t5520: use test_config to set/unset git config variables

diff --git a/t/t3400-rebase.sh b/t/t3400-rebase.sh
index 1de0ebda25c1034fc1b343a8f0e3da9c2c7f8c6e..f6cc10265700730999174347704a0df6989c7f1b 100755 (executable)
--- a/t/t3400-rebase.sh
+++ b/t/t3400-rebase.sh
@@ -138,8 +138,7 @@ test_expect_success 'rebase a single mode change' '
 '
 
 test_expect_success 'rebase is not broken by diff.renames' '
-       git config diff.renames copies &&
-       test_when_finished "git config --unset diff.renames" &&
+       test_config diff.renames copies &&
        git checkout filemove &&
        GIT_TRACE=1 git rebase force-3way
 '