ReflectionParam->getClass() returns null with nullable typehint

[HRMsimon]

<?hh

class A {
  public function b(?A $c) {}
}

var_dump((new ReflectionMethod('A', 'b'))->getParameters()[0]->getClass());

Outputs null when it should be returning a ReflectionClass instance of A (as it does without the nullability type hint)

[paulbiss]

This would appear to be intentional, we seem to forgo setting the type field for any non-vanilla-PHP type annotation, which would cause getClass to be null:

    auto const nonExtendedConstraint =
      fpi.typeConstraint.hasConstraint() &&
      !fpi.typeConstraint.isExtended();
    auto const type = nonExtendedConstraint ? fpi.typeConstraint.typeName()
      : staticEmptyString();

hhvm/hphp/runtime/ext/reflection/ext_reflection.cpp

Lines 644 to 648 in f61be04

	auto const nonExtendedConstraint =
	fpi.typeConstraint.hasConstraint() &&
	!fpi.typeConstraint.isExtended();
	auto const type = nonExtendedConstraint ? fpi.typeConstraint.typeName()
	: staticEmptyString();