f594932080ca5a733ae0ebe5d2584053905ec84e
[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;
109
110 if (set & CE_REMOVE)
111 set |= CE_WT_REMOVE;
112
113 ce->ce_flags = (ce->ce_flags & ~clear) | set;
114 add_index_entry(&o->result, ce,
115 ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
116 }
117
118 static struct cache_entry *dup_entry(const struct cache_entry *ce)
119 {
120 unsigned int size = ce_size(ce);
121 struct cache_entry *new = xmalloc(size);
122
123 memcpy(new, ce, size);
124 return new;
125 }
126
127 static void add_entry(struct unpack_trees_options *o,
128 const struct cache_entry *ce,
129 unsigned int set, unsigned int clear)
130 {
131 do_add_entry(o, dup_entry(ce), set, clear);
132 }
133
134 /*
135 * add error messages on path <path>
136 * corresponding to the type <e> with the message <msg>
137 * indicating if it should be display in porcelain or not
138 */
139 static int add_rejected_path(struct unpack_trees_options *o,
140 enum unpack_trees_error_types e,
141 const char *path)
142 {
143 if (!o->show_all_errors)
144 return error(ERRORMSG(o, e), path);
145
146 /*
147 * Otherwise, insert in a list for future display by
148 * display_error_msgs()
149 */
150 string_list_append(&o->unpack_rejects[e], path);
151 return -1;
152 }
153
154 /*
155 * display all the error messages stored in a nice way
156 */
157 static void display_error_msgs(struct unpack_trees_options *o)
158 {
159 int e, i;
160 int something_displayed = 0;
161 for (e = 0; e < NB_UNPACK_TREES_ERROR_TYPES; e++) {
162 struct string_list *rejects = &o->unpack_rejects[e];
163 if (rejects->nr > 0) {
164 struct strbuf path = STRBUF_INIT;
165 something_displayed = 1;
166 for (i = 0; i < rejects->nr; i++)
167 strbuf_addf(&path, "\t%s\n", rejects->items[i].string);
168 error(ERRORMSG(o, e), path.buf);
169 strbuf_release(&path);
170 }
171 string_list_clear(rejects, 0);
172 }
173 if (something_displayed)
174 fprintf(stderr, "Aborting\n");
175 }
176
177 /*
178 * Unlink the last component and schedule the leading directories for
179 * removal, such that empty directories get removed.
180 */
181 static void unlink_entry(const struct cache_entry *ce)
182 {
183 if (!check_leading_path(ce->name, ce_namelen(ce)))
184 return;
185 if (remove_or_warn(ce->ce_mode, ce->name))
186 return;
187 schedule_dir_for_removal(ce->name, ce_namelen(ce));
188 }
189
190 static struct checkout state;
191 static int check_updates(struct unpack_trees_options *o)
192 {
193 unsigned cnt = 0, total = 0;
194 struct progress *progress = NULL;
195 struct index_state *index = &o->result;
196 int i;
197 int errs = 0;
198
199 if (o->update && o->verbose_update) {
200 for (total = cnt = 0; cnt < index->cache_nr; cnt++) {
201 const struct cache_entry *ce = index->cache[cnt];
202 if (ce->ce_flags & (CE_UPDATE | CE_WT_REMOVE))
203 total++;
204 }
205
206 progress = start_progress_delay(_("Checking out files"),
207 total, 50, 1);
208 cnt = 0;
209 }
210
211 if (o->update)
212 git_attr_set_direction(GIT_ATTR_CHECKOUT, &o->result);
213 for (i = 0; i < index->cache_nr; i++) {
214 const struct cache_entry *ce = index->cache[i];
215
216 if (ce->ce_flags & CE_WT_REMOVE) {
217 display_progress(progress, ++cnt);
218 if (o->update && !o->dry_run)
219 unlink_entry(ce);
220 continue;
221 }
222 }
223 remove_marked_cache_entries(&o->result);
224 remove_scheduled_dirs();
225
226 for (i = 0; i < index->cache_nr; i++) {
227 struct cache_entry *ce = index->cache[i];
228
229 if (ce->ce_flags & CE_UPDATE) {
230 display_progress(progress, ++cnt);
231 ce->ce_flags &= ~CE_UPDATE;
232 if (o->update && !o->dry_run) {
233 errs |= checkout_entry(ce, &state, NULL);
234 }
235 }
236 }
237 stop_progress(&progress);
238 if (o->update)
239 git_attr_set_direction(GIT_ATTR_CHECKIN, NULL);
240 return errs != 0;
241 }
242
243 static int verify_uptodate_sparse(const struct cache_entry *ce,
244 struct unpack_trees_options *o);
245 static int verify_absent_sparse(const struct cache_entry *ce,
246 enum unpack_trees_error_types,
247 struct unpack_trees_options *o);
248
249 static int apply_sparse_checkout(struct index_state *istate,
250 struct cache_entry *ce,
251 struct unpack_trees_options *o)
252 {
253 int was_skip_worktree = ce_skip_worktree(ce);
254
255 if (ce->ce_flags & CE_NEW_SKIP_WORKTREE)
256 ce->ce_flags |= CE_SKIP_WORKTREE;
257 else
258 ce->ce_flags &= ~CE_SKIP_WORKTREE;
259 if (was_skip_worktree != ce_skip_worktree(ce))
260 istate->cache_changed |= CE_ENTRY_CHANGED;
261
262 /*
263 * if (!was_skip_worktree && !ce_skip_worktree()) {
264 * This is perfectly normal. Move on;
265 * }
266 */
267
268 /*
269 * Merge strategies may set CE_UPDATE|CE_REMOVE outside checkout
270 * area as a result of ce_skip_worktree() shortcuts in
271 * verify_absent() and verify_uptodate().
272 * Make sure they don't modify worktree if they are already
273 * outside checkout area
274 */
275 if (was_skip_worktree && ce_skip_worktree(ce)) {
276 ce->ce_flags &= ~CE_UPDATE;
277
278 /*
279 * By default, when CE_REMOVE is on, CE_WT_REMOVE is also
280 * on to get that file removed from both index and worktree.
281 * If that file is already outside worktree area, don't
282 * bother remove it.
283 */
284 if (ce->ce_flags & CE_REMOVE)
285 ce->ce_flags &= ~CE_WT_REMOVE;
286 }
287
288 if (!was_skip_worktree && ce_skip_worktree(ce)) {
289 /*
290 * If CE_UPDATE is set, verify_uptodate() must be called already
291 * also stat info may have lost after merged_entry() so calling
292 * verify_uptodate() again may fail
293 */
294 if (!(ce->ce_flags & CE_UPDATE) && verify_uptodate_sparse(ce, o))
295 return -1;
296 ce->ce_flags |= CE_WT_REMOVE;
297 }
298 if (was_skip_worktree && !ce_skip_worktree(ce)) {
299 if (verify_absent_sparse(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o))
300 return -1;
301 ce->ce_flags |= CE_UPDATE;
302 }
303 return 0;
304 }
305
306 static inline int call_unpack_fn(const struct cache_entry * const *src,
307 struct unpack_trees_options *o)
308 {
309 int ret = o->fn(src, o);
310 if (ret > 0)
311 ret = 0;
312 return ret;
313 }
314
315 static void mark_ce_used(struct cache_entry *ce, struct unpack_trees_options *o)
316 {
317 ce->ce_flags |= CE_UNPACKED;
318
319 if (o->cache_bottom < o->src_index->cache_nr &&
320 o->src_index->cache[o->cache_bottom] == ce) {
321 int bottom = o->cache_bottom;
322 while (bottom < o->src_index->cache_nr &&
323 o->src_index->cache[bottom]->ce_flags & CE_UNPACKED)
324 bottom++;
325 o->cache_bottom = bottom;
326 }
327 }
328
329 static void mark_all_ce_unused(struct index_state *index)
330 {
331 int i;
332 for (i = 0; i < index->cache_nr; i++)
333 index->cache[i]->ce_flags &= ~(CE_UNPACKED | CE_ADDED | CE_NEW_SKIP_WORKTREE);
334 }
335
336 static int locate_in_src_index(const struct cache_entry *ce,
337 struct unpack_trees_options *o)
338 {
339 struct index_state *index = o->src_index;
340 int len = ce_namelen(ce);
341 int pos = index_name_pos(index, ce->name, len);
342 if (pos < 0)
343 pos = -1 - pos;
344 return pos;
345 }
346
347 /*
348 * We call unpack_index_entry() with an unmerged cache entry
349 * only in diff-index, and it wants a single callback. Skip
350 * the other unmerged entry with the same name.
351 */
352 static void mark_ce_used_same_name(struct cache_entry *ce,
353 struct unpack_trees_options *o)
354 {
355 struct index_state *index = o->src_index;
356 int len = ce_namelen(ce);
357 int pos;
358
359 for (pos = locate_in_src_index(ce, o); pos < index->cache_nr; pos++) {
360 struct cache_entry *next = index->cache[pos];
361 if (len != ce_namelen(next) ||
362 memcmp(ce->name, next->name, len))
363 break;
364 mark_ce_used(next, o);
365 }
366 }
367
368 static struct cache_entry *next_cache_entry(struct unpack_trees_options *o)
369 {
370 const struct index_state *index = o->src_index;
371 int pos = o->cache_bottom;
372
373 while (pos < index->cache_nr) {
374 struct cache_entry *ce = index->cache[pos];
375 if (!(ce->ce_flags & CE_UNPACKED))
376 return ce;
377 pos++;
378 }
379 return NULL;
380 }
381
382 static void add_same_unmerged(const struct cache_entry *ce,
383 struct unpack_trees_options *o)
384 {
385 struct index_state *index = o->src_index;
386 int len = ce_namelen(ce);
387 int pos = index_name_pos(index, ce->name, len);
388
389 if (0 <= pos)
390 die("programming error in a caller of mark_ce_used_same_name");
391 for (pos = -pos - 1; pos < index->cache_nr; pos++) {
392 struct cache_entry *next = index->cache[pos];
393 if (len != ce_namelen(next) ||
394 memcmp(ce->name, next->name, len))
395 break;
396 add_entry(o, next, 0, 0);
397 mark_ce_used(next, o);
398 }
399 }
400
401 static int unpack_index_entry(struct cache_entry *ce,
402 struct unpack_trees_options *o)
403 {
404 const struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
405 int ret;
406
407 src[0] = ce;
408
409 mark_ce_used(ce, o);
410 if (ce_stage(ce)) {
411 if (o->skip_unmerged) {
412 add_entry(o, ce, 0, 0);
413 return 0;
414 }
415 }
416 ret = call_unpack_fn(src, o);
417 if (ce_stage(ce))
418 mark_ce_used_same_name(ce, o);
419 return ret;
420 }
421
422 static int find_cache_pos(struct traverse_info *, const struct name_entry *);
423
424 static void restore_cache_bottom(struct traverse_info *info, int bottom)
425 {
426 struct unpack_trees_options *o = info->data;
427
428 if (o->diff_index_cached)
429 return;
430 o->cache_bottom = bottom;
431 }
432
433 static int switch_cache_bottom(struct traverse_info *info)
434 {
435 struct unpack_trees_options *o = info->data;
436 int ret, pos;
437
438 if (o->diff_index_cached)
439 return 0;
440 ret = o->cache_bottom;
441 pos = find_cache_pos(info->prev, &info->name);
442
443 if (pos < -1)
444 o->cache_bottom = -2 - pos;
445 else if (pos < 0)
446 o->cache_bottom = o->src_index->cache_nr;
447 return ret;
448 }
449
450 static int traverse_trees_recursive(int n, unsigned long dirmask,
451 unsigned long df_conflicts,
452 struct name_entry *names,
453 struct traverse_info *info)
454 {
455 int i, ret, bottom;
456 struct tree_desc t[MAX_UNPACK_TREES];
457 void *buf[MAX_UNPACK_TREES];
458 struct traverse_info newinfo;
459 struct name_entry *p;
460
461 p = names;
462 while (!p->mode)
463 p++;
464
465 newinfo = *info;
466 newinfo.prev = info;
467 newinfo.pathspec = info->pathspec;
468 newinfo.name = *p;
469 newinfo.pathlen += tree_entry_len(p) + 1;
470 newinfo.df_conflicts |= df_conflicts;
471
472 for (i = 0; i < n; i++, dirmask >>= 1) {
473 const unsigned char *sha1 = NULL;
474 if (dirmask & 1)
475 sha1 = names[i].sha1;
476 buf[i] = fill_tree_descriptor(t+i, sha1);
477 }
478
479 bottom = switch_cache_bottom(&newinfo);
480 ret = traverse_trees(n, t, &newinfo);
481 restore_cache_bottom(&newinfo, bottom);
482
483 for (i = 0; i < n; i++)
484 free(buf[i]);
485
486 return ret;
487 }
488
489 /*
490 * Compare the traverse-path to the cache entry without actually
491 * having to generate the textual representation of the traverse
492 * path.
493 *
494 * NOTE! This *only* compares up to the size of the traverse path
495 * itself - the caller needs to do the final check for the cache
496 * entry having more data at the end!
497 */
498 static int do_compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
499 {
500 int len, pathlen, ce_len;
501 const char *ce_name;
502
503 if (info->prev) {
504 int cmp = do_compare_entry(ce, info->prev, &info->name);
505 if (cmp)
506 return cmp;
507 }
508 pathlen = info->pathlen;
509 ce_len = ce_namelen(ce);
510
511 /* If ce_len < pathlen then we must have previously hit "name == directory" entry */
512 if (ce_len < pathlen)
513 return -1;
514
515 ce_len -= pathlen;
516 ce_name = ce->name + pathlen;
517
518 len = tree_entry_len(n);
519 return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode);
520 }
521
522 static int compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
523 {
524 int cmp = do_compare_entry(ce, info, n);
525 if (cmp)
526 return cmp;
527
528 /*
529 * Even if the beginning compared identically, the ce should
530 * compare as bigger than a directory leading up to it!
531 */
532 return ce_namelen(ce) > traverse_path_len(info, n);
533 }
534
535 static int ce_in_traverse_path(const struct cache_entry *ce,
536 const struct traverse_info *info)
537 {
538 if (!info->prev)
539 return 1;
540 if (do_compare_entry(ce, info->prev, &info->name))
541 return 0;
542 /*
543 * If ce (blob) is the same name as the path (which is a tree
544 * we will be descending into), it won't be inside it.
545 */
546 return (info->pathlen < ce_namelen(ce));
547 }
548
549 static struct cache_entry *create_ce_entry(const struct traverse_info *info, const struct name_entry *n, int stage)
550 {
551 int len = traverse_path_len(info, n);
552 struct cache_entry *ce = xcalloc(1, cache_entry_size(len));
553
554 ce->ce_mode = create_ce_mode(n->mode);
555 ce->ce_flags = create_ce_flags(stage);
556 ce->ce_namelen = len;
557 hashcpy(ce->sha1, n->sha1);
558 make_traverse_path(ce->name, info, n);
559
560 return ce;
561 }
562
563 static int unpack_nondirectories(int n, unsigned long mask,
564 unsigned long dirmask,
565 struct cache_entry **src,
566 const struct name_entry *names,
567 const struct traverse_info *info)
568 {
569 int i;
570 struct unpack_trees_options *o = info->data;
571 unsigned long conflicts = info->df_conflicts | dirmask;
572
573 /* Do we have *only* directories? Nothing to do */
574 if (mask == dirmask && !src[0])
575 return 0;
576
577 /*
578 * Ok, we've filled in up to any potential index entry in src[0],
579 * now do the rest.
580 */
581 for (i = 0; i < n; i++) {
582 int stage;
583 unsigned int bit = 1ul << i;
584 if (conflicts & bit) {
585 src[i + o->merge] = o->df_conflict_entry;
586 continue;
587 }
588 if (!(mask & bit))
589 continue;
590 if (!o->merge)
591 stage = 0;
592 else if (i + 1 < o->head_idx)
593 stage = 1;
594 else if (i + 1 > o->head_idx)
595 stage = 3;
596 else
597 stage = 2;
598 src[i + o->merge] = create_ce_entry(info, names + i, stage);
599 }
600
601 if (o->merge) {
602 int rc = call_unpack_fn((const struct cache_entry * const *)src,
603 o);
604 for (i = 0; i < n; i++) {
605 struct cache_entry *ce = src[i + o->merge];
606 if (ce != o->df_conflict_entry)
607 free(ce);
608 }
609 return rc;
610 }
611
612 for (i = 0; i < n; i++)
613 if (src[i] && src[i] != o->df_conflict_entry)
614 do_add_entry(o, src[i], 0, 0);
615 return 0;
616 }
617
618 static int unpack_failed(struct unpack_trees_options *o, const char *message)
619 {
620 discard_index(&o->result);
621 if (!o->gently && !o->exiting_early) {
622 if (message)
623 return error("%s", message);
624 return -1;
625 }
626 return -1;
627 }
628
629 /* NEEDSWORK: give this a better name and share with tree-walk.c */
630 static int name_compare(const char *a, int a_len,
631 const char *b, int b_len)
632 {
633 int len = (a_len < b_len) ? a_len : b_len;
634 int cmp = memcmp(a, b, len);
635 if (cmp)
636 return cmp;
637 return (a_len - b_len);
638 }
639
640 /*
641 * The tree traversal is looking at name p. If we have a matching entry,
642 * return it. If name p is a directory in the index, do not return
643 * anything, as we will want to match it when the traversal descends into
644 * the directory.
645 */
646 static int find_cache_pos(struct traverse_info *info,
647 const struct name_entry *p)
648 {
649 int pos;
650 struct unpack_trees_options *o = info->data;
651 struct index_state *index = o->src_index;
652 int pfxlen = info->pathlen;
653 int p_len = tree_entry_len(p);
654
655 for (pos = o->cache_bottom; pos < index->cache_nr; pos++) {
656 const struct cache_entry *ce = index->cache[pos];
657 const char *ce_name, *ce_slash;
658 int cmp, ce_len;
659
660 if (ce->ce_flags & CE_UNPACKED) {
661 /*
662 * cache_bottom entry is already unpacked, so
663 * we can never match it; don't check it
664 * again.
665 */
666 if (pos == o->cache_bottom)
667 ++o->cache_bottom;
668 continue;
669 }
670 if (!ce_in_traverse_path(ce, info))
671 continue;
672 ce_name = ce->name + pfxlen;
673 ce_slash = strchr(ce_name, '/');
674 if (ce_slash)
675 ce_len = ce_slash - ce_name;
676 else
677 ce_len = ce_namelen(ce) - pfxlen;
678 cmp = name_compare(p->path, p_len, ce_name, ce_len);
679 /*
680 * Exact match; if we have a directory we need to
681 * delay returning it.
682 */
683 if (!cmp)
684 return ce_slash ? -2 - pos : pos;
685 if (0 < cmp)
686 continue; /* keep looking */
687 /*
688 * ce_name sorts after p->path; could it be that we
689 * have files under p->path directory in the index?
690 * E.g. ce_name == "t-i", and p->path == "t"; we may
691 * have "t/a" in the index.
692 */
693 if (p_len < ce_len && !memcmp(ce_name, p->path, p_len) &&
694 ce_name[p_len] < '/')
695 continue; /* keep looking */
696 break;
697 }
698 return -1;
699 }
700
701 static struct cache_entry *find_cache_entry(struct traverse_info *info,
702 const struct name_entry *p)
703 {
704 int pos = find_cache_pos(info, p);
705 struct unpack_trees_options *o = info->data;
706
707 if (0 <= pos)
708 return o->src_index->cache[pos];
709 else
710 return NULL;
711 }
712
713 static void debug_path(struct traverse_info *info)
714 {
715 if (info->prev) {
716 debug_path(info->prev);
717 if (*info->prev->name.path)
718 putchar('/');
719 }
720 printf("%s", info->name.path);
721 }
722
723 static void debug_name_entry(int i, struct name_entry *n)
724 {
725 printf("ent#%d %06o %s\n", i,
726 n->path ? n->mode : 0,
727 n->path ? n->path : "(missing)");
728 }
729
730 static void debug_unpack_callback(int n,
731 unsigned long mask,
732 unsigned long dirmask,
733 struct name_entry *names,
734 struct traverse_info *info)
735 {
736 int i;
737 printf("* unpack mask %lu, dirmask %lu, cnt %d ",
738 mask, dirmask, n);
739 debug_path(info);
740 putchar('\n');
741 for (i = 0; i < n; i++)
742 debug_name_entry(i, names + i);
743 }
744
745 static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *names, struct traverse_info *info)
746 {
747 struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
748 struct unpack_trees_options *o = info->data;
749 const struct name_entry *p = names;
750
751 /* Find first entry with a real name (we could use "mask" too) */
752 while (!p->mode)
753 p++;
754
755 if (o->debug_unpack)
756 debug_unpack_callback(n, mask, dirmask, names, info);
757
758 /* Are we supposed to look at the index too? */
759 if (o->merge) {
760 while (1) {
761 int cmp;
762 struct cache_entry *ce;
763
764 if (o->diff_index_cached)
765 ce = next_cache_entry(o);
766 else
767 ce = find_cache_entry(info, p);
768
769 if (!ce)
770 break;
771 cmp = compare_entry(ce, info, p);
772 if (cmp < 0) {
773 if (unpack_index_entry(ce, o) < 0)
774 return unpack_failed(o, NULL);
775 continue;
776 }
777 if (!cmp) {
778 if (ce_stage(ce)) {
779 /*
780 * If we skip unmerged index
781 * entries, we'll skip this
782 * entry *and* the tree
783 * entries associated with it!
784 */
785 if (o->skip_unmerged) {
786 add_same_unmerged(ce, o);
787 return mask;
788 }
789 }
790 src[0] = ce;
791 }
792 break;
793 }
794 }
795
796 if (unpack_nondirectories(n, mask, dirmask, src, names, info) < 0)
797 return -1;
798
799 if (o->merge && src[0]) {
800 if (ce_stage(src[0]))
801 mark_ce_used_same_name(src[0], o);
802 else
803 mark_ce_used(src[0], o);
804 }
805
806 /* Now handle any directories.. */
807 if (dirmask) {
808 /* special case: "diff-index --cached" looking at a tree */
809 if (o->diff_index_cached &&
810 n == 1 && dirmask == 1 && S_ISDIR(names->mode)) {
811 int matches;
812 matches = cache_tree_matches_traversal(o->src_index->cache_tree,
813 names, info);
814 /*
815 * Everything under the name matches; skip the
816 * entire hierarchy. diff_index_cached codepath
817 * special cases D/F conflicts in such a way that
818 * it does not do any look-ahead, so this is safe.
819 */
820 if (matches) {
821 o->cache_bottom += matches;
822 return mask;
823 }
824 }
825
826 if (traverse_trees_recursive(n, dirmask, mask & ~dirmask,
827 names, info) < 0)
828 return -1;
829 return mask;
830 }
831
832 return mask;
833 }
834
835 static int clear_ce_flags_1(struct cache_entry **cache, int nr,
836 struct strbuf *prefix,
837 int select_mask, int clear_mask,
838 struct exclude_list *el, int defval);
839
840 /* Whole directory matching */
841 static int clear_ce_flags_dir(struct cache_entry **cache, int nr,
842 struct strbuf *prefix,
843 char *basename,
844 int select_mask, int clear_mask,
845 struct exclude_list *el, int defval)
846 {
847 struct cache_entry **cache_end;
848 int dtype = DT_DIR;
849 int ret = is_excluded_from_list(prefix->buf, prefix->len,
850 basename, &dtype, el);
851 int rc;
852
853 strbuf_addch(prefix, '/');
854
855 /* If undecided, use matching result of parent dir in defval */
856 if (ret < 0)
857 ret = defval;
858
859 for (cache_end = cache; cache_end != cache + nr; cache_end++) {
860 struct cache_entry *ce = *cache_end;
861 if (strncmp(ce->name, prefix->buf, prefix->len))
862 break;
863 }
864
865 /*
866 * TODO: check el, if there are no patterns that may conflict
867 * with ret (iow, we know in advance the incl/excl
868 * decision for the entire directory), clear flag here without
869 * calling clear_ce_flags_1(). That function will call
870 * the expensive is_excluded_from_list() on every entry.
871 */
872 rc = clear_ce_flags_1(cache, cache_end - cache,
873 prefix,
874 select_mask, clear_mask,
875 el, ret);
876 strbuf_setlen(prefix, prefix->len - 1);
877 return rc;
878 }
879
880 /*
881 * Traverse the index, find every entry that matches according to
882 * o->el. Do "ce_flags &= ~clear_mask" on those entries. Return the
883 * number of traversed entries.
884 *
885 * If select_mask is non-zero, only entries whose ce_flags has on of
886 * those bits enabled are traversed.
887 *
888 * cache : pointer to an index entry
889 * prefix_len : an offset to its path
890 *
891 * The current path ("prefix") including the trailing '/' is
892 * cache[0]->name[0..(prefix_len-1)]
893 * Top level path has prefix_len zero.
894 */
895 static int clear_ce_flags_1(struct cache_entry **cache, int nr,
896 struct strbuf *prefix,
897 int select_mask, int clear_mask,
898 struct exclude_list *el, int defval)
899 {
900 struct cache_entry **cache_end = cache + nr;
901
902 /*
903 * Process all entries that have the given prefix and meet
904 * select_mask condition
905 */
906 while(cache != cache_end) {
907 struct cache_entry *ce = *cache;
908 const char *name, *slash;
909 int len, dtype, ret;
910
911 if (select_mask && !(ce->ce_flags & select_mask)) {
912 cache++;
913 continue;
914 }
915
916 if (prefix->len && strncmp(ce->name, prefix->buf, prefix->len))
917 break;
918
919 name = ce->name + prefix->len;
920 slash = strchr(name, '/');
921
922 /* If it's a directory, try whole directory match first */
923 if (slash) {
924 int processed;
925
926 len = slash - name;
927 strbuf_add(prefix, name, len);
928
929 processed = clear_ce_flags_dir(cache, cache_end - cache,
930 prefix,
931 prefix->buf + prefix->len - len,
932 select_mask, clear_mask,
933 el, defval);
934
935 /* clear_c_f_dir eats a whole dir already? */
936 if (processed) {
937 cache += processed;
938 strbuf_setlen(prefix, prefix->len - len);
939 continue;
940 }
941
942 strbuf_addch(prefix, '/');
943 cache += clear_ce_flags_1(cache, cache_end - cache,
944 prefix,
945 select_mask, clear_mask, el, defval);
946 strbuf_setlen(prefix, prefix->len - len - 1);
947 continue;
948 }
949
950 /* Non-directory */
951 dtype = ce_to_dtype(ce);
952 ret = is_excluded_from_list(ce->name, ce_namelen(ce),
953 name, &dtype, el);
954 if (ret < 0)
955 ret = defval;
956 if (ret > 0)
957 ce->ce_flags &= ~clear_mask;
958 cache++;
959 }
960 return nr - (cache_end - cache);
961 }
962
963 static int clear_ce_flags(struct cache_entry **cache, int nr,
964 int select_mask, int clear_mask,
965 struct exclude_list *el)
966 {
967 static struct strbuf prefix = STRBUF_INIT;
968
969 strbuf_reset(&prefix);
970
971 return clear_ce_flags_1(cache, nr,
972 &prefix,
973 select_mask, clear_mask,
974 el, 0);
975 }
976
977 /*
978 * Set/Clear CE_NEW_SKIP_WORKTREE according to $GIT_DIR/info/sparse-checkout
979 */
980 static void mark_new_skip_worktree(struct exclude_list *el,
981 struct index_state *the_index,
982 int select_flag, int skip_wt_flag)
983 {
984 int i;
985
986 /*
987 * 1. Pretend the narrowest worktree: only unmerged entries
988 * are checked out
989 */
990 for (i = 0; i < the_index->cache_nr; i++) {
991 struct cache_entry *ce = the_index->cache[i];
992
993 if (select_flag && !(ce->ce_flags & select_flag))
994 continue;
995
996 if (!ce_stage(ce))
997 ce->ce_flags |= skip_wt_flag;
998 else
999 ce->ce_flags &= ~skip_wt_flag;
1000 }
1001
1002 /*
1003 * 2. Widen worktree according to sparse-checkout file.
1004 * Matched entries will have skip_wt_flag cleared (i.e. "in")
1005 */
1006 clear_ce_flags(the_index->cache, the_index->cache_nr,
1007 select_flag, skip_wt_flag, el);
1008 }
1009
1010 static int verify_absent(const struct cache_entry *,
1011 enum unpack_trees_error_types,
1012 struct unpack_trees_options *);
1013 /*
1014 * N-way merge "len" trees. Returns 0 on success, -1 on failure to manipulate the
1015 * resulting index, -2 on failure to reflect the changes to the work tree.
1016 *
1017 * CE_ADDED, CE_UNPACKED and CE_NEW_SKIP_WORKTREE are used internally
1018 */
1019 int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
1020 {
1021 int i, ret;
1022 static struct cache_entry *dfc;
1023 struct exclude_list el;
1024
1025 if (len > MAX_UNPACK_TREES)
1026 die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
1027 memset(&state, 0, sizeof(state));
1028 state.base_dir = "";
1029 state.force = 1;
1030 state.quiet = 1;
1031 state.refresh_cache = 1;
1032 state.istate = &o->result;
1033
1034 memset(&el, 0, sizeof(el));
1035 if (!core_apply_sparse_checkout || !o->update)
1036 o->skip_sparse_checkout = 1;
1037 if (!o->skip_sparse_checkout) {
1038 if (add_excludes_from_file_to_list(git_path("info/sparse-checkout"), "", 0, &el, 0) < 0)
1039 o->skip_sparse_checkout = 1;
1040 else
1041 o->el = &el;
1042 }
1043
1044 memset(&o->result, 0, sizeof(o->result));
1045 o->result.initialized = 1;
1046 o->result.timestamp.sec = o->src_index->timestamp.sec;
1047 o->result.timestamp.nsec = o->src_index->timestamp.nsec;
1048 o->result.version = o->src_index->version;
1049 hashcpy(o->result.sha1, o->src_index->sha1);
1050 o->merge_size = len;
1051 mark_all_ce_unused(o->src_index);
1052
1053 /*
1054 * Sparse checkout loop #1: set NEW_SKIP_WORKTREE on existing entries
1055 */
1056 if (!o->skip_sparse_checkout)
1057 mark_new_skip_worktree(o->el, o->src_index, 0, CE_NEW_SKIP_WORKTREE);
1058
1059 if (!dfc)
1060 dfc = xcalloc(1, cache_entry_size(0));
1061 o->df_conflict_entry = dfc;
1062
1063 if (len) {
1064 const char *prefix = o->prefix ? o->prefix : "";
1065 struct traverse_info info;
1066
1067 setup_traverse_info(&info, prefix);
1068 info.fn = unpack_callback;
1069 info.data = o;
1070 info.show_all_errors = o->show_all_errors;
1071 info.pathspec = o->pathspec;
1072
1073 if (o->prefix) {
1074 /*
1075 * Unpack existing index entries that sort before the
1076 * prefix the tree is spliced into. Note that o->merge
1077 * is always true in this case.
1078 */
1079 while (1) {
1080 struct cache_entry *ce = next_cache_entry(o);
1081 if (!ce)
1082 break;
1083 if (ce_in_traverse_path(ce, &info))
1084 break;
1085 if (unpack_index_entry(ce, o) < 0)
1086 goto return_failed;
1087 }
1088 }
1089
1090 if (traverse_trees(len, t, &info) < 0)
1091 goto return_failed;
1092 }
1093
1094 /* Any left-over entries in the index? */
1095 if (o->merge) {
1096 while (1) {
1097 struct cache_entry *ce = next_cache_entry(o);
1098 if (!ce)
1099 break;
1100 if (unpack_index_entry(ce, o) < 0)
1101 goto return_failed;
1102 }
1103 }
1104 mark_all_ce_unused(o->src_index);
1105
1106 if (o->trivial_merges_only && o->nontrivial_merge) {
1107 ret = unpack_failed(o, "Merge requires file-level merging");
1108 goto done;
1109 }
1110
1111 if (!o->skip_sparse_checkout) {
1112 int empty_worktree = 1;
1113
1114 /*
1115 * Sparse checkout loop #2: set NEW_SKIP_WORKTREE on entries not in loop #1
1116 * If the will have NEW_SKIP_WORKTREE, also set CE_SKIP_WORKTREE
1117 * so apply_sparse_checkout() won't attempt to remove it from worktree
1118 */
1119 mark_new_skip_worktree(o->el, &o->result, CE_ADDED, CE_SKIP_WORKTREE | CE_NEW_SKIP_WORKTREE);
1120
1121 ret = 0;
1122 for (i = 0; i < o->result.cache_nr; i++) {
1123 struct cache_entry *ce = o->result.cache[i];
1124
1125 /*
1126 * Entries marked with CE_ADDED in merged_entry() do not have
1127 * verify_absent() check (the check is effectively disabled
1128 * because CE_NEW_SKIP_WORKTREE is set unconditionally).
1129 *
1130 * Do the real check now because we have had
1131 * correct CE_NEW_SKIP_WORKTREE
1132 */
1133 if (ce->ce_flags & CE_ADDED &&
1134 verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o)) {
1135 if (!o->show_all_errors)
1136 goto return_failed;
1137 ret = -1;
1138 }
1139
1140 if (apply_sparse_checkout(&o->result, ce, o)) {
1141 if (!o->show_all_errors)
1142 goto return_failed;
1143 ret = -1;
1144 }
1145 if (!ce_skip_worktree(ce))
1146 empty_worktree = 0;
1147
1148 }
1149 if (ret < 0)
1150 goto return_failed;
1151 /*
1152 * Sparse checkout is meant to narrow down checkout area
1153 * but it does not make sense to narrow down to empty working
1154 * tree. This is usually a mistake in sparse checkout rules.
1155 * Do not allow users to do that.
1156 */
1157 if (o->result.cache_nr && empty_worktree) {
1158 ret = unpack_failed(o, "Sparse checkout leaves no entry on working directory");
1159 goto done;
1160 }
1161 }
1162
1163 o->src_index = NULL;
1164 ret = check_updates(o) ? (-2) : 0;
1165 if (o->dst_index) {
1166 discard_index(o->dst_index);
1167 *o->dst_index = o->result;
1168 }
1169
1170 done:
1171 clear_exclude_list(&el);
1172 return ret;
1173
1174 return_failed:
1175 if (o->show_all_errors)
1176 display_error_msgs(o);
1177 mark_all_ce_unused(o->src_index);
1178 ret = unpack_failed(o, NULL);
1179 if (o->exiting_early)
1180 ret = 0;
1181 goto done;
1182 }
1183
1184 /* Here come the merge functions */
1185
1186 static int reject_merge(const struct cache_entry *ce,
1187 struct unpack_trees_options *o)
1188 {
1189 return add_rejected_path(o, ERROR_WOULD_OVERWRITE, ce->name);
1190 }
1191
1192 static int same(const struct cache_entry *a, const struct cache_entry *b)
1193 {
1194 if (!!a != !!b)
1195 return 0;
1196 if (!a && !b)
1197 return 1;
1198 if ((a->ce_flags | b->ce_flags) & CE_CONFLICTED)
1199 return 0;
1200 return a->ce_mode == b->ce_mode &&
1201 !hashcmp(a->sha1, b->sha1);
1202 }
1203
1204
1205 /*
1206 * When a CE gets turned into an unmerged entry, we
1207 * want it to be up-to-date
1208 */
1209 static int verify_uptodate_1(const struct cache_entry *ce,
1210 struct unpack_trees_options *o,
1211 enum unpack_trees_error_types error_type)
1212 {
1213 struct stat st;
1214
1215 if (o->index_only)
1216 return 0;
1217
1218 /*
1219 * CE_VALID and CE_SKIP_WORKTREE cheat, we better check again
1220 * if this entry is truly up-to-date because this file may be
1221 * overwritten.
1222 */
1223 if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
1224 ; /* keep checking */
1225 else if (o->reset || ce_uptodate(ce))
1226 return 0;
1227
1228 if (!lstat(ce->name, &st)) {
1229 int flags = CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE;
1230 unsigned changed = ie_match_stat(o->src_index, ce, &st, flags);
1231 if (!changed)
1232 return 0;
1233 /*
1234 * NEEDSWORK: the current default policy is to allow
1235 * submodule to be out of sync wrt the superproject
1236 * index. This needs to be tightened later for
1237 * submodules that are marked to be automatically
1238 * checked out.
1239 */
1240 if (S_ISGITLINK(ce->ce_mode))
1241 return 0;
1242 errno = 0;
1243 }
1244 if (errno == ENOENT)
1245 return 0;
1246 return o->gently ? -1 :
1247 add_rejected_path(o, error_type, ce->name);
1248 }
1249
1250 static int verify_uptodate(const struct cache_entry *ce,
1251 struct unpack_trees_options *o)
1252 {
1253 if (!o->skip_sparse_checkout && (ce->ce_flags & CE_NEW_SKIP_WORKTREE))
1254 return 0;
1255 return verify_uptodate_1(ce, o, ERROR_NOT_UPTODATE_FILE);
1256 }
1257
1258 static int verify_uptodate_sparse(const struct cache_entry *ce,
1259 struct unpack_trees_options *o)
1260 {
1261 return verify_uptodate_1(ce, o, ERROR_SPARSE_NOT_UPTODATE_FILE);
1262 }
1263
1264 static void invalidate_ce_path(const struct cache_entry *ce,
1265 struct unpack_trees_options *o)
1266 {
1267 if (ce)
1268 cache_tree_invalidate_path(o->src_index, ce->name);
1269 }
1270
1271 /*
1272 * Check that checking out ce->sha1 in subdir ce->name is not
1273 * going to overwrite any working files.
1274 *
1275 * Currently, git does not checkout subprojects during a superproject
1276 * checkout, so it is not going to overwrite anything.
1277 */
1278 static int verify_clean_submodule(const struct cache_entry *ce,
1279 enum unpack_trees_error_types error_type,
1280 struct unpack_trees_options *o)
1281 {
1282 return 0;
1283 }
1284
1285 static int verify_clean_subdirectory(const struct cache_entry *ce,
1286 enum unpack_trees_error_types error_type,
1287 struct unpack_trees_options *o)
1288 {
1289 /*
1290 * we are about to extract "ce->name"; we would not want to lose
1291 * anything in the existing directory there.
1292 */
1293 int namelen;
1294 int i;
1295 struct dir_struct d;
1296 char *pathbuf;
1297 int cnt = 0;
1298 unsigned char sha1[20];
1299
1300 if (S_ISGITLINK(ce->ce_mode) &&
1301 resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
1302 /* If we are not going to update the submodule, then
1303 * we don't care.
1304 */
1305 if (!hashcmp(sha1, ce->sha1))
1306 return 0;
1307 return verify_clean_submodule(ce, error_type, o);
1308 }
1309
1310 /*
1311 * First let's make sure we do not have a local modification
1312 * in that directory.
1313 */
1314 namelen = ce_namelen(ce);
1315 for (i = locate_in_src_index(ce, o);
1316 i < o->src_index->cache_nr;
1317 i++) {
1318 struct cache_entry *ce2 = o->src_index->cache[i];
1319 int len = ce_namelen(ce2);
1320 if (len < namelen ||
1321 strncmp(ce->name, ce2->name, namelen) ||
1322 ce2->name[namelen] != '/')
1323 break;
1324 /*
1325 * ce2->name is an entry in the subdirectory to be
1326 * removed.
1327 */
1328 if (!ce_stage(ce2)) {
1329 if (verify_uptodate(ce2, o))
1330 return -1;
1331 add_entry(o, ce2, CE_REMOVE, 0);
1332 mark_ce_used(ce2, o);
1333 }
1334 cnt++;
1335 }
1336
1337 /*
1338 * Then we need to make sure that we do not lose a locally
1339 * present file that is not ignored.
1340 */
1341 pathbuf = xmalloc(namelen + 2);
1342 memcpy(pathbuf, ce->name, namelen);
1343 strcpy(pathbuf+namelen, "/");
1344
1345 memset(&d, 0, sizeof(d));
1346 if (o->dir)
1347 d.exclude_per_dir = o->dir->exclude_per_dir;
1348 i = read_directory(&d, pathbuf, namelen+1, NULL);
1349 if (i)
1350 return o->gently ? -1 :
1351 add_rejected_path(o, ERROR_NOT_UPTODATE_DIR, ce->name);
1352 free(pathbuf);
1353 return cnt;
1354 }
1355
1356 /*
1357 * This gets called when there was no index entry for the tree entry 'dst',
1358 * but we found a file in the working tree that 'lstat()' said was fine,
1359 * and we're on a case-insensitive filesystem.
1360 *
1361 * See if we can find a case-insensitive match in the index that also
1362 * matches the stat information, and assume it's that other file!
1363 */
1364 static int icase_exists(struct unpack_trees_options *o, const char *name, int len, struct stat *st)
1365 {
1366 const struct cache_entry *src;
1367
1368 src = index_file_exists(o->src_index, name, len, 1);
1369 return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
1370 }
1371
1372 static int check_ok_to_remove(const char *name, int len, int dtype,
1373 const struct cache_entry *ce, struct stat *st,
1374 enum unpack_trees_error_types error_type,
1375 struct unpack_trees_options *o)
1376 {
1377 const struct cache_entry *result;
1378
1379 /*
1380 * It may be that the 'lstat()' succeeded even though
1381 * target 'ce' was absent, because there is an old
1382 * entry that is different only in case..
1383 *
1384 * Ignore that lstat() if it matches.
1385 */
1386 if (ignore_case && icase_exists(o, name, len, st))
1387 return 0;
1388
1389 if (o->dir &&
1390 is_excluded(o->dir, name, &dtype))
1391 /*
1392 * ce->name is explicitly excluded, so it is Ok to
1393 * overwrite it.
1394 */
1395 return 0;
1396 if (S_ISDIR(st->st_mode)) {
1397 /*
1398 * We are checking out path "foo" and
1399 * found "foo/." in the working tree.
1400 * This is tricky -- if we have modified
1401 * files that are in "foo/" we would lose
1402 * them.
1403 */
1404 if (verify_clean_subdirectory(ce, error_type, o) < 0)
1405 return -1;
1406 return 0;
1407 }
1408
1409 /*
1410 * The previous round may already have decided to
1411 * delete this path, which is in a subdirectory that
1412 * is being replaced with a blob.
1413 */
1414 result = index_file_exists(&o->result, name, len, 0);
1415 if (result) {
1416 if (result->ce_flags & CE_REMOVE)
1417 return 0;
1418 }
1419
1420 return o->gently ? -1 :
1421 add_rejected_path(o, error_type, name);
1422 }
1423
1424 /*
1425 * We do not want to remove or overwrite a working tree file that
1426 * is not tracked, unless it is ignored.
1427 */
1428 static int verify_absent_1(const struct cache_entry *ce,
1429 enum unpack_trees_error_types error_type,
1430 struct unpack_trees_options *o)
1431 {
1432 int len;
1433 struct stat st;
1434
1435 if (o->index_only || o->reset || !o->update)
1436 return 0;
1437
1438 len = check_leading_path(ce->name, ce_namelen(ce));
1439 if (!len)
1440 return 0;
1441 else if (len > 0) {
1442 char path[PATH_MAX + 1];
1443 memcpy(path, ce->name, len);
1444 path[len] = 0;
1445 if (lstat(path, &st))
1446 return error("cannot stat '%s': %s", path,
1447 strerror(errno));
1448
1449 return check_ok_to_remove(path, len, DT_UNKNOWN, NULL, &st,
1450 error_type, o);
1451 } else if (lstat(ce->name, &st)) {
1452 if (errno != ENOENT)
1453 return error("cannot stat '%s': %s", ce->name,
1454 strerror(errno));
1455 return 0;
1456 } else {
1457 return check_ok_to_remove(ce->name, ce_namelen(ce),
1458 ce_to_dtype(ce), ce, &st,
1459 error_type, o);
1460 }
1461 }
1462
1463 static int verify_absent(const struct cache_entry *ce,
1464 enum unpack_trees_error_types error_type,
1465 struct unpack_trees_options *o)
1466 {
1467 if (!o->skip_sparse_checkout && (ce->ce_flags & CE_NEW_SKIP_WORKTREE))
1468 return 0;
1469 return verify_absent_1(ce, error_type, o);
1470 }
1471
1472 static int verify_absent_sparse(const struct cache_entry *ce,
1473 enum unpack_trees_error_types error_type,
1474 struct unpack_trees_options *o)
1475 {
1476 enum unpack_trees_error_types orphaned_error = error_type;
1477 if (orphaned_error == ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN)
1478 orphaned_error = ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN;
1479
1480 return verify_absent_1(ce, orphaned_error, o);
1481 }
1482
1483 static int merged_entry(const struct cache_entry *ce,
1484 const struct cache_entry *old,
1485 struct unpack_trees_options *o)
1486 {
1487 int update = CE_UPDATE;
1488 struct cache_entry *merge = dup_entry(ce);
1489
1490 if (!old) {
1491 /*
1492 * New index entries. In sparse checkout, the following
1493 * verify_absent() will be delayed until after
1494 * traverse_trees() finishes in unpack_trees(), then:
1495 *
1496 * - CE_NEW_SKIP_WORKTREE will be computed correctly
1497 * - verify_absent() be called again, this time with
1498 * correct CE_NEW_SKIP_WORKTREE
1499 *
1500 * verify_absent() call here does nothing in sparse
1501 * checkout (i.e. o->skip_sparse_checkout == 0)
1502 */
1503 update |= CE_ADDED;
1504 merge->ce_flags |= CE_NEW_SKIP_WORKTREE;
1505
1506 if (verify_absent(merge,
1507 ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o)) {
1508 free(merge);
1509 return -1;
1510 }
1511 invalidate_ce_path(merge, o);
1512 } else if (!(old->ce_flags & CE_CONFLICTED)) {
1513 /*
1514 * See if we can re-use the old CE directly?
1515 * That way we get the uptodate stat info.
1516 *
1517 * This also removes the UPDATE flag on a match; otherwise
1518 * we will end up overwriting local changes in the work tree.
1519 */
1520 if (same(old, merge)) {
1521 copy_cache_entry(merge, old);
1522 update = 0;
1523 } else {
1524 if (verify_uptodate(old, o)) {
1525 free(merge);
1526 return -1;
1527 }
1528 /* Migrate old flags over */
1529 update |= old->ce_flags & (CE_SKIP_WORKTREE | CE_NEW_SKIP_WORKTREE);
1530 invalidate_ce_path(old, o);
1531 }
1532 } else {
1533 /*
1534 * Previously unmerged entry left as an existence
1535 * marker by read_index_unmerged();
1536 */
1537 invalidate_ce_path(old, o);
1538 }
1539
1540 do_add_entry(o, merge, update, CE_STAGEMASK);
1541 return 1;
1542 }
1543
1544 static int deleted_entry(const struct cache_entry *ce,
1545 const struct cache_entry *old,
1546 struct unpack_trees_options *o)
1547 {
1548 /* Did it exist in the index? */
1549 if (!old) {
1550 if (verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_REMOVED, o))
1551 return -1;
1552 return 0;
1553 }
1554 if (!(old->ce_flags & CE_CONFLICTED) && verify_uptodate(old, o))
1555 return -1;
1556 add_entry(o, ce, CE_REMOVE, 0);
1557 invalidate_ce_path(ce, o);
1558 return 1;
1559 }
1560
1561 static int keep_entry(const struct cache_entry *ce,
1562 struct unpack_trees_options *o)
1563 {
1564 add_entry(o, ce, 0, 0);
1565 return 1;
1566 }
1567
1568 #if DBRT_DEBUG
1569 static void show_stage_entry(FILE *o,
1570 const char *label, const struct cache_entry *ce)
1571 {
1572 if (!ce)
1573 fprintf(o, "%s (missing)\n", label);
1574 else
1575 fprintf(o, "%s%06o %s %d\t%s\n",
1576 label,
1577 ce->ce_mode,
1578 sha1_to_hex(ce->sha1),
1579 ce_stage(ce),
1580 ce->name);
1581 }
1582 #endif
1583
1584 int threeway_merge(const struct cache_entry * const *stages,
1585 struct unpack_trees_options *o)
1586 {
1587 const struct cache_entry *index;
1588 const struct cache_entry *head;
1589 const struct cache_entry *remote = stages[o->head_idx + 1];
1590 int count;
1591 int head_match = 0;
1592 int remote_match = 0;
1593
1594 int df_conflict_head = 0;
1595 int df_conflict_remote = 0;
1596
1597 int any_anc_missing = 0;
1598 int no_anc_exists = 1;
1599 int i;
1600
1601 for (i = 1; i < o->head_idx; i++) {
1602 if (!stages[i] || stages[i] == o->df_conflict_entry)
1603 any_anc_missing = 1;
1604 else
1605 no_anc_exists = 0;
1606 }
1607
1608 index = stages[0];
1609 head = stages[o->head_idx];
1610
1611 if (head == o->df_conflict_entry) {
1612 df_conflict_head = 1;
1613 head = NULL;
1614 }
1615
1616 if (remote == o->df_conflict_entry) {
1617 df_conflict_remote = 1;
1618 remote = NULL;
1619 }
1620
1621 /*
1622 * First, if there's a #16 situation, note that to prevent #13
1623 * and #14.
1624 */
1625 if (!same(remote, head)) {
1626 for (i = 1; i < o->head_idx; i++) {
1627 if (same(stages[i], head)) {
1628 head_match = i;
1629 }
1630 if (same(stages[i], remote)) {
1631 remote_match = i;
1632 }
1633 }
1634 }
1635
1636 /*
1637 * We start with cases where the index is allowed to match
1638 * something other than the head: #14(ALT) and #2ALT, where it
1639 * is permitted to match the result instead.
1640 */
1641 /* #14, #14ALT, #2ALT */
1642 if (remote && !df_conflict_head && head_match && !remote_match) {
1643 if (index && !same(index, remote) && !same(index, head))
1644 return o->gently ? -1 : reject_merge(index, o);
1645 return merged_entry(remote, index, o);
1646 }
1647 /*
1648 * If we have an entry in the index cache, then we want to
1649 * make sure that it matches head.
1650 */
1651 if (index && !same(index, head))
1652 return o->gently ? -1 : reject_merge(index, o);
1653
1654 if (head) {
1655 /* #5ALT, #15 */
1656 if (same(head, remote))
1657 return merged_entry(head, index, o);
1658 /* #13, #3ALT */
1659 if (!df_conflict_remote && remote_match && !head_match)
1660 return merged_entry(head, index, o);
1661 }
1662
1663 /* #1 */
1664 if (!head && !remote && any_anc_missing)
1665 return 0;
1666
1667 /*
1668 * Under the "aggressive" rule, we resolve mostly trivial
1669 * cases that we historically had git-merge-one-file resolve.
1670 */
1671 if (o->aggressive) {
1672 int head_deleted = !head;
1673 int remote_deleted = !remote;
1674 const struct cache_entry *ce = NULL;
1675
1676 if (index)
1677 ce = index;
1678 else if (head)
1679 ce = head;
1680 else if (remote)
1681 ce = remote;
1682 else {
1683 for (i = 1; i < o->head_idx; i++) {
1684 if (stages[i] && stages[i] != o->df_conflict_entry) {
1685 ce = stages[i];
1686 break;
1687 }
1688 }
1689 }
1690
1691 /*
1692 * Deleted in both.
1693 * Deleted in one and unchanged in the other.
1694 */
1695 if ((head_deleted && remote_deleted) ||
1696 (head_deleted && remote && remote_match) ||
1697 (remote_deleted && head && head_match)) {
1698 if (index)
1699 return deleted_entry(index, index, o);
1700 if (ce && !head_deleted) {
1701 if (verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_REMOVED, o))
1702 return -1;
1703 }
1704 return 0;
1705 }
1706 /*
1707 * Added in both, identically.
1708 */
1709 if (no_anc_exists && head && remote && same(head, remote))
1710 return merged_entry(head, index, o);
1711
1712 }
1713
1714 /* Below are "no merge" cases, which require that the index be
1715 * up-to-date to avoid the files getting overwritten with
1716 * conflict resolution files.
1717 */
1718 if (index) {
1719 if (verify_uptodate(index, o))
1720 return -1;
1721 }
1722
1723 o->nontrivial_merge = 1;
1724
1725 /* #2, #3, #4, #6, #7, #9, #10, #11. */
1726 count = 0;
1727 if (!head_match || !remote_match) {
1728 for (i = 1; i < o->head_idx; i++) {
1729 if (stages[i] && stages[i] != o->df_conflict_entry) {
1730 keep_entry(stages[i], o);
1731 count++;
1732 break;
1733 }
1734 }
1735 }
1736 #if DBRT_DEBUG
1737 else {
1738 fprintf(stderr, "read-tree: warning #16 detected\n");
1739 show_stage_entry(stderr, "head ", stages[head_match]);
1740 show_stage_entry(stderr, "remote ", stages[remote_match]);
1741 }
1742 #endif
1743 if (head) { count += keep_entry(head, o); }
1744 if (remote) { count += keep_entry(remote, o); }
1745 return count;
1746 }
1747
1748 /*
1749 * Two-way merge.
1750 *
1751 * The rule is to "carry forward" what is in the index without losing
1752 * information across a "fast-forward", favoring a successful merge
1753 * over a merge failure when it makes sense. For details of the
1754 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
1755 *
1756 */
1757 int twoway_merge(const struct cache_entry * const *src,
1758 struct unpack_trees_options *o)
1759 {
1760 const struct cache_entry *current = src[0];
1761 const struct cache_entry *oldtree = src[1];
1762 const struct cache_entry *newtree = src[2];
1763
1764 if (o->merge_size != 2)
1765 return error("Cannot do a twoway merge of %d trees",
1766 o->merge_size);
1767
1768 if (oldtree == o->df_conflict_entry)
1769 oldtree = NULL;
1770 if (newtree == o->df_conflict_entry)
1771 newtree = NULL;
1772
1773 if (current) {
1774 if (current->ce_flags & CE_CONFLICTED) {
1775 if (same(oldtree, newtree) || o->reset) {
1776 if (!newtree)
1777 return deleted_entry(current, current, o);
1778 else
1779 return merged_entry(newtree, current, o);
1780 }
1781 return o->gently ? -1 : reject_merge(current, o);
1782 }
1783 else if ((!oldtree && !newtree) || /* 4 and 5 */
1784 (!oldtree && newtree &&
1785 same(current, newtree)) || /* 6 and 7 */
1786 (oldtree && newtree &&
1787 same(oldtree, newtree)) || /* 14 and 15 */
1788 (oldtree && newtree &&
1789 !same(oldtree, newtree) && /* 18 and 19 */
1790 same(current, newtree))) {
1791 return keep_entry(current, o);
1792 }
1793 else if (oldtree && !newtree && same(current, oldtree)) {
1794 /* 10 or 11 */
1795 return deleted_entry(oldtree, current, o);
1796 }
1797 else if (oldtree && newtree &&
1798 same(current, oldtree) && !same(current, newtree)) {
1799 /* 20 or 21 */
1800 return merged_entry(newtree, current, o);
1801 }
1802 else {
1803 /* all other failures */
1804 if (oldtree)
1805 return o->gently ? -1 : reject_merge(oldtree, o);
1806 if (current)
1807 return o->gently ? -1 : reject_merge(current, o);
1808 if (newtree)
1809 return o->gently ? -1 : reject_merge(newtree, o);
1810 return -1;
1811 }
1812 }
1813 else if (newtree) {
1814 if (oldtree && !o->initial_checkout) {
1815 /*
1816 * deletion of the path was staged;
1817 */
1818 if (same(oldtree, newtree))
1819 return 1;
1820 return reject_merge(oldtree, o);
1821 }
1822 return merged_entry(newtree, current, o);
1823 }
1824 return deleted_entry(oldtree, current, o);
1825 }
1826
1827 /*
1828 * Bind merge.
1829 *
1830 * Keep the index entries at stage0, collapse stage1 but make sure
1831 * stage0 does not have anything there.
1832 */
1833 int bind_merge(const struct cache_entry * const *src,
1834 struct unpack_trees_options *o)
1835 {
1836 const struct cache_entry *old = src[0];
1837 const struct cache_entry *a = src[1];
1838
1839 if (o->merge_size != 1)
1840 return error("Cannot do a bind merge of %d trees",
1841 o->merge_size);
1842 if (a && old)
1843 return o->gently ? -1 :
1844 error(ERRORMSG(o, ERROR_BIND_OVERLAP), a->name, old->name);
1845 if (!a)
1846 return keep_entry(old, o);
1847 else
1848 return merged_entry(a, NULL, o);
1849 }
1850
1851 /*
1852 * One-way merge.
1853 *
1854 * The rule is:
1855 * - take the stat information from stage0, take the data from stage1
1856 */
1857 int oneway_merge(const struct cache_entry * const *src,
1858 struct unpack_trees_options *o)
1859 {
1860 const struct cache_entry *old = src[0];
1861 const struct cache_entry *a = src[1];
1862
1863 if (o->merge_size != 1)
1864 return error("Cannot do a oneway merge of %d trees",
1865 o->merge_size);
1866
1867 if (!a || a == o->df_conflict_entry)
1868 return deleted_entry(old, old, o);
1869
1870 if (old && same(old, a)) {
1871 int update = 0;
1872 if (o->reset && o->update && !ce_uptodate(old) && !ce_skip_worktree(old)) {
1873 struct stat st;
1874 if (lstat(old->name, &st) ||
1875 ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE))
1876 update |= CE_UPDATE;
1877 }
1878 add_entry(o, old, update, 0);
1879 return 0;
1880 }
1881 return merged_entry(a, old, o);
1882 }