[PATCH] Improve error message about fetch into current branch

[Alex Riesen <raa.lkml@gmail.com>]

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 <raa.lkml@gmail.com>
---

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