diff-options.txt: describe --stat-{width,name-width,count}
[git/dscho.git] / unpack-trees.c
blob500ebcfd545772fb17e5fb14bba42bf4be468b75
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 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);
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;
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                 printf("Aborting\n");
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)
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) {
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;
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.name = *p;
448         newinfo.pathlen += tree_entry_len(p->path, p->sha1) + 1;
449         newinfo.conflicts |= df_conflicts;
451         for (i = 0; i < n; i++, dirmask >>= 1) {
452                 const unsigned char *sha1 = NULL;
453                 if (dirmask & 1)
454                         sha1 = names[i].sha1;
455                 buf[i] = fill_tree_descriptor(t+i, sha1);
456         }
458         bottom = switch_cache_bottom(&newinfo);
459         ret = traverse_trees(n, t, &newinfo);
460         restore_cache_bottom(&newinfo, bottom);
462         for (i = 0; i < n; i++)
463                 free(buf[i]);
465         return ret;
469  * Compare the traverse-path to the cache entry without actually
470  * having to generate the textual representation of the traverse
471  * path.
473  * NOTE! This *only* compares up to the size of the traverse path
474  * itself - the caller needs to do the final check for the cache
475  * entry having more data at the end!
476  */
477 static int do_compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
479         int len, pathlen, ce_len;
480         const char *ce_name;
482         if (info->prev) {
483                 int cmp = do_compare_entry(ce, info->prev, &info->name);
484                 if (cmp)
485                         return cmp;
486         }
487         pathlen = info->pathlen;
488         ce_len = ce_namelen(ce);
490         /* If ce_len < pathlen then we must have previously hit "name == directory" entry */
491         if (ce_len < pathlen)
492                 return -1;
494         ce_len -= pathlen;
495         ce_name = ce->name + pathlen;
497         len = tree_entry_len(n->path, n->sha1);
498         return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode);
501 static int compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
503         int cmp = do_compare_entry(ce, info, n);
504         if (cmp)
505                 return cmp;
507         /*
508          * Even if the beginning compared identically, the ce should
509          * compare as bigger than a directory leading up to it!
510          */
511         return ce_namelen(ce) > traverse_path_len(info, n);
514 static int ce_in_traverse_path(const struct cache_entry *ce,
515                                const struct traverse_info *info)
517         if (!info->prev)
518                 return 1;
519         if (do_compare_entry(ce, info->prev, &info->name))
520                 return 0;
521         /*
522          * If ce (blob) is the same name as the path (which is a tree
523          * we will be descending into), it won't be inside it.
524          */
525         return (info->pathlen < ce_namelen(ce));
528 static struct cache_entry *create_ce_entry(const struct traverse_info *info, const struct name_entry *n, int stage)
530         int len = traverse_path_len(info, n);
531         struct cache_entry *ce = xcalloc(1, cache_entry_size(len));
533         ce->ce_mode = create_ce_mode(n->mode);
534         ce->ce_flags = create_ce_flags(len, stage);
535         hashcpy(ce->sha1, n->sha1);
536         make_traverse_path(ce->name, info, n);
538         return ce;
541 static int unpack_nondirectories(int n, unsigned long mask,
542                                  unsigned long dirmask,
543                                  struct cache_entry **src,
544                                  const struct name_entry *names,
545                                  const struct traverse_info *info)
547         int i;
548         struct unpack_trees_options *o = info->data;
549         unsigned long conflicts;
551         /* Do we have *only* directories? Nothing to do */
552         if (mask == dirmask && !src[0])
553                 return 0;
555         conflicts = info->conflicts;
556         if (o->merge)
557                 conflicts >>= 1;
558         conflicts |= dirmask;
560         /*
561          * Ok, we've filled in up to any potential index entry in src[0],
562          * now do the rest.
563          */
564         for (i = 0; i < n; i++) {
565                 int stage;
566                 unsigned int bit = 1ul << i;
567                 if (conflicts & bit) {
568                         src[i + o->merge] = o->df_conflict_entry;
569                         continue;
570                 }
571                 if (!(mask & bit))
572                         continue;
573                 if (!o->merge)
574                         stage = 0;
575                 else if (i + 1 < o->head_idx)
576                         stage = 1;
577                 else if (i + 1 > o->head_idx)
578                         stage = 3;
579                 else
580                         stage = 2;
581                 src[i + o->merge] = create_ce_entry(info, names + i, stage);
582         }
584         if (o->merge)
585                 return call_unpack_fn(src, o);
587         for (i = 0; i < n; i++)
588                 if (src[i] && src[i] != o->df_conflict_entry)
589                         add_entry(o, src[i], 0, 0);
590         return 0;
593 static int unpack_failed(struct unpack_trees_options *o, const char *message)
595         discard_index(&o->result);
596         if (!o->gently) {
597                 if (message)
598                         return error("%s", message);
599                 return -1;
600         }
601         return -1;
604 /* NEEDSWORK: give this a better name and share with tree-walk.c */
605 static int name_compare(const char *a, int a_len,
606                         const char *b, int b_len)
608         int len = (a_len < b_len) ? a_len : b_len;
609         int cmp = memcmp(a, b, len);
610         if (cmp)
611                 return cmp;
612         return (a_len - b_len);
616  * The tree traversal is looking at name p.  If we have a matching entry,
617  * return it.  If name p is a directory in the index, do not return
618  * anything, as we will want to match it when the traversal descends into
619  * the directory.
620  */
621 static int find_cache_pos(struct traverse_info *info,
622                           const struct name_entry *p)
624         int pos;
625         struct unpack_trees_options *o = info->data;
626         struct index_state *index = o->src_index;
627         int pfxlen = info->pathlen;
628         int p_len = tree_entry_len(p->path, p->sha1);
630         for (pos = o->cache_bottom; pos < index->cache_nr; pos++) {
631                 struct cache_entry *ce = index->cache[pos];
632                 const char *ce_name, *ce_slash;
633                 int cmp, ce_len;
635                 if (ce->ce_flags & CE_UNPACKED) {
636                         /*
637                          * cache_bottom entry is already unpacked, so
638                          * we can never match it; don't check it
639                          * again.
640                          */
641                         if (pos == o->cache_bottom)
642                                 ++o->cache_bottom;
643                         continue;
644                 }
645                 if (!ce_in_traverse_path(ce, info))
646                         continue;
647                 ce_name = ce->name + pfxlen;
648                 ce_slash = strchr(ce_name, '/');
649                 if (ce_slash)
650                         ce_len = ce_slash - ce_name;
651                 else
652                         ce_len = ce_namelen(ce) - pfxlen;
653                 cmp = name_compare(p->path, p_len, ce_name, ce_len);
654                 /*
655                  * Exact match; if we have a directory we need to
656                  * delay returning it.
657                  */
658                 if (!cmp)
659                         return ce_slash ? -2 - pos : pos;
660                 if (0 < cmp)
661                         continue; /* keep looking */
662                 /*
663                  * ce_name sorts after p->path; could it be that we
664                  * have files under p->path directory in the index?
665                  * E.g.  ce_name == "t-i", and p->path == "t"; we may
666                  * have "t/a" in the index.
667                  */
668                 if (p_len < ce_len && !memcmp(ce_name, p->path, p_len) &&
669                     ce_name[p_len] < '/')
670                         continue; /* keep looking */
671                 break;
672         }
673         return -1;
676 static struct cache_entry *find_cache_entry(struct traverse_info *info,
677                                             const struct name_entry *p)
679         int pos = find_cache_pos(info, p);
680         struct unpack_trees_options *o = info->data;
682         if (0 <= pos)
683                 return o->src_index->cache[pos];
684         else
685                 return NULL;
688 static void debug_path(struct traverse_info *info)
690         if (info->prev) {
691                 debug_path(info->prev);
692                 if (*info->prev->name.path)
693                         putchar('/');
694         }
695         printf("%s", info->name.path);
698 static void debug_name_entry(int i, struct name_entry *n)
700         printf("ent#%d %06o %s\n", i,
701                n->path ? n->mode : 0,
702                n->path ? n->path : "(missing)");
705 static void debug_unpack_callback(int n,
706                                   unsigned long mask,
707                                   unsigned long dirmask,
708                                   struct name_entry *names,
709                                   struct traverse_info *info)
711         int i;
712         printf("* unpack mask %lu, dirmask %lu, cnt %d ",
713                mask, dirmask, n);
714         debug_path(info);
715         putchar('\n');
716         for (i = 0; i < n; i++)
717                 debug_name_entry(i, names + i);
720 static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *names, struct traverse_info *info)
722         struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
723         struct unpack_trees_options *o = info->data;
724         const struct name_entry *p = names;
726         /* Find first entry with a real name (we could use "mask" too) */
727         while (!p->mode)
728                 p++;
730         if (o->debug_unpack)
731                 debug_unpack_callback(n, mask, dirmask, names, info);
733         /* Are we supposed to look at the index too? */
734         if (o->merge) {
735                 while (1) {
736                         int cmp;
737                         struct cache_entry *ce;
739                         if (o->diff_index_cached)
740                                 ce = next_cache_entry(o);
741                         else
742                                 ce = find_cache_entry(info, p);
744                         if (!ce)
745                                 break;
746                         cmp = compare_entry(ce, info, p);
747                         if (cmp < 0) {
748                                 if (unpack_index_entry(ce, o) < 0)
749                                         return unpack_failed(o, NULL);
750                                 continue;
751                         }
752                         if (!cmp) {
753                                 if (ce_stage(ce)) {
754                                         /*
755                                          * If we skip unmerged index
756                                          * entries, we'll skip this
757                                          * entry *and* the tree
758                                          * entries associated with it!
759                                          */
760                                         if (o->skip_unmerged) {
761                                                 add_same_unmerged(ce, o);
762                                                 return mask;
763                                         }
764                                 }
765                                 src[0] = ce;
766                         }
767                         break;
768                 }
769         }
771         if (unpack_nondirectories(n, mask, dirmask, src, names, info) < 0)
772                 return -1;
774         if (src[0]) {
775                 if (ce_stage(src[0]))
776                         mark_ce_used_same_name(src[0], o);
777                 else
778                         mark_ce_used(src[0], o);
779         }
781         /* Now handle any directories.. */
782         if (dirmask) {
783                 unsigned long conflicts = mask & ~dirmask;
784                 if (o->merge) {
785                         conflicts <<= 1;
786                         if (src[0])
787                                 conflicts |= 1;
788                 }
790                 /* special case: "diff-index --cached" looking at a tree */
791                 if (o->diff_index_cached &&
792                     n == 1 && dirmask == 1 && S_ISDIR(names->mode)) {
793                         int matches;
794                         matches = cache_tree_matches_traversal(o->src_index->cache_tree,
795                                                                names, info);
796                         /*
797                          * Everything under the name matches; skip the
798                          * entire hierarchy.  diff_index_cached codepath
799                          * special cases D/F conflicts in such a way that
800                          * it does not do any look-ahead, so this is safe.
801                          */
802                         if (matches) {
803                                 o->cache_bottom += matches;
804                                 return mask;
805                         }
806                 }
808                 if (traverse_trees_recursive(n, dirmask, conflicts,
809                                              names, info) < 0)
810                         return -1;
811                 return mask;
812         }
814         return mask;
817 /* Whole directory matching */
818 static int clear_ce_flags_dir(struct cache_entry **cache, int nr,
819                               char *prefix, int prefix_len,
820                               char *basename,
821                               int select_mask, int clear_mask,
822                               struct exclude_list *el)
824         struct cache_entry **cache_end = cache + nr;
825         int dtype = DT_DIR;
826         int ret = excluded_from_list(prefix, prefix_len, basename, &dtype, el);
828         prefix[prefix_len++] = '/';
830         /* included, no clearing for any entries under this directory */
831         if (!ret) {
832                 for (; cache != cache_end; cache++) {
833                         struct cache_entry *ce = *cache;
834                         if (strncmp(ce->name, prefix, prefix_len))
835                                 break;
836                 }
837                 return nr - (cache_end - cache);
838         }
840         /* excluded, clear all selected entries under this directory. */
841         if (ret == 1) {
842                 for (; cache != cache_end; cache++) {
843                         struct cache_entry *ce = *cache;
844                         if (select_mask && !(ce->ce_flags & select_mask))
845                                 continue;
846                         if (strncmp(ce->name, prefix, prefix_len))
847                                 break;
848                         ce->ce_flags &= ~clear_mask;
849                 }
850                 return nr - (cache_end - cache);
851         }
853         return 0;
857  * Traverse the index, find every entry that matches according to
858  * o->el. Do "ce_flags &= ~clear_mask" on those entries. Return the
859  * number of traversed entries.
861  * If select_mask is non-zero, only entries whose ce_flags has on of
862  * those bits enabled are traversed.
864  * cache        : pointer to an index entry
865  * prefix_len   : an offset to its path
867  * The current path ("prefix") including the trailing '/' is
868  *   cache[0]->name[0..(prefix_len-1)]
869  * Top level path has prefix_len zero.
870  */
871 static int clear_ce_flags_1(struct cache_entry **cache, int nr,
872                             char *prefix, int prefix_len,
873                             int select_mask, int clear_mask,
874                             struct exclude_list *el)
876         struct cache_entry **cache_end = cache + nr;
878         /*
879          * Process all entries that have the given prefix and meet
880          * select_mask condition
881          */
882         while(cache != cache_end) {
883                 struct cache_entry *ce = *cache;
884                 const char *name, *slash;
885                 int len, dtype;
887                 if (select_mask && !(ce->ce_flags & select_mask)) {
888                         cache++;
889                         continue;
890                 }
892                 if (prefix_len && strncmp(ce->name, prefix, prefix_len))
893                         break;
895                 name = ce->name + prefix_len;
896                 slash = strchr(name, '/');
898                 /* If it's a directory, try whole directory match first */
899                 if (slash) {
900                         int processed;
902                         len = slash - name;
903                         memcpy(prefix + prefix_len, name, len);
905                         /*
906                          * terminate the string (no trailing slash),
907                          * clear_c_f_dir needs it
908                          */
909                         prefix[prefix_len + len] = '\0';
910                         processed = clear_ce_flags_dir(cache, cache_end - cache,
911                                                        prefix, prefix_len + len,
912                                                        prefix + prefix_len,
913                                                        select_mask, clear_mask,
914                                                        el);
916                         /* clear_c_f_dir eats a whole dir already? */
917                         if (processed) {
918                                 cache += processed;
919                                 continue;
920                         }
922                         prefix[prefix_len + len++] = '/';
923                         cache += clear_ce_flags_1(cache, cache_end - cache,
924                                                   prefix, prefix_len + len,
925                                                   select_mask, clear_mask, el);
926                         continue;
927                 }
929                 /* Non-directory */
930                 dtype = ce_to_dtype(ce);
931                 if (excluded_from_list(ce->name, ce_namelen(ce), name, &dtype, el) > 0)
932                         ce->ce_flags &= ~clear_mask;
933                 cache++;
934         }
935         return nr - (cache_end - cache);
938 static int clear_ce_flags(struct cache_entry **cache, int nr,
939                             int select_mask, int clear_mask,
940                             struct exclude_list *el)
942         char prefix[PATH_MAX];
943         return clear_ce_flags_1(cache, nr,
944                                 prefix, 0,
945                                 select_mask, clear_mask,
946                                 el);
950  * Set/Clear CE_NEW_SKIP_WORKTREE according to $GIT_DIR/info/sparse-checkout
951  */
952 static void mark_new_skip_worktree(struct exclude_list *el,
953                                    struct index_state *the_index,
954                                    int select_flag, int skip_wt_flag)
956         int i;
958         /*
959          * 1. Pretend the narrowest worktree: only unmerged entries
960          * are checked out
961          */
962         for (i = 0; i < the_index->cache_nr; i++) {
963                 struct cache_entry *ce = the_index->cache[i];
965                 if (select_flag && !(ce->ce_flags & select_flag))
966                         continue;
968                 if (!ce_stage(ce))
969                         ce->ce_flags |= skip_wt_flag;
970                 else
971                         ce->ce_flags &= ~skip_wt_flag;
972         }
974         /*
975          * 2. Widen worktree according to sparse-checkout file.
976          * Matched entries will have skip_wt_flag cleared (i.e. "in")
977          */
978         clear_ce_flags(the_index->cache, the_index->cache_nr,
979                        select_flag, skip_wt_flag, el);
982 static int verify_absent(struct cache_entry *, enum unpack_trees_error_types, struct unpack_trees_options *);
984  * N-way merge "len" trees.  Returns 0 on success, -1 on failure to manipulate the
985  * resulting index, -2 on failure to reflect the changes to the work tree.
987  * CE_ADDED, CE_UNPACKED and CE_NEW_SKIP_WORKTREE are used internally
988  */
989 int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
991         int i, ret;
992         static struct cache_entry *dfc;
993         struct exclude_list el;
995         if (len > MAX_UNPACK_TREES)
996                 die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
997         memset(&state, 0, sizeof(state));
998         state.base_dir = "";
999         state.force = 1;
1000         state.quiet = 1;
1001         state.refresh_cache = 1;
1003         memset(&el, 0, sizeof(el));
1004         if (!core_apply_sparse_checkout || !o->update)
1005                 o->skip_sparse_checkout = 1;
1006         if (!o->skip_sparse_checkout) {
1007                 if (add_excludes_from_file_to_list(git_path("info/sparse-checkout"), "", 0, NULL, &el, 0) < 0)
1008                         o->skip_sparse_checkout = 1;
1009                 else
1010                         o->el = &el;
1011         }
1013         memset(&o->result, 0, sizeof(o->result));
1014         o->result.initialized = 1;
1015         o->result.timestamp.sec = o->src_index->timestamp.sec;
1016         o->result.timestamp.nsec = o->src_index->timestamp.nsec;
1017         o->merge_size = len;
1018         mark_all_ce_unused(o->src_index);
1020         /*
1021          * Sparse checkout loop #1: set NEW_SKIP_WORKTREE on existing entries
1022          */
1023         if (!o->skip_sparse_checkout)
1024                 mark_new_skip_worktree(o->el, o->src_index, 0, CE_NEW_SKIP_WORKTREE);
1026         if (!dfc)
1027                 dfc = xcalloc(1, cache_entry_size(0));
1028         o->df_conflict_entry = dfc;
1030         if (len) {
1031                 const char *prefix = o->prefix ? o->prefix : "";
1032                 struct traverse_info info;
1034                 setup_traverse_info(&info, prefix);
1035                 info.fn = unpack_callback;
1036                 info.data = o;
1037                 info.show_all_errors = o->show_all_errors;
1039                 if (o->prefix) {
1040                         /*
1041                          * Unpack existing index entries that sort before the
1042                          * prefix the tree is spliced into.  Note that o->merge
1043                          * is always true in this case.
1044                          */
1045                         while (1) {
1046                                 struct cache_entry *ce = next_cache_entry(o);
1047                                 if (!ce)
1048                                         break;
1049                                 if (ce_in_traverse_path(ce, &info))
1050                                         break;
1051                                 if (unpack_index_entry(ce, o) < 0)
1052                                         goto return_failed;
1053                         }
1054                 }
1056                 if (traverse_trees(len, t, &info) < 0)
1057                         goto return_failed;
1058         }
1060         /* Any left-over entries in the index? */
1061         if (o->merge) {
1062                 while (1) {
1063                         struct cache_entry *ce = next_cache_entry(o);
1064                         if (!ce)
1065                                 break;
1066                         if (unpack_index_entry(ce, o) < 0)
1067                                 goto return_failed;
1068                 }
1069         }
1070         mark_all_ce_unused(o->src_index);
1072         if (o->trivial_merges_only && o->nontrivial_merge) {
1073                 ret = unpack_failed(o, "Merge requires file-level merging");
1074                 goto done;
1075         }
1077         if (!o->skip_sparse_checkout) {
1078                 int empty_worktree = 1;
1080                 /*
1081                  * Sparse checkout loop #2: set NEW_SKIP_WORKTREE on entries not in loop #1
1082                  * If the will have NEW_SKIP_WORKTREE, also set CE_SKIP_WORKTREE
1083                  * so apply_sparse_checkout() won't attempt to remove it from worktree
1084                  */
1085                 mark_new_skip_worktree(o->el, &o->result, CE_ADDED, CE_SKIP_WORKTREE | CE_NEW_SKIP_WORKTREE);
1087                 for (i = 0; i < o->result.cache_nr; i++) {
1088                         struct cache_entry *ce = o->result.cache[i];
1090                         /*
1091                          * Entries marked with CE_ADDED in merged_entry() do not have
1092                          * verify_absent() check (the check is effectively disabled
1093                          * because CE_NEW_SKIP_WORKTREE is set unconditionally).
1094                          *
1095                          * Do the real check now because we have had
1096                          * correct CE_NEW_SKIP_WORKTREE
1097                          */
1098                         if (ce->ce_flags & CE_ADDED &&
1099                             verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o))
1100                                         return -1;
1102                         if (apply_sparse_checkout(ce, o)) {
1103                                 ret = -1;
1104                                 goto done;
1105                         }
1106                         if (!ce_skip_worktree(ce))
1107                                 empty_worktree = 0;
1109                 }
1110                 if (o->result.cache_nr && empty_worktree) {
1111                         /* dubious---why should this fail??? */
1112                         ret = unpack_failed(o, "Sparse checkout leaves no entry on working directory");
1113                         goto done;
1114                 }
1115         }
1117         o->src_index = NULL;
1118         ret = check_updates(o) ? (-2) : 0;
1119         if (o->dst_index)
1120                 *o->dst_index = o->result;
1122 done:
1123         free_excludes(&el);
1124         return ret;
1126 return_failed:
1127         if (o->show_all_errors)
1128                 display_error_msgs(o);
1129         mark_all_ce_unused(o->src_index);
1130         ret = unpack_failed(o, NULL);
1131         goto done;
1134 /* Here come the merge functions */
1136 static int reject_merge(struct cache_entry *ce, struct unpack_trees_options *o)
1138         return add_rejected_path(o, ERROR_WOULD_OVERWRITE, ce->name);
1141 static int same(struct cache_entry *a, struct cache_entry *b)
1143         if (!!a != !!b)
1144                 return 0;
1145         if (!a && !b)
1146                 return 1;
1147         if ((a->ce_flags | b->ce_flags) & CE_CONFLICTED)
1148                 return 0;
1149         return a->ce_mode == b->ce_mode &&
1150                !hashcmp(a->sha1, b->sha1);
1155  * When a CE gets turned into an unmerged entry, we
1156  * want it to be up-to-date
1157  */
1158 static int verify_uptodate_1(struct cache_entry *ce,
1159                                    struct unpack_trees_options *o,
1160                                    enum unpack_trees_error_types error_type)
1162         struct stat st;
1164         if (o->index_only || (!((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) && (o->reset || ce_uptodate(ce))))
1165                 return 0;
1167         if (!lstat(ce->name, &st)) {
1168                 unsigned changed = ie_match_stat(o->src_index, ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
1169                 if (!changed)
1170                         return 0;
1171                 /*
1172                  * NEEDSWORK: the current default policy is to allow
1173                  * submodule to be out of sync wrt the supermodule
1174                  * index.  This needs to be tightened later for
1175                  * submodules that are marked to be automatically
1176                  * checked out.
1177                  */
1178                 if (S_ISGITLINK(ce->ce_mode))
1179                         return 0;
1180                 errno = 0;
1181         }
1182         if (errno == ENOENT)
1183                 return 0;
1184         return o->gently ? -1 :
1185                 add_rejected_path(o, error_type, ce->name);
1188 static int verify_uptodate(struct cache_entry *ce,
1189                            struct unpack_trees_options *o)
1191         if (!o->skip_sparse_checkout && (ce->ce_flags & CE_NEW_SKIP_WORKTREE))
1192                 return 0;
1193         return verify_uptodate_1(ce, o, ERROR_NOT_UPTODATE_FILE);
1196 static int verify_uptodate_sparse(struct cache_entry *ce,
1197                                   struct unpack_trees_options *o)
1199         return verify_uptodate_1(ce, o, ERROR_SPARSE_NOT_UPTODATE_FILE);
1202 static void invalidate_ce_path(struct cache_entry *ce, struct unpack_trees_options *o)
1204         if (ce)
1205                 cache_tree_invalidate_path(o->src_index->cache_tree, ce->name);
1209  * Check that checking out ce->sha1 in subdir ce->name is not
1210  * going to overwrite any working files.
1212  * Currently, git does not checkout subprojects during a superproject
1213  * checkout, so it is not going to overwrite anything.
1214  */
1215 static int verify_clean_submodule(struct cache_entry *ce,
1216                                       enum unpack_trees_error_types error_type,
1217                                       struct unpack_trees_options *o)
1219         return 0;
1222 static int verify_clean_subdirectory(struct cache_entry *ce,
1223                                       enum unpack_trees_error_types error_type,
1224                                       struct unpack_trees_options *o)
1226         /*
1227          * we are about to extract "ce->name"; we would not want to lose
1228          * anything in the existing directory there.
1229          */
1230         int namelen;
1231         int i;
1232         struct dir_struct d;
1233         char *pathbuf;
1234         int cnt = 0;
1235         unsigned char sha1[20];
1237         if (S_ISGITLINK(ce->ce_mode) &&
1238             resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
1239                 /* If we are not going to update the submodule, then
1240                  * we don't care.
1241                  */
1242                 if (!hashcmp(sha1, ce->sha1))
1243                         return 0;
1244                 return verify_clean_submodule(ce, error_type, o);
1245         }
1247         /*
1248          * First let's make sure we do not have a local modification
1249          * in that directory.
1250          */
1251         namelen = strlen(ce->name);
1252         for (i = locate_in_src_index(ce, o);
1253              i < o->src_index->cache_nr;
1254              i++) {
1255                 struct cache_entry *ce2 = o->src_index->cache[i];
1256                 int len = ce_namelen(ce2);
1257                 if (len < namelen ||
1258                     strncmp(ce->name, ce2->name, namelen) ||
1259                     ce2->name[namelen] != '/')
1260                         break;
1261                 /*
1262                  * ce2->name is an entry in the subdirectory to be
1263                  * removed.
1264                  */
1265                 if (!ce_stage(ce2)) {
1266                         if (verify_uptodate(ce2, o))
1267                                 return -1;
1268                         add_entry(o, ce2, CE_REMOVE, 0);
1269                         mark_ce_used(ce2, o);
1270                 }
1271                 cnt++;
1272         }
1274         /*
1275          * Then we need to make sure that we do not lose a locally
1276          * present file that is not ignored.
1277          */
1278         pathbuf = xmalloc(namelen + 2);
1279         memcpy(pathbuf, ce->name, namelen);
1280         strcpy(pathbuf+namelen, "/");
1282         memset(&d, 0, sizeof(d));
1283         if (o->dir)
1284                 d.exclude_per_dir = o->dir->exclude_per_dir;
1285         i = read_directory(&d, pathbuf, namelen+1, NULL);
1286         if (i)
1287                 return o->gently ? -1 :
1288                         add_rejected_path(o, ERROR_NOT_UPTODATE_DIR, ce->name);
1289         free(pathbuf);
1290         return cnt;
1294  * This gets called when there was no index entry for the tree entry 'dst',
1295  * but we found a file in the working tree that 'lstat()' said was fine,
1296  * and we're on a case-insensitive filesystem.
1298  * See if we can find a case-insensitive match in the index that also
1299  * matches the stat information, and assume it's that other file!
1300  */
1301 static int icase_exists(struct unpack_trees_options *o, const char *name, int len, struct stat *st)
1303         struct cache_entry *src;
1305         src = index_name_exists(o->src_index, name, len, 1);
1306         return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
1309 static int check_ok_to_remove(const char *name, int len, int dtype,
1310                               struct cache_entry *ce, struct stat *st,
1311                               enum unpack_trees_error_types error_type,
1312                               struct unpack_trees_options *o)
1314         struct cache_entry *result;
1316         /*
1317          * It may be that the 'lstat()' succeeded even though
1318          * target 'ce' was absent, because there is an old
1319          * entry that is different only in case..
1320          *
1321          * Ignore that lstat() if it matches.
1322          */
1323         if (ignore_case && icase_exists(o, name, len, st))
1324                 return 0;
1326         if (o->dir && excluded(o->dir, name, &dtype))
1327                 /*
1328                  * ce->name is explicitly excluded, so it is Ok to
1329                  * overwrite it.
1330                  */
1331                 return 0;
1332         if (S_ISDIR(st->st_mode)) {
1333                 /*
1334                  * We are checking out path "foo" and
1335                  * found "foo/." in the working tree.
1336                  * This is tricky -- if we have modified
1337                  * files that are in "foo/" we would lose
1338                  * them.
1339                  */
1340                 if (verify_clean_subdirectory(ce, error_type, o) < 0)
1341                         return -1;
1342                 return 0;
1343         }
1345         /*
1346          * The previous round may already have decided to
1347          * delete this path, which is in a subdirectory that
1348          * is being replaced with a blob.
1349          */
1350         result = index_name_exists(&o->result, name, len, 0);
1351         if (result) {
1352                 if (result->ce_flags & CE_REMOVE)
1353                         return 0;
1354         }
1356         return o->gently ? -1 :
1357                 add_rejected_path(o, error_type, name);
1361  * We do not want to remove or overwrite a working tree file that
1362  * is not tracked, unless it is ignored.
1363  */
1364 static int verify_absent_1(struct cache_entry *ce,
1365                                  enum unpack_trees_error_types error_type,
1366                                  struct unpack_trees_options *o)
1368         int len;
1369         struct stat st;
1371         if (o->index_only || o->reset || !o->update)
1372                 return 0;
1374         len = check_leading_path(ce->name, ce_namelen(ce));
1375         if (!len)
1376                 return 0;
1377         else if (len > 0) {
1378                 char path[PATH_MAX + 1];
1379                 memcpy(path, ce->name, len);
1380                 path[len] = 0;
1381                 if (lstat(path, &st))
1382                         return error("cannot stat '%s': %s", path,
1383                                         strerror(errno));
1385                 return check_ok_to_remove(path, len, DT_UNKNOWN, NULL, &st,
1386                                 error_type, o);
1387         } else if (lstat(ce->name, &st)) {
1388                 if (errno != ENOENT)
1389                         return error("cannot stat '%s': %s", ce->name,
1390                                      strerror(errno));
1391                 return 0;
1392         } else {
1393                 return check_ok_to_remove(ce->name, ce_namelen(ce),
1394                                           ce_to_dtype(ce), ce, &st,
1395                                           error_type, o);
1396         }
1399 static int verify_absent(struct cache_entry *ce,
1400                          enum unpack_trees_error_types error_type,
1401                          struct unpack_trees_options *o)
1403         if (!o->skip_sparse_checkout && (ce->ce_flags & CE_NEW_SKIP_WORKTREE))
1404                 return 0;
1405         return verify_absent_1(ce, error_type, o);
1408 static int verify_absent_sparse(struct cache_entry *ce,
1409                          enum unpack_trees_error_types error_type,
1410                          struct unpack_trees_options *o)
1412         enum unpack_trees_error_types orphaned_error = error_type;
1413         if (orphaned_error == ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN)
1414                 orphaned_error = ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN;
1416         return verify_absent_1(ce, orphaned_error, o);
1419 static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
1420                 struct unpack_trees_options *o)
1422         int update = CE_UPDATE;
1424         if (!old) {
1425                 /*
1426                  * New index entries. In sparse checkout, the following
1427                  * verify_absent() will be delayed until after
1428                  * traverse_trees() finishes in unpack_trees(), then:
1429                  *
1430                  *  - CE_NEW_SKIP_WORKTREE will be computed correctly
1431                  *  - verify_absent() be called again, this time with
1432                  *    correct CE_NEW_SKIP_WORKTREE
1433                  *
1434                  * verify_absent() call here does nothing in sparse
1435                  * checkout (i.e. o->skip_sparse_checkout == 0)
1436                  */
1437                 update |= CE_ADDED;
1438                 merge->ce_flags |= CE_NEW_SKIP_WORKTREE;
1440                 if (verify_absent(merge, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o))
1441                         return -1;
1442                 invalidate_ce_path(merge, o);
1443         } else if (!(old->ce_flags & CE_CONFLICTED)) {
1444                 /*
1445                  * See if we can re-use the old CE directly?
1446                  * That way we get the uptodate stat info.
1447                  *
1448                  * This also removes the UPDATE flag on a match; otherwise
1449                  * we will end up overwriting local changes in the work tree.
1450                  */
1451                 if (same(old, merge)) {
1452                         copy_cache_entry(merge, old);
1453                         update = 0;
1454                 } else {
1455                         if (verify_uptodate(old, o))
1456                                 return -1;
1457                         /* Migrate old flags over */
1458                         update |= old->ce_flags & (CE_SKIP_WORKTREE | CE_NEW_SKIP_WORKTREE);
1459                         invalidate_ce_path(old, o);
1460                 }
1461         } else {
1462                 /*
1463                  * Previously unmerged entry left as an existence
1464                  * marker by read_index_unmerged();
1465                  */
1466                 invalidate_ce_path(old, o);
1467         }
1469         add_entry(o, merge, update, CE_STAGEMASK);
1470         return 1;
1473 static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
1474                 struct unpack_trees_options *o)
1476         /* Did it exist in the index? */
1477         if (!old) {
1478                 if (verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_REMOVED, o))
1479                         return -1;
1480                 return 0;
1481         }
1482         if (!(old->ce_flags & CE_CONFLICTED) && verify_uptodate(old, o))
1483                 return -1;
1484         add_entry(o, ce, CE_REMOVE, 0);
1485         invalidate_ce_path(ce, o);
1486         return 1;
1489 static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o)
1491         add_entry(o, ce, 0, 0);
1492         return 1;
1495 #if DBRT_DEBUG
1496 static void show_stage_entry(FILE *o,
1497                              const char *label, const struct cache_entry *ce)
1499         if (!ce)
1500                 fprintf(o, "%s (missing)\n", label);
1501         else
1502                 fprintf(o, "%s%06o %s %d\t%s\n",
1503                         label,
1504                         ce->ce_mode,
1505                         sha1_to_hex(ce->sha1),
1506                         ce_stage(ce),
1507                         ce->name);
1509 #endif
1511 int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o)
1513         struct cache_entry *index;
1514         struct cache_entry *head;
1515         struct cache_entry *remote = stages[o->head_idx + 1];
1516         int count;
1517         int head_match = 0;
1518         int remote_match = 0;
1520         int df_conflict_head = 0;
1521         int df_conflict_remote = 0;
1523         int any_anc_missing = 0;
1524         int no_anc_exists = 1;
1525         int i;
1527         for (i = 1; i < o->head_idx; i++) {
1528                 if (!stages[i] || stages[i] == o->df_conflict_entry)
1529                         any_anc_missing = 1;
1530                 else
1531                         no_anc_exists = 0;
1532         }
1534         index = stages[0];
1535         head = stages[o->head_idx];
1537         if (head == o->df_conflict_entry) {
1538                 df_conflict_head = 1;
1539                 head = NULL;
1540         }
1542         if (remote == o->df_conflict_entry) {
1543                 df_conflict_remote = 1;
1544                 remote = NULL;
1545         }
1547         /*
1548          * First, if there's a #16 situation, note that to prevent #13
1549          * and #14.
1550          */
1551         if (!same(remote, head)) {
1552                 for (i = 1; i < o->head_idx; i++) {
1553                         if (same(stages[i], head)) {
1554                                 head_match = i;
1555                         }
1556                         if (same(stages[i], remote)) {
1557                                 remote_match = i;
1558                         }
1559                 }
1560         }
1562         /*
1563          * We start with cases where the index is allowed to match
1564          * something other than the head: #14(ALT) and #2ALT, where it
1565          * is permitted to match the result instead.
1566          */
1567         /* #14, #14ALT, #2ALT */
1568         if (remote && !df_conflict_head && head_match && !remote_match) {
1569                 if (index && !same(index, remote) && !same(index, head))
1570                         return o->gently ? -1 : reject_merge(index, o);
1571                 return merged_entry(remote, index, o);
1572         }
1573         /*
1574          * If we have an entry in the index cache, then we want to
1575          * make sure that it matches head.
1576          */
1577         if (index && !same(index, head))
1578                 return o->gently ? -1 : reject_merge(index, o);
1580         if (head) {
1581                 /* #5ALT, #15 */
1582                 if (same(head, remote))
1583                         return merged_entry(head, index, o);
1584                 /* #13, #3ALT */
1585                 if (!df_conflict_remote && remote_match && !head_match)
1586                         return merged_entry(head, index, o);
1587         }
1589         /* #1 */
1590         if (!head && !remote && any_anc_missing)
1591                 return 0;
1593         /*
1594          * Under the "aggressive" rule, we resolve mostly trivial
1595          * cases that we historically had git-merge-one-file resolve.
1596          */
1597         if (o->aggressive) {
1598                 int head_deleted = !head;
1599                 int remote_deleted = !remote;
1600                 struct cache_entry *ce = NULL;
1602                 if (index)
1603                         ce = index;
1604                 else if (head)
1605                         ce = head;
1606                 else if (remote)
1607                         ce = remote;
1608                 else {
1609                         for (i = 1; i < o->head_idx; i++) {
1610                                 if (stages[i] && stages[i] != o->df_conflict_entry) {
1611                                         ce = stages[i];
1612                                         break;
1613                                 }
1614                         }
1615                 }
1617                 /*
1618                  * Deleted in both.
1619                  * Deleted in one and unchanged in the other.
1620                  */
1621                 if ((head_deleted && remote_deleted) ||
1622                     (head_deleted && remote && remote_match) ||
1623                     (remote_deleted && head && head_match)) {
1624                         if (index)
1625                                 return deleted_entry(index, index, o);
1626                         if (ce && !head_deleted) {
1627                                 if (verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_REMOVED, o))
1628                                         return -1;
1629                         }
1630                         return 0;
1631                 }
1632                 /*
1633                  * Added in both, identically.
1634                  */
1635                 if (no_anc_exists && head && remote && same(head, remote))
1636                         return merged_entry(head, index, o);
1638         }
1640         /* Below are "no merge" cases, which require that the index be
1641          * up-to-date to avoid the files getting overwritten with
1642          * conflict resolution files.
1643          */
1644         if (index) {
1645                 if (verify_uptodate(index, o))
1646                         return -1;
1647         }
1649         o->nontrivial_merge = 1;
1651         /* #2, #3, #4, #6, #7, #9, #10, #11. */
1652         count = 0;
1653         if (!head_match || !remote_match) {
1654                 for (i = 1; i < o->head_idx; i++) {
1655                         if (stages[i] && stages[i] != o->df_conflict_entry) {
1656                                 keep_entry(stages[i], o);
1657                                 count++;
1658                                 break;
1659                         }
1660                 }
1661         }
1662 #if DBRT_DEBUG
1663         else {
1664                 fprintf(stderr, "read-tree: warning #16 detected\n");
1665                 show_stage_entry(stderr, "head   ", stages[head_match]);
1666                 show_stage_entry(stderr, "remote ", stages[remote_match]);
1667         }
1668 #endif
1669         if (head) { count += keep_entry(head, o); }
1670         if (remote) { count += keep_entry(remote, o); }
1671         return count;
1675  * Two-way merge.
1677  * The rule is to "carry forward" what is in the index without losing
1678  * information across a "fast-forward", favoring a successful merge
1679  * over a merge failure when it makes sense.  For details of the
1680  * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
1682  */
1683 int twoway_merge(struct cache_entry **src, struct unpack_trees_options *o)
1685         struct cache_entry *current = src[0];
1686         struct cache_entry *oldtree = src[1];
1687         struct cache_entry *newtree = src[2];
1689         if (o->merge_size != 2)
1690                 return error("Cannot do a twoway merge of %d trees",
1691                              o->merge_size);
1693         if (oldtree == o->df_conflict_entry)
1694                 oldtree = NULL;
1695         if (newtree == o->df_conflict_entry)
1696                 newtree = NULL;
1698         if (current) {
1699                 if ((!oldtree && !newtree) || /* 4 and 5 */
1700                     (!oldtree && newtree &&
1701                      same(current, newtree)) || /* 6 and 7 */
1702                     (oldtree && newtree &&
1703                      same(oldtree, newtree)) || /* 14 and 15 */
1704                     (oldtree && newtree &&
1705                      !same(oldtree, newtree) && /* 18 and 19 */
1706                      same(current, newtree))) {
1707                         return keep_entry(current, o);
1708                 }
1709                 else if (oldtree && !newtree && same(current, oldtree)) {
1710                         /* 10 or 11 */
1711                         return deleted_entry(oldtree, current, o);
1712                 }
1713                 else if (oldtree && newtree &&
1714                          same(current, oldtree) && !same(current, newtree)) {
1715                         /* 20 or 21 */
1716                         return merged_entry(newtree, current, o);
1717                 }
1718                 else {
1719                         /* all other failures */
1720                         if (oldtree)
1721                                 return o->gently ? -1 : reject_merge(oldtree, o);
1722                         if (current)
1723                                 return o->gently ? -1 : reject_merge(current, o);
1724                         if (newtree)
1725                                 return o->gently ? -1 : reject_merge(newtree, o);
1726                         return -1;
1727                 }
1728         }
1729         else if (newtree) {
1730                 if (oldtree && !o->initial_checkout) {
1731                         /*
1732                          * deletion of the path was staged;
1733                          */
1734                         if (same(oldtree, newtree))
1735                                 return 1;
1736                         return reject_merge(oldtree, o);
1737                 }
1738                 return merged_entry(newtree, current, o);
1739         }
1740         return deleted_entry(oldtree, current, o);
1744  * Bind merge.
1746  * Keep the index entries at stage0, collapse stage1 but make sure
1747  * stage0 does not have anything there.
1748  */
1749 int bind_merge(struct cache_entry **src,
1750                 struct unpack_trees_options *o)
1752         struct cache_entry *old = src[0];
1753         struct cache_entry *a = src[1];
1755         if (o->merge_size != 1)
1756                 return error("Cannot do a bind merge of %d trees\n",
1757                              o->merge_size);
1758         if (a && old)
1759                 return o->gently ? -1 :
1760                         error(ERRORMSG(o, ERROR_BIND_OVERLAP), a->name, old->name);
1761         if (!a)
1762                 return keep_entry(old, o);
1763         else
1764                 return merged_entry(a, NULL, o);
1768  * One-way merge.
1770  * The rule is:
1771  * - take the stat information from stage0, take the data from stage1
1772  */
1773 int oneway_merge(struct cache_entry **src, struct unpack_trees_options *o)
1775         struct cache_entry *old = src[0];
1776         struct cache_entry *a = src[1];
1778         if (o->merge_size != 1)
1779                 return error("Cannot do a oneway merge of %d trees",
1780                              o->merge_size);
1782         if (!a || a == o->df_conflict_entry)
1783                 return deleted_entry(old, old, o);
1785         if (old && same(old, a)) {
1786                 int update = 0;
1787                 if (o->reset && !ce_uptodate(old) && !ce_skip_worktree(old)) {
1788                         struct stat st;
1789                         if (lstat(old->name, &st) ||
1790                             ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE))
1791                                 update |= CE_UPDATE;
1792                 }
1793                 add_entry(o, old, update, 0);
1794                 return 0;
1795         }
1796         return merged_entry(a, old, o);