Code

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