diff-lib, read-tree, unpack-trees: mark cache_entry pointers const
[git/git.git] / unpack-trees.c
1 #define NO_THE_INDEX_COMPATIBILITY_MACROS
2 #include "cache.h"
3 #include "dir.h"
4 #include "tree.h"
5 #include "tree-walk.h"
6 #include "cache-tree.h"
7 #include "unpack-trees.h"
8 #include "progress.h"
9 #include "refs.h"
10 #include "attr.h"
11
12 /*
13 * Error messages expected by scripts out of plumbing commands such as
14 * read-tree. Non-scripted Porcelain is not required to use these messages
15 * and in fact are encouraged to reword them to better suit their particular
16 * situation better. See how "git checkout" and "git merge" replaces
17 * them using setup_unpack_trees_porcelain(), for example.
18 */
19 static const char *unpack_plumbing_errors[NB_UNPACK_TREES_ERROR_TYPES] = {
20 /* ERROR_WOULD_OVERWRITE */
21 "Entry '%s' would be overwritten by merge. Cannot merge.",
22
23 /* ERROR_NOT_UPTODATE_FILE */
24 "Entry '%s' not uptodate. Cannot merge.",
25
26 /* ERROR_NOT_UPTODATE_DIR */
27 "Updating '%s' would lose untracked files in it",
28
29 /* ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN */
30 "Untracked working tree file '%s' would be overwritten by merge.",
31
32 /* ERROR_WOULD_LOSE_UNTRACKED_REMOVED */
33 "Untracked working tree file '%s' would be removed by merge.",
34
35 /* ERROR_BIND_OVERLAP */
36 "Entry '%s' overlaps with '%s'. Cannot bind.",
37
38 /* ERROR_SPARSE_NOT_UPTODATE_FILE */
39 "Entry '%s' not uptodate. Cannot update sparse checkout.",
40
41 /* ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN */
42 "Working tree file '%s' would be overwritten by sparse checkout update.",
43
44 /* ERROR_WOULD_LOSE_ORPHANED_REMOVED */
45 "Working tree file '%s' would be removed by sparse checkout update.",
46 };
47
48 #define ERRORMSG(o,type) \
49 ( ((o) && (o)->msgs[(type)]) \
50 ? ((o)->msgs[(type)]) \
51 : (unpack_plumbing_errors[(type)]) )
52
53 void setup_unpack_trees_porcelain(struct unpack_trees_options *opts,
54 const char *cmd)
55 {
56 int i;
57 const char **msgs = opts->msgs;
58 const char *msg;
59 char *tmp;
60 const char *cmd2 = strcmp(cmd, "checkout") ? cmd : "switch branches";
61 if (advice_commit_before_merge)
62 msg = "Your local changes to the following files would be overwritten by %s:\n%%s"
63 "Please, commit your changes or stash them before you can %s.";
64 else
65 msg = "Your local changes to the following files would be overwritten by %s:\n%%s";
66 tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen(cmd2) - 2);
67 sprintf(tmp, msg, cmd, cmd2);
68 msgs[ERROR_WOULD_OVERWRITE] = tmp;
69 msgs[ERROR_NOT_UPTODATE_FILE] = tmp;
70
71 msgs[ERROR_NOT_UPTODATE_DIR] =
72 "Updating the following directories would lose untracked files in it:\n%s";
73
74 if (advice_commit_before_merge)
75 msg = "The following untracked working tree files would be %s by %s:\n%%s"
76 "Please move or remove them before you can %s.";
77 else
78 msg = "The following untracked working tree files would be %s by %s:\n%%s";
79 tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen("removed") + strlen(cmd2) - 4);
80 sprintf(tmp, msg, "removed", cmd, cmd2);
81 msgs[ERROR_WOULD_LOSE_UNTRACKED_REMOVED] = tmp;
82 tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen("overwritten") + strlen(cmd2) - 4);
83 sprintf(tmp, msg, "overwritten", cmd, cmd2);
84 msgs[ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN] = tmp;
85
86 /*
87 * Special case: ERROR_BIND_OVERLAP refers to a pair of paths, we
88 * cannot easily display it as a list.
89 */
90 msgs[ERROR_BIND_OVERLAP] = "Entry '%s' overlaps with '%s'. Cannot bind.";
91
92 msgs[ERROR_SPARSE_NOT_UPTODATE_FILE] =
93 "Cannot update sparse checkout: the following entries are not up-to-date:\n%s";
94 msgs[ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN] =
95 "The following Working tree files would be overwritten by sparse checkout update:\n%s";
96 msgs[ERROR_WOULD_LOSE_ORPHANED_REMOVED] =
97 "The following Working tree files would be removed by sparse checkout update:\n%s";
98
99 opts->show_all_errors = 1;
100 /* rejected paths may not have a static buffer */
101 for (i = 0; i < ARRAY_SIZE(opts->unpack_rejects); i++)
102 opts->unpack_rejects[i].strdup_strings = 1;
103 }
104
105 static void do_add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
106 unsigned int set, unsigned int clear)
107 {
108 clear |= CE_HASHED | CE_UNHASHED;
109
110 if (set & CE_REMOVE)
111 set |= CE_WT_REMOVE;
112
113 ce->next = NULL;
114 ce->ce_flags = (ce->ce_flags & ~clear) | set;
115 add_index_entry(&o->result, ce,
116 ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
117 }
118
119 static struct cache_entry *dup_entry(const struct cache_entry *ce)
120 {
121 unsigned int size = ce_size(ce);
122 struct cache_entry *new = xmalloc(size);
123
124 memcpy(new, ce, size);
125 return new;
126 }
127
128 static void add_entry(struct unpack_trees_options *o,
129 const struct cache_entry *ce,
130 unsigned int set, unsigned int clear)
131 {
132 do_add_entry(o, dup_entry(ce), set, clear);
133 }
134
135 /*
136 * add error messages on path <path>
137 * corresponding to the type <e> with the message <msg>
138 * indicating if it should be display in porcelain or not
139 */
140 static int add_rejected_path(struct unpack_trees_options *o,
141 enum unpack_trees_error_types e,
142 const char *path)
143 {
144 if (!o->show_all_errors)
145 return error(ERRORMSG(o, e), path);
146
147 /*
148 * Otherwise, insert in a list for future display by
149 * display_error_msgs()
150 */
151 string_list_append(&o->unpack_rejects[e], path);
152 return -1;
153 }
154
155 /*
156 * display all the error messages stored in a nice way
157 */
158 static void display_error_msgs(struct unpack_trees_options *o)
159 {
160 int e, i;
161 int something_displayed = 0;
162 for (e = 0; e < NB_UNPACK_TREES_ERROR_TYPES; e++) {
163 struct string_list *rejects = &o->unpack_rejects[e];
164 if (rejects->nr > 0) {
165 struct strbuf path = STRBUF_INIT;
166 something_displayed = 1;
167 for (i = 0; i < rejects->nr; i++)
168 strbuf_addf(&path, "\t%s\n", rejects->items[i].string);
169 error(ERRORMSG(o, e), path.buf);
170 strbuf_release(&path);
171 }
172 string_list_clear(rejects, 0);
173 }
174 if (something_displayed)
175 fprintf(stderr, "Aborting\n");
176 }
177
178 /*
179 * Unlink the last component and schedule the leading directories for
180 * removal, such that empty directories get removed.
181 */
182 static void unlink_entry(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 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 struct cache_entry *ce = index->cache[i];
216
217 if (ce->ce_flags & CE_WT_REMOVE) {
218 display_progress(progress, ++cnt);
219 if (o->update && !o->dry_run)
220 unlink_entry(ce);
221 continue;
222 }
223 }
224 remove_marked_cache_entries(&o->result);
225 remove_scheduled_dirs();
226
227 for (i = 0; i < index->cache_nr; i++) {
228 struct cache_entry *ce = index->cache[i];
229
230 if (ce->ce_flags & CE_UPDATE) {
231 display_progress(progress, ++cnt);
232 ce->ce_flags &= ~CE_UPDATE;
233 if (o->update && !o->dry_run) {
234 errs |= checkout_entry(ce, &state, NULL);
235 }
236 }
237 }
238 stop_progress(&progress);
239 if (o->update)
240 git_attr_set_direction(GIT_ATTR_CHECKIN, NULL);
241 return errs != 0;
242 }
243
244 static int verify_uptodate_sparse(const struct cache_entry *ce,
245 struct unpack_trees_options *o);
246 static int verify_absent_sparse(const struct cache_entry *ce,
247 enum unpack_trees_error_types,
248 struct unpack_trees_options *o);
249
250 static int apply_sparse_checkout(struct cache_entry *ce, struct unpack_trees_options *o)
251 {
252 int was_skip_worktree = ce_skip_worktree(ce);
253
254 if (ce->ce_flags & CE_NEW_SKIP_WORKTREE)
255 ce->ce_flags |= CE_SKIP_WORKTREE;
256 else
257 ce->ce_flags &= ~CE_SKIP_WORKTREE;
258
259 /*
260 * if (!was_skip_worktree && !ce_skip_worktree()) {
261 * This is perfectly normal. Move on;
262 * }
263 */
264
265 /*
266 * Merge strategies may set CE_UPDATE|CE_REMOVE outside checkout
267 * area as a result of ce_skip_worktree() shortcuts in
268 * verify_absent() and verify_uptodate().
269 * Make sure they don't modify worktree if they are already
270 * outside checkout area
271 */
272 if (was_skip_worktree && ce_skip_worktree(ce)) {
273 ce->ce_flags &= ~CE_UPDATE;
274
275 /*
276 * By default, when CE_REMOVE is on, CE_WT_REMOVE is also
277 * on to get that file removed from both index and worktree.
278 * If that file is already outside worktree area, don't
279 * bother remove it.
280 */
281 if (ce->ce_flags & CE_REMOVE)
282 ce->ce_flags &= ~CE_WT_REMOVE;
283 }
284
285 if (!was_skip_worktree && ce_skip_worktree(ce)) {
286 /*
287 * If CE_UPDATE is set, verify_uptodate() must be called already
288 * also stat info may have lost after merged_entry() so calling
289 * verify_uptodate() again may fail
290 */
291 if (!(ce->ce_flags & CE_UPDATE) && verify_uptodate_sparse(ce, o))
292 return -1;
293 ce->ce_flags |= CE_WT_REMOVE;
294 }
295 if (was_skip_worktree && !ce_skip_worktree(ce)) {
296 if (verify_absent_sparse(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o))
297 return -1;
298 ce->ce_flags |= CE_UPDATE;
299 }
300 return 0;
301 }
302
303 static inline int call_unpack_fn(struct cache_entry **src, struct unpack_trees_options *o)
304 {
305 int ret = o->fn(src, o);
306 if (ret > 0)
307 ret = 0;
308 return ret;
309 }
310
311 static void mark_ce_used(struct cache_entry *ce, struct unpack_trees_options *o)
312 {
313 ce->ce_flags |= CE_UNPACKED;
314
315 if (o->cache_bottom < o->src_index->cache_nr &&
316 o->src_index->cache[o->cache_bottom] == ce) {
317 int bottom = o->cache_bottom;
318 while (bottom < o->src_index->cache_nr &&
319 o->src_index->cache[bottom]->ce_flags & CE_UNPACKED)
320 bottom++;
321 o->cache_bottom = bottom;
322 }
323 }
324
325 static void mark_all_ce_unused(struct index_state *index)
326 {
327 int i;
328 for (i = 0; i < index->cache_nr; i++)
329 index->cache[i]->ce_flags &= ~(CE_UNPACKED | CE_ADDED | CE_NEW_SKIP_WORKTREE);
330 }
331
332 static int locate_in_src_index(const struct cache_entry *ce,
333 struct unpack_trees_options *o)
334 {
335 struct index_state *index = o->src_index;
336 int len = ce_namelen(ce);
337 int pos = index_name_pos(index, ce->name, len);
338 if (pos < 0)
339 pos = -1 - pos;
340 return pos;
341 }
342
343 /*
344 * We call unpack_index_entry() with an unmerged cache entry
345 * only in diff-index, and it wants a single callback. Skip
346 * the other unmerged entry with the same name.
347 */
348 static void mark_ce_used_same_name(struct cache_entry *ce,
349 struct unpack_trees_options *o)
350 {
351 struct index_state *index = o->src_index;
352 int len = ce_namelen(ce);
353 int pos;
354
355 for (pos = locate_in_src_index(ce, o); pos < index->cache_nr; pos++) {
356 struct cache_entry *next = index->cache[pos];
357 if (len != ce_namelen(next) ||
358 memcmp(ce->name, next->name, len))
359 break;
360 mark_ce_used(next, o);
361 }
362 }
363
364 static struct cache_entry *next_cache_entry(struct unpack_trees_options *o)
365 {
366 const struct index_state *index = o->src_index;
367 int pos = o->cache_bottom;
368
369 while (pos < index->cache_nr) {
370 struct cache_entry *ce = index->cache[pos];
371 if (!(ce->ce_flags & CE_UNPACKED))
372 return ce;
373 pos++;
374 }
375 return NULL;
376 }
377
378 static void add_same_unmerged(struct cache_entry *ce,
379 struct unpack_trees_options *o)
380 {
381 struct index_state *index = o->src_index;
382 int len = ce_namelen(ce);
383 int pos = index_name_pos(index, ce->name, len);
384
385 if (0 <= pos)
386 die("programming error in a caller of mark_ce_used_same_name");
387 for (pos = -pos - 1; pos < index->cache_nr; pos++) {
388 struct cache_entry *next = index->cache[pos];
389 if (len != ce_namelen(next) ||
390 memcmp(ce->name, next->name, len))
391 break;
392 add_entry(o, next, 0, 0);
393 mark_ce_used(next, o);
394 }
395 }
396
397 static int unpack_index_entry(struct cache_entry *ce,
398 struct unpack_trees_options *o)
399 {
400 struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
401 int ret;
402
403 src[0] = ce;
404
405 mark_ce_used(ce, o);
406 if (ce_stage(ce)) {
407 if (o->skip_unmerged) {
408 add_entry(o, ce, 0, 0);
409 return 0;
410 }
411 }
412 ret = call_unpack_fn(src, o);
413 if (ce_stage(ce))
414 mark_ce_used_same_name(ce, o);
415 return ret;
416 }
417
418 static int find_cache_pos(struct traverse_info *, const struct name_entry *);
419
420 static void restore_cache_bottom(struct traverse_info *info, int bottom)
421 {
422 struct unpack_trees_options *o = info->data;
423
424 if (o->diff_index_cached)
425 return;
426 o->cache_bottom = bottom;
427 }
428
429 static int switch_cache_bottom(struct traverse_info *info)
430 {
431 struct unpack_trees_options *o = info->data;
432 int ret, pos;
433
434 if (o->diff_index_cached)
435 return 0;
436 ret = o->cache_bottom;
437 pos = find_cache_pos(info->prev, &info->name);
438
439 if (pos < -1)
440 o->cache_bottom = -2 - pos;
441 else if (pos < 0)
442 o->cache_bottom = o->src_index->cache_nr;
443 return ret;
444 }
445
446 static int traverse_trees_recursive(int n, unsigned long dirmask,
447 unsigned long df_conflicts,
448 struct name_entry *names,
449 struct traverse_info *info)
450 {
451 int i, ret, bottom;
452 struct tree_desc t[MAX_UNPACK_TREES];
453 void *buf[MAX_UNPACK_TREES];
454 struct traverse_info newinfo;
455 struct name_entry *p;
456
457 p = names;
458 while (!p->mode)
459 p++;
460
461 newinfo = *info;
462 newinfo.prev = info;
463 newinfo.pathspec = info->pathspec;
464 newinfo.name = *p;
465 newinfo.pathlen += tree_entry_len(p) + 1;
466 newinfo.conflicts |= df_conflicts;
467
468 for (i = 0; i < n; i++, dirmask >>= 1) {
469 const unsigned char *sha1 = NULL;
470 if (dirmask & 1)
471 sha1 = names[i].sha1;
472 buf[i] = fill_tree_descriptor(t+i, sha1);
473 }
474
475 bottom = switch_cache_bottom(&newinfo);
476 ret = traverse_trees(n, t, &newinfo);
477 restore_cache_bottom(&newinfo, bottom);
478
479 for (i = 0; i < n; i++)
480 free(buf[i]);
481
482 return ret;
483 }
484
485 /*
486 * Compare the traverse-path to the cache entry without actually
487 * having to generate the textual representation of the traverse
488 * path.
489 *
490 * NOTE! This *only* compares up to the size of the traverse path
491 * itself - the caller needs to do the final check for the cache
492 * entry having more data at the end!
493 */
494 static int do_compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
495 {
496 int len, pathlen, ce_len;
497 const char *ce_name;
498
499 if (info->prev) {
500 int cmp = do_compare_entry(ce, info->prev, &info->name);
501 if (cmp)
502 return cmp;
503 }
504 pathlen = info->pathlen;
505 ce_len = ce_namelen(ce);
506
507 /* If ce_len < pathlen then we must have previously hit "name == directory" entry */
508 if (ce_len < pathlen)
509 return -1;
510
511 ce_len -= pathlen;
512 ce_name = ce->name + pathlen;
513
514 len = tree_entry_len(n);
515 return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode);
516 }
517
518 static int compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
519 {
520 int cmp = do_compare_entry(ce, info, n);
521 if (cmp)
522 return cmp;
523
524 /*
525 * Even if the beginning compared identically, the ce should
526 * compare as bigger than a directory leading up to it!
527 */
528 return ce_namelen(ce) > traverse_path_len(info, n);
529 }
530
531 static int ce_in_traverse_path(const struct cache_entry *ce,
532 const struct traverse_info *info)
533 {
534 if (!info->prev)
535 return 1;
536 if (do_compare_entry(ce, info->prev, &info->name))
537 return 0;
538 /*
539 * If ce (blob) is the same name as the path (which is a tree
540 * we will be descending into), it won't be inside it.
541 */
542 return (info->pathlen < ce_namelen(ce));
543 }
544
545 static struct cache_entry *create_ce_entry(const struct traverse_info *info, const struct name_entry *n, int stage)
546 {
547 int len = traverse_path_len(info, n);
548 struct cache_entry *ce = xcalloc(1, cache_entry_size(len));
549
550 ce->ce_mode = create_ce_mode(n->mode);
551 ce->ce_flags = create_ce_flags(stage);
552 ce->ce_namelen = len;
553 hashcpy(ce->sha1, n->sha1);
554 make_traverse_path(ce->name, info, n);
555
556 return ce;
557 }
558
559 static int unpack_nondirectories(int n, unsigned long mask,
560 unsigned long dirmask,
561 struct cache_entry **src,
562 const struct name_entry *names,
563 const struct traverse_info *info)
564 {
565 int i;
566 struct unpack_trees_options *o = info->data;
567 unsigned long conflicts;
568
569 /* Do we have *only* directories? Nothing to do */
570 if (mask == dirmask && !src[0])
571 return 0;
572
573 conflicts = info->conflicts;
574 if (o->merge)
575 conflicts >>= 1;
576 conflicts |= dirmask;
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 return call_unpack_fn(src, o);
604
605 for (i = 0; i < n; i++)
606 if (src[i] && src[i] != o->df_conflict_entry)
607 do_add_entry(o, src[i], 0, 0);
608 return 0;
609 }
610
611 static int unpack_failed(struct unpack_trees_options *o, const char *message)
612 {
613 discard_index(&o->result);
614 if (!o->gently && !o->exiting_early) {
615 if (message)
616 return error("%s", message);
617 return -1;
618 }
619 return -1;
620 }
621
622 /* NEEDSWORK: give this a better name and share with tree-walk.c */
623 static int name_compare(const char *a, int a_len,
624 const char *b, int b_len)
625 {
626 int len = (a_len < b_len) ? a_len : b_len;
627 int cmp = memcmp(a, b, len);
628 if (cmp)
629 return cmp;
630 return (a_len - b_len);
631 }
632
633 /*
634 * The tree traversal is looking at name p. If we have a matching entry,
635 * return it. If name p is a directory in the index, do not return
636 * anything, as we will want to match it when the traversal descends into
637 * the directory.
638 */
639 static int find_cache_pos(struct traverse_info *info,
640 const struct name_entry *p)
641 {
642 int pos;
643 struct unpack_trees_options *o = info->data;
644 struct index_state *index = o->src_index;
645 int pfxlen = info->pathlen;
646 int p_len = tree_entry_len(p);
647
648 for (pos = o->cache_bottom; pos < index->cache_nr; pos++) {
649 struct cache_entry *ce = index->cache[pos];
650 const char *ce_name, *ce_slash;
651 int cmp, ce_len;
652
653 if (ce->ce_flags & CE_UNPACKED) {
654 /*
655 * cache_bottom entry is already unpacked, so
656 * we can never match it; don't check it
657 * again.
658 */
659 if (pos == o->cache_bottom)
660 ++o->cache_bottom;
661 continue;
662 }
663 if (!ce_in_traverse_path(ce, info))
664 continue;
665 ce_name = ce->name + pfxlen;
666 ce_slash = strchr(ce_name, '/');
667 if (ce_slash)
668 ce_len = ce_slash - ce_name;
669 else
670 ce_len = ce_namelen(ce) - pfxlen;
671 cmp = name_compare(p->path, p_len, ce_name, ce_len);
672 /*
673 * Exact match; if we have a directory we need to
674 * delay returning it.
675 */
676 if (!cmp)
677 return ce_slash ? -2 - pos : pos;
678 if (0 < cmp)
679 continue; /* keep looking */
680 /*
681 * ce_name sorts after p->path; could it be that we
682 * have files under p->path directory in the index?
683 * E.g. ce_name == "t-i", and p->path == "t"; we may
684 * have "t/a" in the index.
685 */
686 if (p_len < ce_len && !memcmp(ce_name, p->path, p_len) &&
687 ce_name[p_len] < '/')
688 continue; /* keep looking */
689 break;
690 }
691 return -1;
692 }
693
694 static struct cache_entry *find_cache_entry(struct traverse_info *info,
695 const struct name_entry *p)
696 {
697 int pos = find_cache_pos(info, p);
698 struct unpack_trees_options *o = info->data;
699
700 if (0 <= pos)
701 return o->src_index->cache[pos];
702 else
703 return NULL;
704 }
705
706 static void debug_path(struct traverse_info *info)
707 {
708 if (info->prev) {
709 debug_path(info->prev);
710 if (*info->prev->name.path)
711 putchar('/');
712 }
713 printf("%s", info->name.path);
714 }
715
716 static void debug_name_entry(int i, struct name_entry *n)
717 {
718 printf("ent#%d %06o %s\n", i,
719 n->path ? n->mode : 0,
720 n->path ? n->path : "(missing)");
721 }
722
723 static void debug_unpack_callback(int n,
724 unsigned long mask,
725 unsigned long dirmask,
726 struct name_entry *names,
727 struct traverse_info *info)
728 {
729 int i;
730 printf("* unpack mask %lu, dirmask %lu, cnt %d ",
731 mask, dirmask, n);
732 debug_path(info);
733 putchar('\n');
734 for (i = 0; i < n; i++)
735 debug_name_entry(i, names + i);
736 }
737
738 static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *names, struct traverse_info *info)
739 {
740 struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
741 struct unpack_trees_options *o = info->data;
742 const struct name_entry *p = names;
743
744 /* Find first entry with a real name (we could use "mask" too) */
745 while (!p->mode)
746 p++;
747
748 if (o->debug_unpack)
749 debug_unpack_callback(n, mask, dirmask, names, info);
750
751 /* Are we supposed to look at the index too? */
752 if (o->merge) {
753 while (1) {
754 int cmp;
755 struct cache_entry *ce;
756
757 if (o->diff_index_cached)
758 ce = next_cache_entry(o);
759 else
760 ce = find_cache_entry(info, p);
761
762 if (!ce)
763 break;
764 cmp = compare_entry(ce, info, p);
765 if (cmp < 0) {
766 if (unpack_index_entry(ce, o) < 0)
767 return unpack_failed(o, NULL);
768 continue;
769 }
770 if (!cmp) {
771 if (ce_stage(ce)) {
772 /*
773 * If we skip unmerged index
774 * entries, we'll skip this
775 * entry *and* the tree
776 * entries associated with it!
777 */
778 if (o->skip_unmerged) {
779 add_same_unmerged(ce, o);
780 return mask;
781 }
782 }
783 src[0] = ce;
784 }
785 break;
786 }
787 }
788
789 if (unpack_nondirectories(n, mask, dirmask, src, names, info) < 0)
790 return -1;
791
792 if (o->merge && src[0]) {
793 if (ce_stage(src[0]))
794 mark_ce_used_same_name(src[0], o);
795 else
796 mark_ce_used(src[0], o);
797 }
798
799 /* Now handle any directories.. */
800 if (dirmask) {
801 unsigned long conflicts = mask & ~dirmask;
802 if (o->merge) {
803 conflicts <<= 1;
804 if (src[0])
805 conflicts |= 1;
806 }
807
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, conflicts,
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 char *prefix, int prefix_len,
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 char *prefix, int prefix_len,
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, prefix_len,
850 basename, &dtype, el);
851
852 prefix[prefix_len++] = '/';
853
854 /* If undecided, use matching result of parent dir in defval */
855 if (ret < 0)
856 ret = defval;
857
858 for (cache_end = cache; cache_end != cache + nr; cache_end++) {
859 struct cache_entry *ce = *cache_end;
860 if (strncmp(ce->name, prefix, prefix_len))
861 break;
862 }
863
864 /*
865 * TODO: check el, if there are no patterns that may conflict
866 * with ret (iow, we know in advance the incl/excl
867 * decision for the entire directory), clear flag here without
868 * calling clear_ce_flags_1(). That function will call
869 * the expensive is_excluded_from_list() on every entry.
870 */
871 return clear_ce_flags_1(cache, cache_end - cache,
872 prefix, prefix_len,
873 select_mask, clear_mask,
874 el, ret);
875 }
876
877 /*
878 * Traverse the index, find every entry that matches according to
879 * o->el. Do "ce_flags &= ~clear_mask" on those entries. Return the
880 * number of traversed entries.
881 *
882 * If select_mask is non-zero, only entries whose ce_flags has on of
883 * those bits enabled are traversed.
884 *
885 * cache : pointer to an index entry
886 * prefix_len : an offset to its path
887 *
888 * The current path ("prefix") including the trailing '/' is
889 * cache[0]->name[0..(prefix_len-1)]
890 * Top level path has prefix_len zero.
891 */
892 static int clear_ce_flags_1(struct cache_entry **cache, int nr,
893 char *prefix, int prefix_len,
894 int select_mask, int clear_mask,
895 struct exclude_list *el, int defval)
896 {
897 struct cache_entry **cache_end = cache + nr;
898
899 /*
900 * Process all entries that have the given prefix and meet
901 * select_mask condition
902 */
903 while(cache != cache_end) {
904 struct cache_entry *ce = *cache;
905 const char *name, *slash;
906 int len, dtype, ret;
907
908 if (select_mask && !(ce->ce_flags & select_mask)) {
909 cache++;
910 continue;
911 }
912
913 if (prefix_len && strncmp(ce->name, prefix, prefix_len))
914 break;
915
916 name = ce->name + prefix_len;
917 slash = strchr(name, '/');
918
919 /* If it's a directory, try whole directory match first */
920 if (slash) {
921 int processed;
922
923 len = slash - name;
924 memcpy(prefix + prefix_len, name, len);
925
926 /*
927 * terminate the string (no trailing slash),
928 * clear_c_f_dir needs it
929 */
930 prefix[prefix_len + len] = '\0';
931 processed = clear_ce_flags_dir(cache, cache_end - cache,
932 prefix, prefix_len + len,
933 prefix + prefix_len,
934 select_mask, clear_mask,
935 el, defval);
936
937 /* clear_c_f_dir eats a whole dir already? */
938 if (processed) {
939 cache += processed;
940 continue;
941 }
942
943 prefix[prefix_len + len++] = '/';
944 cache += clear_ce_flags_1(cache, cache_end - cache,
945 prefix, prefix_len + len,
946 select_mask, clear_mask, el, defval);
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 char prefix[PATH_MAX];
968 return clear_ce_flags_1(cache, nr,
969 prefix, 0,
970 select_mask, clear_mask,
971 el, 0);
972 }
973
974 /*
975 * Set/Clear CE_NEW_SKIP_WORKTREE according to $GIT_DIR/info/sparse-checkout
976 */
977 static void mark_new_skip_worktree(struct exclude_list *el,
978 struct index_state *the_index,
979 int select_flag, int skip_wt_flag)
980 {
981 int i;
982
983 /*
984 * 1. Pretend the narrowest worktree: only unmerged entries
985 * are checked out
986 */
987 for (i = 0; i < the_index->cache_nr; i++) {
988 struct cache_entry *ce = the_index->cache[i];
989
990 if (select_flag && !(ce->ce_flags & select_flag))
991 continue;
992
993 if (!ce_stage(ce))
994 ce->ce_flags |= skip_wt_flag;
995 else
996 ce->ce_flags &= ~skip_wt_flag;
997 }
998
999 /*
1000 * 2. Widen worktree according to sparse-checkout file.
1001 * Matched entries will have skip_wt_flag cleared (i.e. "in")
1002 */
1003 clear_ce_flags(the_index->cache, the_index->cache_nr,
1004 select_flag, skip_wt_flag, el);
1005 }
1006
1007 static int verify_absent(const struct cache_entry *,
1008 enum unpack_trees_error_types,
1009 struct unpack_trees_options *);
1010 /*
1011 * N-way merge "len" trees. Returns 0 on success, -1 on failure to manipulate the
1012 * resulting index, -2 on failure to reflect the changes to the work tree.
1013 *
1014 * CE_ADDED, CE_UNPACKED and CE_NEW_SKIP_WORKTREE are used internally
1015 */
1016 int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
1017 {
1018 int i, ret;
1019 static struct cache_entry *dfc;
1020 struct exclude_list el;
1021
1022 if (len > MAX_UNPACK_TREES)
1023 die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
1024 memset(&state, 0, sizeof(state));
1025 state.base_dir = "";
1026 state.force = 1;
1027 state.quiet = 1;
1028 state.refresh_cache = 1;
1029
1030 memset(&el, 0, sizeof(el));
1031 if (!core_apply_sparse_checkout || !o->update)
1032 o->skip_sparse_checkout = 1;
1033 if (!o->skip_sparse_checkout) {
1034 if (add_excludes_from_file_to_list(git_path("info/sparse-checkout"), "", 0, &el, 0) < 0)
1035 o->skip_sparse_checkout = 1;
1036 else
1037 o->el = &el;
1038 }
1039
1040 memset(&o->result, 0, sizeof(o->result));
1041 o->result.initialized = 1;
1042 o->result.timestamp.sec = o->src_index->timestamp.sec;
1043 o->result.timestamp.nsec = o->src_index->timestamp.nsec;
1044 o->result.version = o->src_index->version;
1045 o->merge_size = len;
1046 mark_all_ce_unused(o->src_index);
1047
1048 /*
1049 * Sparse checkout loop #1: set NEW_SKIP_WORKTREE on existing entries
1050 */
1051 if (!o->skip_sparse_checkout)
1052 mark_new_skip_worktree(o->el, o->src_index, 0, CE_NEW_SKIP_WORKTREE);
1053
1054 if (!dfc)
1055 dfc = xcalloc(1, cache_entry_size(0));
1056 o->df_conflict_entry = dfc;
1057
1058 if (len) {
1059 const char *prefix = o->prefix ? o->prefix : "";
1060 struct traverse_info info;
1061
1062 setup_traverse_info(&info, prefix);
1063 info.fn = unpack_callback;
1064 info.data = o;
1065 info.show_all_errors = o->show_all_errors;
1066 info.pathspec = o->pathspec;
1067
1068 if (o->prefix) {
1069 /*
1070 * Unpack existing index entries that sort before the
1071 * prefix the tree is spliced into. Note that o->merge
1072 * is always true in this case.
1073 */
1074 while (1) {
1075 struct cache_entry *ce = next_cache_entry(o);
1076 if (!ce)
1077 break;
1078 if (ce_in_traverse_path(ce, &info))
1079 break;
1080 if (unpack_index_entry(ce, o) < 0)
1081 goto return_failed;
1082 }
1083 }
1084
1085 if (traverse_trees(len, t, &info) < 0)
1086 goto return_failed;
1087 }
1088
1089 /* Any left-over entries in the index? */
1090 if (o->merge) {
1091 while (1) {
1092 struct cache_entry *ce = next_cache_entry(o);
1093 if (!ce)
1094 break;
1095 if (unpack_index_entry(ce, o) < 0)
1096 goto return_failed;
1097 }
1098 }
1099 mark_all_ce_unused(o->src_index);
1100
1101 if (o->trivial_merges_only && o->nontrivial_merge) {
1102 ret = unpack_failed(o, "Merge requires file-level merging");
1103 goto done;
1104 }
1105
1106 if (!o->skip_sparse_checkout) {
1107 int empty_worktree = 1;
1108
1109 /*
1110 * Sparse checkout loop #2: set NEW_SKIP_WORKTREE on entries not in loop #1
1111 * If the will have NEW_SKIP_WORKTREE, also set CE_SKIP_WORKTREE
1112 * so apply_sparse_checkout() won't attempt to remove it from worktree
1113 */
1114 mark_new_skip_worktree(o->el, &o->result, CE_ADDED, CE_SKIP_WORKTREE | CE_NEW_SKIP_WORKTREE);
1115
1116 ret = 0;
1117 for (i = 0; i < o->result.cache_nr; i++) {
1118 struct cache_entry *ce = o->result.cache[i];
1119
1120 /*
1121 * Entries marked with CE_ADDED in merged_entry() do not have
1122 * verify_absent() check (the check is effectively disabled
1123 * because CE_NEW_SKIP_WORKTREE is set unconditionally).
1124 *
1125 * Do the real check now because we have had
1126 * correct CE_NEW_SKIP_WORKTREE
1127 */
1128 if (ce->ce_flags & CE_ADDED &&
1129 verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o)) {
1130 if (!o->show_all_errors)
1131 goto return_failed;
1132 ret = -1;
1133 }
1134
1135 if (apply_sparse_checkout(ce, o)) {
1136 if (!o->show_all_errors)
1137 goto return_failed;
1138 ret = -1;
1139 }
1140 if (!ce_skip_worktree(ce))
1141 empty_worktree = 0;
1142
1143 }
1144 if (ret < 0)
1145 goto return_failed;
1146 /*
1147 * Sparse checkout is meant to narrow down checkout area
1148 * but it does not make sense to narrow down to empty working
1149 * tree. This is usually a mistake in sparse checkout rules.
1150 * Do not allow users to do that.
1151 */
1152 if (o->result.cache_nr && empty_worktree) {
1153 ret = unpack_failed(o, "Sparse checkout leaves no entry on working directory");
1154 goto done;
1155 }
1156 }
1157
1158 o->src_index = NULL;
1159 ret = check_updates(o) ? (-2) : 0;
1160 if (o->dst_index)
1161 *o->dst_index = o->result;
1162
1163 done:
1164 clear_exclude_list(&el);
1165 return ret;
1166
1167 return_failed:
1168 if (o->show_all_errors)
1169 display_error_msgs(o);
1170 mark_all_ce_unused(o->src_index);
1171 ret = unpack_failed(o, NULL);
1172 if (o->exiting_early)
1173 ret = 0;
1174 goto done;
1175 }
1176
1177 /* Here come the merge functions */
1178
1179 static int reject_merge(const struct cache_entry *ce,
1180 struct unpack_trees_options *o)
1181 {
1182 return add_rejected_path(o, ERROR_WOULD_OVERWRITE, ce->name);
1183 }
1184
1185 static int same(const struct cache_entry *a, const struct cache_entry *b)
1186 {
1187 if (!!a != !!b)
1188 return 0;
1189 if (!a && !b)
1190 return 1;
1191 if ((a->ce_flags | b->ce_flags) & CE_CONFLICTED)
1192 return 0;
1193 return a->ce_mode == b->ce_mode &&
1194 !hashcmp(a->sha1, b->sha1);
1195 }
1196
1197
1198 /*
1199 * When a CE gets turned into an unmerged entry, we
1200 * want it to be up-to-date
1201 */
1202 static int verify_uptodate_1(const struct cache_entry *ce,
1203 struct unpack_trees_options *o,
1204 enum unpack_trees_error_types error_type)
1205 {
1206 struct stat st;
1207
1208 if (o->index_only)
1209 return 0;
1210
1211 /*
1212 * CE_VALID and CE_SKIP_WORKTREE cheat, we better check again
1213 * if this entry is truly up-to-date because this file may be
1214 * overwritten.
1215 */
1216 if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
1217 ; /* keep checking */
1218 else if (o->reset || ce_uptodate(ce))
1219 return 0;
1220
1221 if (!lstat(ce->name, &st)) {
1222 int flags = CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE;
1223 unsigned changed = ie_match_stat(o->src_index, ce, &st, flags);
1224 if (!changed)
1225 return 0;
1226 /*
1227 * NEEDSWORK: the current default policy is to allow
1228 * submodule to be out of sync wrt the superproject
1229 * index. This needs to be tightened later for
1230 * submodules that are marked to be automatically
1231 * checked out.
1232 */
1233 if (S_ISGITLINK(ce->ce_mode))
1234 return 0;
1235 errno = 0;
1236 }
1237 if (errno == ENOENT)
1238 return 0;
1239 return o->gently ? -1 :
1240 add_rejected_path(o, error_type, ce->name);
1241 }
1242
1243 static int verify_uptodate(const struct cache_entry *ce,
1244 struct unpack_trees_options *o)
1245 {
1246 if (!o->skip_sparse_checkout && (ce->ce_flags & CE_NEW_SKIP_WORKTREE))
1247 return 0;
1248 return verify_uptodate_1(ce, o, ERROR_NOT_UPTODATE_FILE);
1249 }
1250
1251 static int verify_uptodate_sparse(const struct cache_entry *ce,
1252 struct unpack_trees_options *o)
1253 {
1254 return verify_uptodate_1(ce, o, ERROR_SPARSE_NOT_UPTODATE_FILE);
1255 }
1256
1257 static void invalidate_ce_path(const struct cache_entry *ce,
1258 struct unpack_trees_options *o)
1259 {
1260 if (ce)
1261 cache_tree_invalidate_path(o->src_index->cache_tree, ce->name);
1262 }
1263
1264 /*
1265 * Check that checking out ce->sha1 in subdir ce->name is not
1266 * going to overwrite any working files.
1267 *
1268 * Currently, git does not checkout subprojects during a superproject
1269 * checkout, so it is not going to overwrite anything.
1270 */
1271 static int verify_clean_submodule(const struct cache_entry *ce,
1272 enum unpack_trees_error_types error_type,
1273 struct unpack_trees_options *o)
1274 {
1275 return 0;
1276 }
1277
1278 static int verify_clean_subdirectory(const struct cache_entry *ce,
1279 enum unpack_trees_error_types error_type,
1280 struct unpack_trees_options *o)
1281 {
1282 /*
1283 * we are about to extract "ce->name"; we would not want to lose
1284 * anything in the existing directory there.
1285 */
1286 int namelen;
1287 int i;
1288 struct dir_struct d;
1289 char *pathbuf;
1290 int cnt = 0;
1291 unsigned char sha1[20];
1292
1293 if (S_ISGITLINK(ce->ce_mode) &&
1294 resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
1295 /* If we are not going to update the submodule, then
1296 * we don't care.
1297 */
1298 if (!hashcmp(sha1, ce->sha1))
1299 return 0;
1300 return verify_clean_submodule(ce, error_type, o);
1301 }
1302
1303 /*
1304 * First let's make sure we do not have a local modification
1305 * in that directory.
1306 */
1307 namelen = ce_namelen(ce);
1308 for (i = locate_in_src_index(ce, o);
1309 i < o->src_index->cache_nr;
1310 i++) {
1311 struct cache_entry *ce2 = o->src_index->cache[i];
1312 int len = ce_namelen(ce2);
1313 if (len < namelen ||
1314 strncmp(ce->name, ce2->name, namelen) ||
1315 ce2->name[namelen] != '/')
1316 break;
1317 /*
1318 * ce2->name is an entry in the subdirectory to be
1319 * removed.
1320 */
1321 if (!ce_stage(ce2)) {
1322 if (verify_uptodate(ce2, o))
1323 return -1;
1324 add_entry(o, ce2, CE_REMOVE, 0);
1325 mark_ce_used(ce2, o);
1326 }
1327 cnt++;
1328 }
1329
1330 /*
1331 * Then we need to make sure that we do not lose a locally
1332 * present file that is not ignored.
1333 */
1334 pathbuf = xmalloc(namelen + 2);
1335 memcpy(pathbuf, ce->name, namelen);
1336 strcpy(pathbuf+namelen, "/");
1337
1338 memset(&d, 0, sizeof(d));
1339 if (o->dir)
1340 d.exclude_per_dir = o->dir->exclude_per_dir;
1341 i = read_directory(&d, pathbuf, namelen+1, NULL);
1342 if (i)
1343 return o->gently ? -1 :
1344 add_rejected_path(o, ERROR_NOT_UPTODATE_DIR, ce->name);
1345 free(pathbuf);
1346 return cnt;
1347 }
1348
1349 /*
1350 * This gets called when there was no index entry for the tree entry 'dst',
1351 * but we found a file in the working tree that 'lstat()' said was fine,
1352 * and we're on a case-insensitive filesystem.
1353 *
1354 * See if we can find a case-insensitive match in the index that also
1355 * matches the stat information, and assume it's that other file!
1356 */
1357 static int icase_exists(struct unpack_trees_options *o, const char *name, int len, struct stat *st)
1358 {
1359 struct cache_entry *src;
1360
1361 src = index_name_exists(o->src_index, name, len, 1);
1362 return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
1363 }
1364
1365 static int check_ok_to_remove(const char *name, int len, int dtype,
1366 const struct cache_entry *ce, struct stat *st,
1367 enum unpack_trees_error_types error_type,
1368 struct unpack_trees_options *o)
1369 {
1370 struct cache_entry *result;
1371
1372 /*
1373 * It may be that the 'lstat()' succeeded even though
1374 * target 'ce' was absent, because there is an old
1375 * entry that is different only in case..
1376 *
1377 * Ignore that lstat() if it matches.
1378 */
1379 if (ignore_case && icase_exists(o, name, len, st))
1380 return 0;
1381
1382 if (o->dir &&
1383 is_excluded(o->dir, name, &dtype))
1384 /*
1385 * ce->name is explicitly excluded, so it is Ok to
1386 * overwrite it.
1387 */
1388 return 0;
1389 if (S_ISDIR(st->st_mode)) {
1390 /*
1391 * We are checking out path "foo" and
1392 * found "foo/." in the working tree.
1393 * This is tricky -- if we have modified
1394 * files that are in "foo/" we would lose
1395 * them.
1396 */
1397 if (verify_clean_subdirectory(ce, error_type, o) < 0)
1398 return -1;
1399 return 0;
1400 }
1401
1402 /*
1403 * The previous round may already have decided to
1404 * delete this path, which is in a subdirectory that
1405 * is being replaced with a blob.
1406 */
1407 result = index_name_exists(&o->result, name, len, 0);
1408 if (result) {
1409 if (result->ce_flags & CE_REMOVE)
1410 return 0;
1411 }
1412
1413 return o->gently ? -1 :
1414 add_rejected_path(o, error_type, name);
1415 }
1416
1417 /*
1418 * We do not want to remove or overwrite a working tree file that
1419 * is not tracked, unless it is ignored.
1420 */
1421 static int verify_absent_1(const struct cache_entry *ce,
1422 enum unpack_trees_error_types error_type,
1423 struct unpack_trees_options *o)
1424 {
1425 int len;
1426 struct stat st;
1427
1428 if (o->index_only || o->reset || !o->update)
1429 return 0;
1430
1431 len = check_leading_path(ce->name, ce_namelen(ce));
1432 if (!len)
1433 return 0;
1434 else if (len > 0) {
1435 char path[PATH_MAX + 1];
1436 memcpy(path, ce->name, len);
1437 path[len] = 0;
1438 if (lstat(path, &st))
1439 return error("cannot stat '%s': %s", path,
1440 strerror(errno));
1441
1442 return check_ok_to_remove(path, len, DT_UNKNOWN, NULL, &st,
1443 error_type, o);
1444 } else if (lstat(ce->name, &st)) {
1445 if (errno != ENOENT)
1446 return error("cannot stat '%s': %s", ce->name,
1447 strerror(errno));
1448 return 0;
1449 } else {
1450 return check_ok_to_remove(ce->name, ce_namelen(ce),
1451 ce_to_dtype(ce), ce, &st,
1452 error_type, o);
1453 }
1454 }
1455
1456 static int verify_absent(const struct cache_entry *ce,
1457 enum unpack_trees_error_types error_type,
1458 struct unpack_trees_options *o)
1459 {
1460 if (!o->skip_sparse_checkout && (ce->ce_flags & CE_NEW_SKIP_WORKTREE))
1461 return 0;
1462 return verify_absent_1(ce, error_type, o);
1463 }
1464
1465 static int verify_absent_sparse(const struct cache_entry *ce,
1466 enum unpack_trees_error_types error_type,
1467 struct unpack_trees_options *o)
1468 {
1469 enum unpack_trees_error_types orphaned_error = error_type;
1470 if (orphaned_error == ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN)
1471 orphaned_error = ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN;
1472
1473 return verify_absent_1(ce, orphaned_error, o);
1474 }
1475
1476 static int merged_entry(const struct cache_entry *ce,
1477 const struct cache_entry *old,
1478 struct unpack_trees_options *o)
1479 {
1480 int update = CE_UPDATE;
1481 struct cache_entry *merge = dup_entry(ce);
1482
1483 if (!old) {
1484 /*
1485 * New index entries. In sparse checkout, the following
1486 * verify_absent() will be delayed until after
1487 * traverse_trees() finishes in unpack_trees(), then:
1488 *
1489 * - CE_NEW_SKIP_WORKTREE will be computed correctly
1490 * - verify_absent() be called again, this time with
1491 * correct CE_NEW_SKIP_WORKTREE
1492 *
1493 * verify_absent() call here does nothing in sparse
1494 * checkout (i.e. o->skip_sparse_checkout == 0)
1495 */
1496 update |= CE_ADDED;
1497 merge->ce_flags |= CE_NEW_SKIP_WORKTREE;
1498
1499 if (verify_absent(merge,
1500 ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o)) {
1501 free(merge);
1502 return -1;
1503 }
1504 invalidate_ce_path(merge, o);
1505 } else if (!(old->ce_flags & CE_CONFLICTED)) {
1506 /*
1507 * See if we can re-use the old CE directly?
1508 * That way we get the uptodate stat info.
1509 *
1510 * This also removes the UPDATE flag on a match; otherwise
1511 * we will end up overwriting local changes in the work tree.
1512 */
1513 if (same(old, merge)) {
1514 copy_cache_entry(merge, old);
1515 update = 0;
1516 } else {
1517 if (verify_uptodate(old, o)) {
1518 free(merge);
1519 return -1;
1520 }
1521 /* Migrate old flags over */
1522 update |= old->ce_flags & (CE_SKIP_WORKTREE | CE_NEW_SKIP_WORKTREE);
1523 invalidate_ce_path(old, o);
1524 }
1525 } else {
1526 /*
1527 * Previously unmerged entry left as an existence
1528 * marker by read_index_unmerged();
1529 */
1530 invalidate_ce_path(old, o);
1531 }
1532
1533 do_add_entry(o, merge, update, CE_STAGEMASK);
1534 return 1;
1535 }
1536
1537 static int deleted_entry(const struct cache_entry *ce,
1538 const struct cache_entry *old,
1539 struct unpack_trees_options *o)
1540 {
1541 /* Did it exist in the index? */
1542 if (!old) {
1543 if (verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_REMOVED, o))
1544 return -1;
1545 return 0;
1546 }
1547 if (!(old->ce_flags & CE_CONFLICTED) && verify_uptodate(old, o))
1548 return -1;
1549 add_entry(o, ce, CE_REMOVE, 0);
1550 invalidate_ce_path(ce, o);
1551 return 1;
1552 }
1553
1554 static int keep_entry(const struct cache_entry *ce,
1555 struct unpack_trees_options *o)
1556 {
1557 add_entry(o, ce, 0, 0);
1558 return 1;
1559 }
1560
1561 #if DBRT_DEBUG
1562 static void show_stage_entry(FILE *o,
1563 const char *label, const struct cache_entry *ce)
1564 {
1565 if (!ce)
1566 fprintf(o, "%s (missing)\n", label);
1567 else
1568 fprintf(o, "%s%06o %s %d\t%s\n",
1569 label,
1570 ce->ce_mode,
1571 sha1_to_hex(ce->sha1),
1572 ce_stage(ce),
1573 ce->name);
1574 }
1575 #endif
1576
1577 int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o)
1578 {
1579 const struct cache_entry *index;
1580 const struct cache_entry *head;
1581 const struct cache_entry *remote = stages[o->head_idx + 1];
1582 int count;
1583 int head_match = 0;
1584 int remote_match = 0;
1585
1586 int df_conflict_head = 0;
1587 int df_conflict_remote = 0;
1588
1589 int any_anc_missing = 0;
1590 int no_anc_exists = 1;
1591 int i;
1592
1593 for (i = 1; i < o->head_idx; i++) {
1594 if (!stages[i] || stages[i] == o->df_conflict_entry)
1595 any_anc_missing = 1;
1596 else
1597 no_anc_exists = 0;
1598 }
1599
1600 index = stages[0];
1601 head = stages[o->head_idx];
1602
1603 if (head == o->df_conflict_entry) {
1604 df_conflict_head = 1;
1605 head = NULL;
1606 }
1607
1608 if (remote == o->df_conflict_entry) {
1609 df_conflict_remote = 1;
1610 remote = NULL;
1611 }
1612
1613 /*
1614 * First, if there's a #16 situation, note that to prevent #13
1615 * and #14.
1616 */
1617 if (!same(remote, head)) {
1618 for (i = 1; i < o->head_idx; i++) {
1619 if (same(stages[i], head)) {
1620 head_match = i;
1621 }
1622 if (same(stages[i], remote)) {
1623 remote_match = i;
1624 }
1625 }
1626 }
1627
1628 /*
1629 * We start with cases where the index is allowed to match
1630 * something other than the head: #14(ALT) and #2ALT, where it
1631 * is permitted to match the result instead.
1632 */
1633 /* #14, #14ALT, #2ALT */
1634 if (remote && !df_conflict_head && head_match && !remote_match) {
1635 if (index && !same(index, remote) && !same(index, head))
1636 return o->gently ? -1 : reject_merge(index, o);
1637 return merged_entry(remote, index, o);
1638 }
1639 /*
1640 * If we have an entry in the index cache, then we want to
1641 * make sure that it matches head.
1642 */
1643 if (index && !same(index, head))
1644 return o->gently ? -1 : reject_merge(index, o);
1645
1646 if (head) {
1647 /* #5ALT, #15 */
1648 if (same(head, remote))
1649 return merged_entry(head, index, o);
1650 /* #13, #3ALT */
1651 if (!df_conflict_remote && remote_match && !head_match)
1652 return merged_entry(head, index, o);
1653 }
1654
1655 /* #1 */
1656 if (!head && !remote && any_anc_missing)
1657 return 0;
1658
1659 /*
1660 * Under the "aggressive" rule, we resolve mostly trivial
1661 * cases that we historically had git-merge-one-file resolve.
1662 */
1663 if (o->aggressive) {
1664 int head_deleted = !head;
1665 int remote_deleted = !remote;
1666 const struct cache_entry *ce = NULL;
1667
1668 if (index)
1669 ce = index;
1670 else if (head)
1671 ce = head;
1672 else if (remote)
1673 ce = remote;
1674 else {
1675 for (i = 1; i < o->head_idx; i++) {
1676 if (stages[i] && stages[i] != o->df_conflict_entry) {
1677 ce = stages[i];
1678 break;
1679 }
1680 }
1681 }
1682
1683 /*
1684 * Deleted in both.
1685 * Deleted in one and unchanged in the other.
1686 */
1687 if ((head_deleted && remote_deleted) ||
1688 (head_deleted && remote && remote_match) ||
1689 (remote_deleted && head && head_match)) {
1690 if (index)
1691 return deleted_entry(index, index, o);
1692 if (ce && !head_deleted) {
1693 if (verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_REMOVED, o))
1694 return -1;
1695 }
1696 return 0;
1697 }
1698 /*
1699 * Added in both, identically.
1700 */
1701 if (no_anc_exists && head && remote && same(head, remote))
1702 return merged_entry(head, index, o);
1703
1704 }
1705
1706 /* Below are "no merge" cases, which require that the index be
1707 * up-to-date to avoid the files getting overwritten with
1708 * conflict resolution files.
1709 */
1710 if (index) {
1711 if (verify_uptodate(index, o))
1712 return -1;
1713 }
1714
1715 o->nontrivial_merge = 1;
1716
1717 /* #2, #3, #4, #6, #7, #9, #10, #11. */
1718 count = 0;
1719 if (!head_match || !remote_match) {
1720 for (i = 1; i < o->head_idx; i++) {
1721 if (stages[i] && stages[i] != o->df_conflict_entry) {
1722 keep_entry(stages[i], o);
1723 count++;
1724 break;
1725 }
1726 }
1727 }
1728 #if DBRT_DEBUG
1729 else {
1730 fprintf(stderr, "read-tree: warning #16 detected\n");
1731 show_stage_entry(stderr, "head ", stages[head_match]);
1732 show_stage_entry(stderr, "remote ", stages[remote_match]);
1733 }
1734 #endif
1735 if (head) { count += keep_entry(head, o); }
1736 if (remote) { count += keep_entry(remote, o); }
1737 return count;
1738 }
1739
1740 /*
1741 * Two-way merge.
1742 *
1743 * The rule is to "carry forward" what is in the index without losing
1744 * information across a "fast-forward", favoring a successful merge
1745 * over a merge failure when it makes sense. For details of the
1746 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
1747 *
1748 */
1749 int twoway_merge(struct cache_entry **src, struct unpack_trees_options *o)
1750 {
1751 const struct cache_entry *current = src[0];
1752 const struct cache_entry *oldtree = src[1];
1753 const struct cache_entry *newtree = src[2];
1754
1755 if (o->merge_size != 2)
1756 return error("Cannot do a twoway merge of %d trees",
1757 o->merge_size);
1758
1759 if (oldtree == o->df_conflict_entry)
1760 oldtree = NULL;
1761 if (newtree == o->df_conflict_entry)
1762 newtree = NULL;
1763
1764 if (current) {
1765 if ((!oldtree && !newtree) || /* 4 and 5 */
1766 (!oldtree && newtree &&
1767 same(current, newtree)) || /* 6 and 7 */
1768 (oldtree && newtree &&
1769 same(oldtree, newtree)) || /* 14 and 15 */
1770 (oldtree && newtree &&
1771 !same(oldtree, newtree) && /* 18 and 19 */
1772 same(current, newtree))) {
1773 return keep_entry(current, o);
1774 }
1775 else if (oldtree && !newtree && same(current, oldtree)) {
1776 /* 10 or 11 */
1777 return deleted_entry(oldtree, current, o);
1778 }
1779 else if (oldtree && newtree &&
1780 same(current, oldtree) && !same(current, newtree)) {
1781 /* 20 or 21 */
1782 return merged_entry(newtree, current, o);
1783 }
1784 else {
1785 /* all other failures */
1786 if (oldtree)
1787 return o->gently ? -1 : reject_merge(oldtree, o);
1788 if (current)
1789 return o->gently ? -1 : reject_merge(current, o);
1790 if (newtree)
1791 return o->gently ? -1 : reject_merge(newtree, o);
1792 return -1;
1793 }
1794 }
1795 else if (newtree) {
1796 if (oldtree && !o->initial_checkout) {
1797 /*
1798 * deletion of the path was staged;
1799 */
1800 if (same(oldtree, newtree))
1801 return 1;
1802 return reject_merge(oldtree, o);
1803 }
1804 return merged_entry(newtree, current, o);
1805 }
1806 return deleted_entry(oldtree, current, o);
1807 }
1808
1809 /*
1810 * Bind merge.
1811 *
1812 * Keep the index entries at stage0, collapse stage1 but make sure
1813 * stage0 does not have anything there.
1814 */
1815 int bind_merge(struct cache_entry **src,
1816 struct unpack_trees_options *o)
1817 {
1818 const struct cache_entry *old = src[0];
1819 const struct cache_entry *a = src[1];
1820
1821 if (o->merge_size != 1)
1822 return error("Cannot do a bind merge of %d trees",
1823 o->merge_size);
1824 if (a && old)
1825 return o->gently ? -1 :
1826 error(ERRORMSG(o, ERROR_BIND_OVERLAP), a->name, old->name);
1827 if (!a)
1828 return keep_entry(old, o);
1829 else
1830 return merged_entry(a, NULL, o);
1831 }
1832
1833 /*
1834 * One-way merge.
1835 *
1836 * The rule is:
1837 * - take the stat information from stage0, take the data from stage1
1838 */
1839 int oneway_merge(struct cache_entry **src, struct unpack_trees_options *o)
1840 {
1841 const struct cache_entry *old = src[0];
1842 const struct cache_entry *a = src[1];
1843
1844 if (o->merge_size != 1)
1845 return error("Cannot do a oneway merge of %d trees",
1846 o->merge_size);
1847
1848 if (!a || a == o->df_conflict_entry)
1849 return deleted_entry(old, old, o);
1850
1851 if (old && same(old, a)) {
1852 int update = 0;
1853 if (o->reset && o->update && !ce_uptodate(old) && !ce_skip_worktree(old)) {
1854 struct stat st;
1855 if (lstat(old->name, &st) ||
1856 ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE))
1857 update |= CE_UPDATE;
1858 }
1859 add_entry(o, old, update, 0);
1860 return 0;
1861 }
1862 return merged_entry(a, old, o);
1863 }