Re: can I remove or move a tag in a remote repository?

From: Junio C Hamano <junkio@cox.net>
Date: Nov 28, 2006, 21:46 UTC
Message-ID: <7virgz1bz7.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <87wt5rffbm.fsf@rho.meyering.net>

Jim Meyering <jim@meyering.net> writes:

Show 13 quoted lines

> Here's the problem:
> When I try to push the new tags, git-push fails:
>
>   $ git-push -f --tags ssh+git://git.sv.gnu.org/srv/git/coreutils master:refs/heads/master
>   updating 'refs/tags/cvs-head'
>     from 2fd3fd29a8b40be695bc2327c8cd3bd33e521100
>     to   db18f53ffb221e9957124d8af81c11a7e350ac3b
>   ...
>   Total 1, written 1 (delta 0), reused 0 (delta 0)
>   Unpacking 1 objects
>   error: denying non-fast forward; you should pull first
>
> I get the same error also when using --force.

I think this is due to overeager receive.denyNonFastForwards configuration setting at the repository you are pushing into.

I _think_ what receive-pack does in this case is totally wrong. It should either:

 (1) deny overwriting existing tags -- tags are meant to be
     immutable so it should not allow them to be "updated"
     regardless of fast-forwardness, or

 (2) allow overwriting things under refs/tags/ without any
     fast-forward checking.  After all, a tag could point at a
     tree or a blob, and there is no fast-forwardness among
     trees.

The client side check in "git fetch" takes the latter viewpoint, and I think we should be consistent with it.

Johannes, what do you think? Does the following patch look sane to you?

---

diff --git a/receive-pack.c b/receive-pack.c
index 1a141dc..6c3de47 100644
--- a/receive-pack.c
+++ b/receive-pack.c
@@ -120,7 +120,7 @@ static int update(struct command *cmd)
 			     "but I can't find it!", new_hex);
 	}
 	if (deny_non_fast_forwards && !is_null_sha1(new_sha1) &&
-	    !is_null_sha1(old_sha1)) {
+	    !is_null_sha1(old_sha1) && !strncmp(name, "refs/heads/", 11)) {
 		struct commit *old_commit, *new_commit;
 		struct commit_list *bases, *ent;