read-tree: --trivial

This adds an option --trivial to restrict 3-way 'read-tree -m -u'
to happen only if there is no file-level merging required.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/read-tree.c b/read-tree.c
index 390fe2f..5fdf58d 100644 (file)
--- a/read-tree.c
+++ b/read-tree.c
@@ -13,6 +13,8 @@
 static int merge = 0;
 static int update = 0;
 static int index_only = 0;
+static int nontrivial_merge = 0;
+static int trivial_merges_only = 0;
 
 static int head_idx = -1;
 static int merge_size = 0;
@@ -275,6 +277,9 @@ static int unpack_trees(merge_fn_t fn)
        if (unpack_trees_rec(posns, len, "", fn, &indpos))
                return -1;
 
+       if (trivial_merges_only && nontrivial_merge)
+               die("Merge requires file-level merging");
+
        check_updates(active_cache, active_nr);
        return 0;
 }
@@ -460,6 +465,8 @@ static int threeway_merge(struct cache_entry **stages)
                verify_uptodate(index);
        }
 
+       nontrivial_merge = 1;
+
        /* #2, #3, #4, #6, #7, #9, #11. */
        count = 0;
        if (!head_match || !remote_match) {
@@ -629,6 +636,11 @@ int main(int argc, char **argv)
                        continue;
                }
 
+               if (!strcmp(arg, "--trivial")) {
+                       trivial_merges_only = 1;
+                       continue;
+               }
+
                /* "-m" stands for "merge", meaning we start in stage 1 */
                if (!strcmp(arg, "-m")) {
                        if (stage || merge)