builtin/submodule--helper: factor out submodule updating

diff --git a/t/t7502-commit.sh b/t/t7502-commit.sh
index 725687d5d5f26d6535b3f26d1fa221a8c567d57c..d33a3cb331b6c022343aff0bb7091cf8219b40df 100755 (executable)
--- a/t/t7502-commit.sh
+++ b/t/t7502-commit.sh
@@ -171,9 +171,9 @@ test_expect_success 'verbose' '
 
 test_expect_success 'verbose respects diff config' '
 
-       test_config color.diff always &&
+       test_config diff.noprefix true &&
        git status -v >actual &&
-       grep "\[1mdiff --git" actual
+       grep "diff --git negative negative" actual
 '
 
 mesg_with_comment_and_newlines='