FlxSubState: fix close() if used in two different states

[JoeCreates]

If you have persistent substates which you open from multiple parent states, you want the parent state of the substate to change even if the state has already been created, otherwise _parentState will be incorrect when you open the substate from a second location.

[Gama11]

Unit test? :)

[JoeCreates]

I think it would be something like this:

@Test
    @:access(flixel.FlxSubState)
    function testOpenPersistentSubStateFromNewParent()
    {
        var state1 = new FlxState();
        var state2 = new FlxState();
        state1.destroySubStates = false;
        FlxG.state.switchTo(state1);
        step();
        FlxG.state.openSubState(subState1);
        step();

        Assert.areEqual(subState1._parentState, state1);

        subState1.close();
        step();
        FlxG.state.switchTo(state2);
        step();
        FlxG.state.openSubState(subState1);
        step();

        Assert.areEqual(subState1._parentState, state2);
    }

Could you possibly check this over and add it in if it's correct? I can't run hamcrest (I think because I need to change haxe version, which I can't do at the moment).

[Gama11]

I think you meant to call FlxG.switchState() instead of FlxG.state.switchTo()? The latter doesn't really do anything by default / isn't supposed to be called manually.

With that fixed, the test works.

It's a bit unusual to check the value of private fields though.. I usually check whatever effect that would have on the public API, in this case close() not working correctly I guess.

[Gama11]

Thanks!