At present javac don't fire a potentially ambiguous warning in the following cases:

interface I {
    void foo(Consumer<Integer> c);
}

interface J {
    void foo(IntConsumer c);
}

interface K extends I, J { }

--

interface I<T> {
    void foo(Consumer<Integer> c);
    void foo(T c);
}

interface J extends I<IntConsumer> { }

The current implementation should be improved to cover these cases too.

Consider implementing a combo test to check the scheme implementation.