[PATCH] Fix `git svn rebase` if top-level HEAD directory exist

[ojab]

Oh hai!
I have a svn repo with the top-level directory named HEAD and `git svn 
rebase [HEAD] [--]` fails with
$ git svn rebase
fatal: ambiguous argument 'HEAD': both revision and filename
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]'
rev-list --first-parent --pretty=medium HEAD: command returned error: 128

Works fine with patch in the attached file. please review.

//wbr ojab
From 522cbc8b8a7c4f2ab4268551a550585753164677 Mon Sep 17 00:00:00 2001
From: ojab <o...@ojab.ru>
Date: Tue, 4 Jun 2013 11:28:16 +0400
Subject: [PATCH] Fix `git svn rebase` if top-level HEAD directory exist
Signed-off-by: ojab <o...@ojab.ru>

---
 git-svn.perl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/git-svn.perl b/git-svn.perl
index d070de0..e35a66a 100755
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -1932,7 +1932,7 @@ sub cmt_sha2rev_batch {
 sub working_head_info {
        my ($head, $refs) = @_;
        my @args = qw/rev-list --first-parent --pretty=medium/;
-       my ($fh, $ctx) = command_output_pipe(@args, $head);
+       my ($fh, $ctx) = command_output_pipe(@args, $head, "--");
        my $hash;
        my %max;
        while (<$fh>) {
-- 
1.8.2