t1200: use --topo-order to keep the show-branch output stable.

diff --git a/t/t4000-diff-format.sh b/t/t4000-diff-format.sh
index 91015d76fc5b63e0ffa68eb121bb514aa9a74f8f..beb6d8f4877c157bdf9e3efa2c914e74da863cd5 100755 (executable)
--- a/t/t4000-diff-format.sh
+++ b/t/t4000-diff-format.sh
@@ -7,6 +7,7 @@ test_description='Test built-in diff output engine.
 
 '
 . ./test-lib.sh
+. ../diff-lib.sh
 
 echo >path0 'Line 1
 Line 2
@@ -48,15 +49,6 @@ EOF
 
 test_expect_success \
     'validate git-diff-files -p output.' \
-    'cmp -s current expected'
-
-test_expect_success \
-    'build same diff using git-diff-helper.' \
-    'git-diff-files -z | git-diff-helper -z >current'
-
-
-test_expect_success \
-    'validate git-diff-helper output.' \
-    'cmp -s current expected'
+    'compare_diff_patch current expected'
 
 test_done