refs: implement simple transactions for the packed-refs file

diff --git a/t/t7400-submodule-basic.sh b/t/t7400-submodule-basic.sh
index af0248d48fb2ff7b8e26047230ed988af643a483..ff265353a375d02bb578fed29ea00f07dc08a6fc 100755 (executable)
--- a/t/t7400-submodule-basic.sh
+++ b/t/t7400-submodule-basic.sh
@@ -133,6 +133,7 @@ test_expect_success 'submodule add --branch' '
        (
                cd addtest &&
                git submodule add -b initial "$submodurl" submod-branch &&
+               test "initial" = "$(git config -f .gitmodules submodule.submod-branch.branch)" &&
                git submodule init
        ) &&