read-cache: split-index mode
[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 #include "split-index.h"
12
13 /*
14 * Error messages expected by scripts out of plumbing commands such as
15 * read-tree. Non-scripted Porcelain is not required to use these messages
16 * and in fact are encouraged to reword them to better suit their particular
17 * situation better. See how "git checkout" and "git merge" replaces
18 * them using setup_unpack_trees_porcelain(), for example.
19 */
20 static const char *unpack_plumbing_errors[NB_UNPACK_TREES_ERROR_TYPES] = {
21 /* ERROR_WOULD_OVERWRITE */
22 "Entry '%s' would be overwritten by merge. Cannot merge.",
23
24 /* ERROR_NOT_UPTODATE_FILE */
25 "Entry '%s' not uptodate. Cannot merge.",
26
27 /* ERROR_NOT_UPTODATE_DIR */
28 "Updating '%s' would lose untracked files in it",
29
30 /* ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN */
31 "Untracked working tree file '%s' would be overwritten by merge.",
32
33 /* ERROR_WOULD_LOSE_UNTRACKED_REMOVED */
34 "Untracked working tree file '%s' would be removed by merge.",
35
36 /* ERROR_BIND_OVERLAP */
37 "Entry '%s' overlaps with '%s'. Cannot bind.",
38
39 /* ERROR_SPARSE_NOT_UPTODATE_FILE */
40 "Entry '%s' not uptodate. Cannot update sparse checkout.",
41
42 /* ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN */
43 "Working tree file '%s' would be overwritten by sparse checkout update.",
44
45 /* ERROR_WOULD_LOSE_ORPHANED_REMOVED */
46 "Working tree file '%s' would be removed by sparse checkout update.",
47 };
48
49 #define ERRORMSG(o,type) \
50 ( ((o) && (o)->msgs[(type)]) \
51 ? ((o)->msgs[(type)]) \
52 : (unpack_plumbing_errors[(type)]) )
53
54 void setup_unpack_trees_porcelain(struct unpack_trees_options *opts,
55 const char *cmd)
56 {
57 int i;
58 const char **msgs = opts->msgs;
59 const char *msg;
60 char *tmp;
61 const char *cmd2 = strcmp(cmd, "checkout") ? cmd : "switch branches";
62 if (advice_commit_before_merge)
63 msg = "Your local changes to the following files would be overwritten by %s:\n%%s"
64 "Please, commit your changes or stash them before you can %s.";
65 else
66 msg = "Your local changes to the following files would be overwritten by %s:\n%%s";
67 tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen(cmd2) - 2);
68 sprintf(tmp, msg, cmd, cmd2);
69 msgs[ERROR_WOULD_OVERWRITE] = tmp;
70 msgs[ERROR_NOT_UPTODATE_FILE] = tmp;
71
72 msgs[ERROR_NOT_UPTODATE_DIR] =
73 "Updating the following directories would lose untracked files in it:\n%s";
74
75 if (advice_commit_before_merge)
76 msg = "The following untracked working tree files would be %s by %s:\n%%s"
77 "Please move or remove them before you can %s.";
78 else
79 msg = "The following untracked working tree files would be %s by %s:\n%%s";
80 tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen("removed") + strlen(cmd2) - 4);
81 sprintf(tmp, msg, "removed", cmd, cmd2);
82 msgs[ERROR_WOULD_LOSE_UNTRACKED_REMOVED] = tmp;
83 tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen("overwritten") + strlen(cmd2) - 4);
84 sprintf(tmp, msg, "overwritten", cmd, cmd2);
85 msgs[ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN] = tmp;
86
87 /*
88 * Special case: ERROR_BIND_OVERLAP refers to a pair of paths, we
89 * cannot easily display it as a list.
90 */
91 msgs[ERROR_BIND_OVERLAP] = "Entry '%s' overlaps with '%s'. Cannot bind.";
92
93 msgs[ERROR_SPARSE_NOT_UPTODATE_FILE] =
94 "Cannot update sparse checkout: the following entries are not up-to-date:\n%s";
95 msgs[ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN] =
96 "The following Working tree files would be overwritten by sparse checkout update:\n%s";
97 msgs[ERROR_WOULD_LOSE_ORPHANED_REMOVED] =
98 "The following Working tree files would be removed by sparse checkout update:\n%s";
99
100 opts->show_all_errors = 1;
101 /* rejected paths may not have a static buffer */
102 for (i = 0; i < ARRAY_SIZE(opts->unpack_rejects); i++)
103 opts->unpack_rejects[i].strdup_strings = 1;
104 }
105
106 static void do_add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
107 unsigned int set, unsigned int clear)
108 {
109 clear |= CE_HASHED;
110
111 if (set & CE_REMOVE)
112 set |= CE_WT_REMOVE;
113
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 index_state *istate,
251 struct cache_entry *ce,
252 struct unpack_trees_options *o)
253 {
254 int was_skip_worktree = ce_skip_worktree(ce);
255
256 if (ce->ce_flags & CE_NEW_SKIP_WORKTREE)
257 ce->ce_flags |= CE_SKIP_WORKTREE;
258 else
259 ce->ce_flags &= ~CE_SKIP_WORKTREE;
260 if (was_skip_worktree != ce_skip_worktree(ce))
261 istate->cache_changed |= CE_ENTRY_CHANGED;
262
263 /*
264 * if (!was_skip_worktree && !ce_skip_worktree()) {
265 * This is perfectly normal. Move on;
266 * }
267 */
268
269 /*
270 * Merge strategies may set CE_UPDATE|CE_REMOVE outside checkout
271 * area as a result of ce_skip_worktree() shortcuts in
272 * verify_absent() and verify_uptodate().
273 * Make sure they don't modify worktree if they are already
274 * outside checkout area
275 */
276 if (was_skip_worktree && ce_skip_worktree(ce)) {
277 ce->ce_flags &= ~CE_UPDATE;
278
279 /*
280 * By default, when CE_REMOVE is on, CE_WT_REMOVE is also
281 * on to get that file removed from both index and worktree.
282 * If that file is already outside worktree area, don't
283 * bother remove it.
284 */
285 if (ce->ce_flags & CE_REMOVE)
286 ce->ce_flags &= ~CE_WT_REMOVE;
287 }
288
289 if (!was_skip_worktree && ce_skip_worktree(ce)) {
290 /*
291 * If CE_UPDATE is set, verify_uptodate() must be called already
292 * also stat info may have lost after merged_entry() so calling
293 * verify_uptodate() again may fail
294 */
295 if (!(ce->ce_flags & CE_UPDATE) && verify_uptodate_sparse(ce, o))
296 return -1;
297 ce->ce_flags |= CE_WT_REMOVE;
298 }
299 if (was_skip_worktree && !ce_skip_worktree(ce)) {
300 if (verify_absent_sparse(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o))
301 return -1;
302 ce->ce_flags |= CE_UPDATE;
303 }
304 return 0;
305 }
306
307 static inline int call_unpack_fn(const struct cache_entry * const *src,
308 struct unpack_trees_options *o)
309 {
310 int ret = o->fn(src, o);
311 if (ret > 0)
312 ret = 0;
313 return ret;
314 }
315
316 static void mark_ce_used(struct cache_entry *ce, struct unpack_trees_options *o)
317 {
318 ce->ce_flags |= CE_UNPACKED;
319
320 if (o->cache_bottom < o->src_index->cache_nr &&
321 o->src_index->cache[o->cache_bottom] == ce) {
322 int bottom = o->cache_bottom;
323 while (bottom < o->src_index->cache_nr &&
324 o->src_index->cache[bottom]->ce_flags & CE_UNPACKED)
325 bottom++;
326 o->cache_bottom = bottom;
327 }
328 }
329
330 static void mark_all_ce_unused(struct index_state *index)
331 {
332 int i;
333 for (i = 0; i < index->cache_nr; i++)
334 index->cache[i]->ce_flags &= ~(CE_UNPACKED | CE_ADDED | CE_NEW_SKIP_WORKTREE);
335 }
336
337 static int locate_in_src_index(const struct cache_entry *ce,
338 struct unpack_trees_options *o)
339 {
340 struct index_state *index = o->src_index;
341 int len = ce_namelen(ce);
342 int pos = index_name_pos(index, ce->name, len);
343 if (pos < 0)
344 pos = -1 - pos;
345 return pos;
346 }
347
348 /*
349 * We call unpack_index_entry() with an unmerged cache entry
350 * only in diff-index, and it wants a single callback. Skip
351 * the other unmerged entry with the same name.
352 */
353 static void mark_ce_used_same_name(struct cache_entry *ce,
354 struct unpack_trees_options *o)
355 {
356 struct index_state *index = o->src_index;
357 int len = ce_namelen(ce);
358 int pos;
359
360 for (pos = locate_in_src_index(ce, o); pos < index->cache_nr; pos++) {
361 struct cache_entry *next = index->cache[pos];
362 if (len != ce_namelen(next) ||
363 memcmp(ce->name, next->name, len))
364 break;
365 mark_ce_used(next, o);
366 }
367 }
368
369 static struct cache_entry *next_cache_entry(struct unpack_trees_options *o)
370 {
371 const struct index_state *index = o->src_index;
372 int pos = o->cache_bottom;
373
374 while (pos < index->cache_nr) {
375 struct cache_entry *ce = index->cache[pos];
376 if (!(ce->ce_flags & CE_UNPACKED))
377 return ce;
378 pos++;
379 }
380 return NULL;
381 }
382
383 static void add_same_unmerged(const struct cache_entry *ce,
384 struct unpack_trees_options *o)
385 {
386 struct index_state *index = o->src_index;
387 int len = ce_namelen(ce);
388 int pos = index_name_pos(index, ce->name, len);
389
390 if (0 <= pos)
391 die("programming error in a caller of mark_ce_used_same_name");
392 for (pos = -pos - 1; pos < index->cache_nr; pos++) {
393 struct cache_entry *next = index->cache[pos];
394 if (len != ce_namelen(next) ||
395 memcmp(ce->name, next->name, len))
396 break;
397 add_entry(o, next, 0, 0);
398 mark_ce_used(next, o);
399 }
400 }
401
402 static int unpack_index_entry(struct cache_entry *ce,
403 struct unpack_trees_options *o)
404 {
405 const struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
406 int ret;
407
408 src[0] = ce;
409
410 mark_ce_used(ce, o);
411 if (ce_stage(ce)) {
412 if (o->skip_unmerged) {
413 add_entry(o, ce, 0, 0);
414 return 0;
415 }
416 }
417 ret = call_unpack_fn(src, o);
418 if (ce_stage(ce))
419 mark_ce_used_same_name(ce, o);
420 return ret;
421 }
422
423 static int find_cache_pos(struct traverse_info *, const struct name_entry *);
424
425 static void restore_cache_bottom(struct traverse_info *info, int bottom)
426 {
427 struct unpack_trees_options *o = info->data;
428
429 if (o->diff_index_cached)
430 return;
431 o->cache_bottom = bottom;
432 }
433
434 static int switch_cache_bottom(struct traverse_info *info)
435 {
436 struct unpack_trees_options *o = info->data;
437 int ret, pos;
438
439 if (o->diff_index_cached)
440 return 0;
441 ret = o->cache_bottom;
442 pos = find_cache_pos(info->prev, &info->name);
443
444 if (pos < -1)
445 o->cache_bottom = -2 - pos;
446 else if (pos < 0)
447 o->cache_bottom = o->src_index->cache_nr;
448 return ret;
449 }
450
451 static int traverse_trees_recursive(int n, unsigned long dirmask,
452 unsigned long df_conflicts,
453 struct name_entry *names,
454 struct traverse_info *info)
455 {
456 int i, ret, bottom;
457 struct tree_desc t[MAX_UNPACK_TREES];
458 void *buf[MAX_UNPACK_TREES];
459 struct traverse_info newinfo;
460 struct name_entry *p;
461
462 p = names;
463 while (!p->mode)
464 p++;
465
466 newinfo = *info;
467 newinfo.prev = info;
468 newinfo.pathspec = info->pathspec;
469 newinfo.name = *p;
470 newinfo.pathlen += tree_entry_len(p) + 1;
471 newinfo.df_conflicts |= df_conflicts;
472
473 for (i = 0; i < n; i++, dirmask >>= 1) {
474 const unsigned char *sha1 = NULL;
475 if (dirmask & 1)
476 sha1 = names[i].sha1;
477 buf[i] = fill_tree_descriptor(t+i, sha1);
478 }
479
480 bottom = switch_cache_bottom(&newinfo);
481 ret = traverse_trees(n, t, &newinfo);
482 restore_cache_bottom(&newinfo, bottom);
483
484 for (i = 0; i < n; i++)
485 free(buf[i]);
486
487 return ret;
488 }
489
490 /*
491 * Compare the traverse-path to the cache entry without actually
492 * having to generate the textual representation of the traverse
493 * path.
494 *
495 * NOTE! This *only* compares up to the size of the traverse path
496 * itself - the caller needs to do the final check for the cache
497 * entry having more data at the end!
498 */
499 static int do_compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
500 {
501 int len, pathlen, ce_len;
502 const char *ce_name;
503
504 if (info->prev) {
505 int cmp = do_compare_entry(ce, info->prev, &info->name);
506 if (cmp)
507 return cmp;
508 }
509 pathlen = info->pathlen;
510 ce_len = ce_namelen(ce);
511
512 /* If ce_len < pathlen then we must have previously hit "name == directory" entry */
513 if (ce_len < pathlen)
514 return -1;
515
516 ce_len -= pathlen;
517 ce_name = ce->name + pathlen;
518
519 len = tree_entry_len(n);
520 return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode);
521 }
522
523 static int compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
524 {
525 int cmp = do_compare_entry(ce, info, n);
526 if (cmp)
527 return cmp;
528
529 /*
530 * Even if the beginning compared identically, the ce should
531 * compare as bigger than a directory leading up to it!
532 */
533 return ce_namelen(ce) > traverse_path_len(info, n);
534 }
535
536 static int ce_in_traverse_path(const struct cache_entry *ce,
537 const struct traverse_info *info)
538 {
539 if (!info->prev)
540 return 1;
541 if (do_compare_entry(ce, info->prev, &info->name))
542 return 0;
543 /*
544 * If ce (blob) is the same name as the path (which is a tree
545 * we will be descending into), it won't be inside it.
546 */
547 return (info->pathlen < ce_namelen(ce));
548 }
549
550 static struct cache_entry *create_ce_entry(const struct traverse_info *info, const struct name_entry *n, int stage)
551 {
552 int len = traverse_path_len(info, n);
553 struct cache_entry *ce = xcalloc(1, cache_entry_size(len));
554
555 ce->ce_mode = create_ce_mode(n->mode);
556 ce->ce_flags = create_ce_flags(stage);
557 ce->ce_namelen = len;
558 hashcpy(ce->sha1, n->sha1);
559 make_traverse_path(ce->name, info, n);
560
561 return ce;
562 }
563
564 static int unpack_nondirectories(int n, unsigned long mask,
565 unsigned long dirmask,
566 struct cache_entry **src,
567 const struct name_entry *names,
568 const struct traverse_info *info)
569 {
570 int i;
571 struct unpack_trees_options *o = info->data;
572 unsigned long conflicts = info->df_conflicts | dirmask;
573
574 /* Do we have *only* directories? Nothing to do */
575 if (mask == dirmask && !src[0])
576 return 0;
577
578 /*
579 * Ok, we've filled in up to any potential index entry in src[0],
580 * now do the rest.
581 */
582 for (i = 0; i < n; i++) {
583 int stage;
584 unsigned int bit = 1ul << i;
585 if (conflicts & bit) {
586 src[i + o->merge] = o->df_conflict_entry;
587 continue;
588 }
589 if (!(mask & bit))
590 continue;
591 if (!o->merge)
592 stage = 0;
593 else if (i + 1 < o->head_idx)
594 stage = 1;
595 else if (i + 1 > o->head_idx)
596 stage = 3;
597 else
598 stage = 2;
599 src[i + o->merge] = create_ce_entry(info, names + i, stage);
600 }
601
602 if (o->merge) {
603 int rc = call_unpack_fn((const struct cache_entry * const *)src,
604 o);
605 for (i = 0; i < n; i++) {
606 struct cache_entry *ce = src[i + o->merge];
607 if (ce != o->df_conflict_entry)
608 free(ce);
609 }
610 return rc;
611 }
612
613 for (i = 0; i < n; i++)
614 if (src[i] && src[i] != o->df_conflict_entry)
615 do_add_entry(o, src[i], 0, 0);
616 return 0;
617 }
618
619 static int unpack_failed(struct unpack_trees_options *o, const char *message)
620 {
621 discard_index(&o->result);
622 if (!o->gently && !o->exiting_early) {
623 if (message)
624 return error("%s", message);
625 return -1;
626 }
627 return -1;
628 }
629
630 /* NEEDSWORK: give this a better name and share with tree-walk.c */
631 static int name_compare(const char *a, int a_len,
632 const char *b, int b_len)
633 {
634 int len = (a_len < b_len) ? a_len : b_len;
635 int cmp = memcmp(a, b, len);
636 if (cmp)
637 return cmp;
638 return (a_len - b_len);
639 }
640
641 /*
642 * The tree traversal is looking at name p. If we have a matching entry,
643 * return it. If name p is a directory in the index, do not return
644 * anything, as we will want to match it when the traversal descends into
645 * the directory.
646 */
647 static int find_cache_pos(struct traverse_info *info,
648 const struct name_entry *p)
649 {
650 int pos;
651 struct unpack_trees_options *o = info->data;
652 struct index_state *index = o->src_index;
653 int pfxlen = info->pathlen;
654 int p_len = tree_entry_len(p);
655
656 for (pos = o->cache_bottom; pos < index->cache_nr; pos++) {
657 const struct cache_entry *ce = index->cache[pos];
658 const char *ce_name, *ce_slash;
659 int cmp, ce_len;
660
661 if (ce->ce_flags & CE_UNPACKED) {
662 /*
663 * cache_bottom entry is already unpacked, so
664 * we can never match it; don't check it
665 * again.
666 */
667 if (pos == o->cache_bottom)
668 ++o->cache_bottom;
669 continue;
670 }
671 if (!ce_in_traverse_path(ce, info))
672 continue;
673 ce_name = ce->name + pfxlen;
674 ce_slash = strchr(ce_name, '/');
675 if (ce_slash)
676 ce_len = ce_slash - ce_name;
677 else
678 ce_len = ce_namelen(ce) - pfxlen;
679 cmp = name_compare(p->path, p_len, ce_name, ce_len);
680 /*
681 * Exact match; if we have a directory we need to
682 * delay returning it.
683 */
684 if (!cmp)
685 return ce_slash ? -2 - pos : pos;
686 if (0 < cmp)
687 continue; /* keep looking */
688 /*
689 * ce_name sorts after p->path; could it be that we
690 * have files under p->path directory in the index?
691 * E.g. ce_name == "t-i", and p->path == "t"; we may
692 * have "t/a" in the index.
693 */
694 if (p_len < ce_len && !memcmp(ce_name, p->path, p_len) &&
695 ce_name[p_len] < '/')
696 continue; /* keep looking */
697 break;
698 }
699 return -1;
700 }
701
702 static struct cache_entry *find_cache_entry(struct traverse_info *info,
703 const struct name_entry *p)
704 {
705 int pos = find_cache_pos(info, p);
706 struct unpack_trees_options *o = info->data;
707
708 if (0 <= pos)
709 return o->src_index->cache[pos];
710 else
711 return NULL;
712 }
713
714 static void debug_path(struct traverse_info *info)
715 {
716 if (info->prev) {
717 debug_path(info->prev);
718 if (*info->prev->name.path)
719 putchar('/');
720 }
721 printf("%s", info->name.path);
722 }
723
724 static void debug_name_entry(int i, struct name_entry *n)
725 {
726 printf("ent#%d %06o %s\n", i,
727 n->path ? n->mode : 0,
728 n->path ? n->path : "(missing)");
729 }
730
731 static void debug_unpack_callback(int n,
732 unsigned long mask,
733 unsigned long dirmask,
734 struct name_entry *names,
735 struct traverse_info *info)
736 {
737 int i;
738 printf("* unpack mask %lu, dirmask %lu, cnt %d ",
739 mask, dirmask, n);
740 debug_path(info);
741 putchar('\n');
742 for (i = 0; i < n; i++)
743 debug_name_entry(i, names + i);
744 }
745
746 static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *names, struct traverse_info *info)
747 {
748 struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
749 struct unpack_trees_options *o = info->data;
750 const struct name_entry *p = names;
751
752 /* Find first entry with a real name (we could use "mask" too) */
753 while (!p->mode)
754 p++;
755
756 if (o->debug_unpack)
757 debug_unpack_callback(n, mask, dirmask, names, info);
758
759 /* Are we supposed to look at the index too? */
760 if (o->merge) {
761 while (1) {
762 int cmp;
763 struct cache_entry *ce;
764
765 if (o->diff_index_cached)
766 ce = next_cache_entry(o);
767 else
768 ce = find_cache_entry(info, p);
769
770 if (!ce)
771 break;
772 cmp = compare_entry(ce, info, p);
773 if (cmp < 0) {
774 if (unpack_index_entry(ce, o) < 0)
775 return unpack_failed(o, NULL);
776 continue;
777 }
778 if (!cmp) {
779 if (ce_stage(ce)) {
780 /*
781 * If we skip unmerged index
782 * entries, we'll skip this
783 * entry *and* the tree
784 * entries associated with it!
785 */
786 if (o->skip_unmerged) {
787 add_same_unmerged(ce, o);
788 return mask;
789 }
790 }
791 src[0] = ce;
792 }
793 break;
794 }
795 }
796
797 if (unpack_nondirectories(n, mask, dirmask, src, names, info) < 0)
798 return -1;
799
800 if (o->merge && src[0]) {
801 if (ce_stage(src[0]))
802 mark_ce_used_same_name(src[0], o);
803 else
804 mark_ce_used(src[0], o);
805 }
806
807 /* Now handle any directories.. */
808 if (dirmask) {
809 /* special case: "diff-index --cached" looking at a tree */
810 if (o->diff_index_cached &&
811 n == 1 && dirmask == 1 && S_ISDIR(names->mode)) {
812 int matches;
813 matches = cache_tree_matches_traversal(o->src_index->cache_tree,
814 names, info);
815 /*
816 * Everything under the name matches; skip the
817 * entire hierarchy. diff_index_cached codepath
818 * special cases D/F conflicts in such a way that
819 * it does not do any look-ahead, so this is safe.
820 */
821 if (matches) {
822 o->cache_bottom += matches;
823 return mask;
824 }
825 }
826
827 if (traverse_trees_recursive(n, dirmask, mask & ~dirmask,
828 names, info) < 0)
829 return -1;
830 return mask;
831 }
832
833 return mask;
834 }
835
836 static int clear_ce_flags_1(struct cache_entry **cache, int nr,
837 struct strbuf *prefix,
838 int select_mask, int clear_mask,
839 struct exclude_list *el, int defval);
840
841 /* Whole directory matching */
842 static int clear_ce_flags_dir(struct cache_entry **cache, int nr,
843 struct strbuf *prefix,
844 char *basename,
845 int select_mask, int clear_mask,
846 struct exclude_list *el, int defval)
847 {
848 struct cache_entry **cache_end;
849 int dtype = DT_DIR;
850 int ret = is_excluded_from_list(prefix->buf, prefix->len,
851 basename, &dtype, el);
852 int rc;
853
854 strbuf_addch(prefix, '/');
855
856 /* If undecided, use matching result of parent dir in defval */
857 if (ret < 0)
858 ret = defval;
859
860 for (cache_end = cache; cache_end != cache + nr; cache_end++) {
861 struct cache_entry *ce = *cache_end;
862 if (strncmp(ce->name, prefix->buf, prefix->len))
863 break;
864 }
865
866 /*
867 * TODO: check el, if there are no patterns that may conflict
868 * with ret (iow, we know in advance the incl/excl
869 * decision for the entire directory), clear flag here without
870 * calling clear_ce_flags_1(). That function will call
871 * the expensive is_excluded_from_list() on every entry.
872 */
873 rc = clear_ce_flags_1(cache, cache_end - cache,
874 prefix,
875 select_mask, clear_mask,
876 el, ret);
877 strbuf_setlen(prefix, prefix->len - 1);
878 return rc;
879 }
880
881 /*
882 * Traverse the index, find every entry that matches according to
883 * o->el. Do "ce_flags &= ~clear_mask" on those entries. Return the
884 * number of traversed entries.
885 *
886 * If select_mask is non-zero, only entries whose ce_flags has on of
887 * those bits enabled are traversed.
888 *
889 * cache : pointer to an index entry
890 * prefix_len : an offset to its path
891 *
892 * The current path ("prefix") including the trailing '/' is
893 * cache[0]->name[0..(prefix_len-1)]
894 * Top level path has prefix_len zero.
895 */
896 static int clear_ce_flags_1(struct cache_entry **cache, int nr,
897 struct strbuf *prefix,
898 int select_mask, int clear_mask,
899 struct exclude_list *el, int defval)
900 {
901 struct cache_entry **cache_end = cache + nr;
902
903 /*
904 * Process all entries that have the given prefix and meet
905 * select_mask condition
906 */
907 while(cache != cache_end) {
908 struct cache_entry *ce = *cache;
909 const char *name, *slash;
910 int len, dtype, ret;
911
912 if (select_mask && !(ce->ce_flags & select_mask)) {
913 cache++;
914 continue;
915 }
916
917 if (prefix->len && strncmp(ce->name, prefix->buf, prefix->len))
918 break;
919
920 name = ce->name + prefix->len;
921 slash = strchr(name, '/');
922
923 /* If it's a directory, try whole directory match first */
924 if (slash) {
925 int processed;
926
927 len = slash - name;
928 strbuf_add(prefix, name, len);
929
930 processed = clear_ce_flags_dir(cache, cache_end - cache,
931 prefix,
932 prefix->buf + prefix->len - len,
933 select_mask, clear_mask,
934 el, defval);
935
936 /* clear_c_f_dir eats a whole dir already? */
937 if (processed) {
938 cache += processed;
939 strbuf_setlen(prefix, prefix->len - len);
940 continue;
941 }
942
943 strbuf_addch(prefix, '/');
944 cache += clear_ce_flags_1(cache, cache_end - cache,
945 prefix,
946 select_mask, clear_mask, el, defval);
947 strbuf_setlen(prefix, prefix->len - len - 1);
948 continue;
949 }
950
951 /* Non-directory */
952 dtype = ce_to_dtype(ce);
953 ret = is_excluded_from_list(ce->name, ce_namelen(ce),
954 name, &dtype, el);
955 if (ret < 0)
956 ret = defval;
957 if (ret > 0)
958 ce->ce_flags &= ~clear_mask;
959 cache++;
960 }
961 return nr - (cache_end - cache);
962 }
963
964 static int clear_ce_flags(struct cache_entry **cache, int nr,
965 int select_mask, int clear_mask,
966 struct exclude_list *el)
967 {
968 static struct strbuf prefix = STRBUF_INIT;
969
970 strbuf_reset(&prefix);
971
972 return clear_ce_flags_1(cache, nr,
973 &prefix,
974 select_mask, clear_mask,
975 el, 0);
976 }
977
978 /*
979 * Set/Clear CE_NEW_SKIP_WORKTREE according to $GIT_DIR/info/sparse-checkout
980 */
981 static void mark_new_skip_worktree(struct exclude_list *el,
982 struct index_state *the_index,
983 int select_flag, int skip_wt_flag)
984 {
985 int i;
986
987 /*
988 * 1. Pretend the narrowest worktree: only unmerged entries
989 * are checked out
990 */
991 for (i = 0; i < the_index->cache_nr; i++) {
992 struct cache_entry *ce = the_index->cache[i];
993
994 if (select_flag && !(ce->ce_flags & select_flag))
995 continue;
996
997 if (!ce_stage(ce))
998 ce->ce_flags |= skip_wt_flag;
999 else
1000 ce->ce_flags &= ~skip_wt_flag;
1001 }
1002
1003 /*
1004 * 2. Widen worktree according to sparse-checkout file.
1005 * Matched entries will have skip_wt_flag cleared (i.e. "in")
1006 */
1007 clear_ce_flags(the_index->cache, the_index->cache_nr,
1008 select_flag, skip_wt_flag, el);
1009 }
1010
1011 static int verify_absent(const struct cache_entry *,
1012 enum unpack_trees_error_types,
1013 struct unpack_trees_options *);
1014 /*
1015 * N-way merge "len" trees. Returns 0 on success, -1 on failure to manipulate the
1016 * resulting index, -2 on failure to reflect the changes to the work tree.
1017 *
1018 * CE_ADDED, CE_UNPACKED and CE_NEW_SKIP_WORKTREE are used internally
1019 */
1020 int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
1021 {
1022 int i, ret;
1023 static struct cache_entry *dfc;
1024 struct exclude_list el;
1025
1026 if (len > MAX_UNPACK_TREES)
1027 die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
1028 memset(&state, 0, sizeof(state));
1029 state.base_dir = "";
1030 state.force = 1;
1031 state.quiet = 1;
1032 state.refresh_cache = 1;
1033 state.istate = &o->result;
1034
1035 memset(&el, 0, sizeof(el));
1036 if (!core_apply_sparse_checkout || !o->update)
1037 o->skip_sparse_checkout = 1;
1038 if (!o->skip_sparse_checkout) {
1039 if (add_excludes_from_file_to_list(git_path("info/sparse-checkout"), "", 0, &el, 0) < 0)
1040 o->skip_sparse_checkout = 1;
1041 else
1042 o->el = &el;
1043 }
1044
1045 memset(&o->result, 0, sizeof(o->result));
1046 o->result.initialized = 1;
1047 o->result.timestamp.sec = o->src_index->timestamp.sec;
1048 o->result.timestamp.nsec = o->src_index->timestamp.nsec;
1049 o->result.version = o->src_index->version;
1050 o->result.split_index = o->src_index->split_index;
1051 if (o->result.split_index)
1052 o->result.split_index->refcount++;
1053 hashcpy(o->result.sha1, o->src_index->sha1);
1054 o->merge_size = len;
1055 mark_all_ce_unused(o->src_index);
1056
1057 /*
1058 * Sparse checkout loop #1: set NEW_SKIP_WORKTREE on existing entries
1059 */
1060 if (!o->skip_sparse_checkout)
1061 mark_new_skip_worktree(o->el, o->src_index, 0, CE_NEW_SKIP_WORKTREE);
1062
1063 if (!dfc)
1064 dfc = xcalloc(1, cache_entry_size(0));
1065 o->df_conflict_entry = dfc;
1066
1067 if (len) {
1068 const char *prefix = o->prefix ? o->prefix : "";
1069 struct traverse_info info;
1070
1071 setup_traverse_info(&info, prefix);
1072 info.fn = unpack_callback;
1073 info.data = o;
1074 info.show_all_errors = o->show_all_errors;
1075 info.pathspec = o->pathspec;
1076
1077 if (o->prefix) {
1078 /*
1079 * Unpack existing index entries that sort before the
1080 * prefix the tree is spliced into. Note that o->merge
1081 * is always true in this case.
1082 */
1083 while (1) {
1084 struct cache_entry *ce = next_cache_entry(o);
1085 if (!ce)
1086 break;
1087 if (ce_in_traverse_path(ce, &info))
1088 break;
1089 if (unpack_index_entry(ce, o) < 0)
1090 goto return_failed;
1091 }
1092 }
1093
1094 if (traverse_trees(len, t, &info) < 0)
1095 goto return_failed;
1096 }
1097
1098 /* Any left-over entries in the index? */
1099 if (o->merge) {
1100 while (1) {
1101 struct cache_entry *ce = next_cache_entry(o);
1102 if (!ce)
1103 break;
1104 if (unpack_index_entry(ce, o) < 0)
1105 goto return_failed;
1106 }
1107 }
1108 mark_all_ce_unused(o->src_index);
1109
1110 if (o->trivial_merges_only && o->nontrivial_merge) {
1111 ret = unpack_failed(o, "Merge requires file-level merging");
1112 goto done;
1113 }
1114
1115 if (!o->skip_sparse_checkout) {
1116 int empty_worktree = 1;
1117
1118 /*
1119 * Sparse checkout loop #2: set NEW_SKIP_WORKTREE on entries not in loop #1
1120 * If the will have NEW_SKIP_WORKTREE, also set CE_SKIP_WORKTREE
1121 * so apply_sparse_checkout() won't attempt to remove it from worktree
1122 */
1123 mark_new_skip_worktree(o->el, &o->result, CE_ADDED, CE_SKIP_WORKTREE | CE_NEW_SKIP_WORKTREE);
1124
1125 ret = 0;
1126 for (i = 0; i < o->result.cache_nr; i++) {
1127 struct cache_entry *ce = o->result.cache[i];
1128
1129 /*
1130 * Entries marked with CE_ADDED in merged_entry() do not have
1131 * verify_absent() check (the check is effectively disabled
1132 * because CE_NEW_SKIP_WORKTREE is set unconditionally).
1133 *
1134 * Do the real check now because we have had
1135 * correct CE_NEW_SKIP_WORKTREE
1136 */
1137 if (ce->ce_flags & CE_ADDED &&
1138 verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o)) {
1139 if (!o->show_all_errors)
1140 goto return_failed;
1141 ret = -1;
1142 }
1143
1144 if (apply_sparse_checkout(&o->result, ce, o)) {
1145 if (!o->show_all_errors)
1146 goto return_failed;
1147 ret = -1;
1148 }
1149 if (!ce_skip_worktree(ce))
1150 empty_worktree = 0;
1151
1152 }
1153 if (ret < 0)
1154 goto return_failed;
1155 /*
1156 * Sparse checkout is meant to narrow down checkout area
1157 * but it does not make sense to narrow down to empty working
1158 * tree. This is usually a mistake in sparse checkout rules.
1159 * Do not allow users to do that.
1160 */
1161 if (o->result.cache_nr && empty_worktree) {
1162 ret = unpack_failed(o, "Sparse checkout leaves no entry on working directory");
1163 goto done;
1164 }
1165 }
1166
1167 o->src_index = NULL;
1168 ret = check_updates(o) ? (-2) : 0;
1169 if (o->dst_index) {
1170 discard_index(o->dst_index);
1171 *o->dst_index = o->result;
1172 }
1173
1174 done:
1175 clear_exclude_list(&el);
1176 return ret;
1177
1178 return_failed:
1179 if (o->show_all_errors)
1180 display_error_msgs(o);
1181 mark_all_ce_unused(o->src_index);
1182 ret = unpack_failed(o, NULL);
1183 if (o->exiting_early)
1184 ret = 0;
1185 goto done;
1186 }
1187
1188 /* Here come the merge functions */
1189
1190 static int reject_merge(const struct cache_entry *ce,
1191 struct unpack_trees_options *o)
1192 {
1193 return add_rejected_path(o, ERROR_WOULD_OVERWRITE, ce->name);
1194 }
1195
1196 static int same(const struct cache_entry *a, const struct cache_entry *b)
1197 {
1198 if (!!a != !!b)
1199 return 0;
1200 if (!a && !b)
1201 return 1;
1202 if ((a->ce_flags | b->ce_flags) & CE_CONFLICTED)
1203 return 0;
1204 return a->ce_mode == b->ce_mode &&
1205 !hashcmp(a->sha1, b->sha1);
1206 }
1207
1208
1209 /*
1210 * When a CE gets turned into an unmerged entry, we
1211 * want it to be up-to-date
1212 */
1213 static int verify_uptodate_1(const struct cache_entry *ce,
1214 struct unpack_trees_options *o,
1215 enum unpack_trees_error_types error_type)
1216 {
1217 struct stat st;
1218
1219 if (o->index_only)
1220 return 0;
1221
1222 /*
1223 * CE_VALID and CE_SKIP_WORKTREE cheat, we better check again
1224 * if this entry is truly up-to-date because this file may be
1225 * overwritten.
1226 */
1227 if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
1228 ; /* keep checking */
1229 else if (o->reset || ce_uptodate(ce))
1230 return 0;
1231
1232 if (!lstat(ce->name, &st)) {
1233 int flags = CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE;
1234 unsigned changed = ie_match_stat(o->src_index, ce, &st, flags);
1235 if (!changed)
1236 return 0;
1237 /*
1238 * NEEDSWORK: the current default policy is to allow
1239 * submodule to be out of sync wrt the superproject
1240 * index. This needs to be tightened later for
1241 * submodules that are marked to be automatically
1242 * checked out.
1243 */
1244 if (S_ISGITLINK(ce->ce_mode))
1245 return 0;
1246 errno = 0;
1247 }
1248 if (errno == ENOENT)
1249 return 0;
1250 return o->gently ? -1 :
1251 add_rejected_path(o, error_type, ce->name);
1252 }
1253
1254 static int verify_uptodate(const struct cache_entry *ce,
1255 struct unpack_trees_options *o)
1256 {
1257 if (!o->skip_sparse_checkout && (ce->ce_flags & CE_NEW_SKIP_WORKTREE))
1258 return 0;
1259 return verify_uptodate_1(ce, o, ERROR_NOT_UPTODATE_FILE);
1260 }
1261
1262 static int verify_uptodate_sparse(const struct cache_entry *ce,
1263 struct unpack_trees_options *o)
1264 {
1265 return verify_uptodate_1(ce, o, ERROR_SPARSE_NOT_UPTODATE_FILE);
1266 }
1267
1268 static void invalidate_ce_path(const struct cache_entry *ce,
1269 struct unpack_trees_options *o)
1270 {
1271 if (ce)
1272 cache_tree_invalidate_path(o->src_index, ce->name);
1273 }
1274
1275 /*
1276 * Check that checking out ce->sha1 in subdir ce->name is not
1277 * going to overwrite any working files.
1278 *
1279 * Currently, git does not checkout subprojects during a superproject
1280 * checkout, so it is not going to overwrite anything.
1281 */
1282 static int verify_clean_submodule(const struct cache_entry *ce,
1283 enum unpack_trees_error_types error_type,
1284 struct unpack_trees_options *o)
1285 {
1286 return 0;
1287 }
1288
1289 static int verify_clean_subdirectory(const struct cache_entry *ce,
1290 enum unpack_trees_error_types error_type,
1291 struct unpack_trees_options *o)
1292 {
1293 /*
1294 * we are about to extract "ce->name"; we would not want to lose
1295 * anything in the existing directory there.
1296 */
1297 int namelen;
1298 int i;
1299 struct dir_struct d;
1300 char *pathbuf;
1301 int cnt = 0;
1302 unsigned char sha1[20];
1303
1304 if (S_ISGITLINK(ce->ce_mode) &&
1305 resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
1306 /* If we are not going to update the submodule, then
1307 * we don't care.
1308 */
1309 if (!hashcmp(sha1, ce->sha1))
1310 return 0;
1311 return verify_clean_submodule(ce, error_type, o);
1312 }
1313
1314 /*
1315 * First let's make sure we do not have a local modification
1316 * in that directory.
1317 */
1318 namelen = ce_namelen(ce);
1319 for (i = locate_in_src_index(ce, o);
1320 i < o->src_index->cache_nr;
1321 i++) {
1322 struct cache_entry *ce2 = o->src_index->cache[i];
1323 int len = ce_namelen(ce2);
1324 if (len < namelen ||
1325 strncmp(ce->name, ce2->name, namelen) ||
1326 ce2->name[namelen] != '/')
1327 break;
1328 /*
1329 * ce2->name is an entry in the subdirectory to be
1330 * removed.
1331 */
1332 if (!ce_stage(ce2)) {
1333 if (verify_uptodate(ce2, o))
1334 return -1;
1335 add_entry(o, ce2, CE_REMOVE, 0);
1336 mark_ce_used(ce2, o);
1337 }
1338 cnt++;
1339 }
1340
1341 /*
1342 * Then we need to make sure that we do not lose a locally
1343 * present file that is not ignored.
1344 */
1345 pathbuf = xmalloc(namelen + 2);
1346 memcpy(pathbuf, ce->name, namelen);
1347 strcpy(pathbuf+namelen, "/");
1348
1349 memset(&d, 0, sizeof(d));
1350 if (o->dir)
1351 d.exclude_per_dir = o->dir->exclude_per_dir;
1352 i = read_directory(&d, pathbuf, namelen+1, NULL);
1353 if (i)
1354 return o->gently ? -1 :
1355 add_rejected_path(o, ERROR_NOT_UPTODATE_DIR, ce->name);
1356 free(pathbuf);
1357 return cnt;
1358 }
1359
1360 /*
1361 * This gets called when there was no index entry for the tree entry 'dst',
1362 * but we found a file in the working tree that 'lstat()' said was fine,
1363 * and we're on a case-insensitive filesystem.
1364 *
1365 * See if we can find a case-insensitive match in the index that also
1366 * matches the stat information, and assume it's that other file!
1367 */
1368 static int icase_exists(struct unpack_trees_options *o, const char *name, int len, struct stat *st)
1369 {
1370 const struct cache_entry *src;
1371
1372 src = index_file_exists(o->src_index, name, len, 1);
1373 return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
1374 }
1375
1376 static int check_ok_to_remove(const char *name, int len, int dtype,
1377 const struct cache_entry *ce, struct stat *st,
1378 enum unpack_trees_error_types error_type,
1379 struct unpack_trees_options *o)
1380 {
1381 const struct cache_entry *result;
1382
1383 /*
1384 * It may be that the 'lstat()' succeeded even though
1385 * target 'ce' was absent, because there is an old
1386 * entry that is different only in case..
1387 *
1388 * Ignore that lstat() if it matches.
1389 */
1390 if (ignore_case && icase_exists(o, name, len, st))
1391 return 0;
1392
1393 if (o->dir &&
1394 is_excluded(o->dir, name, &dtype))
1395 /*
1396 * ce->name is explicitly excluded, so it is Ok to
1397 * overwrite it.
1398 */
1399 return 0;
1400 if (S_ISDIR(st->st_mode)) {
1401 /*
1402 * We are checking out path "foo" and
1403 * found "foo/." in the working tree.
1404 * This is tricky -- if we have modified
1405 * files that are in "foo/" we would lose
1406 * them.
1407 */
1408 if (verify_clean_subdirectory(ce, error_type, o) < 0)
1409 return -1;
1410 return 0;
1411 }
1412
1413 /*
1414 * The previous round may already have decided to
1415 * delete this path, which is in a subdirectory that
1416 * is being replaced with a blob.
1417 */
1418 result = index_file_exists(&o->result, name, len, 0);
1419 if (result) {
1420 if (result->ce_flags & CE_REMOVE)
1421 return 0;
1422 }
1423
1424 return o->gently ? -1 :
1425 add_rejected_path(o, error_type, name);
1426 }
1427
1428 /*
1429 * We do not want to remove or overwrite a working tree file that
1430 * is not tracked, unless it is ignored.
1431 */
1432 static int verify_absent_1(const struct cache_entry *ce,
1433 enum unpack_trees_error_types error_type,
1434 struct unpack_trees_options *o)
1435 {
1436 int len;
1437 struct stat st;
1438
1439 if (o->index_only || o->reset || !o->update)
1440 return 0;
1441
1442 len = check_leading_path(ce->name, ce_namelen(ce));
1443 if (!len)
1444 return 0;
1445 else if (len > 0) {
1446 char path[PATH_MAX + 1];
1447 memcpy(path, ce->name, len);
1448 path[len] = 0;
1449 if (lstat(path, &st))
1450 return error("cannot stat '%s': %s", path,
1451 strerror(errno));
1452
1453 return check_ok_to_remove(path, len, DT_UNKNOWN, NULL, &st,
1454 error_type, o);
1455 } else if (lstat(ce->name, &st)) {
1456 if (errno != ENOENT)
1457 return error("cannot stat '%s': %s", ce->name,
1458 strerror(errno));
1459 return 0;
1460 } else {
1461 return check_ok_to_remove(ce->name, ce_namelen(ce),
1462 ce_to_dtype(ce), ce, &st,
1463 error_type, o);
1464 }
1465 }
1466
1467 static int verify_absent(const struct cache_entry *ce,
1468 enum unpack_trees_error_types error_type,
1469 struct unpack_trees_options *o)
1470 {
1471 if (!o->skip_sparse_checkout && (ce->ce_flags & CE_NEW_SKIP_WORKTREE))
1472 return 0;
1473 return verify_absent_1(ce, error_type, o);
1474 }
1475
1476 static int verify_absent_sparse(const struct cache_entry *ce,
1477 enum unpack_trees_error_types error_type,
1478 struct unpack_trees_options *o)
1479 {
1480 enum unpack_trees_error_types orphaned_error = error_type;
1481 if (orphaned_error == ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN)
1482 orphaned_error = ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN;
1483
1484 return verify_absent_1(ce, orphaned_error, o);
1485 }
1486
1487 static int merged_entry(const struct cache_entry *ce,
1488 const struct cache_entry *old,
1489 struct unpack_trees_options *o)
1490 {
1491 int update = CE_UPDATE;
1492 struct cache_entry *merge = dup_entry(ce);
1493
1494 if (!old) {
1495 /*
1496 * New index entries. In sparse checkout, the following
1497 * verify_absent() will be delayed until after
1498 * traverse_trees() finishes in unpack_trees(), then:
1499 *
1500 * - CE_NEW_SKIP_WORKTREE will be computed correctly
1501 * - verify_absent() be called again, this time with
1502 * correct CE_NEW_SKIP_WORKTREE
1503 *
1504 * verify_absent() call here does nothing in sparse
1505 * checkout (i.e. o->skip_sparse_checkout == 0)
1506 */
1507 update |= CE_ADDED;
1508 merge->ce_flags |= CE_NEW_SKIP_WORKTREE;
1509
1510 if (verify_absent(merge,
1511 ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o)) {
1512 free(merge);
1513 return -1;
1514 }
1515 invalidate_ce_path(merge, o);
1516 } else if (!(old->ce_flags & CE_CONFLICTED)) {
1517 /*
1518 * See if we can re-use the old CE directly?
1519 * That way we get the uptodate stat info.
1520 *
1521 * This also removes the UPDATE flag on a match; otherwise
1522 * we will end up overwriting local changes in the work tree.
1523 */
1524 if (same(old, merge)) {
1525 copy_cache_entry(merge, old);
1526 update = 0;
1527 } else {
1528 if (verify_uptodate(old, o)) {
1529 free(merge);
1530 return -1;
1531 }
1532 /* Migrate old flags over */
1533 update |= old->ce_flags & (CE_SKIP_WORKTREE | CE_NEW_SKIP_WORKTREE);
1534 invalidate_ce_path(old, o);
1535 }
1536 } else {
1537 /*
1538 * Previously unmerged entry left as an existence
1539 * marker by read_index_unmerged();
1540 */
1541 invalidate_ce_path(old, o);
1542 }
1543
1544 do_add_entry(o, merge, update, CE_STAGEMASK);
1545 return 1;
1546 }
1547
1548 static int deleted_entry(const struct cache_entry *ce,
1549 const struct cache_entry *old,
1550 struct unpack_trees_options *o)
1551 {
1552 /* Did it exist in the index? */
1553 if (!old) {
1554 if (verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_REMOVED, o))
1555 return -1;
1556 return 0;
1557 }
1558 if (!(old->ce_flags & CE_CONFLICTED) && verify_uptodate(old, o))
1559 return -1;
1560 add_entry(o, ce, CE_REMOVE, 0);
1561 invalidate_ce_path(ce, o);
1562 return 1;
1563 }
1564
1565 static int keep_entry(const struct cache_entry *ce,
1566 struct unpack_trees_options *o)
1567 {
1568 add_entry(o, ce, 0, 0);
1569 return 1;
1570 }
1571
1572 #if DBRT_DEBUG
1573 static void show_stage_entry(FILE *o,
1574 const char *label, const struct cache_entry *ce)
1575 {
1576 if (!ce)
1577 fprintf(o, "%s (missing)\n", label);
1578 else
1579 fprintf(o, "%s%06o %s %d\t%s\n",
1580 label,
1581 ce->ce_mode,
1582 sha1_to_hex(ce->sha1),
1583 ce_stage(ce),
1584 ce->name);
1585 }
1586 #endif
1587
1588 int threeway_merge(const struct cache_entry * const *stages,
1589 struct unpack_trees_options *o)
1590 {
1591 const struct cache_entry *index;
1592 const struct cache_entry *head;
1593 const struct cache_entry *remote = stages[o->head_idx + 1];
1594 int count;
1595 int head_match = 0;
1596 int remote_match = 0;
1597
1598 int df_conflict_head = 0;
1599 int df_conflict_remote = 0;
1600
1601 int any_anc_missing = 0;
1602 int no_anc_exists = 1;
1603 int i;
1604
1605 for (i = 1; i < o->head_idx; i++) {
1606 if (!stages[i] || stages[i] == o->df_conflict_entry)
1607 any_anc_missing = 1;
1608 else
1609 no_anc_exists = 0;
1610 }
1611
1612 index = stages[0];
1613 head = stages[o->head_idx];
1614
1615 if (head == o->df_conflict_entry) {
1616 df_conflict_head = 1;
1617 head = NULL;
1618 }
1619
1620 if (remote == o->df_conflict_entry) {
1621 df_conflict_remote = 1;
1622 remote = NULL;
1623 }
1624
1625 /*
1626 * First, if there's a #16 situation, note that to prevent #13
1627 * and #14.
1628 */
1629 if (!same(remote, head)) {
1630 for (i = 1; i < o->head_idx; i++) {
1631 if (same(stages[i], head)) {
1632 head_match = i;
1633 }
1634 if (same(stages[i], remote)) {
1635 remote_match = i;
1636 }
1637 }
1638 }
1639
1640 /*
1641 * We start with cases where the index is allowed to match
1642 * something other than the head: #14(ALT) and #2ALT, where it
1643 * is permitted to match the result instead.
1644 */
1645 /* #14, #14ALT, #2ALT */
1646 if (remote && !df_conflict_head && head_match && !remote_match) {
1647 if (index && !same(index, remote) && !same(index, head))
1648 return o->gently ? -1 : reject_merge(index, o);
1649 return merged_entry(remote, index, o);
1650 }
1651 /*
1652 * If we have an entry in the index cache, then we want to
1653 * make sure that it matches head.
1654 */
1655 if (index && !same(index, head))
1656 return o->gently ? -1 : reject_merge(index, o);
1657
1658 if (head) {
1659 /* #5ALT, #15 */
1660 if (same(head, remote))
1661 return merged_entry(head, index, o);
1662 /* #13, #3ALT */
1663 if (!df_conflict_remote && remote_match && !head_match)
1664 return merged_entry(head, index, o);
1665 }
1666
1667 /* #1 */
1668 if (!head && !remote && any_anc_missing)
1669 return 0;
1670
1671 /*
1672 * Under the "aggressive" rule, we resolve mostly trivial
1673 * cases that we historically had git-merge-one-file resolve.
1674 */
1675 if (o->aggressive) {
1676 int head_deleted = !head;
1677 int remote_deleted = !remote;
1678 const struct cache_entry *ce = NULL;
1679
1680 if (index)
1681 ce = index;
1682 else if (head)
1683 ce = head;
1684 else if (remote)
1685 ce = remote;
1686 else {
1687 for (i = 1; i < o->head_idx; i++) {
1688 if (stages[i] && stages[i] != o->df_conflict_entry) {
1689 ce = stages[i];
1690 break;
1691 }
1692 }
1693 }
1694
1695 /*
1696 * Deleted in both.
1697 * Deleted in one and unchanged in the other.
1698 */
1699 if ((head_deleted && remote_deleted) ||
1700 (head_deleted && remote && remote_match) ||
1701 (remote_deleted && head && head_match)) {
1702 if (index)
1703 return deleted_entry(index, index, o);
1704 if (ce && !head_deleted) {
1705 if (verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_REMOVED, o))
1706 return -1;
1707 }
1708 return 0;
1709 }
1710 /*
1711 * Added in both, identically.
1712 */
1713 if (no_anc_exists && head && remote && same(head, remote))
1714 return merged_entry(head, index, o);
1715
1716 }
1717
1718 /* Below are "no merge" cases, which require that the index be
1719 * up-to-date to avoid the files getting overwritten with
1720 * conflict resolution files.
1721 */
1722 if (index) {
1723 if (verify_uptodate(index, o))
1724 return -1;
1725 }
1726
1727 o->nontrivial_merge = 1;
1728
1729 /* #2, #3, #4, #6, #7, #9, #10, #11. */
1730 count = 0;
1731 if (!head_match || !remote_match) {
1732 for (i = 1; i < o->head_idx; i++) {
1733 if (stages[i] && stages[i] != o->df_conflict_entry) {
1734 keep_entry(stages[i], o);
1735 count++;
1736 break;
1737 }
1738 }
1739 }
1740 #if DBRT_DEBUG
1741 else {
1742 fprintf(stderr, "read-tree: warning #16 detected\n");
1743 show_stage_entry(stderr, "head ", stages[head_match]);
1744 show_stage_entry(stderr, "remote ", stages[remote_match]);
1745 }
1746 #endif
1747 if (head) { count += keep_entry(head, o); }
1748 if (remote) { count += keep_entry(remote, o); }
1749 return count;
1750 }
1751
1752 /*
1753 * Two-way merge.
1754 *
1755 * The rule is to "carry forward" what is in the index without losing
1756 * information across a "fast-forward", favoring a successful merge
1757 * over a merge failure when it makes sense. For details of the
1758 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
1759 *
1760 */
1761 int twoway_merge(const struct cache_entry * const *src,
1762 struct unpack_trees_options *o)
1763 {
1764 const struct cache_entry *current = src[0];
1765 const struct cache_entry *oldtree = src[1];
1766 const struct cache_entry *newtree = src[2];
1767
1768 if (o->merge_size != 2)
1769 return error("Cannot do a twoway merge of %d trees",
1770 o->merge_size);
1771
1772 if (oldtree == o->df_conflict_entry)
1773 oldtree = NULL;
1774 if (newtree == o->df_conflict_entry)
1775 newtree = NULL;
1776
1777 if (current) {
1778 if (current->ce_flags & CE_CONFLICTED) {
1779 if (same(oldtree, newtree) || o->reset) {
1780 if (!newtree)
1781 return deleted_entry(current, current, o);
1782 else
1783 return merged_entry(newtree, current, o);
1784 }
1785 return o->gently ? -1 : reject_merge(current, o);
1786 }
1787 else if ((!oldtree && !newtree) || /* 4 and 5 */
1788 (!oldtree && newtree &&
1789 same(current, newtree)) || /* 6 and 7 */
1790 (oldtree && newtree &&
1791 same(oldtree, newtree)) || /* 14 and 15 */
1792 (oldtree && newtree &&
1793 !same(oldtree, newtree) && /* 18 and 19 */
1794 same(current, newtree))) {
1795 return keep_entry(current, o);
1796 }
1797 else if (oldtree && !newtree && same(current, oldtree)) {
1798 /* 10 or 11 */
1799 return deleted_entry(oldtree, current, o);
1800 }
1801 else if (oldtree && newtree &&
1802 same(current, oldtree) && !same(current, newtree)) {
1803 /* 20 or 21 */
1804 return merged_entry(newtree, current, o);
1805 }
1806 else {
1807 /* all other failures */
1808 if (oldtree)
1809 return o->gently ? -1 : reject_merge(oldtree, o);
1810 if (current)
1811 return o->gently ? -1 : reject_merge(current, o);
1812 if (newtree)
1813 return o->gently ? -1 : reject_merge(newtree, o);
1814 return -1;
1815 }
1816 }
1817 else if (newtree) {
1818 if (oldtree && !o->initial_checkout) {
1819 /*
1820 * deletion of the path was staged;
1821 */
1822 if (same(oldtree, newtree))
1823 return 1;
1824 return reject_merge(oldtree, o);
1825 }
1826 return merged_entry(newtree, current, o);
1827 }
1828 return deleted_entry(oldtree, current, o);
1829 }
1830
1831 /*
1832 * Bind merge.
1833 *
1834 * Keep the index entries at stage0, collapse stage1 but make sure
1835 * stage0 does not have anything there.
1836 */
1837 int bind_merge(const struct cache_entry * const *src,
1838 struct unpack_trees_options *o)
1839 {
1840 const struct cache_entry *old = src[0];
1841 const struct cache_entry *a = src[1];
1842
1843 if (o->merge_size != 1)
1844 return error("Cannot do a bind merge of %d trees",
1845 o->merge_size);
1846 if (a && old)
1847 return o->gently ? -1 :
1848 error(ERRORMSG(o, ERROR_BIND_OVERLAP), a->name, old->name);
1849 if (!a)
1850 return keep_entry(old, o);
1851 else
1852 return merged_entry(a, NULL, o);
1853 }
1854
1855 /*
1856 * One-way merge.
1857 *
1858 * The rule is:
1859 * - take the stat information from stage0, take the data from stage1
1860 */
1861 int oneway_merge(const struct cache_entry * const *src,
1862 struct unpack_trees_options *o)
1863 {
1864 const struct cache_entry *old = src[0];
1865 const struct cache_entry *a = src[1];
1866
1867 if (o->merge_size != 1)
1868 return error("Cannot do a oneway merge of %d trees",
1869 o->merge_size);
1870
1871 if (!a || a == o->df_conflict_entry)
1872 return deleted_entry(old, old, o);
1873
1874 if (old && same(old, a)) {
1875 int update = 0;
1876 if (o->reset && o->update && !ce_uptodate(old) && !ce_skip_worktree(old)) {
1877 struct stat st;
1878 if (lstat(old->name, &st) ||
1879 ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE))
1880 update |= CE_UPDATE;
1881 }
1882 add_entry(o, old, update, 0);
1883 return 0;
1884 }
1885 return merged_entry(a, old, o);
1886 }