Re: [PATCH v6 09/10] submodule: support reading .gitmodules when it's not in the working tree

+test_expect_success 'not writing gitmodules config file when it is not checked out' '
+        test_must_fail git -C super submodule--helper config submodule.submodule.url newurl

This only checks the exit code, do we also want to check for

    test_path_is_missing .gitmodules ?

+test_expect_success 'initialising submodule when the gitmodules config is not checked out' '
+       git -C super submodule init
+'
+
+test_expect_success 'showing submodule summary when the gitmodules config is not checked out' '
+       git -C super submodule summary
+'

Same for these, is the exit code enough, or do we want to look at
specific things?

+
+test_expect_success 'updating submodule when the gitmodules config is not checked out' '
+       (cd submodule &&
+               echo file2 >file2 &&
+               git add file2 &&
+               git commit -m "add file2 to submodule"
+       ) &&
+       git -C super submodule update

git status would want to be clean afterwards?