get_ref_dir(): return early if directory cannot be read

diff --git a/git-filter-branch.sh b/git-filter-branch.sh
index 6b5f2251b6b5f0b9a43e16296c390e991c6fa13a..add2c0247fa91e0f629428c295fc581f19cf85e1 100755 (executable)
--- a/git-filter-branch.sh
+++ b/git-filter-branch.sh
@@ -12,7 +12,7 @@
 
 functions=$(cat << \EOF
 warn () {
-        echo "$*" >&2
+       echo "$*" >&2
 }
 
 map()
@@ -98,19 +98,17 @@ set_ident () {
 }
 
 USAGE="[--env-filter <command>] [--tree-filter <command>]
-            [--index-filter <command>] [--parent-filter <command>]
-            [--msg-filter <command>] [--commit-filter <command>]
-            [--tag-name-filter <command>] [--subdirectory-filter <directory>]
-            [--original <namespace>] [-d <directory>] [-f | --force]
-            [<rev-list options>...]"
+       [--index-filter <command>] [--parent-filter <command>]
+       [--msg-filter <command>] [--commit-filter <command>]
+       [--tag-name-filter <command>] [--subdirectory-filter <directory>]
+       [--original <namespace>] [-d <directory>] [-f | --force]
+       [<rev-list options>...]"
 
 OPTIONS_SPEC=
 . git-sh-setup
 
 if [ "$(is_bare_repository)" = false ]; then
-       git diff-files --ignore-submodules --quiet &&
-       git diff-index --cached --quiet HEAD -- ||
-       die "Cannot rewrite branch(es) with a dirty working directory."
+       require_clean_work_tree 'rewrite branches'
 fi
 
 tempdir=.git-rewrite