Merge branch 'jk/two-way-merge-corner-case-fix'
[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 static 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 int i;
57 const char **msgs = opts->msgs;
58 const char *msg;
59 char *tmp;
60 const char *cmd2 = strcmp(cmd, "checkout") ? cmd : "switch branches";
61 if (advice_commit_before_merge)
62 msg = "Your local changes to the following files would be overwritten by %s:\n%%s"
63 "Please, commit your changes or stash them before you can %s.";
64 else
65 msg = "Your local changes to the following files would be overwritten by %s:\n%%s";
66 tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen(cmd2) - 2);
67 sprintf(tmp, msg, cmd, cmd2);
68 msgs[ERROR_WOULD_OVERWRITE] = tmp;
69 msgs[ERROR_NOT_UPTODATE_FILE] = tmp;
70
71 msgs[ERROR_NOT_UPTODATE_DIR] =
72 "Updating the following directories would lose untracked files in it:\n%s";
73
74 if (advice_commit_before_merge)
75 msg = "The following untracked working tree files would be %s by %s:\n%%s"
76 "Please move or remove them before you can %s.";
77 else
78 msg = "The following untracked working tree files would be %s by %s:\n%%s";
79 tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen("removed") + strlen(cmd2) - 4);
80 sprintf(tmp, msg, "removed", cmd, cmd2);
81 msgs[ERROR_WOULD_LOSE_UNTRACKED_REMOVED] = tmp;
82 tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen("overwritten") + strlen(cmd2) - 4);
83 sprintf(tmp, msg, "overwritten", cmd, cmd2);
84 msgs[ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN] = tmp;
85
86 /*
87 * Special case: ERROR_BIND_OVERLAP refers to a pair of paths, we
88 * cannot easily display it as a list.
89 */
90 msgs[ERROR_BIND_OVERLAP] = "Entry '%s' overlaps with '%s'. Cannot bind.";
91
92 msgs[ERROR_SPARSE_NOT_UPTODATE_FILE] =
93 "Cannot update sparse checkout: the following entries are not up-to-date:\n%s";
94 msgs[ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN] =
95 "The following Working tree files would be overwritten by sparse checkout update:\n%s";
96 msgs[ERROR_WOULD_LOSE_ORPHANED_REMOVED] =
97 "The following Working tree files would be removed by sparse checkout update:\n%s";
98
99 opts->show_all_errors = 1;
100 /* rejected paths may not have a static buffer */
101 for (i = 0; i < ARRAY_SIZE(opts->unpack_rejects); i++)
102 opts->unpack_rejects[i].strdup_strings = 1;
103 }
104
105 static void do_add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
106 unsigned int set, unsigned int clear)
107 {
108 clear |= CE_HASHED | CE_UNHASHED;
109
110 if (set & CE_REMOVE)
111 set |= CE_WT_REMOVE;
112
113 ce->next = NULL;
114 ce->ce_flags = (ce->ce_flags & ~clear) | set;
115 add_index_entry(&o->result, ce,
116 ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
117 }
118
119 static struct cache_entry *dup_entry(const struct cache_entry *ce)
120 {
121 unsigned int size = ce_size(ce);
122 struct cache_entry *new = xmalloc(size);
123
124 memcpy(new, ce, size);
125 return new;
126 }
127
128 static void add_entry(struct unpack_trees_options *o,
129 const struct cache_entry *ce,
130 unsigned int set, unsigned int clear)
131 {
132 do_add_entry(o, dup_entry(ce), set, clear);
133 }
134
135 /*
136 * add error messages on path <path>
137 * corresponding to the type <e> with the message <msg>
138 * indicating if it should be display in porcelain or not
139 */
140 static int add_rejected_path(struct unpack_trees_options *o,
141 enum unpack_trees_error_types e,
142 const char *path)
143 {
144 if (!o->show_all_errors)
145 return error(ERRORMSG(o, e), path);
146
147 /*
148 * Otherwise, insert in a list for future display by
149 * display_error_msgs()
150 */
151 string_list_append(&o->unpack_rejects[e], path);
152 return -1;
153 }
154
155 /*
156 * display all the error messages stored in a nice way
157 */
158 static void display_error_msgs(struct unpack_trees_options *o)
159 {
160 int e, i;
161 int something_displayed = 0;
162 for (e = 0; e < NB_UNPACK_TREES_ERROR_TYPES; e++) {
163 struct string_list *rejects = &o->unpack_rejects[e];
164 if (rejects->nr > 0) {
165 struct strbuf path = STRBUF_INIT;
166 something_displayed = 1;
167 for (i = 0; i < rejects->nr; i++)
168 strbuf_addf(&path, "\t%s\n", rejects->items[i].string);
169 error(ERRORMSG(o, e), path.buf);
170 strbuf_release(&path);
171 }
172 string_list_clear(rejects, 0);
173 }
174 if (something_displayed)
175 fprintf(stderr, "Aborting\n");
176 }
177
178 /*
179 * Unlink the last component and schedule the leading directories for
180 * removal, such that empty directories get removed.
181 */
182 static void unlink_entry(const struct cache_entry *ce)
183 {
184 if (!check_leading_path(ce->name, ce_namelen(ce)))
185 return;
186 if (remove_or_warn(ce->ce_mode, ce->name))
187 return;
188 schedule_dir_for_removal(ce->name, ce_namelen(ce));
189 }
190
191 static struct checkout state;
192 static int check_updates(struct unpack_trees_options *o)
193 {
194 unsigned cnt = 0, total = 0;
195 struct progress *progress = NULL;
196 struct index_state *index = &o->result;
197 int i;
198 int errs = 0;
199
200 if (o->update && o->verbose_update) {
201 for (total = cnt = 0; cnt < index->cache_nr; cnt++) {
202 const struct cache_entry *ce = index->cache[cnt];
203 if (ce->ce_flags & (CE_UPDATE | CE_WT_REMOVE))
204 total++;
205 }
206
207 progress = start_progress_delay("Checking out files",
208 total, 50, 1);
209 cnt = 0;
210 }
211
212 if (o->update)
213 git_attr_set_direction(GIT_ATTR_CHECKOUT, &o->result);
214 for (i = 0; i < index->cache_nr; i++) {
215 const struct cache_entry *ce = index->cache[i];
216
217 if (ce->ce_flags & CE_WT_REMOVE) {
218 display_progress(progress, ++cnt);
219 if (o->update && !o->dry_run)
220 unlink_entry(ce);
221 continue;
222 }
223 }
224 remove_marked_cache_entries(&o->result);
225 remove_scheduled_dirs();
226
227 for (i = 0; i < index->cache_nr; i++) {
228 struct cache_entry *ce = index->cache[i];
229
230 if (ce->ce_flags & CE_UPDATE) {
231 display_progress(progress, ++cnt);
232 ce->ce_flags &= ~CE_UPDATE;
233 if (o->update && !o->dry_run) {
234 errs |= checkout_entry(ce, &state, NULL);
235 }
236 }
237 }
238 stop_progress(&progress);
239 if (o->update)
240 git_attr_set_direction(GIT_ATTR_CHECKIN, NULL);
241 return errs != 0;
242 }
243
244 static int verify_uptodate_sparse(const struct cache_entry *ce,
245 struct unpack_trees_options *o);
246 static int verify_absent_sparse(const struct cache_entry *ce,
247 enum unpack_trees_error_types,
248 struct unpack_trees_options *o);
249
250 static int apply_sparse_checkout(struct cache_entry *ce, struct unpack_trees_options *o)
251 {
252 int was_skip_worktree = ce_skip_worktree(ce);
253
254 if (ce->ce_flags & CE_NEW_SKIP_WORKTREE)
255 ce->ce_flags |= CE_SKIP_WORKTREE;
256 else
257 ce->ce_flags &= ~CE_SKIP_WORKTREE;
258
259 /*
260 * if (!was_skip_worktree && !ce_skip_worktree()) {
261 * This is perfectly normal. Move on;
262 * }
263 */
264
265 /*
266 * Merge strategies may set CE_UPDATE|CE_REMOVE outside checkout
267 * area as a result of ce_skip_worktree() shortcuts in
268 * verify_absent() and verify_uptodate().
269 * Make sure they don't modify worktree if they are already
270 * outside checkout area
271 */
272 if (was_skip_worktree && ce_skip_worktree(ce)) {
273 ce->ce_flags &= ~CE_UPDATE;
274
275 /*
276 * By default, when CE_REMOVE is on, CE_WT_REMOVE is also
277 * on to get that file removed from both index and worktree.
278 * If that file is already outside worktree area, don't
279 * bother remove it.
280 */
281 if (ce->ce_flags & CE_REMOVE)
282 ce->ce_flags &= ~CE_WT_REMOVE;
283 }
284
285 if (!was_skip_worktree && ce_skip_worktree(ce)) {
286 /*
287 * If CE_UPDATE is set, verify_uptodate() must be called already
288 * also stat info may have lost after merged_entry() so calling
289 * verify_uptodate() again may fail
290 */
291 if (!(ce->ce_flags & CE_UPDATE) && verify_uptodate_sparse(ce, o))
292 return -1;
293 ce->ce_flags |= CE_WT_REMOVE;
294 }
295 if (was_skip_worktree && !ce_skip_worktree(ce)) {
296 if (verify_absent_sparse(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o))
297 return -1;
298 ce->ce_flags |= CE_UPDATE;
299 }
300 return 0;
301 }
302
303 static inline int call_unpack_fn(const struct cache_entry * const *src,
304 struct unpack_trees_options *o)
305 {
306 int ret = o->fn(src, o);
307 if (ret > 0)
308 ret = 0;
309 return ret;
310 }
311
312 static void mark_ce_used(struct cache_entry *ce, struct unpack_trees_options *o)
313 {
314 ce->ce_flags |= CE_UNPACKED;
315
316 if (o->cache_bottom < o->src_index->cache_nr &&
317 o->src_index->cache[o->cache_bottom] == ce) {
318 int bottom = o->cache_bottom;
319 while (bottom < o->src_index->cache_nr &&
320 o->src_index->cache[bottom]->ce_flags & CE_UNPACKED)
321 bottom++;
322 o->cache_bottom = bottom;
323 }
324 }
325
326 static void mark_all_ce_unused(struct index_state *index)
327 {
328 int i;
329 for (i = 0; i < index->cache_nr; i++)
330 index->cache[i]->ce_flags &= ~(CE_UNPACKED | CE_ADDED | CE_NEW_SKIP_WORKTREE);
331 }
332
333 static int locate_in_src_index(const struct cache_entry *ce,
334 struct unpack_trees_options *o)
335 {
336 struct index_state *index = o->src_index;
337 int len = ce_namelen(ce);
338 int pos = index_name_pos(index, ce->name, len);
339 if (pos < 0)
340 pos = -1 - pos;
341 return pos;
342 }
343
344 /*
345 * We call unpack_index_entry() with an unmerged cache entry
346 * only in diff-index, and it wants a single callback. Skip
347 * the other unmerged entry with the same name.
348 */
349 static void mark_ce_used_same_name(struct cache_entry *ce,
350 struct unpack_trees_options *o)
351 {
352 struct index_state *index = o->src_index;
353 int len = ce_namelen(ce);
354 int pos;
355
356 for (pos = locate_in_src_index(ce, o); pos < index->cache_nr; pos++) {
357 struct cache_entry *next = index->cache[pos];
358 if (len != ce_namelen(next) ||
359 memcmp(ce->name, next->name, len))
360 break;
361 mark_ce_used(next, o);
362 }
363 }
364
365 static struct cache_entry *next_cache_entry(struct unpack_trees_options *o)
366 {
367 const struct index_state *index = o->src_index;
368 int pos = o->cache_bottom;
369
370 while (pos < index->cache_nr) {
371 struct cache_entry *ce = index->cache[pos];
372 if (!(ce->ce_flags & CE_UNPACKED))
373 return ce;
374 pos++;
375 }
376 return NULL;
377 }
378
379 static void add_same_unmerged(const struct cache_entry *ce,
380 struct unpack_trees_options *o)
381 {
382 struct index_state *index = o->src_index;
383 int len = ce_namelen(ce);
384 int pos = index_name_pos(index, ce->name, len);
385
386 if (0 <= pos)
387 die("programming error in a caller of mark_ce_used_same_name");
388 for (pos = -pos - 1; pos < index->cache_nr; pos++) {
389 struct cache_entry *next = index->cache[pos];
390 if (len != ce_namelen(next) ||
391 memcmp(ce->name, next->name, len))
392 break;
393 add_entry(o, next, 0, 0);
394 mark_ce_used(next, o);
395 }
396 }
397
398 static int unpack_index_entry(struct cache_entry *ce,
399 struct unpack_trees_options *o)
400 {
401 const struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
402 int ret;
403
404 src[0] = ce;
405
406 mark_ce_used(ce, o);
407 if (ce_stage(ce)) {
408 if (o->skip_unmerged) {
409 add_entry(o, ce, 0, 0);
410 return 0;
411 }
412 }
413 ret = call_unpack_fn(src, o);
414 if (ce_stage(ce))
415 mark_ce_used_same_name(ce, o);
416 return ret;
417 }
418
419 static int find_cache_pos(struct traverse_info *, const struct name_entry *);
420
421 static void restore_cache_bottom(struct traverse_info *info, int bottom)
422 {
423 struct unpack_trees_options *o = info->data;
424
425 if (o->diff_index_cached)
426 return;
427 o->cache_bottom = bottom;
428 }
429
430 static int switch_cache_bottom(struct traverse_info *info)
431 {
432 struct unpack_trees_options *o = info->data;
433 int ret, pos;
434
435 if (o->diff_index_cached)
436 return 0;
437 ret = o->cache_bottom;
438 pos = find_cache_pos(info->prev, &info->name);
439
440 if (pos < -1)
441 o->cache_bottom = -2 - pos;
442 else if (pos < 0)
443 o->cache_bottom = o->src_index->cache_nr;
444 return ret;
445 }
446
447 static int traverse_trees_recursive(int n, unsigned long dirmask,
448 unsigned long df_conflicts,
449 struct name_entry *names,
450 struct traverse_info *info)
451 {
452 int i, ret, bottom;
453 struct tree_desc t[MAX_UNPACK_TREES];
454 void *buf[MAX_UNPACK_TREES];
455 struct traverse_info newinfo;
456 struct name_entry *p;
457
458 p = names;
459 while (!p->mode)
460 p++;
461
462 newinfo = *info;
463 newinfo.prev = info;
464 newinfo.pathspec = info->pathspec;
465 newinfo.name = *p;
466 newinfo.pathlen += tree_entry_len(p) + 1;
467 newinfo.df_conflicts |= df_conflicts;
468
469 for (i = 0; i < n; i++, dirmask >>= 1) {
470 const unsigned char *sha1 = NULL;
471 if (dirmask & 1)
472 sha1 = names[i].sha1;
473 buf[i] = fill_tree_descriptor(t+i, sha1);
474 }
475
476 bottom = switch_cache_bottom(&newinfo);
477 ret = traverse_trees(n, t, &newinfo);
478 restore_cache_bottom(&newinfo, bottom);
479
480 for (i = 0; i < n; i++)
481 free(buf[i]);
482
483 return ret;
484 }
485
486 /*
487 * Compare the traverse-path to the cache entry without actually
488 * having to generate the textual representation of the traverse
489 * path.
490 *
491 * NOTE! This *only* compares up to the size of the traverse path
492 * itself - the caller needs to do the final check for the cache
493 * entry having more data at the end!
494 */
495 static int do_compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
496 {
497 int len, pathlen, ce_len;
498 const char *ce_name;
499
500 if (info->prev) {
501 int cmp = do_compare_entry(ce, info->prev, &info->name);
502 if (cmp)
503 return cmp;
504 }
505 pathlen = info->pathlen;
506 ce_len = ce_namelen(ce);
507
508 /* If ce_len < pathlen then we must have previously hit "name == directory" entry */
509 if (ce_len < pathlen)
510 return -1;
511
512 ce_len -= pathlen;
513 ce_name = ce->name + pathlen;
514
515 len = tree_entry_len(n);
516 return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode);
517 }
518
519 static int compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
520 {
521 int cmp = do_compare_entry(ce, info, n);
522 if (cmp)
523 return cmp;
524
525 /*
526 * Even if the beginning compared identically, the ce should
527 * compare as bigger than a directory leading up to it!
528 */
529 return ce_namelen(ce) > traverse_path_len(info, n);
530 }
531
532 static int ce_in_traverse_path(const struct cache_entry *ce,
533 const struct traverse_info *info)
534 {
535 if (!info->prev)
536 return 1;
537 if (do_compare_entry(ce, info->prev, &info->name))
538 return 0;
539 /*
540 * If ce (blob) is the same name as the path (which is a tree
541 * we will be descending into), it won't be inside it.
542 */
543 return (info->pathlen < ce_namelen(ce));
544 }
545
546 static struct cache_entry *create_ce_entry(const struct traverse_info *info, const struct name_entry *n, int stage)
547 {
548 int len = traverse_path_len(info, n);
549 struct cache_entry *ce = xcalloc(1, cache_entry_size(len));
550
551 ce->ce_mode = create_ce_mode(n->mode);
552 ce->ce_flags = create_ce_flags(stage);
553 ce->ce_namelen = len;
554 hashcpy(ce->sha1, n->sha1);
555 make_traverse_path(ce->name, info, n);
556
557 return ce;
558 }
559
560 static int unpack_nondirectories(int n, unsigned long mask,
561 unsigned long dirmask,
562 struct cache_entry **src,
563 const struct name_entry *names,
564 const struct traverse_info *info)
565 {
566 int i;
567 struct unpack_trees_options *o = info->data;
568 unsigned long conflicts = info->df_conflicts | dirmask;
569
570 /* Do we have *only* directories? Nothing to do */
571 if (mask == dirmask && !src[0])
572 return 0;
573
574 /*
575 * Ok, we've filled in up to any potential index entry in src[0],
576 * now do the rest.
577 */
578 for (i = 0; i < n; i++) {
579 int stage;
580 unsigned int bit = 1ul << i;
581 if (conflicts & bit) {
582 src[i + o->merge] = o->df_conflict_entry;
583 continue;
584 }
585 if (!(mask & bit))
586 continue;
587 if (!o->merge)
588 stage = 0;
589 else if (i + 1 < o->head_idx)
590 stage = 1;
591 else if (i + 1 > o->head_idx)
592 stage = 3;
593 else
594 stage = 2;
595 src[i + o->merge] = create_ce_entry(info, names + i, stage);
596 }
597
598 if (o->merge) {
599 int rc = call_unpack_fn((const struct cache_entry * const *)src,
600 o);
601 for (i = 0; i < n; i++) {
602 struct cache_entry *ce = src[i + o->merge];
603 if (ce != o->df_conflict_entry)
604 free(ce);
605 }
606 return rc;
607 }
608
609 for (i = 0; i < n; i++)
610 if (src[i] && src[i] != o->df_conflict_entry)
611 do_add_entry(o, src[i], 0, 0);
612 return 0;
613 }
614
615 static int unpack_failed(struct unpack_trees_options *o, const char *message)
616 {
617 discard_index(&o->result);
618 if (!o->gently && !o->exiting_early) {
619 if (message)
620 return error("%s", message);
621 return -1;
622 }
623 return -1;
624 }
625
626 /* NEEDSWORK: give this a better name and share with tree-walk.c */
627 static int name_compare(const char *a, int a_len,
628 const char *b, int b_len)
629 {
630 int len = (a_len < b_len) ? a_len : b_len;
631 int cmp = memcmp(a, b, len);
632 if (cmp)
633 return cmp;
634 return (a_len - b_len);
635 }
636
637 /*
638 * The tree traversal is looking at name p. If we have a matching entry,
639 * return it. If name p is a directory in the index, do not return
640 * anything, as we will want to match it when the traversal descends into
641 * the directory.
642 */
643 static int find_cache_pos(struct traverse_info *info,
644 const struct name_entry *p)
645 {
646 int pos;
647 struct unpack_trees_options *o = info->data;
648 struct index_state *index = o->src_index;
649 int pfxlen = info->pathlen;
650 int p_len = tree_entry_len(p);
651
652 for (pos = o->cache_bottom; pos < index->cache_nr; pos++) {
653 const struct cache_entry *ce = index->cache[pos];
654 const char *ce_name, *ce_slash;
655 int cmp, ce_len;
656
657 if (ce->ce_flags & CE_UNPACKED) {
658 /*
659 * cache_bottom entry is already unpacked, so
660 * we can never match it; don't check it
661 * again.
662 */
663 if (pos == o->cache_bottom)
664 ++o->cache_bottom;
665 continue;
666 }
667 if (!ce_in_traverse_path(ce, info))
668 continue;
669 ce_name = ce->name + pfxlen;
670 ce_slash = strchr(ce_name, '/');
671 if (ce_slash)
672 ce_len = ce_slash - ce_name;
673 else
674 ce_len = ce_namelen(ce) - pfxlen;
675 cmp = name_compare(p->path, p_len, ce_name, ce_len);
676 /*
677 * Exact match; if we have a directory we need to
678 * delay returning it.
679 */
680 if (!cmp)
681 return ce_slash ? -2 - pos : pos;
682 if (0 < cmp)
683 continue; /* keep looking */
684 /*
685 * ce_name sorts after p->path; could it be that we
686 * have files under p->path directory in the index?
687 * E.g. ce_name == "t-i", and p->path == "t"; we may
688 * have "t/a" in the index.
689 */
690 if (p_len < ce_len && !memcmp(ce_name, p->path, p_len) &&
691 ce_name[p_len] < '/')
692 continue; /* keep looking */
693 break;
694 }
695 return -1;
696 }
697
698 static struct cache_entry *find_cache_entry(struct traverse_info *info,
699 const struct name_entry *p)
700 {
701 int pos = find_cache_pos(info, p);
702 struct unpack_trees_options *o = info->data;
703
704 if (0 <= pos)
705 return o->src_index->cache[pos];
706 else
707 return NULL;
708 }
709
710 static void debug_path(struct traverse_info *info)
711 {
712 if (info->prev) {
713 debug_path(info->prev);
714 if (*info->prev->name.path)
715 putchar('/');
716 }
717 printf("%s", info->name.path);
718 }
719
720 static void debug_name_entry(int i, struct name_entry *n)
721 {
722 printf("ent#%d %06o %s\n", i,
723 n->path ? n->mode : 0,
724 n->path ? n->path : "(missing)");
725 }
726
727 static void debug_unpack_callback(int n,
728 unsigned long mask,
729 unsigned long dirmask,
730 struct name_entry *names,
731 struct traverse_info *info)
732 {
733 int i;
734 printf("* unpack mask %lu, dirmask %lu, cnt %d ",
735 mask, dirmask, n);
736 debug_path(info);
737 putchar('\n');
738 for (i = 0; i < n; i++)
739 debug_name_entry(i, names + i);
740 }
741
742 static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *names, struct traverse_info *info)
743 {
744 struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
745 struct unpack_trees_options *o = info->data;
746 const struct name_entry *p = names;
747
748 /* Find first entry with a real name (we could use "mask" too) */
749 while (!p->mode)
750 p++;
751
752 if (o->debug_unpack)
753 debug_unpack_callback(n, mask, dirmask, names, info);
754
755 /* Are we supposed to look at the index too? */
756 if (o->merge) {
757 while (1) {
758 int cmp;
759 struct cache_entry *ce;
760
761 if (o->diff_index_cached)
762 ce = next_cache_entry(o);
763 else
764 ce = find_cache_entry(info, p);
765
766 if (!ce)
767 break;
768 cmp = compare_entry(ce, info, p);
769 if (cmp < 0) {
770 if (unpack_index_entry(ce, o) < 0)
771 return unpack_failed(o, NULL);
772 continue;
773 }
774 if (!cmp) {
775 if (ce_stage(ce)) {
776 /*
777 * If we skip unmerged index
778 * entries, we'll skip this
779 * entry *and* the tree
780 * entries associated with it!
781 */
782 if (o->skip_unmerged) {
783 add_same_unmerged(ce, o);
784 return mask;
785 }
786 }
787 src[0] = ce;
788 }
789 break;
790 }
791 }
792
793 if (unpack_nondirectories(n, mask, dirmask, src, names, info) < 0)
794 return -1;
795
796 if (o->merge && src[0]) {
797 if (ce_stage(src[0]))
798 mark_ce_used_same_name(src[0], o);
799 else
800 mark_ce_used(src[0], o);
801 }
802
803 /* Now handle any directories.. */
804 if (dirmask) {
805 /* special case: "diff-index --cached" looking at a tree */
806 if (o->diff_index_cached &&
807 n == 1 && dirmask == 1 && S_ISDIR(names->mode)) {
808 int matches;
809 matches = cache_tree_matches_traversal(o->src_index->cache_tree,
810 names, info);
811 /*
812 * Everything under the name matches; skip the
813 * entire hierarchy. diff_index_cached codepath
814 * special cases D/F conflicts in such a way that
815 * it does not do any look-ahead, so this is safe.
816 */
817 if (matches) {
818 o->cache_bottom += matches;
819 return mask;
820 }
821 }
822
823 if (traverse_trees_recursive(n, dirmask, mask & ~dirmask,
824 names, info) < 0)
825 return -1;
826 return mask;
827 }
828
829 return mask;
830 }
831
832 static int clear_ce_flags_1(struct cache_entry **cache, int nr,
833 char *prefix, int prefix_len,
834 int select_mask, int clear_mask,
835 struct exclude_list *el, int defval);
836
837 /* Whole directory matching */
838 static int clear_ce_flags_dir(struct cache_entry **cache, int nr,
839 char *prefix, int prefix_len,
840 char *basename,
841 int select_mask, int clear_mask,
842 struct exclude_list *el, int defval)
843 {
844 struct cache_entry **cache_end;
845 int dtype = DT_DIR;
846 int ret = is_excluded_from_list(prefix, prefix_len,
847 basename, &dtype, el);
848
849 prefix[prefix_len++] = '/';
850
851 /* If undecided, use matching result of parent dir in defval */
852 if (ret < 0)
853 ret = defval;
854
855 for (cache_end = cache; cache_end != cache + nr; cache_end++) {
856 struct cache_entry *ce = *cache_end;
857 if (strncmp(ce->name, prefix, prefix_len))
858 break;
859 }
860
861 /*
862 * TODO: check el, if there are no patterns that may conflict
863 * with ret (iow, we know in advance the incl/excl
864 * decision for the entire directory), clear flag here without
865 * calling clear_ce_flags_1(). That function will call
866 * the expensive is_excluded_from_list() on every entry.
867 */
868 return clear_ce_flags_1(cache, cache_end - cache,
869 prefix, prefix_len,
870 select_mask, clear_mask,
871 el, ret);
872 }
873
874 /*
875 * Traverse the index, find every entry that matches according to
876 * o->el. Do "ce_flags &= ~clear_mask" on those entries. Return the
877 * number of traversed entries.
878 *
879 * If select_mask is non-zero, only entries whose ce_flags has on of
880 * those bits enabled are traversed.
881 *
882 * cache : pointer to an index entry
883 * prefix_len : an offset to its path
884 *
885 * The current path ("prefix") including the trailing '/' is
886 * cache[0]->name[0..(prefix_len-1)]
887 * Top level path has prefix_len zero.
888 */
889 static int clear_ce_flags_1(struct cache_entry **cache, int nr,
890 char *prefix, int prefix_len,
891 int select_mask, int clear_mask,
892 struct exclude_list *el, int defval)
893 {
894 struct cache_entry **cache_end = cache + nr;
895
896 /*
897 * Process all entries that have the given prefix and meet
898 * select_mask condition
899 */
900 while(cache != cache_end) {
901 struct cache_entry *ce = *cache;
902 const char *name, *slash;
903 int len, dtype, ret;
904
905 if (select_mask && !(ce->ce_flags & select_mask)) {
906 cache++;
907 continue;
908 }
909
910 if (prefix_len && strncmp(ce->name, prefix, prefix_len))
911 break;
912
913 name = ce->name + prefix_len;
914 slash = strchr(name, '/');
915
916 /* If it's a directory, try whole directory match first */
917 if (slash) {
918 int processed;
919
920 len = slash - name;
921 memcpy(prefix + prefix_len, name, len);
922
923 /*
924 * terminate the string (no trailing slash),
925 * clear_c_f_dir needs it
926 */
927 prefix[prefix_len + len] = '\0';
928 processed = clear_ce_flags_dir(cache, cache_end - cache,
929 prefix, prefix_len + len,
930 prefix + prefix_len,
931 select_mask, clear_mask,
932 el, defval);
933
934 /* clear_c_f_dir eats a whole dir already? */
935 if (processed) {
936 cache += processed;
937 continue;
938 }
939
940 prefix[prefix_len + len++] = '/';
941 cache += clear_ce_flags_1(cache, cache_end - cache,
942 prefix, prefix_len + len,
943 select_mask, clear_mask, el, defval);
944 continue;
945 }
946
947 /* Non-directory */
948 dtype = ce_to_dtype(ce);
949 ret = is_excluded_from_list(ce->name, ce_namelen(ce),
950 name, &dtype, el);
951 if (ret < 0)
952 ret = defval;
953 if (ret > 0)
954 ce->ce_flags &= ~clear_mask;
955 cache++;
956 }
957 return nr - (cache_end - cache);
958 }
959
960 static int clear_ce_flags(struct cache_entry **cache, int nr,
961 int select_mask, int clear_mask,
962 struct exclude_list *el)
963 {
964 char prefix[PATH_MAX];
965 return clear_ce_flags_1(cache, nr,
966 prefix, 0,
967 select_mask, clear_mask,
968 el, 0);
969 }
970
971 /*
972 * Set/Clear CE_NEW_SKIP_WORKTREE according to $GIT_DIR/info/sparse-checkout
973 */
974 static void mark_new_skip_worktree(struct exclude_list *el,
975 struct index_state *the_index,
976 int select_flag, int skip_wt_flag)
977 {
978 int i;
979
980 /*
981 * 1. Pretend the narrowest worktree: only unmerged entries
982 * are checked out
983 */
984 for (i = 0; i < the_index->cache_nr; i++) {
985 struct cache_entry *ce = the_index->cache[i];
986
987 if (select_flag && !(ce->ce_flags & select_flag))
988 continue;
989
990 if (!ce_stage(ce))
991 ce->ce_flags |= skip_wt_flag;
992 else
993 ce->ce_flags &= ~skip_wt_flag;
994 }
995
996 /*
997 * 2. Widen worktree according to sparse-checkout file.
998 * Matched entries will have skip_wt_flag cleared (i.e. "in")
999 */
1000 clear_ce_flags(the_index->cache, the_index->cache_nr,
1001 select_flag, skip_wt_flag, el);
1002 }
1003
1004 static int verify_absent(const struct cache_entry *,
1005 enum unpack_trees_error_types,
1006 struct unpack_trees_options *);
1007 /*
1008 * N-way merge "len" trees. Returns 0 on success, -1 on failure to manipulate the
1009 * resulting index, -2 on failure to reflect the changes to the work tree.
1010 *
1011 * CE_ADDED, CE_UNPACKED and CE_NEW_SKIP_WORKTREE are used internally
1012 */
1013 int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
1014 {
1015 int i, ret;
1016 static struct cache_entry *dfc;
1017 struct exclude_list el;
1018
1019 if (len > MAX_UNPACK_TREES)
1020 die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
1021 memset(&state, 0, sizeof(state));
1022 state.base_dir = "";
1023 state.force = 1;
1024 state.quiet = 1;
1025 state.refresh_cache = 1;
1026
1027 memset(&el, 0, sizeof(el));
1028 if (!core_apply_sparse_checkout || !o->update)
1029 o->skip_sparse_checkout = 1;
1030 if (!o->skip_sparse_checkout) {
1031 if (add_excludes_from_file_to_list(git_path("info/sparse-checkout"), "", 0, &el, 0) < 0)
1032 o->skip_sparse_checkout = 1;
1033 else
1034 o->el = &el;
1035 }
1036
1037 memset(&o->result, 0, sizeof(o->result));
1038 o->result.initialized = 1;
1039 o->result.timestamp.sec = o->src_index->timestamp.sec;
1040 o->result.timestamp.nsec = o->src_index->timestamp.nsec;
1041 o->result.version = o->src_index->version;
1042 o->merge_size = len;
1043 mark_all_ce_unused(o->src_index);
1044
1045 /*
1046 * Sparse checkout loop #1: set NEW_SKIP_WORKTREE on existing entries
1047 */
1048 if (!o->skip_sparse_checkout)
1049 mark_new_skip_worktree(o->el, o->src_index, 0, CE_NEW_SKIP_WORKTREE);
1050
1051 if (!dfc)
1052 dfc = xcalloc(1, cache_entry_size(0));
1053 o->df_conflict_entry = dfc;
1054
1055 if (len) {
1056 const char *prefix = o->prefix ? o->prefix : "";
1057 struct traverse_info info;
1058
1059 setup_traverse_info(&info, prefix);
1060 info.fn = unpack_callback;
1061 info.data = o;
1062 info.show_all_errors = o->show_all_errors;
1063 info.pathspec = o->pathspec;
1064
1065 if (o->prefix) {
1066 /*
1067 * Unpack existing index entries that sort before the
1068 * prefix the tree is spliced into. Note that o->merge
1069 * is always true in this case.
1070 */
1071 while (1) {
1072 struct cache_entry *ce = next_cache_entry(o);
1073 if (!ce)
1074 break;
1075 if (ce_in_traverse_path(ce, &info))
1076 break;
1077 if (unpack_index_entry(ce, o) < 0)
1078 goto return_failed;
1079 }
1080 }
1081
1082 if (traverse_trees(len, t, &info) < 0)
1083 goto return_failed;
1084 }
1085
1086 /* Any left-over entries in the index? */
1087 if (o->merge) {
1088 while (1) {
1089 struct cache_entry *ce = next_cache_entry(o);
1090 if (!ce)
1091 break;
1092 if (unpack_index_entry(ce, o) < 0)
1093 goto return_failed;
1094 }
1095 }
1096 mark_all_ce_unused(o->src_index);
1097
1098 if (o->trivial_merges_only && o->nontrivial_merge) {
1099 ret = unpack_failed(o, "Merge requires file-level merging");
1100 goto done;
1101 }
1102
1103 if (!o->skip_sparse_checkout) {
1104 int empty_worktree = 1;
1105
1106 /*
1107 * Sparse checkout loop #2: set NEW_SKIP_WORKTREE on entries not in loop #1
1108 * If the will have NEW_SKIP_WORKTREE, also set CE_SKIP_WORKTREE
1109 * so apply_sparse_checkout() won't attempt to remove it from worktree
1110 */
1111 mark_new_skip_worktree(o->el, &o->result, CE_ADDED, CE_SKIP_WORKTREE | CE_NEW_SKIP_WORKTREE);
1112
1113 ret = 0;
1114 for (i = 0; i < o->result.cache_nr; i++) {
1115 struct cache_entry *ce = o->result.cache[i];
1116
1117 /*
1118 * Entries marked with CE_ADDED in merged_entry() do not have
1119 * verify_absent() check (the check is effectively disabled
1120 * because CE_NEW_SKIP_WORKTREE is set unconditionally).
1121 *
1122 * Do the real check now because we have had
1123 * correct CE_NEW_SKIP_WORKTREE
1124 */
1125 if (ce->ce_flags & CE_ADDED &&
1126 verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o)) {
1127 if (!o->show_all_errors)
1128 goto return_failed;
1129 ret = -1;
1130 }
1131
1132 if (apply_sparse_checkout(ce, o)) {
1133 if (!o->show_all_errors)
1134 goto return_failed;
1135 ret = -1;
1136 }
1137 if (!ce_skip_worktree(ce))
1138 empty_worktree = 0;
1139
1140 }
1141 if (ret < 0)
1142 goto return_failed;
1143 /*
1144 * Sparse checkout is meant to narrow down checkout area
1145 * but it does not make sense to narrow down to empty working
1146 * tree. This is usually a mistake in sparse checkout rules.
1147 * Do not allow users to do that.
1148 */
1149 if (o->result.cache_nr && empty_worktree) {
1150 ret = unpack_failed(o, "Sparse checkout leaves no entry on working directory");
1151 goto done;
1152 }
1153 }
1154
1155 o->src_index = NULL;
1156 ret = check_updates(o) ? (-2) : 0;
1157 if (o->dst_index) {
1158 discard_index(o->dst_index);
1159 *o->dst_index = o->result;
1160 }
1161
1162 done:
1163 clear_exclude_list(&el);
1164 return ret;
1165
1166 return_failed:
1167 if (o->show_all_errors)
1168 display_error_msgs(o);
1169 mark_all_ce_unused(o->src_index);
1170 ret = unpack_failed(o, NULL);
1171 if (o->exiting_early)
1172 ret = 0;
1173 goto done;
1174 }
1175
1176 /* Here come the merge functions */
1177
1178 static int reject_merge(const struct cache_entry *ce,
1179 struct unpack_trees_options *o)
1180 {
1181 return add_rejected_path(o, ERROR_WOULD_OVERWRITE, ce->name);
1182 }
1183
1184 static int same(const struct cache_entry *a, const struct cache_entry *b)
1185 {
1186 if (!!a != !!b)
1187 return 0;
1188 if (!a && !b)
1189 return 1;
1190 if ((a->ce_flags | b->ce_flags) & CE_CONFLICTED)
1191 return 0;
1192 return a->ce_mode == b->ce_mode &&
1193 !hashcmp(a->sha1, b->sha1);
1194 }
1195
1196
1197 /*
1198 * When a CE gets turned into an unmerged entry, we
1199 * want it to be up-to-date
1200 */
1201 static int verify_uptodate_1(const struct cache_entry *ce,
1202 struct unpack_trees_options *o,
1203 enum unpack_trees_error_types error_type)
1204 {
1205 struct stat st;
1206
1207 if (o->index_only)
1208 return 0;
1209
1210 /*
1211 * CE_VALID and CE_SKIP_WORKTREE cheat, we better check again
1212 * if this entry is truly up-to-date because this file may be
1213 * overwritten.
1214 */
1215 if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
1216 ; /* keep checking */
1217 else if (o->reset || ce_uptodate(ce))
1218 return 0;
1219
1220 if (!lstat(ce->name, &st)) {
1221 int flags = CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE;
1222 unsigned changed = ie_match_stat(o->src_index, ce, &st, flags);
1223 if (!changed)
1224 return 0;
1225 /*
1226 * NEEDSWORK: the current default policy is to allow
1227 * submodule to be out of sync wrt the superproject
1228 * index. This needs to be tightened later for
1229 * submodules that are marked to be automatically
1230 * checked out.
1231 */
1232 if (S_ISGITLINK(ce->ce_mode))
1233 return 0;
1234 errno = 0;
1235 }
1236 if (errno == ENOENT)
1237 return 0;
1238 return o->gently ? -1 :
1239 add_rejected_path(o, error_type, ce->name);
1240 }
1241
1242 static int verify_uptodate(const struct cache_entry *ce,
1243 struct unpack_trees_options *o)
1244 {
1245 if (!o->skip_sparse_checkout && (ce->ce_flags & CE_NEW_SKIP_WORKTREE))
1246 return 0;
1247 return verify_uptodate_1(ce, o, ERROR_NOT_UPTODATE_FILE);
1248 }
1249
1250 static int verify_uptodate_sparse(const struct cache_entry *ce,
1251 struct unpack_trees_options *o)
1252 {
1253 return verify_uptodate_1(ce, o, ERROR_SPARSE_NOT_UPTODATE_FILE);
1254 }
1255
1256 static void invalidate_ce_path(const struct cache_entry *ce,
1257 struct unpack_trees_options *o)
1258 {
1259 if (ce)
1260 cache_tree_invalidate_path(o->src_index->cache_tree, ce->name);
1261 }
1262
1263 /*
1264 * Check that checking out ce->sha1 in subdir ce->name is not
1265 * going to overwrite any working files.
1266 *
1267 * Currently, git does not checkout subprojects during a superproject
1268 * checkout, so it is not going to overwrite anything.
1269 */
1270 static int verify_clean_submodule(const struct cache_entry *ce,
1271 enum unpack_trees_error_types error_type,
1272 struct unpack_trees_options *o)
1273 {
1274 return 0;
1275 }
1276
1277 static int verify_clean_subdirectory(const struct cache_entry *ce,
1278 enum unpack_trees_error_types error_type,
1279 struct unpack_trees_options *o)
1280 {
1281 /*
1282 * we are about to extract "ce->name"; we would not want to lose
1283 * anything in the existing directory there.
1284 */
1285 int namelen;
1286 int i;
1287 struct dir_struct d;
1288 char *pathbuf;
1289 int cnt = 0;
1290 unsigned char sha1[20];
1291
1292 if (S_ISGITLINK(ce->ce_mode) &&
1293 resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
1294 /* If we are not going to update the submodule, then
1295 * we don't care.
1296 */
1297 if (!hashcmp(sha1, ce->sha1))
1298 return 0;
1299 return verify_clean_submodule(ce, error_type, o);
1300 }
1301
1302 /*
1303 * First let's make sure we do not have a local modification
1304 * in that directory.
1305 */
1306 namelen = ce_namelen(ce);
1307 for (i = locate_in_src_index(ce, o);
1308 i < o->src_index->cache_nr;
1309 i++) {
1310 struct cache_entry *ce2 = o->src_index->cache[i];
1311 int len = ce_namelen(ce2);
1312 if (len < namelen ||
1313 strncmp(ce->name, ce2->name, namelen) ||
1314 ce2->name[namelen] != '/')
1315 break;
1316 /*
1317 * ce2->name is an entry in the subdirectory to be
1318 * removed.
1319 */
1320 if (!ce_stage(ce2)) {
1321 if (verify_uptodate(ce2, o))
1322 return -1;
1323 add_entry(o, ce2, CE_REMOVE, 0);
1324 mark_ce_used(ce2, o);
1325 }
1326 cnt++;
1327 }
1328
1329 /*
1330 * Then we need to make sure that we do not lose a locally
1331 * present file that is not ignored.
1332 */
1333 pathbuf = xmalloc(namelen + 2);
1334 memcpy(pathbuf, ce->name, namelen);
1335 strcpy(pathbuf+namelen, "/");
1336
1337 memset(&d, 0, sizeof(d));
1338 if (o->dir)
1339 d.exclude_per_dir = o->dir->exclude_per_dir;
1340 i = read_directory(&d, pathbuf, namelen+1, NULL);
1341 if (i)
1342 return o->gently ? -1 :
1343 add_rejected_path(o, ERROR_NOT_UPTODATE_DIR, ce->name);
1344 free(pathbuf);
1345 return cnt;
1346 }
1347
1348 /*
1349 * This gets called when there was no index entry for the tree entry 'dst',
1350 * but we found a file in the working tree that 'lstat()' said was fine,
1351 * and we're on a case-insensitive filesystem.
1352 *
1353 * See if we can find a case-insensitive match in the index that also
1354 * matches the stat information, and assume it's that other file!
1355 */
1356 static int icase_exists(struct unpack_trees_options *o, const char *name, int len, struct stat *st)
1357 {
1358 const struct cache_entry *src;
1359
1360 src = index_file_exists(o->src_index, name, len, 1);
1361 return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
1362 }
1363
1364 static int check_ok_to_remove(const char *name, int len, int dtype,
1365 const struct cache_entry *ce, struct stat *st,
1366 enum unpack_trees_error_types error_type,
1367 struct unpack_trees_options *o)
1368 {
1369 const struct cache_entry *result;
1370
1371 /*
1372 * It may be that the 'lstat()' succeeded even though
1373 * target 'ce' was absent, because there is an old
1374 * entry that is different only in case..
1375 *
1376 * Ignore that lstat() if it matches.
1377 */
1378 if (ignore_case && icase_exists(o, name, len, st))
1379 return 0;
1380
1381 if (o->dir &&
1382 is_excluded(o->dir, name, &dtype))
1383 /*
1384 * ce->name is explicitly excluded, so it is Ok to
1385 * overwrite it.
1386 */
1387 return 0;
1388 if (S_ISDIR(st->st_mode)) {
1389 /*
1390 * We are checking out path "foo" and
1391 * found "foo/." in the working tree.
1392 * This is tricky -- if we have modified
1393 * files that are in "foo/" we would lose
1394 * them.
1395 */
1396 if (verify_clean_subdirectory(ce, error_type, o) < 0)
1397 return -1;
1398 return 0;
1399 }
1400
1401 /*
1402 * The previous round may already have decided to
1403 * delete this path, which is in a subdirectory that
1404 * is being replaced with a blob.
1405 */
1406 result = index_file_exists(&o->result, name, len, 0);
1407 if (result) {
1408 if (result->ce_flags & CE_REMOVE)
1409 return 0;
1410 }
1411
1412 return o->gently ? -1 :
1413 add_rejected_path(o, error_type, name);
1414 }
1415
1416 /*
1417 * We do not want to remove or overwrite a working tree file that
1418 * is not tracked, unless it is ignored.
1419 */
1420 static int verify_absent_1(const struct cache_entry *ce,
1421 enum unpack_trees_error_types error_type,
1422 struct unpack_trees_options *o)
1423 {
1424 int len;
1425 struct stat st;
1426
1427 if (o->index_only || o->reset || !o->update)
1428 return 0;
1429
1430 len = check_leading_path(ce->name, ce_namelen(ce));
1431 if (!len)
1432 return 0;
1433 else if (len > 0) {
1434 char path[PATH_MAX + 1];
1435 memcpy(path, ce->name, len);
1436 path[len] = 0;
1437 if (lstat(path, &st))
1438 return error("cannot stat '%s': %s", path,
1439 strerror(errno));
1440
1441 return check_ok_to_remove(path, len, DT_UNKNOWN, NULL, &st,
1442 error_type, o);
1443 } else if (lstat(ce->name, &st)) {
1444 if (errno != ENOENT)
1445 return error("cannot stat '%s': %s", ce->name,
1446 strerror(errno));
1447 return 0;
1448 } else {
1449 return check_ok_to_remove(ce->name, ce_namelen(ce),
1450 ce_to_dtype(ce), ce, &st,
1451 error_type, o);
1452 }
1453 }
1454
1455 static int verify_absent(const struct cache_entry *ce,
1456 enum unpack_trees_error_types error_type,
1457 struct unpack_trees_options *o)
1458 {
1459 if (!o->skip_sparse_checkout && (ce->ce_flags & CE_NEW_SKIP_WORKTREE))
1460 return 0;
1461 return verify_absent_1(ce, error_type, o);
1462 }
1463
1464 static int verify_absent_sparse(const struct cache_entry *ce,
1465 enum unpack_trees_error_types error_type,
1466 struct unpack_trees_options *o)
1467 {
1468 enum unpack_trees_error_types orphaned_error = error_type;
1469 if (orphaned_error == ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN)
1470 orphaned_error = ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN;
1471
1472 return verify_absent_1(ce, orphaned_error, o);
1473 }
1474
1475 static int merged_entry(const struct cache_entry *ce,
1476 const struct cache_entry *old,
1477 struct unpack_trees_options *o)
1478 {
1479 int update = CE_UPDATE;
1480 struct cache_entry *merge = dup_entry(ce);
1481
1482 if (!old) {
1483 /*
1484 * New index entries. In sparse checkout, the following
1485 * verify_absent() will be delayed until after
1486 * traverse_trees() finishes in unpack_trees(), then:
1487 *
1488 * - CE_NEW_SKIP_WORKTREE will be computed correctly
1489 * - verify_absent() be called again, this time with
1490 * correct CE_NEW_SKIP_WORKTREE
1491 *
1492 * verify_absent() call here does nothing in sparse
1493 * checkout (i.e. o->skip_sparse_checkout == 0)
1494 */
1495 update |= CE_ADDED;
1496 merge->ce_flags |= CE_NEW_SKIP_WORKTREE;
1497
1498 if (verify_absent(merge,
1499 ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o)) {
1500 free(merge);
1501 return -1;
1502 }
1503 invalidate_ce_path(merge, o);
1504 } else if (!(old->ce_flags & CE_CONFLICTED)) {
1505 /*
1506 * See if we can re-use the old CE directly?
1507 * That way we get the uptodate stat info.
1508 *
1509 * This also removes the UPDATE flag on a match; otherwise
1510 * we will end up overwriting local changes in the work tree.
1511 */
1512 if (same(old, merge)) {
1513 copy_cache_entry(merge, old);
1514 update = 0;
1515 } else {
1516 if (verify_uptodate(old, o)) {
1517 free(merge);
1518 return -1;
1519 }
1520 /* Migrate old flags over */
1521 update |= old->ce_flags & (CE_SKIP_WORKTREE | CE_NEW_SKIP_WORKTREE);
1522 invalidate_ce_path(old, o);
1523 }
1524 } else {
1525 /*
1526 * Previously unmerged entry left as an existence
1527 * marker by read_index_unmerged();
1528 */
1529 invalidate_ce_path(old, o);
1530 }
1531
1532 do_add_entry(o, merge, update, CE_STAGEMASK);
1533 return 1;
1534 }
1535
1536 static int deleted_entry(const struct cache_entry *ce,
1537 const struct cache_entry *old,
1538 struct unpack_trees_options *o)
1539 {
1540 /* Did it exist in the index? */
1541 if (!old) {
1542 if (verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_REMOVED, o))
1543 return -1;
1544 return 0;
1545 }
1546 if (!(old->ce_flags & CE_CONFLICTED) && verify_uptodate(old, o))
1547 return -1;
1548 add_entry(o, ce, CE_REMOVE, 0);
1549 invalidate_ce_path(ce, o);
1550 return 1;
1551 }
1552
1553 static int keep_entry(const struct cache_entry *ce,
1554 struct unpack_trees_options *o)
1555 {
1556 add_entry(o, ce, 0, 0);
1557 return 1;
1558 }
1559
1560 #if DBRT_DEBUG
1561 static void show_stage_entry(FILE *o,
1562 const char *label, const struct cache_entry *ce)
1563 {
1564 if (!ce)
1565 fprintf(o, "%s (missing)\n", label);
1566 else
1567 fprintf(o, "%s%06o %s %d\t%s\n",
1568 label,
1569 ce->ce_mode,
1570 sha1_to_hex(ce->sha1),
1571 ce_stage(ce),
1572 ce->name);
1573 }
1574 #endif
1575
1576 int threeway_merge(const struct cache_entry * const *stages,
1577 struct unpack_trees_options *o)
1578 {
1579 const struct cache_entry *index;
1580 const struct cache_entry *head;
1581 const struct cache_entry *remote = stages[o->head_idx + 1];
1582 int count;
1583 int head_match = 0;
1584 int remote_match = 0;
1585
1586 int df_conflict_head = 0;
1587 int df_conflict_remote = 0;
1588
1589 int any_anc_missing = 0;
1590 int no_anc_exists = 1;
1591 int i;
1592
1593 for (i = 1; i < o->head_idx; i++) {
1594 if (!stages[i] || stages[i] == o->df_conflict_entry)
1595 any_anc_missing = 1;
1596 else
1597 no_anc_exists = 0;
1598 }
1599
1600 index = stages[0];
1601 head = stages[o->head_idx];
1602
1603 if (head == o->df_conflict_entry) {
1604 df_conflict_head = 1;
1605 head = NULL;
1606 }
1607
1608 if (remote == o->df_conflict_entry) {
1609 df_conflict_remote = 1;
1610 remote = NULL;
1611 }
1612
1613 /*
1614 * First, if there's a #16 situation, note that to prevent #13
1615 * and #14.
1616 */
1617 if (!same(remote, head)) {
1618 for (i = 1; i < o->head_idx; i++) {
1619 if (same(stages[i], head)) {
1620 head_match = i;
1621 }
1622 if (same(stages[i], remote)) {
1623 remote_match = i;
1624 }
1625 }
1626 }
1627
1628 /*
1629 * We start with cases where the index is allowed to match
1630 * something other than the head: #14(ALT) and #2ALT, where it
1631 * is permitted to match the result instead.
1632 */
1633 /* #14, #14ALT, #2ALT */
1634 if (remote && !df_conflict_head && head_match && !remote_match) {
1635 if (index && !same(index, remote) && !same(index, head))
1636 return o->gently ? -1 : reject_merge(index, o);
1637 return merged_entry(remote, index, o);
1638 }
1639 /*
1640 * If we have an entry in the index cache, then we want to
1641 * make sure that it matches head.
1642 */
1643 if (index && !same(index, head))
1644 return o->gently ? -1 : reject_merge(index, o);
1645
1646 if (head) {
1647 /* #5ALT, #15 */
1648 if (same(head, remote))
1649 return merged_entry(head, index, o);
1650 /* #13, #3ALT */
1651 if (!df_conflict_remote && remote_match && !head_match)
1652 return merged_entry(head, index, o);
1653 }
1654
1655 /* #1 */
1656 if (!head && !remote && any_anc_missing)
1657 return 0;
1658
1659 /*
1660 * Under the "aggressive" rule, we resolve mostly trivial
1661 * cases that we historically had git-merge-one-file resolve.
1662 */
1663 if (o->aggressive) {
1664 int head_deleted = !head;
1665 int remote_deleted = !remote;
1666 const struct cache_entry *ce = NULL;
1667
1668 if (index)
1669 ce = index;
1670 else if (head)
1671 ce = head;
1672 else if (remote)
1673 ce = remote;
1674 else {
1675 for (i = 1; i < o->head_idx; i++) {
1676 if (stages[i] && stages[i] != o->df_conflict_entry) {
1677 ce = stages[i];
1678 break;
1679 }
1680 }
1681 }
1682
1683 /*
1684 * Deleted in both.
1685 * Deleted in one and unchanged in the other.
1686 */
1687 if ((head_deleted && remote_deleted) ||
1688 (head_deleted && remote && remote_match) ||
1689 (remote_deleted && head && head_match)) {
1690 if (index)
1691 return deleted_entry(index, index, o);
1692 if (ce && !head_deleted) {
1693 if (verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_REMOVED, o))
1694 return -1;
1695 }
1696 return 0;
1697 }
1698 /*
1699 * Added in both, identically.
1700 */
1701 if (no_anc_exists && head && remote && same(head, remote))
1702 return merged_entry(head, index, o);
1703
1704 }
1705
1706 /* Below are "no merge" cases, which require that the index be
1707 * up-to-date to avoid the files getting overwritten with
1708 * conflict resolution files.
1709 */
1710 if (index) {
1711 if (verify_uptodate(index, o))
1712 return -1;
1713 }
1714
1715 o->nontrivial_merge = 1;
1716
1717 /* #2, #3, #4, #6, #7, #9, #10, #11. */
1718 count = 0;
1719 if (!head_match || !remote_match) {
1720 for (i = 1; i < o->head_idx; i++) {
1721 if (stages[i] && stages[i] != o->df_conflict_entry) {
1722 keep_entry(stages[i], o);
1723 count++;
1724 break;
1725 }
1726 }
1727 }
1728 #if DBRT_DEBUG
1729 else {
1730 fprintf(stderr, "read-tree: warning #16 detected\n");
1731 show_stage_entry(stderr, "head ", stages[head_match]);
1732 show_stage_entry(stderr, "remote ", stages[remote_match]);
1733 }
1734 #endif
1735 if (head) { count += keep_entry(head, o); }
1736 if (remote) { count += keep_entry(remote, o); }
1737 return count;
1738 }
1739
1740 /*
1741 * Two-way merge.
1742 *
1743 * The rule is to "carry forward" what is in the index without losing
1744 * information across a "fast-forward", favoring a successful merge
1745 * over a merge failure when it makes sense. For details of the
1746 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
1747 *
1748 */
1749 int twoway_merge(const struct cache_entry * const *src,
1750 struct unpack_trees_options *o)
1751 {
1752 const struct cache_entry *current = src[0];
1753 const struct cache_entry *oldtree = src[1];
1754 const struct cache_entry *newtree = src[2];
1755
1756 if (o->merge_size != 2)
1757 return error("Cannot do a twoway merge of %d trees",
1758 o->merge_size);
1759
1760 if (oldtree == o->df_conflict_entry)
1761 oldtree = NULL;
1762 if (newtree == o->df_conflict_entry)
1763 newtree = NULL;
1764
1765 if (current) {
1766 if (current->ce_flags & CE_CONFLICTED) {
1767 if (same(oldtree, newtree) || o->reset) {
1768 if (!newtree)
1769 return deleted_entry(current, current, o);
1770 else
1771 return merged_entry(newtree, current, o);
1772 }
1773 return o->gently ? -1 : reject_merge(current, o);
1774 }
1775 else if ((!oldtree && !newtree) || /* 4 and 5 */
1776 (!oldtree && newtree &&
1777 same(current, newtree)) || /* 6 and 7 */
1778 (oldtree && newtree &&
1779 same(oldtree, newtree)) || /* 14 and 15 */
1780 (oldtree && newtree &&
1781 !same(oldtree, newtree) && /* 18 and 19 */
1782 same(current, newtree))) {
1783 return keep_entry(current, o);
1784 }
1785 else if (oldtree && !newtree && same(current, oldtree)) {
1786 /* 10 or 11 */
1787 return deleted_entry(oldtree, current, o);
1788 }
1789 else if (oldtree && newtree &&
1790 same(current, oldtree) && !same(current, newtree)) {
1791 /* 20 or 21 */
1792 return merged_entry(newtree, current, o);
1793 }
1794 else {
1795 /* all other failures */
1796 if (oldtree)
1797 return o->gently ? -1 : reject_merge(oldtree, o);
1798 if (current)
1799 return o->gently ? -1 : reject_merge(current, o);
1800 if (newtree)
1801 return o->gently ? -1 : reject_merge(newtree, o);
1802 return -1;
1803 }
1804 }
1805 else if (newtree) {
1806 if (oldtree && !o->initial_checkout) {
1807 /*
1808 * deletion of the path was staged;
1809 */
1810 if (same(oldtree, newtree))
1811 return 1;
1812 return reject_merge(oldtree, o);
1813 }
1814 return merged_entry(newtree, current, o);
1815 }
1816 return deleted_entry(oldtree, current, o);
1817 }
1818
1819 /*
1820 * Bind merge.
1821 *
1822 * Keep the index entries at stage0, collapse stage1 but make sure
1823 * stage0 does not have anything there.
1824 */
1825 int bind_merge(const struct cache_entry * const *src,
1826 struct unpack_trees_options *o)
1827 {
1828 const struct cache_entry *old = src[0];
1829 const struct cache_entry *a = src[1];
1830
1831 if (o->merge_size != 1)
1832 return error("Cannot do a bind merge of %d trees",
1833 o->merge_size);
1834 if (a && old)
1835 return o->gently ? -1 :
1836 error(ERRORMSG(o, ERROR_BIND_OVERLAP), a->name, old->name);
1837 if (!a)
1838 return keep_entry(old, o);
1839 else
1840 return merged_entry(a, NULL, o);
1841 }
1842
1843 /*
1844 * One-way merge.
1845 *
1846 * The rule is:
1847 * - take the stat information from stage0, take the data from stage1
1848 */
1849 int oneway_merge(const struct cache_entry * const *src,
1850 struct unpack_trees_options *o)
1851 {
1852 const struct cache_entry *old = src[0];
1853 const struct cache_entry *a = src[1];
1854
1855 if (o->merge_size != 1)
1856 return error("Cannot do a oneway merge of %d trees",
1857 o->merge_size);
1858
1859 if (!a || a == o->df_conflict_entry)
1860 return deleted_entry(old, old, o);
1861
1862 if (old && same(old, a)) {
1863 int update = 0;
1864 if (o->reset && o->update && !ce_uptodate(old) && !ce_skip_worktree(old)) {
1865 struct stat st;
1866 if (lstat(old->name, &st) ||
1867 ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE))
1868 update |= CE_UPDATE;
1869 }
1870 add_entry(o, old, update, 0);
1871 return 0;
1872 }
1873 return merged_entry(a, old, o);
1874 }