Re: [PATCH] Use git-update-ref in scripts.

[Linus Torvalds <torvalds@osdl.org>]

On Wed, 28 Sep 2005, Junio C Hamano wrote:
> 
> Hmph.  That sort of makes sense but to make the unconditional
> simple case really fast it should use read-tree -m -u which
> _would_ smudge if things do not go well, which implies you need
> savestate before that which would make it slower -- wouldn't it?

Yeah, we'd have to do something like this.. (untested, surprise, surprise)

NOTE! Even if you don't take this, I noticed what looks like a missing 
"continue" in the "--head" case. That just can't work without it, afaik. 

Not that I know what "--head" is supposed to do.. 

		Linus
---
diff --git a/read-tree.c b/read-tree.c
--- 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_e
 		verify_uptodate(index);
 	}
 
+	nontrivial_merge = 1;
+
 	/* #2, #3, #4, #6, #7, #9, #11. */
 	count = 0;
 	if (!head_match || !remote_match) {
@@ -629,9 +636,15 @@ int main(int argc, char **argv)
 			continue;
 		}
 
+		if (!strcmp(arg, "--trivial")) {
+			trivial_merges_only = 1;
+			continue;
+		}
+
 		if (!strcmp(arg, "--head")) {
 			head_idx = stage - 1;
 			fn = threeway_merge;
+			continue;
 		}
 
 		/* "-m" stands for "merge", meaning we start in stage 1 */