This is similar to bug 6695.
class Foo {}
class Bar : Foo
{
void func() immutable {
pragma(msg, typeof(this)); // immutable(Bar)
auto t = this;
pragma(msg, typeof(t)); // immutable(Bar)
pragma(msg, typeof(super)); // Foo instead of immutable(Foo)
auto s = super;
pragma(msg, typeof(s)); // Foo instead of immutable(Foo)
}
}