[PATCH] Improve error message about fetch into current branch

Otherwise, it is hard to guess why the fetch failed.
Make sure we at least mention that the repository must be bare.
Also the current branch is printed.

Signed-off-by: Alex Riesen <redacted>
---

In particular, a repository not marked bare with core.bare is, for
some reason, considered non-bare even if there is no work tree nor
index. I found about the message while trying to run git remote,
in an essentially bare repository without core.bare set. Funny,
git --bare fetch worked properly, but git --bare remote update failed:

    $ GIT_TRACE=1 ~/projects/git/git --bare remote -v update
    trace: built-in: git 'remote' '-v' 'update'
    Updating origin
    trace: run_command: 'fetch' '-v' 'origin'
    trace: exec: 'git' 'fetch' '-v' 'origin'
    trace: built-in: git 'fetch' '-v' 'origin'
    fatal: Refusing to fetch into current branch refs/heads/master
    error: Could not fetch origin
    $ git --bare fetch -v origin
    From git://git.kernel.org/pub/scm/linux/hotplug/udev
     = [up to date]      master     -> master
    $

Looks like --bare is lost somewhere.

 builtin-fetch.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/builtin-fetch.c b/builtin-fetch.c
index 7fb35fc..7293146 100644
--- a/builtin-fetch.c
+++ b/builtin-fetch.c

@@ -544,7 +544,8 @@ static void check_not_current_branch(struct ref *ref_map)
 	for (; ref_map; ref_map = ref_map->next)
 		if (ref_map->peer_ref && !strcmp(current_branch->refname,
 					ref_map->peer_ref->name))
-			die("Refusing to fetch into current branch");
+			die("Refusing to fetch into current branch %s "
+			    "of non-bare repository", current_branch->refname);
 }
 
 static int do_fetch(struct transport *transport,

-- 
1.6.2.1.316.g4241