git-branch: add -r switch to list refs/remotes/*

If we decide to use refs/remotes/, having a convenient way to
list them would be nice.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>

git-branch.sh

@@ -48,6 +48,12 @@ If you are sure you want to delete it, run 'git branch -D $branch_name'."
     exit 0
 }
 
+ls_remote_branches () {
+    git-rev-parse --symbolic --all |
+    sed -ne 's|^refs/\(remotes/\)|\1|p' |
+    sort
+}
+
 force=
 while case "$#,$1" in 0,*) break ;; *,-*) ;; *) break ;; esac
 do
@@ -56,6 +62,10 @@ do
 		delete_branch "$@"
 		exit
 		;;
+	-r)
+		ls_remote_branches
+		exit
+		;;
 	-f)
 		force="$1"
 		;;