diff options
| -rw-r--r-- | unpack-trees.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/unpack-trees.c b/unpack-trees.c index aa585be1b0..e1b4e996ae 100644 --- a/unpack-trees.c +++ b/unpack-trees.c @@ -436,6 +436,10 @@ static int switch_cache_bottom(struct traverse_info *info) return ret; } +static int fast_forward_merge(int n, unsigned long dirmask, + struct name_entry *names, + struct traverse_info *info); + static int traverse_trees_recursive(int n, unsigned long dirmask, unsigned long df_conflicts, struct name_entry *names, @@ -447,6 +451,11 @@ static int traverse_trees_recursive(int n, unsigned long dirmask, struct traverse_info newinfo; struct name_entry *p; + if (!df_conflicts) { + int status = fast_forward_merge(n, dirmask, names, info); + if (status) + return status; + } p = names; while (!p->mode) p++; @@ -694,6 +703,53 @@ static struct cache_entry *find_cache_entry(struct traverse_info *info, return NULL; } +static int fast_forward_merge(int n, unsigned long dirmask, + struct name_entry *names, + struct traverse_info *info) +{ + int i; + struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, }; + struct unpack_trees_options *o = info->data; + + /* merging two or more trees with an identical subdirectory? */ + if ((n < 2) || ((1UL << n) - 1) != dirmask || + !o->merge || o->reset || o->initial_checkout) + return 0; + for (i = 1; i < n; i++) + if (hashcmp(names[i-1].sha1, names[i].sha1)) + return 0; + + /* + * Instead of descending into the directory, keep the contents + * of the current index. + */ + while (1) { + struct cache_entry *ce; + ce = next_cache_entry(o); + if (!ce) + break; + /* Is the entry still in that directory? */ + if (do_compare_entry(ce, info, names)) + break; + /* + * Note: we do not just run unpack_index_entry() here, + * as the callback may want to compare what is in the + * index with what are from the HEAD and the other tree + * and reject the merge. We pretend that ancestors, the + * HEAD and the other tree all have the same contents as + * the current index, which is a lie, but it works. + */ + for (i = 0; i < n + 1; i++) + src[i] = ce; + mark_ce_used(ce, o); + if (call_unpack_fn(src, o) < 0) + return unpack_failed(o, NULL); + if (ce_stage(ce)) + mark_ce_used_same_name(ce, o); + } + return dirmask; +} + static void debug_path(struct traverse_info *info) { if (info->prev) { |