t5801: skip without hg
[git/dscho.git] / unpack-trees.c
blobbcee99c52e3a9ee8d67f70c577e57bbde8a8b610
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"
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.",
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)
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 do_add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
106                          unsigned int set, unsigned int clear)
108         clear |= CE_HASHED | CE_UNHASHED;
110         if (set & CE_REMOVE)
111                 set |= CE_WT_REMOVE;
113         ce->next = NULL;
114         ce->ce_flags = (ce->ce_flags & ~clear) | set;
115         add_index_entry(&o->result, ce,
116                         ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
119 static void add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
120         unsigned int set, unsigned int clear)
122         unsigned int size = ce_size(ce);
123         struct cache_entry *new = xmalloc(size);
125         memcpy(new, ce, size);
126         do_add_entry(o, new, set, clear);
130  * add error messages on path <path>
131  * corresponding to the type <e> with the message <msg>
132  * indicating if it should be display in porcelain or not
133  */
134 static int add_rejected_path(struct unpack_trees_options *o,
135                              enum unpack_trees_error_types e,
136                              const char *path)
138         if (!o->show_all_errors)
139                 return error(ERRORMSG(o, e), path);
141         /*
142          * Otherwise, insert in a list for future display by
143          * display_error_msgs()
144          */
145         string_list_append(&o->unpack_rejects[e], path);
146         return -1;
150  * display all the error messages stored in a nice way
151  */
152 static void display_error_msgs(struct unpack_trees_options *o)
154         int e, i;
155         int something_displayed = 0;
156         for (e = 0; e < NB_UNPACK_TREES_ERROR_TYPES; e++) {
157                 struct string_list *rejects = &o->unpack_rejects[e];
158                 if (rejects->nr > 0) {
159                         struct strbuf path = STRBUF_INIT;
160                         something_displayed = 1;
161                         for (i = 0; i < rejects->nr; i++)
162                                 strbuf_addf(&path, "\t%s\n", rejects->items[i].string);
163                         error(ERRORMSG(o, e), path.buf);
164                         strbuf_release(&path);
165                 }
166                 string_list_clear(rejects, 0);
167         }
168         if (something_displayed)
169                 fprintf(stderr, "Aborting\n");
173  * Unlink the last component and schedule the leading directories for
174  * removal, such that empty directories get removed.
175  */
176 static void unlink_entry(struct cache_entry *ce)
178         if (!check_leading_path(ce->name, ce_namelen(ce)))
179                 return;
180         if (remove_or_warn(ce->ce_mode, ce->name))
181                 return;
182         schedule_dir_for_removal(ce->name, ce_namelen(ce));
185 static struct checkout state;
186 static int check_updates(struct unpack_trees_options *o)
188         unsigned cnt = 0, total = 0;
189         struct progress *progress = NULL;
190         struct index_state *index = &o->result;
191         int i;
192         int errs = 0;
194         if (o->update && o->verbose_update) {
195                 for (total = cnt = 0; cnt < index->cache_nr; cnt++) {
196                         struct cache_entry *ce = index->cache[cnt];
197                         if (ce->ce_flags & (CE_UPDATE | CE_WT_REMOVE))
198                                 total++;
199                 }
201                 progress = start_progress_delay("Checking out files",
202                                                 total, 50, 1);
203                 cnt = 0;
204         }
206         if (o->update)
207                 git_attr_set_direction(GIT_ATTR_CHECKOUT, &o->result);
208         for (i = 0; i < index->cache_nr; i++) {
209                 struct cache_entry *ce = index->cache[i];
211                 if (ce->ce_flags & CE_WT_REMOVE) {
212                         display_progress(progress, ++cnt);
213                         if (o->update && !o->dry_run)
214                                 unlink_entry(ce);
215                         continue;
216                 }
217         }
218         remove_marked_cache_entries(&o->result);
219         remove_scheduled_dirs();
221         for (i = 0; i < index->cache_nr; i++) {
222                 struct cache_entry *ce = index->cache[i];
224                 if (ce->ce_flags & CE_UPDATE) {
225                         display_progress(progress, ++cnt);
226                         ce->ce_flags &= ~CE_UPDATE;
227                         if (o->update && !o->dry_run) {
228                                 errs |= checkout_entry(ce, &state, NULL);
229                         }
230                 }
231         }
232         stop_progress(&progress);
233         if (o->update)
234                 git_attr_set_direction(GIT_ATTR_CHECKIN, NULL);
235         return errs != 0;
238 static int verify_uptodate_sparse(struct cache_entry *ce, struct unpack_trees_options *o);
239 static int verify_absent_sparse(struct cache_entry *ce, enum unpack_trees_error_types, struct unpack_trees_options *o);
241 static int apply_sparse_checkout(struct cache_entry *ce, struct unpack_trees_options *o)
243         int was_skip_worktree = ce_skip_worktree(ce);
245         if (ce->ce_flags & CE_NEW_SKIP_WORKTREE)
246                 ce->ce_flags |= CE_SKIP_WORKTREE;
247         else
248                 ce->ce_flags &= ~CE_SKIP_WORKTREE;
250         /*
251          * if (!was_skip_worktree && !ce_skip_worktree()) {
252          *      This is perfectly normal. Move on;
253          * }
254          */
256         /*
257          * Merge strategies may set CE_UPDATE|CE_REMOVE outside checkout
258          * area as a result of ce_skip_worktree() shortcuts in
259          * verify_absent() and verify_uptodate().
260          * Make sure they don't modify worktree if they are already
261          * outside checkout area
262          */
263         if (was_skip_worktree && ce_skip_worktree(ce)) {
264                 ce->ce_flags &= ~CE_UPDATE;
266                 /*
267                  * By default, when CE_REMOVE is on, CE_WT_REMOVE is also
268                  * on to get that file removed from both index and worktree.
269                  * If that file is already outside worktree area, don't
270                  * bother remove it.
271                  */
272                 if (ce->ce_flags & CE_REMOVE)
273                         ce->ce_flags &= ~CE_WT_REMOVE;
274         }
276         if (!was_skip_worktree && ce_skip_worktree(ce)) {
277                 /*
278                  * If CE_UPDATE is set, verify_uptodate() must be called already
279                  * also stat info may have lost after merged_entry() so calling
280                  * verify_uptodate() again may fail
281                  */
282                 if (!(ce->ce_flags & CE_UPDATE) && verify_uptodate_sparse(ce, o))
283                         return -1;
284                 ce->ce_flags |= CE_WT_REMOVE;
285         }
286         if (was_skip_worktree && !ce_skip_worktree(ce)) {
287                 if (verify_absent_sparse(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o))
288                         return -1;
289                 ce->ce_flags |= CE_UPDATE;
290         }
291         return 0;
294 static inline int call_unpack_fn(struct cache_entry **src, struct unpack_trees_options *o)
296         int ret = o->fn(src, o);
297         if (ret > 0)
298                 ret = 0;
299         return ret;
302 static void mark_ce_used(struct cache_entry *ce, struct unpack_trees_options *o)
304         ce->ce_flags |= CE_UNPACKED;
306         if (o->cache_bottom < o->src_index->cache_nr &&
307             o->src_index->cache[o->cache_bottom] == ce) {
308                 int bottom = o->cache_bottom;
309                 while (bottom < o->src_index->cache_nr &&
310                        o->src_index->cache[bottom]->ce_flags & CE_UNPACKED)
311                         bottom++;
312                 o->cache_bottom = bottom;
313         }
316 static void mark_all_ce_unused(struct index_state *index)
318         int i;
319         for (i = 0; i < index->cache_nr; i++)
320                 index->cache[i]->ce_flags &= ~(CE_UNPACKED | CE_ADDED | CE_NEW_SKIP_WORKTREE);
323 static int locate_in_src_index(struct cache_entry *ce,
324                                struct unpack_trees_options *o)
326         struct index_state *index = o->src_index;
327         int len = ce_namelen(ce);
328         int pos = index_name_pos(index, ce->name, len);
329         if (pos < 0)
330                 pos = -1 - pos;
331         return pos;
335  * We call unpack_index_entry() with an unmerged cache entry
336  * only in diff-index, and it wants a single callback.  Skip
337  * the other unmerged entry with the same name.
338  */
339 static void mark_ce_used_same_name(struct cache_entry *ce,
340                                    struct unpack_trees_options *o)
342         struct index_state *index = o->src_index;
343         int len = ce_namelen(ce);
344         int pos;
346         for (pos = locate_in_src_index(ce, o); pos < index->cache_nr; pos++) {
347                 struct cache_entry *next = index->cache[pos];
348                 if (len != ce_namelen(next) ||
349                     memcmp(ce->name, next->name, len))
350                         break;
351                 mark_ce_used(next, o);
352         }
355 static struct cache_entry *next_cache_entry(struct unpack_trees_options *o)
357         const struct index_state *index = o->src_index;
358         int pos = o->cache_bottom;
360         while (pos < index->cache_nr) {
361                 struct cache_entry *ce = index->cache[pos];
362                 if (!(ce->ce_flags & CE_UNPACKED))
363                         return ce;
364                 pos++;
365         }
366         return NULL;
369 static void add_same_unmerged(struct cache_entry *ce,
370                               struct unpack_trees_options *o)
372         struct index_state *index = o->src_index;
373         int len = ce_namelen(ce);
374         int pos = index_name_pos(index, ce->name, len);
376         if (0 <= pos)
377                 die("programming error in a caller of mark_ce_used_same_name");
378         for (pos = -pos - 1; pos < index->cache_nr; pos++) {
379                 struct cache_entry *next = index->cache[pos];
380                 if (len != ce_namelen(next) ||
381                     memcmp(ce->name, next->name, len))
382                         break;
383                 add_entry(o, next, 0, 0);
384                 mark_ce_used(next, o);
385         }
388 static int unpack_index_entry(struct cache_entry *ce,
389                               struct unpack_trees_options *o)
391         struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
392         int ret;
394         src[0] = ce;
396         mark_ce_used(ce, o);
397         if (ce_stage(ce)) {
398                 if (o->skip_unmerged) {
399                         add_entry(o, ce, 0, 0);
400                         return 0;
401                 }
402         }
403         ret = call_unpack_fn(src, o);
404         if (ce_stage(ce))
405                 mark_ce_used_same_name(ce, o);
406         return ret;
409 static int find_cache_pos(struct traverse_info *, const struct name_entry *);
411 static void restore_cache_bottom(struct traverse_info *info, int bottom)
413         struct unpack_trees_options *o = info->data;
415         if (o->diff_index_cached)
416                 return;
417         o->cache_bottom = bottom;
420 static int switch_cache_bottom(struct traverse_info *info)
422         struct unpack_trees_options *o = info->data;
423         int ret, pos;
425         if (o->diff_index_cached)
426                 return 0;
427         ret = o->cache_bottom;
428         pos = find_cache_pos(info->prev, &info->name);
430         if (pos < -1)
431                 o->cache_bottom = -2 - pos;
432         else if (pos < 0)
433                 o->cache_bottom = o->src_index->cache_nr;
434         return ret;
437 static int traverse_trees_recursive(int n, unsigned long dirmask,
438                                     unsigned long df_conflicts,
439                                     struct name_entry *names,
440                                     struct traverse_info *info)
442         int i, ret, bottom;
443         struct tree_desc t[MAX_UNPACK_TREES];
444         void *buf[MAX_UNPACK_TREES];
445         struct traverse_info newinfo;
446         struct name_entry *p;
448         p = names;
449         while (!p->mode)
450                 p++;
452         newinfo = *info;
453         newinfo.prev = info;
454         newinfo.pathspec = info->pathspec;
455         newinfo.name = *p;
456         newinfo.pathlen += tree_entry_len(p) + 1;
457         newinfo.conflicts |= df_conflicts;
459         for (i = 0; i < n; i++, dirmask >>= 1) {
460                 const unsigned char *sha1 = NULL;
461                 if (dirmask & 1)
462                         sha1 = names[i].sha1;
463                 buf[i] = fill_tree_descriptor(t+i, sha1);
464         }
466         bottom = switch_cache_bottom(&newinfo);
467         ret = traverse_trees(n, t, &newinfo);
468         restore_cache_bottom(&newinfo, bottom);
470         for (i = 0; i < n; i++)
471                 free(buf[i]);
473         return ret;
477  * Compare the traverse-path to the cache entry without actually
478  * having to generate the textual representation of the traverse
479  * path.
481  * NOTE! This *only* compares up to the size of the traverse path
482  * itself - the caller needs to do the final check for the cache
483  * entry having more data at the end!
484  */
485 static int do_compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
487         int len, pathlen, ce_len;
488         const char *ce_name;
490         if (info->prev) {
491                 int cmp = do_compare_entry(ce, info->prev, &info->name);
492                 if (cmp)
493                         return cmp;
494         }
495         pathlen = info->pathlen;
496         ce_len = ce_namelen(ce);
498         /* If ce_len < pathlen then we must have previously hit "name == directory" entry */
499         if (ce_len < pathlen)
500                 return -1;
502         ce_len -= pathlen;
503         ce_name = ce->name + pathlen;
505         len = tree_entry_len(n);
506         return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode);
509 static int compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
511         int cmp = do_compare_entry(ce, info, n);
512         if (cmp)
513                 return cmp;
515         /*
516          * Even if the beginning compared identically, the ce should
517          * compare as bigger than a directory leading up to it!
518          */
519         return ce_namelen(ce) > traverse_path_len(info, n);
522 static int ce_in_traverse_path(const struct cache_entry *ce,
523                                const struct traverse_info *info)
525         if (!info->prev)
526                 return 1;
527         if (do_compare_entry(ce, info->prev, &info->name))
528                 return 0;
529         /*
530          * If ce (blob) is the same name as the path (which is a tree
531          * we will be descending into), it won't be inside it.
532          */
533         return (info->pathlen < ce_namelen(ce));
536 static struct cache_entry *create_ce_entry(const struct traverse_info *info, const struct name_entry *n, int stage)
538         int len = traverse_path_len(info, n);
539         struct cache_entry *ce = xcalloc(1, cache_entry_size(len));
541         ce->ce_mode = create_ce_mode(n->mode);
542         ce->ce_flags = create_ce_flags(len, stage);
543         hashcpy(ce->sha1, n->sha1);
544         make_traverse_path(ce->name, info, n);
546         return ce;
549 static int unpack_nondirectories(int n, unsigned long mask,
550                                  unsigned long dirmask,
551                                  struct cache_entry **src,
552                                  const struct name_entry *names,
553                                  const struct traverse_info *info)
555         int i;
556         struct unpack_trees_options *o = info->data;
557         unsigned long conflicts;
559         /* Do we have *only* directories? Nothing to do */
560         if (mask == dirmask && !src[0])
561                 return 0;
563         conflicts = info->conflicts;
564         if (o->merge)
565                 conflicts >>= 1;
566         conflicts |= dirmask;
568         /*
569          * Ok, we've filled in up to any potential index entry in src[0],
570          * now do the rest.
571          */
572         for (i = 0; i < n; i++) {
573                 int stage;
574                 unsigned int bit = 1ul << i;
575                 if (conflicts & bit) {
576                         src[i + o->merge] = o->df_conflict_entry;
577                         continue;
578                 }
579                 if (!(mask & bit))
580                         continue;
581                 if (!o->merge)
582                         stage = 0;
583                 else if (i + 1 < o->head_idx)
584                         stage = 1;
585                 else if (i + 1 > o->head_idx)
586                         stage = 3;
587                 else
588                         stage = 2;
589                 src[i + o->merge] = create_ce_entry(info, names + i, stage);
590         }
592         if (o->merge)
593                 return call_unpack_fn(src, o);
595         for (i = 0; i < n; i++)
596                 if (src[i] && src[i] != o->df_conflict_entry)
597                         do_add_entry(o, src[i], 0, 0);
598         return 0;
601 static int unpack_failed(struct unpack_trees_options *o, const char *message)
603         discard_index(&o->result);
604         if (!o->gently && !o->exiting_early) {
605                 if (message)
606                         return error("%s", message);
607                 return -1;
608         }
609         return -1;
612 /* NEEDSWORK: give this a better name and share with tree-walk.c */
613 static int name_compare(const char *a, int a_len,
614                         const char *b, int b_len)
616         int len = (a_len < b_len) ? a_len : b_len;
617         int cmp = memcmp(a, b, len);
618         if (cmp)
619                 return cmp;
620         return (a_len - b_len);
624  * The tree traversal is looking at name p.  If we have a matching entry,
625  * return it.  If name p is a directory in the index, do not return
626  * anything, as we will want to match it when the traversal descends into
627  * the directory.
628  */
629 static int find_cache_pos(struct traverse_info *info,
630                           const struct name_entry *p)
632         int pos;
633         struct unpack_trees_options *o = info->data;
634         struct index_state *index = o->src_index;
635         int pfxlen = info->pathlen;
636         int p_len = tree_entry_len(p);
638         for (pos = o->cache_bottom; pos < index->cache_nr; pos++) {
639                 struct cache_entry *ce = index->cache[pos];
640                 const char *ce_name, *ce_slash;
641                 int cmp, ce_len;
643                 if (ce->ce_flags & CE_UNPACKED) {
644                         /*
645                          * cache_bottom entry is already unpacked, so
646                          * we can never match it; don't check it
647                          * again.
648                          */
649                         if (pos == o->cache_bottom)
650                                 ++o->cache_bottom;
651                         continue;
652                 }
653                 if (!ce_in_traverse_path(ce, info))
654                         continue;
655                 ce_name = ce->name + pfxlen;
656                 ce_slash = strchr(ce_name, '/');
657                 if (ce_slash)
658                         ce_len = ce_slash - ce_name;
659                 else
660                         ce_len = ce_namelen(ce) - pfxlen;
661                 cmp = name_compare(p->path, p_len, ce_name, ce_len);
662                 /*
663                  * Exact match; if we have a directory we need to
664                  * delay returning it.
665                  */
666                 if (!cmp)
667                         return ce_slash ? -2 - pos : pos;
668                 if (0 < cmp)
669                         continue; /* keep looking */
670                 /*
671                  * ce_name sorts after p->path; could it be that we
672                  * have files under p->path directory in the index?
673                  * E.g.  ce_name == "t-i", and p->path == "t"; we may
674                  * have "t/a" in the index.
675                  */
676                 if (p_len < ce_len && !memcmp(ce_name, p->path, p_len) &&
677                     ce_name[p_len] < '/')
678                         continue; /* keep looking */
679                 break;
680         }
681         return -1;
684 static struct cache_entry *find_cache_entry(struct traverse_info *info,
685                                             const struct name_entry *p)
687         int pos = find_cache_pos(info, p);
688         struct unpack_trees_options *o = info->data;
690         if (0 <= pos)
691                 return o->src_index->cache[pos];
692         else
693                 return NULL;
696 static void debug_path(struct traverse_info *info)
698         if (info->prev) {
699                 debug_path(info->prev);
700                 if (*info->prev->name.path)
701                         putchar('/');
702         }
703         printf("%s", info->name.path);
706 static void debug_name_entry(int i, struct name_entry *n)
708         printf("ent#%d %06o %s\n", i,
709                n->path ? n->mode : 0,
710                n->path ? n->path : "(missing)");
713 static void debug_unpack_callback(int n,
714                                   unsigned long mask,
715                                   unsigned long dirmask,
716                                   struct name_entry *names,
717                                   struct traverse_info *info)
719         int i;
720         printf("* unpack mask %lu, dirmask %lu, cnt %d ",
721                mask, dirmask, n);
722         debug_path(info);
723         putchar('\n');
724         for (i = 0; i < n; i++)
725                 debug_name_entry(i, names + i);
728 static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *names, struct traverse_info *info)
730         struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
731         struct unpack_trees_options *o = info->data;
732         const struct name_entry *p = names;
734         /* Find first entry with a real name (we could use "mask" too) */
735         while (!p->mode)
736                 p++;
738         if (o->debug_unpack)
739                 debug_unpack_callback(n, mask, dirmask, names, info);
741         /* Are we supposed to look at the index too? */
742         if (o->merge) {
743                 while (1) {
744                         int cmp;
745                         struct cache_entry *ce;
747                         if (o->diff_index_cached)
748                                 ce = next_cache_entry(o);
749                         else
750                                 ce = find_cache_entry(info, p);
752                         if (!ce)
753                                 break;
754                         cmp = compare_entry(ce, info, p);
755                         if (cmp < 0) {
756                                 if (unpack_index_entry(ce, o) < 0)
757                                         return unpack_failed(o, NULL);
758                                 continue;
759                         }
760                         if (!cmp) {
761                                 if (ce_stage(ce)) {
762                                         /*
763                                          * If we skip unmerged index
764                                          * entries, we'll skip this
765                                          * entry *and* the tree
766                                          * entries associated with it!
767                                          */
768                                         if (o->skip_unmerged) {
769                                                 add_same_unmerged(ce, o);
770                                                 return mask;
771                                         }
772                                 }
773                                 src[0] = ce;
774                         }
775                         break;
776                 }
777         }
779         if (unpack_nondirectories(n, mask, dirmask, src, names, info) < 0)
780                 return -1;
782         if (o->merge && src[0]) {
783                 if (ce_stage(src[0]))
784                         mark_ce_used_same_name(src[0], o);
785                 else
786                         mark_ce_used(src[0], o);
787         }
789         /* Now handle any directories.. */
790         if (dirmask) {
791                 unsigned long conflicts = mask & ~dirmask;
792                 if (o->merge) {
793                         conflicts <<= 1;
794                         if (src[0])
795                                 conflicts |= 1;
796                 }
798                 /* special case: "diff-index --cached" looking at a tree */
799                 if (o->diff_index_cached &&
800                     n == 1 && dirmask == 1 && S_ISDIR(names->mode)) {
801                         int matches;
802                         matches = cache_tree_matches_traversal(o->src_index->cache_tree,
803                                                                names, info);
804                         /*
805                          * Everything under the name matches; skip the
806                          * entire hierarchy.  diff_index_cached codepath
807                          * special cases D/F conflicts in such a way that
808                          * it does not do any look-ahead, so this is safe.
809                          */
810                         if (matches) {
811                                 o->cache_bottom += matches;
812                                 return mask;
813                         }
814                 }
816                 if (traverse_trees_recursive(n, dirmask, conflicts,
817                                              names, info) < 0)
818                         return -1;
819                 return mask;
820         }
822         return mask;
825 static int clear_ce_flags_1(struct cache_entry **cache, int nr,
826                             char *prefix, int prefix_len,
827                             int select_mask, int clear_mask,
828                             struct exclude_list *el, int defval);
830 /* Whole directory matching */
831 static int clear_ce_flags_dir(struct cache_entry **cache, int nr,
832                               char *prefix, int prefix_len,
833                               char *basename,
834                               int select_mask, int clear_mask,
835                               struct exclude_list *el, int defval)
837         struct cache_entry **cache_end;
838         int dtype = DT_DIR;
839         int ret = excluded_from_list(prefix, prefix_len, basename, &dtype, el);
841         prefix[prefix_len++] = '/';
843         /* If undecided, use matching result of parent dir in defval */
844         if (ret < 0)
845                 ret = defval;
847         for (cache_end = cache; cache_end != cache + nr; cache_end++) {
848                 struct cache_entry *ce = *cache_end;
849                 if (strncmp(ce->name, prefix, prefix_len))
850                         break;
851         }
853         /*
854          * TODO: check el, if there are no patterns that may conflict
855          * with ret (iow, we know in advance the incl/excl
856          * decision for the entire directory), clear flag here without
857          * calling clear_ce_flags_1(). That function will call
858          * the expensive excluded_from_list() on every entry.
859          */
860         return clear_ce_flags_1(cache, cache_end - cache,
861                                 prefix, prefix_len,
862                                 select_mask, clear_mask,
863                                 el, ret);
867  * Traverse the index, find every entry that matches according to
868  * o->el. Do "ce_flags &= ~clear_mask" on those entries. Return the
869  * number of traversed entries.
871  * If select_mask is non-zero, only entries whose ce_flags has on of
872  * those bits enabled are traversed.
874  * cache        : pointer to an index entry
875  * prefix_len   : an offset to its path
877  * The current path ("prefix") including the trailing '/' is
878  *   cache[0]->name[0..(prefix_len-1)]
879  * Top level path has prefix_len zero.
880  */
881 static int clear_ce_flags_1(struct cache_entry **cache, int nr,
882                             char *prefix, int prefix_len,
883                             int select_mask, int clear_mask,
884                             struct exclude_list *el, int defval)
886         struct cache_entry **cache_end = cache + nr;
888         /*
889          * Process all entries that have the given prefix and meet
890          * select_mask condition
891          */
892         while(cache != cache_end) {
893                 struct cache_entry *ce = *cache;
894                 const char *name, *slash;
895                 int len, dtype, ret;
897                 if (select_mask && !(ce->ce_flags & select_mask)) {
898                         cache++;
899                         continue;
900                 }
902                 if (prefix_len && strncmp(ce->name, prefix, prefix_len))
903                         break;
905                 name = ce->name + prefix_len;
906                 slash = strchr(name, '/');
908                 /* If it's a directory, try whole directory match first */
909                 if (slash) {
910                         int processed;
912                         len = slash - name;
913                         memcpy(prefix + prefix_len, name, len);
915                         /*
916                          * terminate the string (no trailing slash),
917                          * clear_c_f_dir needs it
918                          */
919                         prefix[prefix_len + len] = '\0';
920                         processed = clear_ce_flags_dir(cache, cache_end - cache,
921                                                        prefix, prefix_len + len,
922                                                        prefix + prefix_len,
923                                                        select_mask, clear_mask,
924                                                        el, defval);
926                         /* clear_c_f_dir eats a whole dir already? */
927                         if (processed) {
928                                 cache += processed;
929                                 continue;
930                         }
932                         prefix[prefix_len + len++] = '/';
933                         cache += clear_ce_flags_1(cache, cache_end - cache,
934                                                   prefix, prefix_len + len,
935                                                   select_mask, clear_mask, el, defval);
936                         continue;
937                 }
939                 /* Non-directory */
940                 dtype = ce_to_dtype(ce);
941                 ret = excluded_from_list(ce->name, ce_namelen(ce), name, &dtype, el);
942                 if (ret < 0)
943                         ret = defval;
944                 if (ret > 0)
945                         ce->ce_flags &= ~clear_mask;
946                 cache++;
947         }
948         return nr - (cache_end - cache);
951 static int clear_ce_flags(struct cache_entry **cache, int nr,
952                             int select_mask, int clear_mask,
953                             struct exclude_list *el)
955         char prefix[PATH_MAX];
956         return clear_ce_flags_1(cache, nr,
957                                 prefix, 0,
958                                 select_mask, clear_mask,
959                                 el, 0);
963  * Set/Clear CE_NEW_SKIP_WORKTREE according to $GIT_DIR/info/sparse-checkout
964  */
965 static void mark_new_skip_worktree(struct exclude_list *el,
966                                    struct index_state *the_index,
967                                    int select_flag, int skip_wt_flag)
969         int i;
971         /*
972          * 1. Pretend the narrowest worktree: only unmerged entries
973          * are checked out
974          */
975         for (i = 0; i < the_index->cache_nr; i++) {
976                 struct cache_entry *ce = the_index->cache[i];
978                 if (select_flag && !(ce->ce_flags & select_flag))
979                         continue;
981                 if (!ce_stage(ce))
982                         ce->ce_flags |= skip_wt_flag;
983                 else
984                         ce->ce_flags &= ~skip_wt_flag;
985         }
987         /*
988          * 2. Widen worktree according to sparse-checkout file.
989          * Matched entries will have skip_wt_flag cleared (i.e. "in")
990          */
991         clear_ce_flags(the_index->cache, the_index->cache_nr,
992                        select_flag, skip_wt_flag, el);
995 static int verify_absent(struct cache_entry *, enum unpack_trees_error_types, struct unpack_trees_options *);
997  * N-way merge "len" trees.  Returns 0 on success, -1 on failure to manipulate the
998  * resulting index, -2 on failure to reflect the changes to the work tree.
1000  * CE_ADDED, CE_UNPACKED and CE_NEW_SKIP_WORKTREE are used internally
1001  */
1002 int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
1004         int i, ret;
1005         static struct cache_entry *dfc;
1006         struct exclude_list el;
1008         if (len > MAX_UNPACK_TREES)
1009                 die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
1010         memset(&state, 0, sizeof(state));
1011         state.base_dir = "";
1012         state.force = 1;
1013         state.quiet = 1;
1014         state.refresh_cache = 1;
1016         memset(&el, 0, sizeof(el));
1017         if (!core_apply_sparse_checkout || !o->update)
1018                 o->skip_sparse_checkout = 1;
1019         if (!o->skip_sparse_checkout) {
1020                 if (add_excludes_from_file_to_list(git_path("info/sparse-checkout"), "", 0, NULL, &el, 0) < 0)
1021                         o->skip_sparse_checkout = 1;
1022                 else
1023                         o->el = &el;
1024         }
1026         memset(&o->result, 0, sizeof(o->result));
1027         o->result.initialized = 1;
1028         o->result.timestamp.sec = o->src_index->timestamp.sec;
1029         o->result.timestamp.nsec = o->src_index->timestamp.nsec;
1030         o->result.version = o->src_index->version;
1031         o->merge_size = len;
1032         mark_all_ce_unused(o->src_index);
1034         /*
1035          * Sparse checkout loop #1: set NEW_SKIP_WORKTREE on existing entries
1036          */
1037         if (!o->skip_sparse_checkout)
1038                 mark_new_skip_worktree(o->el, o->src_index, 0, CE_NEW_SKIP_WORKTREE);
1040         if (!dfc)
1041                 dfc = xcalloc(1, cache_entry_size(0));
1042         o->df_conflict_entry = dfc;
1044         if (len) {
1045                 const char *prefix = o->prefix ? o->prefix : "";
1046                 struct traverse_info info;
1048                 setup_traverse_info(&info, prefix);
1049                 info.fn = unpack_callback;
1050                 info.data = o;
1051                 info.show_all_errors = o->show_all_errors;
1052                 info.pathspec = o->pathspec;
1054                 if (o->prefix) {
1055                         /*
1056                          * Unpack existing index entries that sort before the
1057                          * prefix the tree is spliced into.  Note that o->merge
1058                          * is always true in this case.
1059                          */
1060                         while (1) {
1061                                 struct cache_entry *ce = next_cache_entry(o);
1062                                 if (!ce)
1063                                         break;
1064                                 if (ce_in_traverse_path(ce, &info))
1065                                         break;
1066                                 if (unpack_index_entry(ce, o) < 0)
1067                                         goto return_failed;
1068                         }
1069                 }
1071                 if (traverse_trees(len, t, &info) < 0)
1072                         goto return_failed;
1073         }
1075         /* Any left-over entries in the index? */
1076         if (o->merge) {
1077                 while (1) {
1078                         struct cache_entry *ce = next_cache_entry(o);
1079                         if (!ce)
1080                                 break;
1081                         if (unpack_index_entry(ce, o) < 0)
1082                                 goto return_failed;
1083                 }
1084         }
1085         mark_all_ce_unused(o->src_index);
1087         if (o->trivial_merges_only && o->nontrivial_merge) {
1088                 ret = unpack_failed(o, "Merge requires file-level merging");
1089                 goto done;
1090         }
1092         if (!o->skip_sparse_checkout) {
1093                 int empty_worktree = 1;
1095                 /*
1096                  * Sparse checkout loop #2: set NEW_SKIP_WORKTREE on entries not in loop #1
1097                  * If the will have NEW_SKIP_WORKTREE, also set CE_SKIP_WORKTREE
1098                  * so apply_sparse_checkout() won't attempt to remove it from worktree
1099                  */
1100                 mark_new_skip_worktree(o->el, &o->result, CE_ADDED, CE_SKIP_WORKTREE | CE_NEW_SKIP_WORKTREE);
1102                 ret = 0;
1103                 for (i = 0; i < o->result.cache_nr; i++) {
1104                         struct cache_entry *ce = o->result.cache[i];
1106                         /*
1107                          * Entries marked with CE_ADDED in merged_entry() do not have
1108                          * verify_absent() check (the check is effectively disabled
1109                          * because CE_NEW_SKIP_WORKTREE is set unconditionally).
1110                          *
1111                          * Do the real check now because we have had
1112                          * correct CE_NEW_SKIP_WORKTREE
1113                          */
1114                         if (ce->ce_flags & CE_ADDED &&
1115                             verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o)) {
1116                                 if (!o->show_all_errors)
1117                                         goto return_failed;
1118                                 ret = -1;
1119                         }
1121                         if (apply_sparse_checkout(ce, o)) {
1122                                 if (!o->show_all_errors)
1123                                         goto return_failed;
1124                                 ret = -1;
1125                         }
1126                         if (!ce_skip_worktree(ce))
1127                                 empty_worktree = 0;
1129                 }
1130                 if (ret < 0)
1131                         goto return_failed;
1132                 /*
1133                  * Sparse checkout is meant to narrow down checkout area
1134                  * but it does not make sense to narrow down to empty working
1135                  * tree. This is usually a mistake in sparse checkout rules.
1136                  * Do not allow users to do that.
1137                  */
1138                 if (o->result.cache_nr && empty_worktree) {
1139                         ret = unpack_failed(o, "Sparse checkout leaves no entry on working directory");
1140                         goto done;
1141                 }
1142         }
1144         o->src_index = NULL;
1145         ret = check_updates(o) ? (-2) : 0;
1146         if (o->dst_index)
1147                 *o->dst_index = o->result;
1149 done:
1150         free_excludes(&el);
1151         return ret;
1153 return_failed:
1154         if (o->show_all_errors)
1155                 display_error_msgs(o);
1156         mark_all_ce_unused(o->src_index);
1157         ret = unpack_failed(o, NULL);
1158         if (o->exiting_early)
1159                 ret = 0;
1160         goto done;
1163 /* Here come the merge functions */
1165 static int reject_merge(struct cache_entry *ce, struct unpack_trees_options *o)
1167         return add_rejected_path(o, ERROR_WOULD_OVERWRITE, ce->name);
1170 static int same(struct cache_entry *a, struct cache_entry *b)
1172         if (!!a != !!b)
1173                 return 0;
1174         if (!a && !b)
1175                 return 1;
1176         if ((a->ce_flags | b->ce_flags) & CE_CONFLICTED)
1177                 return 0;
1178         return a->ce_mode == b->ce_mode &&
1179                !hashcmp(a->sha1, b->sha1);
1184  * When a CE gets turned into an unmerged entry, we
1185  * want it to be up-to-date
1186  */
1187 static int verify_uptodate_1(struct cache_entry *ce,
1188                                    struct unpack_trees_options *o,
1189                                    enum unpack_trees_error_types error_type)
1191         struct stat st;
1193         if (o->index_only)
1194                 return 0;
1196         /*
1197          * CE_VALID and CE_SKIP_WORKTREE cheat, we better check again
1198          * if this entry is truly up-to-date because this file may be
1199          * overwritten.
1200          */
1201         if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
1202                 ; /* keep checking */
1203         else if (o->reset || ce_uptodate(ce))
1204                 return 0;
1206         if (!lstat(ce->name, &st)) {
1207                 int flags = CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE;
1208                 unsigned changed = ie_match_stat(o->src_index, ce, &st, flags);
1209                 if (!changed)
1210                         return 0;
1211                 /*
1212                  * NEEDSWORK: the current default policy is to allow
1213                  * submodule to be out of sync wrt the supermodule
1214                  * index.  This needs to be tightened later for
1215                  * submodules that are marked to be automatically
1216                  * checked out.
1217                  */
1218                 if (S_ISGITLINK(ce->ce_mode))
1219                         return 0;
1220                 errno = 0;
1221         }
1222         if (errno == ENOENT)
1223                 return 0;
1224         return o->gently ? -1 :
1225                 add_rejected_path(o, error_type, ce->name);
1228 static int verify_uptodate(struct cache_entry *ce,
1229                            struct unpack_trees_options *o)
1231         if (!o->skip_sparse_checkout && (ce->ce_flags & CE_NEW_SKIP_WORKTREE))
1232                 return 0;
1233         return verify_uptodate_1(ce, o, ERROR_NOT_UPTODATE_FILE);
1236 static int verify_uptodate_sparse(struct cache_entry *ce,
1237                                   struct unpack_trees_options *o)
1239         return verify_uptodate_1(ce, o, ERROR_SPARSE_NOT_UPTODATE_FILE);
1242 static void invalidate_ce_path(struct cache_entry *ce, struct unpack_trees_options *o)
1244         if (ce)
1245                 cache_tree_invalidate_path(o->src_index->cache_tree, ce->name);
1249  * Check that checking out ce->sha1 in subdir ce->name is not
1250  * going to overwrite any working files.
1252  * Currently, git does not checkout subprojects during a superproject
1253  * checkout, so it is not going to overwrite anything.
1254  */
1255 static int verify_clean_submodule(struct cache_entry *ce,
1256                                       enum unpack_trees_error_types error_type,
1257                                       struct unpack_trees_options *o)
1259         return 0;
1262 static int verify_clean_subdirectory(struct cache_entry *ce,
1263                                       enum unpack_trees_error_types error_type,
1264                                       struct unpack_trees_options *o)
1266         /*
1267          * we are about to extract "ce->name"; we would not want to lose
1268          * anything in the existing directory there.
1269          */
1270         int namelen;
1271         int i;
1272         struct dir_struct d;
1273         char *pathbuf;
1274         int cnt = 0;
1275         unsigned char sha1[20];
1277         if (S_ISGITLINK(ce->ce_mode) &&
1278             resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
1279                 /* If we are not going to update the submodule, then
1280                  * we don't care.
1281                  */
1282                 if (!hashcmp(sha1, ce->sha1))
1283                         return 0;
1284                 return verify_clean_submodule(ce, error_type, o);
1285         }
1287         /*
1288          * First let's make sure we do not have a local modification
1289          * in that directory.
1290          */
1291         namelen = strlen(ce->name);
1292         for (i = locate_in_src_index(ce, o);
1293              i < o->src_index->cache_nr;
1294              i++) {
1295                 struct cache_entry *ce2 = o->src_index->cache[i];
1296                 int len = ce_namelen(ce2);
1297                 if (len < namelen ||
1298                     strncmp(ce->name, ce2->name, namelen) ||
1299                     ce2->name[namelen] != '/')
1300                         break;
1301                 /*
1302                  * ce2->name is an entry in the subdirectory to be
1303                  * removed.
1304                  */
1305                 if (!ce_stage(ce2)) {
1306                         if (verify_uptodate(ce2, o))
1307                                 return -1;
1308                         add_entry(o, ce2, CE_REMOVE, 0);
1309                         mark_ce_used(ce2, o);
1310                 }
1311                 cnt++;
1312         }
1314         /*
1315          * Then we need to make sure that we do not lose a locally
1316          * present file that is not ignored.
1317          */
1318         pathbuf = xmalloc(namelen + 2);
1319         memcpy(pathbuf, ce->name, namelen);
1320         strcpy(pathbuf+namelen, "/");
1322         memset(&d, 0, sizeof(d));
1323         if (o->dir)
1324                 d.exclude_per_dir = o->dir->exclude_per_dir;
1325         i = read_directory(&d, pathbuf, namelen+1, NULL);
1326         if (i)
1327                 return o->gently ? -1 :
1328                         add_rejected_path(o, ERROR_NOT_UPTODATE_DIR, ce->name);
1329         free(pathbuf);
1330         return cnt;
1334  * This gets called when there was no index entry for the tree entry 'dst',
1335  * but we found a file in the working tree that 'lstat()' said was fine,
1336  * and we're on a case-insensitive filesystem.
1338  * See if we can find a case-insensitive match in the index that also
1339  * matches the stat information, and assume it's that other file!
1340  */
1341 static int icase_exists(struct unpack_trees_options *o, const char *name, int len, struct stat *st)
1343         struct cache_entry *src;
1345         src = index_name_exists(o->src_index, name, len, 1);
1346         return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
1349 static int check_ok_to_remove(const char *name, int len, int dtype,
1350                               struct cache_entry *ce, struct stat *st,
1351                               enum unpack_trees_error_types error_type,
1352                               struct unpack_trees_options *o)
1354         struct cache_entry *result;
1356         /*
1357          * It may be that the 'lstat()' succeeded even though
1358          * target 'ce' was absent, because there is an old
1359          * entry that is different only in case..
1360          *
1361          * Ignore that lstat() if it matches.
1362          */
1363         if (ignore_case && icase_exists(o, name, len, st))
1364                 return 0;
1366         if (o->dir && excluded(o->dir, name, &dtype))
1367                 /*
1368                  * ce->name is explicitly excluded, so it is Ok to
1369                  * overwrite it.
1370                  */
1371                 return 0;
1372         if (S_ISDIR(st->st_mode)) {
1373                 /*
1374                  * We are checking out path "foo" and
1375                  * found "foo/." in the working tree.
1376                  * This is tricky -- if we have modified
1377                  * files that are in "foo/" we would lose
1378                  * them.
1379                  */
1380                 if (verify_clean_subdirectory(ce, error_type, o) < 0)
1381                         return -1;
1382                 return 0;
1383         }
1385         /*
1386          * The previous round may already have decided to
1387          * delete this path, which is in a subdirectory that
1388          * is being replaced with a blob.
1389          */
1390         result = index_name_exists(&o->result, name, len, 0);
1391         if (result) {
1392                 if (result->ce_flags & CE_REMOVE)
1393                         return 0;
1394         }
1396         return o->gently ? -1 :
1397                 add_rejected_path(o, error_type, name);
1401  * We do not want to remove or overwrite a working tree file that
1402  * is not tracked, unless it is ignored.
1403  */
1404 static int verify_absent_1(struct cache_entry *ce,
1405                                  enum unpack_trees_error_types error_type,
1406                                  struct unpack_trees_options *o)
1408         int len;
1409         struct stat st;
1411         if (o->index_only || o->reset || !o->update)
1412                 return 0;
1414         len = check_leading_path(ce->name, ce_namelen(ce));
1415         if (!len)
1416                 return 0;
1417         else if (len > 0) {
1418                 char path[PATH_MAX + 1];
1419                 memcpy(path, ce->name, len);
1420                 path[len] = 0;
1421                 if (lstat(path, &st))
1422                         return error("cannot stat '%s': %s", path,
1423                                         strerror(errno));
1425                 return check_ok_to_remove(path, len, DT_UNKNOWN, NULL, &st,
1426                                 error_type, o);
1427         } else if (lstat(ce->name, &st)) {
1428                 if (errno != ENOENT)
1429                         return error("cannot stat '%s': %s", ce->name,
1430                                      strerror(errno));
1431                 return 0;
1432         } else {
1433                 return check_ok_to_remove(ce->name, ce_namelen(ce),
1434                                           ce_to_dtype(ce), ce, &st,
1435                                           error_type, o);
1436         }
1439 static int verify_absent(struct cache_entry *ce,
1440                          enum unpack_trees_error_types error_type,
1441                          struct unpack_trees_options *o)
1443         if (!o->skip_sparse_checkout && (ce->ce_flags & CE_NEW_SKIP_WORKTREE))
1444                 return 0;
1445         return verify_absent_1(ce, error_type, o);
1448 static int verify_absent_sparse(struct cache_entry *ce,
1449                          enum unpack_trees_error_types error_type,
1450                          struct unpack_trees_options *o)
1452         enum unpack_trees_error_types orphaned_error = error_type;
1453         if (orphaned_error == ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN)
1454                 orphaned_error = ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN;
1456         return verify_absent_1(ce, orphaned_error, o);
1459 static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
1460                 struct unpack_trees_options *o)
1462         int update = CE_UPDATE;
1464         if (!old) {
1465                 /*
1466                  * New index entries. In sparse checkout, the following
1467                  * verify_absent() will be delayed until after
1468                  * traverse_trees() finishes in unpack_trees(), then:
1469                  *
1470                  *  - CE_NEW_SKIP_WORKTREE will be computed correctly
1471                  *  - verify_absent() be called again, this time with
1472                  *    correct CE_NEW_SKIP_WORKTREE
1473                  *
1474                  * verify_absent() call here does nothing in sparse
1475                  * checkout (i.e. o->skip_sparse_checkout == 0)
1476                  */
1477                 update |= CE_ADDED;
1478                 merge->ce_flags |= CE_NEW_SKIP_WORKTREE;
1480                 if (verify_absent(merge, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o))
1481                         return -1;
1482                 invalidate_ce_path(merge, o);
1483         } else if (!(old->ce_flags & CE_CONFLICTED)) {
1484                 /*
1485                  * See if we can re-use the old CE directly?
1486                  * That way we get the uptodate stat info.
1487                  *
1488                  * This also removes the UPDATE flag on a match; otherwise
1489                  * we will end up overwriting local changes in the work tree.
1490                  */
1491                 if (same(old, merge)) {
1492                         copy_cache_entry(merge, old);
1493                         update = 0;
1494                 } else {
1495                         if (verify_uptodate(old, o))
1496                                 return -1;
1497                         /* Migrate old flags over */
1498                         update |= old->ce_flags & (CE_SKIP_WORKTREE | CE_NEW_SKIP_WORKTREE);
1499                         invalidate_ce_path(old, o);
1500                 }
1501         } else {
1502                 /*
1503                  * Previously unmerged entry left as an existence
1504                  * marker by read_index_unmerged();
1505                  */
1506                 invalidate_ce_path(old, o);
1507         }
1509         add_entry(o, merge, update, CE_STAGEMASK);
1510         return 1;
1513 static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
1514                 struct unpack_trees_options *o)
1516         /* Did it exist in the index? */
1517         if (!old) {
1518                 if (verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_REMOVED, o))
1519                         return -1;
1520                 return 0;
1521         }
1522         if (!(old->ce_flags & CE_CONFLICTED) && verify_uptodate(old, o))
1523                 return -1;
1524         add_entry(o, ce, CE_REMOVE, 0);
1525         invalidate_ce_path(ce, o);
1526         return 1;
1529 static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o)
1531         add_entry(o, ce, 0, 0);
1532         return 1;
1535 #if DBRT_DEBUG
1536 static void show_stage_entry(FILE *o,
1537                              const char *label, const struct cache_entry *ce)
1539         if (!ce)
1540                 fprintf(o, "%s (missing)\n", label);
1541         else
1542                 fprintf(o, "%s%06o %s %d\t%s\n",
1543                         label,
1544                         ce->ce_mode,
1545                         sha1_to_hex(ce->sha1),
1546                         ce_stage(ce),
1547                         ce->name);
1549 #endif
1551 int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o)
1553         struct cache_entry *index;
1554         struct cache_entry *head;
1555         struct cache_entry *remote = stages[o->head_idx + 1];
1556         int count;
1557         int head_match = 0;
1558         int remote_match = 0;
1560         int df_conflict_head = 0;
1561         int df_conflict_remote = 0;
1563         int any_anc_missing = 0;
1564         int no_anc_exists = 1;
1565         int i;
1567         for (i = 1; i < o->head_idx; i++) {
1568                 if (!stages[i] || stages[i] == o->df_conflict_entry)
1569                         any_anc_missing = 1;
1570                 else
1571                         no_anc_exists = 0;
1572         }
1574         index = stages[0];
1575         head = stages[o->head_idx];
1577         if (head == o->df_conflict_entry) {
1578                 df_conflict_head = 1;
1579                 head = NULL;
1580         }
1582         if (remote == o->df_conflict_entry) {
1583                 df_conflict_remote = 1;
1584                 remote = NULL;
1585         }
1587         /*
1588          * First, if there's a #16 situation, note that to prevent #13
1589          * and #14.
1590          */
1591         if (!same(remote, head)) {
1592                 for (i = 1; i < o->head_idx; i++) {
1593                         if (same(stages[i], head)) {
1594                                 head_match = i;
1595                         }
1596                         if (same(stages[i], remote)) {
1597                                 remote_match = i;
1598                         }
1599                 }
1600         }
1602         /*
1603          * We start with cases where the index is allowed to match
1604          * something other than the head: #14(ALT) and #2ALT, where it
1605          * is permitted to match the result instead.
1606          */
1607         /* #14, #14ALT, #2ALT */
1608         if (remote && !df_conflict_head && head_match && !remote_match) {
1609                 if (index && !same(index, remote) && !same(index, head))
1610                         return o->gently ? -1 : reject_merge(index, o);
1611                 return merged_entry(remote, index, o);
1612         }
1613         /*
1614          * If we have an entry in the index cache, then we want to
1615          * make sure that it matches head.
1616          */
1617         if (index && !same(index, head))
1618                 return o->gently ? -1 : reject_merge(index, o);
1620         if (head) {
1621                 /* #5ALT, #15 */
1622                 if (same(head, remote))
1623                         return merged_entry(head, index, o);
1624                 /* #13, #3ALT */
1625                 if (!df_conflict_remote && remote_match && !head_match)
1626                         return merged_entry(head, index, o);
1627         }
1629         /* #1 */
1630         if (!head && !remote && any_anc_missing)
1631                 return 0;
1633         /*
1634          * Under the "aggressive" rule, we resolve mostly trivial
1635          * cases that we historically had git-merge-one-file resolve.
1636          */
1637         if (o->aggressive) {
1638                 int head_deleted = !head;
1639                 int remote_deleted = !remote;
1640                 struct cache_entry *ce = NULL;
1642                 if (index)
1643                         ce = index;
1644                 else if (head)
1645                         ce = head;
1646                 else if (remote)
1647                         ce = remote;
1648                 else {
1649                         for (i = 1; i < o->head_idx; i++) {
1650                                 if (stages[i] && stages[i] != o->df_conflict_entry) {
1651                                         ce = stages[i];
1652                                         break;
1653                                 }
1654                         }
1655                 }
1657                 /*
1658                  * Deleted in both.
1659                  * Deleted in one and unchanged in the other.
1660                  */
1661                 if ((head_deleted && remote_deleted) ||
1662                     (head_deleted && remote && remote_match) ||
1663                     (remote_deleted && head && head_match)) {
1664                         if (index)
1665                                 return deleted_entry(index, index, o);
1666                         if (ce && !head_deleted) {
1667                                 if (verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_REMOVED, o))
1668                                         return -1;
1669                         }
1670                         return 0;
1671                 }
1672                 /*
1673                  * Added in both, identically.
1674                  */
1675                 if (no_anc_exists && head && remote && same(head, remote))
1676                         return merged_entry(head, index, o);
1678         }
1680         /* Below are "no merge" cases, which require that the index be
1681          * up-to-date to avoid the files getting overwritten with
1682          * conflict resolution files.
1683          */
1684         if (index) {
1685                 if (verify_uptodate(index, o))
1686                         return -1;
1687         }
1689         o->nontrivial_merge = 1;
1691         /* #2, #3, #4, #6, #7, #9, #10, #11. */
1692         count = 0;
1693         if (!head_match || !remote_match) {
1694                 for (i = 1; i < o->head_idx; i++) {
1695                         if (stages[i] && stages[i] != o->df_conflict_entry) {
1696                                 keep_entry(stages[i], o);
1697                                 count++;
1698                                 break;
1699                         }
1700                 }
1701         }
1702 #if DBRT_DEBUG
1703         else {
1704                 fprintf(stderr, "read-tree: warning #16 detected\n");
1705                 show_stage_entry(stderr, "head   ", stages[head_match]);
1706                 show_stage_entry(stderr, "remote ", stages[remote_match]);
1707         }
1708 #endif
1709         if (head) { count += keep_entry(head, o); }
1710         if (remote) { count += keep_entry(remote, o); }
1711         return count;
1715  * Two-way merge.
1717  * The rule is to "carry forward" what is in the index without losing
1718  * information across a "fast-forward", favoring a successful merge
1719  * over a merge failure when it makes sense.  For details of the
1720  * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
1722  */
1723 int twoway_merge(struct cache_entry **src, struct unpack_trees_options *o)
1725         struct cache_entry *current = src[0];
1726         struct cache_entry *oldtree = src[1];
1727         struct cache_entry *newtree = src[2];
1729         if (o->merge_size != 2)
1730                 return error("Cannot do a twoway merge of %d trees",
1731                              o->merge_size);
1733         if (oldtree == o->df_conflict_entry)
1734                 oldtree = NULL;
1735         if (newtree == o->df_conflict_entry)
1736                 newtree = NULL;
1738         if (current) {
1739                 if ((!oldtree && !newtree) || /* 4 and 5 */
1740                     (!oldtree && newtree &&
1741                      same(current, newtree)) || /* 6 and 7 */
1742                     (oldtree && newtree &&
1743                      same(oldtree, newtree)) || /* 14 and 15 */
1744                     (oldtree && newtree &&
1745                      !same(oldtree, newtree) && /* 18 and 19 */
1746                      same(current, newtree))) {
1747                         return keep_entry(current, o);
1748                 }
1749                 else if (oldtree && !newtree && same(current, oldtree)) {
1750                         /* 10 or 11 */
1751                         return deleted_entry(oldtree, current, o);
1752                 }
1753                 else if (oldtree && newtree &&
1754                          same(current, oldtree) && !same(current, newtree)) {
1755                         /* 20 or 21 */
1756                         return merged_entry(newtree, current, o);
1757                 }
1758                 else {
1759                         /* all other failures */
1760                         if (oldtree)
1761                                 return o->gently ? -1 : reject_merge(oldtree, o);
1762                         if (current)
1763                                 return o->gently ? -1 : reject_merge(current, o);
1764                         if (newtree)
1765                                 return o->gently ? -1 : reject_merge(newtree, o);
1766                         return -1;
1767                 }
1768         }
1769         else if (newtree) {
1770                 if (oldtree && !o->initial_checkout) {
1771                         /*
1772                          * deletion of the path was staged;
1773                          */
1774                         if (same(oldtree, newtree))
1775                                 return 1;
1776                         return reject_merge(oldtree, o);
1777                 }
1778                 return merged_entry(newtree, current, o);
1779         }
1780         return deleted_entry(oldtree, current, o);
1784  * Bind merge.
1786  * Keep the index entries at stage0, collapse stage1 but make sure
1787  * stage0 does not have anything there.
1788  */
1789 int bind_merge(struct cache_entry **src,
1790                 struct unpack_trees_options *o)
1792         struct cache_entry *old = src[0];
1793         struct cache_entry *a = src[1];
1795         if (o->merge_size != 1)
1796                 return error("Cannot do a bind merge of %d trees",
1797                              o->merge_size);
1798         if (a && old)
1799                 return o->gently ? -1 :
1800                         error(ERRORMSG(o, ERROR_BIND_OVERLAP), a->name, old->name);
1801         if (!a)
1802                 return keep_entry(old, o);
1803         else
1804                 return merged_entry(a, NULL, o);
1808  * One-way merge.
1810  * The rule is:
1811  * - take the stat information from stage0, take the data from stage1
1812  */
1813 int oneway_merge(struct cache_entry **src, struct unpack_trees_options *o)
1815         struct cache_entry *old = src[0];
1816         struct cache_entry *a = src[1];
1818         if (o->merge_size != 1)
1819                 return error("Cannot do a oneway merge of %d trees",
1820                              o->merge_size);
1822         if (!a || a == o->df_conflict_entry)
1823                 return deleted_entry(old, old, o);
1825         if (old && same(old, a)) {
1826                 int update = 0;
1827                 if (o->reset && !ce_uptodate(old) && !ce_skip_worktree(old)) {
1828                         struct stat st;
1829                         if (lstat(old->name, &st) ||
1830                             ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE))
1831                                 update |= CE_UPDATE;
1832                 }
1833                 add_entry(o, old, update, 0);
1834                 return 0;
1835         }
1836         return merged_entry(a, old, o);