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"
12 /*
13 * Error messages expected by scripts out of plumbing commands such as
14 * read-tree. Non-scripted Porcelain is not required to use these messages
15 * and in fact are encouraged to reword them to better suit their particular
16 * situation better. See how "git checkout" and "git merge" replaces
17 * them using setup_unpack_trees_porcelain(), for example.
18 */
19 const char *unpack_plumbing_errors[NB_UNPACK_TREES_ERROR_TYPES] = {
20 /* ERROR_WOULD_OVERWRITE */
21 "Entry '%s' would be overwritten by merge. Cannot merge.",
23 /* ERROR_NOT_UPTODATE_FILE */
24 "Entry '%s' not uptodate. Cannot merge.",
26 /* ERROR_NOT_UPTODATE_DIR */
27 "Updating '%s' would lose untracked files in it",
29 /* ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN */
30 "Untracked working tree file '%s' would be overwritten by merge.",
32 /* ERROR_WOULD_LOSE_UNTRACKED_REMOVED */
33 "Untracked working tree file '%s' would be removed by merge.",
35 /* ERROR_BIND_OVERLAP */
36 "Entry '%s' overlaps with '%s'. Cannot bind.",
38 /* ERROR_SPARSE_NOT_UPTODATE_FILE */
39 "Entry '%s' not uptodate. Cannot update sparse checkout.",
41 /* ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN */
42 "Working tree file '%s' would be overwritten by sparse checkout update.",
44 /* ERROR_WOULD_LOSE_ORPHANED_REMOVED */
45 "Working tree file '%s' would be removed by sparse checkout update.",
46 };
48 #define ERRORMSG(o,type) \
49 ( ((o) && (o)->msgs[(type)]) \
50 ? ((o)->msgs[(type)]) \
51 : (unpack_plumbing_errors[(type)]) )
53 void setup_unpack_trees_porcelain(struct unpack_trees_options *opts,
54 const char *cmd)
55 {
56 const char **msgs = opts->msgs;
57 const char *msg;
58 char *tmp;
59 const char *cmd2 = strcmp(cmd, "checkout") ? cmd : "switch branches";
60 if (advice_commit_before_merge)
61 msg = "Your local changes to the following files would be overwritten by %s:\n%%s"
62 "Please, commit your changes or stash them before you can %s.";
63 else
64 msg = "Your local changes to the following files would be overwritten by %s:\n%%s";
65 tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen(cmd2) - 2);
66 sprintf(tmp, msg, cmd, cmd2);
67 msgs[ERROR_WOULD_OVERWRITE] = tmp;
68 msgs[ERROR_NOT_UPTODATE_FILE] = tmp;
70 msgs[ERROR_NOT_UPTODATE_DIR] =
71 "Updating the following directories would lose untracked files in it:\n%s";
73 if (advice_commit_before_merge)
74 msg = "The following untracked working tree files would be %s by %s:\n%%s"
75 "Please move or remove them before you can %s.";
76 else
77 msg = "The following untracked working tree files would be %s by %s:\n%%s";
78 tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen("removed") + strlen(cmd2) - 4);
79 sprintf(tmp, msg, "removed", cmd, cmd2);
80 msgs[ERROR_WOULD_LOSE_UNTRACKED_REMOVED] = tmp;
81 tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen("overwritten") + strlen(cmd2) - 4);
82 sprintf(tmp, msg, "overwritten", cmd, cmd2);
83 msgs[ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN] = tmp;
85 /*
86 * Special case: ERROR_BIND_OVERLAP refers to a pair of paths, we
87 * cannot easily display it as a list.
88 */
89 msgs[ERROR_BIND_OVERLAP] = "Entry '%s' overlaps with '%s'. Cannot bind.";
91 msgs[ERROR_SPARSE_NOT_UPTODATE_FILE] =
92 "Cannot update sparse checkout: the following entries are not up-to-date:\n%s";
93 msgs[ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN] =
94 "The following Working tree files would be overwritten by sparse checkout update:\n%s";
95 msgs[ERROR_WOULD_LOSE_ORPHANED_REMOVED] =
96 "The following Working tree files would be removed by sparse checkout update:\n%s";
98 opts->show_all_errors = 1;
99 }
101 static void add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
102 unsigned int set, unsigned int clear)
103 {
104 unsigned int size = ce_size(ce);
105 struct cache_entry *new = xmalloc(size);
107 clear |= CE_HASHED | CE_UNHASHED;
109 if (set & CE_REMOVE)
110 set |= CE_WT_REMOVE;
112 memcpy(new, ce, size);
113 new->next = NULL;
114 new->ce_flags = (new->ce_flags & ~clear) | set;
115 add_index_entry(&o->result, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
116 }
118 /*
119 * add error messages on path <path>
120 * corresponding to the type <e> with the message <msg>
121 * indicating if it should be display in porcelain or not
122 */
123 static int add_rejected_path(struct unpack_trees_options *o,
124 enum unpack_trees_error_types e,
125 const char *path)
126 {
127 struct rejected_paths_list *newentry;
128 if (!o->show_all_errors)
129 return error(ERRORMSG(o, e), path);
131 /*
132 * Otherwise, insert in a list for future display by
133 * display_error_msgs()
134 */
135 newentry = xmalloc(sizeof(struct rejected_paths_list));
136 newentry->path = (char *)path;
137 newentry->next = o->unpack_rejects[e];
138 o->unpack_rejects[e] = newentry;
139 return -1;
140 }
142 /*
143 * free all the structures allocated for the error <e>
144 */
145 static void free_rejected_paths(struct unpack_trees_options *o,
146 enum unpack_trees_error_types e)
147 {
148 while (o->unpack_rejects[e]) {
149 struct rejected_paths_list *del = o->unpack_rejects[e];
150 o->unpack_rejects[e] = o->unpack_rejects[e]->next;
151 free(del);
152 }
153 free(o->unpack_rejects[e]);
154 }
156 /*
157 * display all the error messages stored in a nice way
158 */
159 static void display_error_msgs(struct unpack_trees_options *o)
160 {
161 int e;
162 int something_displayed = 0;
163 for (e = 0; e < NB_UNPACK_TREES_ERROR_TYPES; e++) {
164 if (o->unpack_rejects[e]) {
165 struct rejected_paths_list *rp;
166 struct strbuf path = STRBUF_INIT;
167 something_displayed = 1;
168 for (rp = o->unpack_rejects[e]; rp; rp = rp->next)
169 strbuf_addf(&path, "\t%s\n", rp->path);
170 error(ERRORMSG(o, e), path.buf);
171 strbuf_release(&path);
172 free_rejected_paths(o, e);
173 }
174 }
175 if (something_displayed)
176 printf("Aborting\n");
177 }
179 /*
180 * Unlink the last component and schedule the leading directories for
181 * removal, such that empty directories get removed.
182 */
183 static void unlink_entry(struct cache_entry *ce)
184 {
185 if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
186 return;
187 if (remove_or_warn(ce->ce_mode, ce->name))
188 return;
189 schedule_dir_for_removal(ce->name, ce_namelen(ce));
190 }
192 static struct checkout state;
193 static int check_updates(struct unpack_trees_options *o)
194 {
195 unsigned cnt = 0, total = 0;
196 struct progress *progress = NULL;
197 struct index_state *index = &o->result;
198 int i;
199 int errs = 0;
201 if (o->update && o->verbose_update) {
202 for (total = cnt = 0; cnt < index->cache_nr; cnt++) {
203 struct cache_entry *ce = index->cache[cnt];
204 if (ce->ce_flags & (CE_UPDATE | CE_WT_REMOVE))
205 total++;
206 }
208 progress = start_progress_delay("Checking out files",
209 total, 50, 1);
210 cnt = 0;
211 }
213 if (o->update)
214 git_attr_set_direction(GIT_ATTR_CHECKOUT, &o->result);
215 for (i = 0; i < index->cache_nr; i++) {
216 struct cache_entry *ce = index->cache[i];
218 if (ce->ce_flags & CE_WT_REMOVE) {
219 display_progress(progress, ++cnt);
220 if (o->update)
221 unlink_entry(ce);
222 continue;
223 }
224 }
225 remove_marked_cache_entries(&o->result);
226 remove_scheduled_dirs();
228 for (i = 0; i < index->cache_nr; i++) {
229 struct cache_entry *ce = index->cache[i];
231 if (ce->ce_flags & CE_UPDATE) {
232 display_progress(progress, ++cnt);
233 ce->ce_flags &= ~CE_UPDATE;
234 if (o->update) {
235 errs |= checkout_entry(ce, &state, NULL);
236 }
237 }
238 }
239 stop_progress(&progress);
240 if (o->update)
241 git_attr_set_direction(GIT_ATTR_CHECKIN, NULL);
242 return errs != 0;
243 }
245 static int verify_uptodate_sparse(struct cache_entry *ce, struct unpack_trees_options *o);
246 static int verify_absent_sparse(struct cache_entry *ce, enum unpack_trees_error_types, struct unpack_trees_options *o);
248 static int will_have_skip_worktree(const struct cache_entry *ce, struct unpack_trees_options *o)
249 {
250 const char *basename;
252 basename = strrchr(ce->name, '/');
253 basename = basename ? basename+1 : ce->name;
254 return excluded_from_list(ce->name, ce_namelen(ce), basename, NULL, o->el) <= 0;
255 }
257 static int apply_sparse_checkout(struct cache_entry *ce, struct unpack_trees_options *o)
258 {
259 int was_skip_worktree = ce_skip_worktree(ce);
261 if (ce->ce_flags & CE_NEW_SKIP_WORKTREE)
262 ce->ce_flags |= CE_SKIP_WORKTREE;
263 else
264 ce->ce_flags &= ~CE_SKIP_WORKTREE;
266 /*
267 * if (!was_skip_worktree && !ce_skip_worktree()) {
268 * This is perfectly normal. Move on;
269 * }
270 */
272 /*
273 * Merge strategies may set CE_UPDATE|CE_REMOVE outside checkout
274 * area as a result of ce_skip_worktree() shortcuts in
275 * verify_absent() and verify_uptodate().
276 * Make sure they don't modify worktree if they are already
277 * outside checkout area
278 */
279 if (was_skip_worktree && ce_skip_worktree(ce)) {
280 ce->ce_flags &= ~CE_UPDATE;
282 /*
283 * By default, when CE_REMOVE is on, CE_WT_REMOVE is also
284 * on to get that file removed from both index and worktree.
285 * If that file is already outside worktree area, don't
286 * bother remove it.
287 */
288 if (ce->ce_flags & CE_REMOVE)
289 ce->ce_flags &= ~CE_WT_REMOVE;
290 }
292 if (!was_skip_worktree && ce_skip_worktree(ce)) {
293 /*
294 * If CE_UPDATE is set, verify_uptodate() must be called already
295 * also stat info may have lost after merged_entry() so calling
296 * verify_uptodate() again may fail
297 */
298 if (!(ce->ce_flags & CE_UPDATE) && verify_uptodate_sparse(ce, o))
299 return -1;
300 ce->ce_flags |= CE_WT_REMOVE;
301 }
302 if (was_skip_worktree && !ce_skip_worktree(ce)) {
303 if (verify_absent_sparse(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o))
304 return -1;
305 ce->ce_flags |= CE_UPDATE;
306 }
307 return 0;
308 }
310 static inline int call_unpack_fn(struct cache_entry **src, struct unpack_trees_options *o)
311 {
312 int ret = o->fn(src, o);
313 if (ret > 0)
314 ret = 0;
315 return ret;
316 }
318 static void mark_ce_used(struct cache_entry *ce, struct unpack_trees_options *o)
319 {
320 ce->ce_flags |= CE_UNPACKED;
322 if (o->cache_bottom < o->src_index->cache_nr &&
323 o->src_index->cache[o->cache_bottom] == ce) {
324 int bottom = o->cache_bottom;
325 while (bottom < o->src_index->cache_nr &&
326 o->src_index->cache[bottom]->ce_flags & CE_UNPACKED)
327 bottom++;
328 o->cache_bottom = bottom;
329 }
330 }
332 static void mark_all_ce_unused(struct index_state *index)
333 {
334 int i;
335 for (i = 0; i < index->cache_nr; i++)
336 index->cache[i]->ce_flags &= ~(CE_UNPACKED | CE_ADDED | CE_NEW_SKIP_WORKTREE);
337 }
339 static int locate_in_src_index(struct cache_entry *ce,
340 struct unpack_trees_options *o)
341 {
342 struct index_state *index = o->src_index;
343 int len = ce_namelen(ce);
344 int pos = index_name_pos(index, ce->name, len);
345 if (pos < 0)
346 pos = -1 - pos;
347 return pos;
348 }
350 /*
351 * We call unpack_index_entry() with an unmerged cache entry
352 * only in diff-index, and it wants a single callback. Skip
353 * the other unmerged entry with the same name.
354 */
355 static void mark_ce_used_same_name(struct cache_entry *ce,
356 struct unpack_trees_options *o)
357 {
358 struct index_state *index = o->src_index;
359 int len = ce_namelen(ce);
360 int pos;
362 for (pos = locate_in_src_index(ce, o); pos < index->cache_nr; pos++) {
363 struct cache_entry *next = index->cache[pos];
364 if (len != ce_namelen(next) ||
365 memcmp(ce->name, next->name, len))
366 break;
367 mark_ce_used(next, o);
368 }
369 }
371 static struct cache_entry *next_cache_entry(struct unpack_trees_options *o)
372 {
373 const struct index_state *index = o->src_index;
374 int pos = o->cache_bottom;
376 while (pos < index->cache_nr) {
377 struct cache_entry *ce = index->cache[pos];
378 if (!(ce->ce_flags & CE_UNPACKED))
379 return ce;
380 pos++;
381 }
382 return NULL;
383 }
385 static void add_same_unmerged(struct cache_entry *ce,
386 struct unpack_trees_options *o)
387 {
388 struct index_state *index = o->src_index;
389 int len = ce_namelen(ce);
390 int pos = index_name_pos(index, ce->name, len);
392 if (0 <= pos)
393 die("programming error in a caller of mark_ce_used_same_name");
394 for (pos = -pos - 1; pos < index->cache_nr; pos++) {
395 struct cache_entry *next = index->cache[pos];
396 if (len != ce_namelen(next) ||
397 memcmp(ce->name, next->name, len))
398 break;
399 add_entry(o, next, 0, 0);
400 mark_ce_used(next, o);
401 }
402 }
404 static int unpack_index_entry(struct cache_entry *ce,
405 struct unpack_trees_options *o)
406 {
407 struct cache_entry *src[5] = { NULL };
408 int ret;
410 src[0] = ce;
412 mark_ce_used(ce, o);
413 if (ce_stage(ce)) {
414 if (o->skip_unmerged) {
415 add_entry(o, ce, 0, 0);
416 return 0;
417 }
418 }
419 ret = call_unpack_fn(src, o);
420 if (ce_stage(ce))
421 mark_ce_used_same_name(ce, o);
422 return ret;
423 }
425 static int find_cache_pos(struct traverse_info *, const struct name_entry *);
427 static void restore_cache_bottom(struct traverse_info *info, int bottom)
428 {
429 struct unpack_trees_options *o = info->data;
431 if (o->diff_index_cached)
432 return;
433 o->cache_bottom = bottom;
434 }
436 static int switch_cache_bottom(struct traverse_info *info)
437 {
438 struct unpack_trees_options *o = info->data;
439 int ret, pos;
441 if (o->diff_index_cached)
442 return 0;
443 ret = o->cache_bottom;
444 pos = find_cache_pos(info->prev, &info->name);
446 if (pos < -1)
447 o->cache_bottom = -2 - pos;
448 else if (pos < 0)
449 o->cache_bottom = o->src_index->cache_nr;
450 return ret;
451 }
453 static int traverse_trees_recursive(int n, unsigned long dirmask, unsigned long df_conflicts, struct name_entry *names, struct traverse_info *info)
454 {
455 int i, ret, bottom;
456 struct tree_desc t[MAX_UNPACK_TREES];
457 void *buf[MAX_UNPACK_TREES];
458 struct traverse_info newinfo;
459 struct name_entry *p;
461 p = names;
462 while (!p->mode)
463 p++;
465 newinfo = *info;
466 newinfo.prev = info;
467 newinfo.name = *p;
468 newinfo.pathlen += tree_entry_len(p->path, p->sha1) + 1;
469 newinfo.conflicts |= df_conflicts;
471 for (i = 0; i < n; i++, dirmask >>= 1) {
472 const unsigned char *sha1 = NULL;
473 if (dirmask & 1)
474 sha1 = names[i].sha1;
475 buf[i] = fill_tree_descriptor(t+i, sha1);
476 }
478 bottom = switch_cache_bottom(&newinfo);
479 ret = traverse_trees(n, t, &newinfo);
480 restore_cache_bottom(&newinfo, bottom);
482 for (i = 0; i < n; i++)
483 free(buf[i]);
485 return ret;
486 }
488 /*
489 * Compare the traverse-path to the cache entry without actually
490 * having to generate the textual representation of the traverse
491 * path.
492 *
493 * NOTE! This *only* compares up to the size of the traverse path
494 * itself - the caller needs to do the final check for the cache
495 * entry having more data at the end!
496 */
497 static int do_compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
498 {
499 int len, pathlen, ce_len;
500 const char *ce_name;
502 if (info->prev) {
503 int cmp = do_compare_entry(ce, info->prev, &info->name);
504 if (cmp)
505 return cmp;
506 }
507 pathlen = info->pathlen;
508 ce_len = ce_namelen(ce);
510 /* If ce_len < pathlen then we must have previously hit "name == directory" entry */
511 if (ce_len < pathlen)
512 return -1;
514 ce_len -= pathlen;
515 ce_name = ce->name + pathlen;
517 len = tree_entry_len(n->path, n->sha1);
518 return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode);
519 }
521 static int compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
522 {
523 int cmp = do_compare_entry(ce, info, n);
524 if (cmp)
525 return cmp;
527 /*
528 * Even if the beginning compared identically, the ce should
529 * compare as bigger than a directory leading up to it!
530 */
531 return ce_namelen(ce) > traverse_path_len(info, n);
532 }
534 static int ce_in_traverse_path(const struct cache_entry *ce,
535 const struct traverse_info *info)
536 {
537 if (!info->prev)
538 return 1;
539 if (do_compare_entry(ce, info->prev, &info->name))
540 return 0;
541 /*
542 * If ce (blob) is the same name as the path (which is a tree
543 * we will be descending into), it won't be inside it.
544 */
545 return (info->pathlen < ce_namelen(ce));
546 }
548 static struct cache_entry *create_ce_entry(const struct traverse_info *info, const struct name_entry *n, int stage)
549 {
550 int len = traverse_path_len(info, n);
551 struct cache_entry *ce = xcalloc(1, cache_entry_size(len));
553 ce->ce_mode = create_ce_mode(n->mode);
554 ce->ce_flags = create_ce_flags(len, stage);
555 hashcpy(ce->sha1, n->sha1);
556 make_traverse_path(ce->name, info, n);
558 return ce;
559 }
561 static int unpack_nondirectories(int n, unsigned long mask,
562 unsigned long dirmask,
563 struct cache_entry **src,
564 const struct name_entry *names,
565 const struct traverse_info *info)
566 {
567 int i;
568 struct unpack_trees_options *o = info->data;
569 unsigned long conflicts;
571 /* Do we have *only* directories? Nothing to do */
572 if (mask == dirmask && !src[0])
573 return 0;
575 conflicts = info->conflicts;
576 if (o->merge)
577 conflicts >>= 1;
578 conflicts |= dirmask;
580 /*
581 * Ok, we've filled in up to any potential index entry in src[0],
582 * now do the rest.
583 */
584 for (i = 0; i < n; i++) {
585 int stage;
586 unsigned int bit = 1ul << i;
587 if (conflicts & bit) {
588 src[i + o->merge] = o->df_conflict_entry;
589 continue;
590 }
591 if (!(mask & bit))
592 continue;
593 if (!o->merge)
594 stage = 0;
595 else if (i + 1 < o->head_idx)
596 stage = 1;
597 else if (i + 1 > o->head_idx)
598 stage = 3;
599 else
600 stage = 2;
601 src[i + o->merge] = create_ce_entry(info, names + i, stage);
602 }
604 if (o->merge)
605 return call_unpack_fn(src, o);
607 for (i = 0; i < n; i++)
608 if (src[i] && src[i] != o->df_conflict_entry)
609 add_entry(o, src[i], 0, 0);
610 return 0;
611 }
613 static int unpack_failed(struct unpack_trees_options *o, const char *message)
614 {
615 discard_index(&o->result);
616 if (!o->gently) {
617 if (message)
618 return error("%s", message);
619 return -1;
620 }
621 return -1;
622 }
624 /* NEEDSWORK: give this a better name and share with tree-walk.c */
625 static int name_compare(const char *a, int a_len,
626 const char *b, int b_len)
627 {
628 int len = (a_len < b_len) ? a_len : b_len;
629 int cmp = memcmp(a, b, len);
630 if (cmp)
631 return cmp;
632 return (a_len - b_len);
633 }
635 /*
636 * The tree traversal is looking at name p. If we have a matching entry,
637 * return it. If name p is a directory in the index, do not return
638 * anything, as we will want to match it when the traversal descends into
639 * the directory.
640 */
641 static int find_cache_pos(struct traverse_info *info,
642 const struct name_entry *p)
643 {
644 int pos;
645 struct unpack_trees_options *o = info->data;
646 struct index_state *index = o->src_index;
647 int pfxlen = info->pathlen;
648 int p_len = tree_entry_len(p->path, p->sha1);
650 for (pos = o->cache_bottom; pos < index->cache_nr; pos++) {
651 struct cache_entry *ce = index->cache[pos];
652 const char *ce_name, *ce_slash;
653 int cmp, ce_len;
655 if (ce->ce_flags & CE_UNPACKED) {
656 /*
657 * cache_bottom entry is already unpacked, so
658 * we can never match it; don't check it
659 * again.
660 */
661 if (pos == o->cache_bottom)
662 ++o->cache_bottom;
663 continue;
664 }
665 if (!ce_in_traverse_path(ce, info))
666 continue;
667 ce_name = ce->name + pfxlen;
668 ce_slash = strchr(ce_name, '/');
669 if (ce_slash)
670 ce_len = ce_slash - ce_name;
671 else
672 ce_len = ce_namelen(ce) - pfxlen;
673 cmp = name_compare(p->path, p_len, ce_name, ce_len);
674 /*
675 * Exact match; if we have a directory we need to
676 * delay returning it.
677 */
678 if (!cmp)
679 return ce_slash ? -2 - pos : pos;
680 if (0 < cmp)
681 continue; /* keep looking */
682 /*
683 * ce_name sorts after p->path; could it be that we
684 * have files under p->path directory in the index?
685 * E.g. ce_name == "t-i", and p->path == "t"; we may
686 * have "t/a" in the index.
687 */
688 if (p_len < ce_len && !memcmp(ce_name, p->path, p_len) &&
689 ce_name[p_len] < '/')
690 continue; /* keep looking */
691 break;
692 }
693 return -1;
694 }
696 static struct cache_entry *find_cache_entry(struct traverse_info *info,
697 const struct name_entry *p)
698 {
699 int pos = find_cache_pos(info, p);
700 struct unpack_trees_options *o = info->data;
702 if (0 <= pos)
703 return o->src_index->cache[pos];
704 else
705 return NULL;
706 }
708 static void debug_path(struct traverse_info *info)
709 {
710 if (info->prev) {
711 debug_path(info->prev);
712 if (*info->prev->name.path)
713 putchar('/');
714 }
715 printf("%s", info->name.path);
716 }
718 static void debug_name_entry(int i, struct name_entry *n)
719 {
720 printf("ent#%d %06o %s\n", i,
721 n->path ? n->mode : 0,
722 n->path ? n->path : "(missing)");
723 }
725 static void debug_unpack_callback(int n,
726 unsigned long mask,
727 unsigned long dirmask,
728 struct name_entry *names,
729 struct traverse_info *info)
730 {
731 int i;
732 printf("* unpack mask %lu, dirmask %lu, cnt %d ",
733 mask, dirmask, n);
734 debug_path(info);
735 putchar('\n');
736 for (i = 0; i < n; i++)
737 debug_name_entry(i, names + i);
738 }
740 static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *names, struct traverse_info *info)
741 {
742 struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
743 struct unpack_trees_options *o = info->data;
744 const struct name_entry *p = names;
746 /* Find first entry with a real name (we could use "mask" too) */
747 while (!p->mode)
748 p++;
750 if (o->debug_unpack)
751 debug_unpack_callback(n, mask, dirmask, names, info);
753 /* Are we supposed to look at the index too? */
754 if (o->merge) {
755 while (1) {
756 int cmp;
757 struct cache_entry *ce;
759 if (o->diff_index_cached)
760 ce = next_cache_entry(o);
761 else
762 ce = find_cache_entry(info, p);
764 if (!ce)
765 break;
766 cmp = compare_entry(ce, info, p);
767 if (cmp < 0) {
768 if (unpack_index_entry(ce, o) < 0)
769 return unpack_failed(o, NULL);
770 continue;
771 }
772 if (!cmp) {
773 if (ce_stage(ce)) {
774 /*
775 * If we skip unmerged index
776 * entries, we'll skip this
777 * entry *and* the tree
778 * entries associated with it!
779 */
780 if (o->skip_unmerged) {
781 add_same_unmerged(ce, o);
782 return mask;
783 }
784 }
785 src[0] = ce;
786 }
787 break;
788 }
789 }
791 if (unpack_nondirectories(n, mask, dirmask, src, names, info) < 0)
792 return -1;
794 if (src[0]) {
795 if (ce_stage(src[0]))
796 mark_ce_used_same_name(src[0], o);
797 else
798 mark_ce_used(src[0], o);
799 }
801 /* Now handle any directories.. */
802 if (dirmask) {
803 unsigned long conflicts = mask & ~dirmask;
804 if (o->merge) {
805 conflicts <<= 1;
806 if (src[0])
807 conflicts |= 1;
808 }
810 /* special case: "diff-index --cached" looking at a tree */
811 if (o->diff_index_cached &&
812 n == 1 && dirmask == 1 && S_ISDIR(names->mode)) {
813 int matches;
814 matches = cache_tree_matches_traversal(o->src_index->cache_tree,
815 names, info);
816 /*
817 * Everything under the name matches; skip the
818 * entire hierarchy. diff_index_cached codepath
819 * special cases D/F conflicts in such a way that
820 * it does not do any look-ahead, so this is safe.
821 */
822 if (matches) {
823 o->cache_bottom += matches;
824 return mask;
825 }
826 }
828 if (traverse_trees_recursive(n, dirmask, conflicts,
829 names, info) < 0)
830 return -1;
831 return mask;
832 }
834 return mask;
835 }
837 /*
838 * Set/Clear CE_NEW_SKIP_WORKTREE according to $GIT_DIR/info/sparse-checkout
839 */
840 static void mark_new_skip_worktree(struct exclude_list *el,
841 struct index_state *the_index,
842 int select_flag, int skip_wt_flag)
843 {
844 int i;
846 for (i = 0; i < the_index->cache_nr; i++) {
847 struct cache_entry *ce = the_index->cache[i];
849 if (select_flag && !(ce->ce_flags & select_flag))
850 continue;
852 if (!ce_stage(ce) && will_have_skip_worktree(ce, o))
853 ce->ce_flags |= skip_wt_flag;
854 else
855 ce->ce_flags &= ~skip_wt_flag;
856 }
857 }
859 static int verify_absent(struct cache_entry *, enum unpack_trees_error_types, struct unpack_trees_options *);
860 /*
861 * N-way merge "len" trees. Returns 0 on success, -1 on failure to manipulate the
862 * resulting index, -2 on failure to reflect the changes to the work tree.
863 *
864 * CE_ADDED, CE_UNPACKED and CE_NEW_SKIP_WORKTREE are used internally
865 */
866 int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
867 {
868 int i, ret;
869 static struct cache_entry *dfc;
870 struct exclude_list el;
872 if (len > MAX_UNPACK_TREES)
873 die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
874 memset(&state, 0, sizeof(state));
875 state.base_dir = "";
876 state.force = 1;
877 state.quiet = 1;
878 state.refresh_cache = 1;
880 memset(&el, 0, sizeof(el));
881 if (!core_apply_sparse_checkout || !o->update)
882 o->skip_sparse_checkout = 1;
883 if (!o->skip_sparse_checkout) {
884 if (add_excludes_from_file_to_list(git_path("info/sparse-checkout"), "", 0, NULL, &el, 0) < 0)
885 o->skip_sparse_checkout = 1;
886 else
887 o->el = ⪙
888 }
890 memset(&o->result, 0, sizeof(o->result));
891 o->result.initialized = 1;
892 o->result.timestamp.sec = o->src_index->timestamp.sec;
893 o->result.timestamp.nsec = o->src_index->timestamp.nsec;
894 o->merge_size = len;
895 mark_all_ce_unused(o->src_index);
897 /*
898 * Sparse checkout loop #1: set NEW_SKIP_WORKTREE on existing entries
899 */
900 if (!o->skip_sparse_checkout)
901 mark_new_skip_worktree(o->el, o->src_index, 0, CE_NEW_SKIP_WORKTREE);
903 if (!dfc)
904 dfc = xcalloc(1, cache_entry_size(0));
905 o->df_conflict_entry = dfc;
907 if (len) {
908 const char *prefix = o->prefix ? o->prefix : "";
909 struct traverse_info info;
911 setup_traverse_info(&info, prefix);
912 info.fn = unpack_callback;
913 info.data = o;
914 info.show_all_errors = o->show_all_errors;
916 if (o->prefix) {
917 /*
918 * Unpack existing index entries that sort before the
919 * prefix the tree is spliced into. Note that o->merge
920 * is always true in this case.
921 */
922 while (1) {
923 struct cache_entry *ce = next_cache_entry(o);
924 if (!ce)
925 break;
926 if (ce_in_traverse_path(ce, &info))
927 break;
928 if (unpack_index_entry(ce, o) < 0)
929 goto return_failed;
930 }
931 }
933 if (traverse_trees(len, t, &info) < 0)
934 goto return_failed;
935 }
937 /* Any left-over entries in the index? */
938 if (o->merge) {
939 while (1) {
940 struct cache_entry *ce = next_cache_entry(o);
941 if (!ce)
942 break;
943 if (unpack_index_entry(ce, o) < 0)
944 goto return_failed;
945 }
946 }
947 mark_all_ce_unused(o->src_index);
949 if (o->trivial_merges_only && o->nontrivial_merge) {
950 ret = unpack_failed(o, "Merge requires file-level merging");
951 goto done;
952 }
954 if (!o->skip_sparse_checkout) {
955 int empty_worktree = 1;
957 /*
958 * Sparse checkout loop #2: set NEW_SKIP_WORKTREE on entries not in loop #1
959 * If the will have NEW_SKIP_WORKTREE, also set CE_SKIP_WORKTREE
960 * so apply_sparse_checkout() won't attempt to remove it from worktree
961 */
962 mark_new_skip_worktree(o->el, &o->result, CE_ADDED, CE_SKIP_WORKTREE | CE_NEW_SKIP_WORKTREE);
964 for (i = 0; i < o->result.cache_nr; i++) {
965 struct cache_entry *ce = o->result.cache[i];
967 /*
968 * Entries marked with CE_ADDED in merged_entry() do not have
969 * verify_absent() check (the check is effectively disabled
970 * because CE_NEW_SKIP_WORKTREE is set unconditionally).
971 *
972 * Do the real check now because we have had
973 * correct CE_NEW_SKIP_WORKTREE
974 */
975 if (ce->ce_flags & CE_ADDED &&
976 verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o))
977 return -1;
979 if (apply_sparse_checkout(ce, o)) {
980 ret = -1;
981 goto done;
982 }
983 if (!ce_skip_worktree(ce))
984 empty_worktree = 0;
986 }
987 if (o->result.cache_nr && empty_worktree) {
988 ret = unpack_failed(o, "Sparse checkout leaves no entry on working directory");
989 goto done;
990 }
991 }
993 o->src_index = NULL;
994 ret = check_updates(o) ? (-2) : 0;
995 if (o->dst_index)
996 *o->dst_index = o->result;
998 done:
999 free_excludes(&el);
1000 return ret;
1002 return_failed:
1003 if (o->show_all_errors)
1004 display_error_msgs(o);
1005 mark_all_ce_unused(o->src_index);
1006 ret = unpack_failed(o, NULL);
1007 goto done;
1008 }
1010 /* Here come the merge functions */
1012 static int reject_merge(struct cache_entry *ce, struct unpack_trees_options *o)
1013 {
1014 return add_rejected_path(o, ERROR_WOULD_OVERWRITE, ce->name);
1015 }
1017 static int same(struct cache_entry *a, struct cache_entry *b)
1018 {
1019 if (!!a != !!b)
1020 return 0;
1021 if (!a && !b)
1022 return 1;
1023 if ((a->ce_flags | b->ce_flags) & CE_CONFLICTED)
1024 return 0;
1025 return a->ce_mode == b->ce_mode &&
1026 !hashcmp(a->sha1, b->sha1);
1027 }
1030 /*
1031 * When a CE gets turned into an unmerged entry, we
1032 * want it to be up-to-date
1033 */
1034 static int verify_uptodate_1(struct cache_entry *ce,
1035 struct unpack_trees_options *o,
1036 enum unpack_trees_error_types error_type)
1037 {
1038 struct stat st;
1040 if (o->index_only || (!((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) && (o->reset || ce_uptodate(ce))))
1041 return 0;
1043 if (!lstat(ce->name, &st)) {
1044 unsigned changed = ie_match_stat(o->src_index, ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
1045 if (!changed)
1046 return 0;
1047 /*
1048 * NEEDSWORK: the current default policy is to allow
1049 * submodule to be out of sync wrt the supermodule
1050 * index. This needs to be tightened later for
1051 * submodules that are marked to be automatically
1052 * checked out.
1053 */
1054 if (S_ISGITLINK(ce->ce_mode))
1055 return 0;
1056 errno = 0;
1057 }
1058 if (errno == ENOENT)
1059 return 0;
1060 return o->gently ? -1 :
1061 add_rejected_path(o, error_type, ce->name);
1062 }
1064 static int verify_uptodate(struct cache_entry *ce,
1065 struct unpack_trees_options *o)
1066 {
1067 if (!o->skip_sparse_checkout && (ce->ce_flags & CE_NEW_SKIP_WORKTREE))
1068 return 0;
1069 return verify_uptodate_1(ce, o, ERROR_NOT_UPTODATE_FILE);
1070 }
1072 static int verify_uptodate_sparse(struct cache_entry *ce,
1073 struct unpack_trees_options *o)
1074 {
1075 return verify_uptodate_1(ce, o, ERROR_SPARSE_NOT_UPTODATE_FILE);
1076 }
1078 static void invalidate_ce_path(struct cache_entry *ce, struct unpack_trees_options *o)
1079 {
1080 if (ce)
1081 cache_tree_invalidate_path(o->src_index->cache_tree, ce->name);
1082 }
1084 /*
1085 * Check that checking out ce->sha1 in subdir ce->name is not
1086 * going to overwrite any working files.
1087 *
1088 * Currently, git does not checkout subprojects during a superproject
1089 * checkout, so it is not going to overwrite anything.
1090 */
1091 static int verify_clean_submodule(struct cache_entry *ce,
1092 enum unpack_trees_error_types error_type,
1093 struct unpack_trees_options *o)
1094 {
1095 return 0;
1096 }
1098 static int verify_clean_subdirectory(struct cache_entry *ce,
1099 enum unpack_trees_error_types error_type,
1100 struct unpack_trees_options *o)
1101 {
1102 /*
1103 * we are about to extract "ce->name"; we would not want to lose
1104 * anything in the existing directory there.
1105 */
1106 int namelen;
1107 int i;
1108 struct dir_struct d;
1109 char *pathbuf;
1110 int cnt = 0;
1111 unsigned char sha1[20];
1113 if (S_ISGITLINK(ce->ce_mode) &&
1114 resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
1115 /* If we are not going to update the submodule, then
1116 * we don't care.
1117 */
1118 if (!hashcmp(sha1, ce->sha1))
1119 return 0;
1120 return verify_clean_submodule(ce, error_type, o);
1121 }
1123 /*
1124 * First let's make sure we do not have a local modification
1125 * in that directory.
1126 */
1127 namelen = strlen(ce->name);
1128 for (i = locate_in_src_index(ce, o);
1129 i < o->src_index->cache_nr;
1130 i++) {
1131 struct cache_entry *ce2 = o->src_index->cache[i];
1132 int len = ce_namelen(ce2);
1133 if (len < namelen ||
1134 strncmp(ce->name, ce2->name, namelen) ||
1135 ce2->name[namelen] != '/')
1136 break;
1137 /*
1138 * ce2->name is an entry in the subdirectory to be
1139 * removed.
1140 */
1141 if (!ce_stage(ce2)) {
1142 if (verify_uptodate(ce2, o))
1143 return -1;
1144 add_entry(o, ce2, CE_REMOVE, 0);
1145 mark_ce_used(ce2, o);
1146 }
1147 cnt++;
1148 }
1150 /*
1151 * Then we need to make sure that we do not lose a locally
1152 * present file that is not ignored.
1153 */
1154 pathbuf = xmalloc(namelen + 2);
1155 memcpy(pathbuf, ce->name, namelen);
1156 strcpy(pathbuf+namelen, "/");
1158 memset(&d, 0, sizeof(d));
1159 if (o->dir)
1160 d.exclude_per_dir = o->dir->exclude_per_dir;
1161 i = read_directory(&d, pathbuf, namelen+1, NULL);
1162 if (i)
1163 return o->gently ? -1 :
1164 add_rejected_path(o, ERROR_NOT_UPTODATE_DIR, ce->name);
1165 free(pathbuf);
1166 return cnt;
1167 }
1169 /*
1170 * This gets called when there was no index entry for the tree entry 'dst',
1171 * but we found a file in the working tree that 'lstat()' said was fine,
1172 * and we're on a case-insensitive filesystem.
1173 *
1174 * See if we can find a case-insensitive match in the index that also
1175 * matches the stat information, and assume it's that other file!
1176 */
1177 static int icase_exists(struct unpack_trees_options *o, struct cache_entry *dst, struct stat *st)
1178 {
1179 struct cache_entry *src;
1181 src = index_name_exists(o->src_index, dst->name, ce_namelen(dst), 1);
1182 return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
1183 }
1185 /*
1186 * We do not want to remove or overwrite a working tree file that
1187 * is not tracked, unless it is ignored.
1188 */
1189 static int verify_absent_1(struct cache_entry *ce,
1190 enum unpack_trees_error_types error_type,
1191 struct unpack_trees_options *o)
1192 {
1193 struct stat st;
1195 if (o->index_only || o->reset || !o->update)
1196 return 0;
1198 if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
1199 return 0;
1201 if (!lstat(ce->name, &st)) {
1202 int dtype = ce_to_dtype(ce);
1203 struct cache_entry *result;
1205 /*
1206 * It may be that the 'lstat()' succeeded even though
1207 * target 'ce' was absent, because there is an old
1208 * entry that is different only in case..
1209 *
1210 * Ignore that lstat() if it matches.
1211 */
1212 if (ignore_case && icase_exists(o, ce, &st))
1213 return 0;
1215 if (o->dir && excluded(o->dir, ce->name, &dtype))
1216 /*
1217 * ce->name is explicitly excluded, so it is Ok to
1218 * overwrite it.
1219 */
1220 return 0;
1221 if (S_ISDIR(st.st_mode)) {
1222 /*
1223 * We are checking out path "foo" and
1224 * found "foo/." in the working tree.
1225 * This is tricky -- if we have modified
1226 * files that are in "foo/" we would lose
1227 * them.
1228 */
1229 if (verify_clean_subdirectory(ce, error_type, o) < 0)
1230 return -1;
1231 return 0;
1232 }
1234 /*
1235 * The previous round may already have decided to
1236 * delete this path, which is in a subdirectory that
1237 * is being replaced with a blob.
1238 */
1239 result = index_name_exists(&o->result, ce->name, ce_namelen(ce), 0);
1240 if (result) {
1241 if (result->ce_flags & CE_REMOVE)
1242 return 0;
1243 }
1245 return o->gently ? -1 :
1246 add_rejected_path(o, error_type, ce->name);
1247 }
1248 return 0;
1249 }
1250 static int verify_absent(struct cache_entry *ce,
1251 enum unpack_trees_error_types error_type,
1252 struct unpack_trees_options *o)
1253 {
1254 if (!o->skip_sparse_checkout && (ce->ce_flags & CE_NEW_SKIP_WORKTREE))
1255 return 0;
1256 return verify_absent_1(ce, error_type, o);
1257 }
1259 static int verify_absent_sparse(struct cache_entry *ce,
1260 enum unpack_trees_error_types error_type,
1261 struct unpack_trees_options *o)
1262 {
1263 enum unpack_trees_error_types orphaned_error = error_type;
1264 if (orphaned_error == ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN)
1265 orphaned_error = ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN;
1267 return verify_absent_1(ce, orphaned_error, o);
1268 }
1270 static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
1271 struct unpack_trees_options *o)
1272 {
1273 int update = CE_UPDATE;
1275 if (!old) {
1276 /*
1277 * New index entries. In sparse checkout, the following
1278 * verify_absent() will be delayed until after
1279 * traverse_trees() finishes in unpack_trees(), then:
1280 *
1281 * - CE_NEW_SKIP_WORKTREE will be computed correctly
1282 * - verify_absent() be called again, this time with
1283 * correct CE_NEW_SKIP_WORKTREE
1284 *
1285 * verify_absent() call here does nothing in sparse
1286 * checkout (i.e. o->skip_sparse_checkout == 0)
1287 */
1288 update |= CE_ADDED;
1289 merge->ce_flags |= CE_NEW_SKIP_WORKTREE;
1291 if (verify_absent(merge, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o))
1292 return -1;
1293 invalidate_ce_path(merge, o);
1294 } else if (!(old->ce_flags & CE_CONFLICTED)) {
1295 /*
1296 * See if we can re-use the old CE directly?
1297 * That way we get the uptodate stat info.
1298 *
1299 * This also removes the UPDATE flag on a match; otherwise
1300 * we will end up overwriting local changes in the work tree.
1301 */
1302 if (same(old, merge)) {
1303 copy_cache_entry(merge, old);
1304 update = 0;
1305 } else {
1306 if (verify_uptodate(old, o))
1307 return -1;
1308 /* Migrate old flags over */
1309 update |= old->ce_flags & (CE_SKIP_WORKTREE | CE_NEW_SKIP_WORKTREE);
1310 invalidate_ce_path(old, o);
1311 }
1312 } else {
1313 /*
1314 * Previously unmerged entry left as an existence
1315 * marker by read_index_unmerged();
1316 */
1317 invalidate_ce_path(old, o);
1318 }
1320 add_entry(o, merge, update, CE_STAGEMASK);
1321 return 1;
1322 }
1324 static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
1325 struct unpack_trees_options *o)
1326 {
1327 /* Did it exist in the index? */
1328 if (!old) {
1329 if (verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_REMOVED, o))
1330 return -1;
1331 return 0;
1332 }
1333 if (!(old->ce_flags & CE_CONFLICTED) && verify_uptodate(old, o))
1334 return -1;
1335 add_entry(o, ce, CE_REMOVE, 0);
1336 invalidate_ce_path(ce, o);
1337 return 1;
1338 }
1340 static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o)
1341 {
1342 add_entry(o, ce, 0, 0);
1343 return 1;
1344 }
1346 #if DBRT_DEBUG
1347 static void show_stage_entry(FILE *o,
1348 const char *label, const struct cache_entry *ce)
1349 {
1350 if (!ce)
1351 fprintf(o, "%s (missing)\n", label);
1352 else
1353 fprintf(o, "%s%06o %s %d\t%s\n",
1354 label,
1355 ce->ce_mode,
1356 sha1_to_hex(ce->sha1),
1357 ce_stage(ce),
1358 ce->name);
1359 }
1360 #endif
1362 int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o)
1363 {
1364 struct cache_entry *index;
1365 struct cache_entry *head;
1366 struct cache_entry *remote = stages[o->head_idx + 1];
1367 int count;
1368 int head_match = 0;
1369 int remote_match = 0;
1371 int df_conflict_head = 0;
1372 int df_conflict_remote = 0;
1374 int any_anc_missing = 0;
1375 int no_anc_exists = 1;
1376 int i;
1378 for (i = 1; i < o->head_idx; i++) {
1379 if (!stages[i] || stages[i] == o->df_conflict_entry)
1380 any_anc_missing = 1;
1381 else
1382 no_anc_exists = 0;
1383 }
1385 index = stages[0];
1386 head = stages[o->head_idx];
1388 if (head == o->df_conflict_entry) {
1389 df_conflict_head = 1;
1390 head = NULL;
1391 }
1393 if (remote == o->df_conflict_entry) {
1394 df_conflict_remote = 1;
1395 remote = NULL;
1396 }
1398 /*
1399 * First, if there's a #16 situation, note that to prevent #13
1400 * and #14.
1401 */
1402 if (!same(remote, head)) {
1403 for (i = 1; i < o->head_idx; i++) {
1404 if (same(stages[i], head)) {
1405 head_match = i;
1406 }
1407 if (same(stages[i], remote)) {
1408 remote_match = i;
1409 }
1410 }
1411 }
1413 /*
1414 * We start with cases where the index is allowed to match
1415 * something other than the head: #14(ALT) and #2ALT, where it
1416 * is permitted to match the result instead.
1417 */
1418 /* #14, #14ALT, #2ALT */
1419 if (remote && !df_conflict_head && head_match && !remote_match) {
1420 if (index && !same(index, remote) && !same(index, head))
1421 return o->gently ? -1 : reject_merge(index, o);
1422 return merged_entry(remote, index, o);
1423 }
1424 /*
1425 * If we have an entry in the index cache, then we want to
1426 * make sure that it matches head.
1427 */
1428 if (index && !same(index, head))
1429 return o->gently ? -1 : reject_merge(index, o);
1431 if (head) {
1432 /* #5ALT, #15 */
1433 if (same(head, remote))
1434 return merged_entry(head, index, o);
1435 /* #13, #3ALT */
1436 if (!df_conflict_remote && remote_match && !head_match)
1437 return merged_entry(head, index, o);
1438 }
1440 /* #1 */
1441 if (!head && !remote && any_anc_missing)
1442 return 0;
1444 /*
1445 * Under the "aggressive" rule, we resolve mostly trivial
1446 * cases that we historically had git-merge-one-file resolve.
1447 */
1448 if (o->aggressive) {
1449 int head_deleted = !head;
1450 int remote_deleted = !remote;
1451 struct cache_entry *ce = NULL;
1453 if (index)
1454 ce = index;
1455 else if (head)
1456 ce = head;
1457 else if (remote)
1458 ce = remote;
1459 else {
1460 for (i = 1; i < o->head_idx; i++) {
1461 if (stages[i] && stages[i] != o->df_conflict_entry) {
1462 ce = stages[i];
1463 break;
1464 }
1465 }
1466 }
1468 /*
1469 * Deleted in both.
1470 * Deleted in one and unchanged in the other.
1471 */
1472 if ((head_deleted && remote_deleted) ||
1473 (head_deleted && remote && remote_match) ||
1474 (remote_deleted && head && head_match)) {
1475 if (index)
1476 return deleted_entry(index, index, o);
1477 if (ce && !head_deleted) {
1478 if (verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_REMOVED, o))
1479 return -1;
1480 }
1481 return 0;
1482 }
1483 /*
1484 * Added in both, identically.
1485 */
1486 if (no_anc_exists && head && remote && same(head, remote))
1487 return merged_entry(head, index, o);
1489 }
1491 /* Below are "no merge" cases, which require that the index be
1492 * up-to-date to avoid the files getting overwritten with
1493 * conflict resolution files.
1494 */
1495 if (index) {
1496 if (verify_uptodate(index, o))
1497 return -1;
1498 }
1500 o->nontrivial_merge = 1;
1502 /* #2, #3, #4, #6, #7, #9, #10, #11. */
1503 count = 0;
1504 if (!head_match || !remote_match) {
1505 for (i = 1; i < o->head_idx; i++) {
1506 if (stages[i] && stages[i] != o->df_conflict_entry) {
1507 keep_entry(stages[i], o);
1508 count++;
1509 break;
1510 }
1511 }
1512 }
1513 #if DBRT_DEBUG
1514 else {
1515 fprintf(stderr, "read-tree: warning #16 detected\n");
1516 show_stage_entry(stderr, "head ", stages[head_match]);
1517 show_stage_entry(stderr, "remote ", stages[remote_match]);
1518 }
1519 #endif
1520 if (head) { count += keep_entry(head, o); }
1521 if (remote) { count += keep_entry(remote, o); }
1522 return count;
1523 }
1525 /*
1526 * Two-way merge.
1527 *
1528 * The rule is to "carry forward" what is in the index without losing
1529 * information across a "fast-forward", favoring a successful merge
1530 * over a merge failure when it makes sense. For details of the
1531 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
1532 *
1533 */
1534 int twoway_merge(struct cache_entry **src, struct unpack_trees_options *o)
1535 {
1536 struct cache_entry *current = src[0];
1537 struct cache_entry *oldtree = src[1];
1538 struct cache_entry *newtree = src[2];
1540 if (o->merge_size != 2)
1541 return error("Cannot do a twoway merge of %d trees",
1542 o->merge_size);
1544 if (oldtree == o->df_conflict_entry)
1545 oldtree = NULL;
1546 if (newtree == o->df_conflict_entry)
1547 newtree = NULL;
1549 if (current) {
1550 if ((!oldtree && !newtree) || /* 4 and 5 */
1551 (!oldtree && newtree &&
1552 same(current, newtree)) || /* 6 and 7 */
1553 (oldtree && newtree &&
1554 same(oldtree, newtree)) || /* 14 and 15 */
1555 (oldtree && newtree &&
1556 !same(oldtree, newtree) && /* 18 and 19 */
1557 same(current, newtree))) {
1558 return keep_entry(current, o);
1559 }
1560 else if (oldtree && !newtree && same(current, oldtree)) {
1561 /* 10 or 11 */
1562 return deleted_entry(oldtree, current, o);
1563 }
1564 else if (oldtree && newtree &&
1565 same(current, oldtree) && !same(current, newtree)) {
1566 /* 20 or 21 */
1567 return merged_entry(newtree, current, o);
1568 }
1569 else {
1570 /* all other failures */
1571 if (oldtree)
1572 return o->gently ? -1 : reject_merge(oldtree, o);
1573 if (current)
1574 return o->gently ? -1 : reject_merge(current, o);
1575 if (newtree)
1576 return o->gently ? -1 : reject_merge(newtree, o);
1577 return -1;
1578 }
1579 }
1580 else if (newtree) {
1581 if (oldtree && !o->initial_checkout) {
1582 /*
1583 * deletion of the path was staged;
1584 */
1585 if (same(oldtree, newtree))
1586 return 1;
1587 return reject_merge(oldtree, o);
1588 }
1589 return merged_entry(newtree, current, o);
1590 }
1591 return deleted_entry(oldtree, current, o);
1592 }
1594 /*
1595 * Bind merge.
1596 *
1597 * Keep the index entries at stage0, collapse stage1 but make sure
1598 * stage0 does not have anything there.
1599 */
1600 int bind_merge(struct cache_entry **src,
1601 struct unpack_trees_options *o)
1602 {
1603 struct cache_entry *old = src[0];
1604 struct cache_entry *a = src[1];
1606 if (o->merge_size != 1)
1607 return error("Cannot do a bind merge of %d trees\n",
1608 o->merge_size);
1609 if (a && old)
1610 return o->gently ? -1 :
1611 error(ERRORMSG(o, ERROR_BIND_OVERLAP), a->name, old->name);
1612 if (!a)
1613 return keep_entry(old, o);
1614 else
1615 return merged_entry(a, NULL, o);
1616 }
1618 /*
1619 * One-way merge.
1620 *
1621 * The rule is:
1622 * - take the stat information from stage0, take the data from stage1
1623 */
1624 int oneway_merge(struct cache_entry **src, struct unpack_trees_options *o)
1625 {
1626 struct cache_entry *old = src[0];
1627 struct cache_entry *a = src[1];
1629 if (o->merge_size != 1)
1630 return error("Cannot do a oneway merge of %d trees",
1631 o->merge_size);
1633 if (!a || a == o->df_conflict_entry)
1634 return deleted_entry(old, old, o);
1636 if (old && same(old, a)) {
1637 int update = 0;
1638 if (o->reset && !ce_uptodate(old) && !ce_skip_worktree(old)) {
1639 struct stat st;
1640 if (lstat(old->name, &st) ||
1641 ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE))
1642 update |= CE_UPDATE;
1643 }
1644 add_entry(o, old, update, 0);
1645 return 0;
1646 }
1647 return merged_entry(a, old, o);
1648 }