+test_expect_success 'checkout superproject with subproject already present' '
+ git-checkout initial &&
+ git-checkout master
+'
+
+test_expect_success 'apply submodule diff' '
+ git branch second &&
+ (
+ cd init &&
+ echo s >s &&
+ git add s &&
+ git commit -m "change subproject"
+ ) &&
+ git update-index --add init &&
+ git-commit -m "change init" &&
+ git-format-patch -1 --stdout >P.diff &&
+ git checkout second &&
+ git apply --index P.diff &&
+ D=$(git diff --cached master) &&
+ test -z "$D"
+'
+