct cache_entry *a = src[1];
1534
1535 if (o->merge_size != 1)
1536 return error("Cannot do a bind merge of %d trees\n",
1537 o->merge_size);
1538 if (a && old)
1539 return o->gently ? -1 :
1540 error(ERRORMSG(o, ERROR_BIND_OVERLAP), a->name, old->name);
1541 if (!a)
1542 return keep_entry(old, o);
1543 else
1544 return merged_entry(a, NULL, o);
1545 }
1546
1547 /*
1548 * One-way merge.
1549 *
1550 * The rule is:
1551 * - take the stat information from stage0, take the data from stage1
1552 */
1553 int oneway_merge(struct cache_entry **src, struct unpack_trees_options *o)
1554 {
1555 struct cache_entry *old = src[0];
1556 struct cache_entry *a = src[1];
1557
1558 if (o->merge_size != 1)
1559 return error("Cannot do a oneway merge of %d trees",
1560 o->merge_size);
1561
1562 if (!a || a == o->df_conflict_entry)
1563 return deleted_entry(old, old, o);
1564
1565 if (old && same(old, a)) {
1566 int update = 0;
1567 if (o->reset && !ce_uptodate(old) && !ce_skip_worktree(old)) {
1568 struct stat st;
1569 if (lstat(old->name, &st) ||
1570 ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE))
1571 update |= CE_UPDATE;
1572 }
1573 add_entry(o, old, update, 0);
1574 return 0;
1575 }
1576 return merged_entry(a, old, o);
1577 }