8.2 height calculation error

HorizontalLayouts which have no components in them have non-zero height, but apparently aren't included in height calculation, which causes issues with calculating the height of expanding components.

Sample:

public class LayoutCalculation extends VerticalLayout {

    public LayoutCalculation() {
        setSizeFull();
        addComponent(new HorizontalLayout());
        Panel p = new Panel();
        p.setSizeFull();
        addComponent(p);
        setExpandRatio(p, 1.0f);
        addComponent(new HorizontalLayout());
        addComponent(new Button("TEST"));
    }

}

The button will be rendered partially outside the screen.

Start by reproducing the LayoutCalculation sample with empty HorizontalLayout instances, an expanding Panel, and the Button. Trace the layout height-calculation entry points for HorizontalLayout and VerticalLayout; done means empty horizontal layouts contribute their non-zero height and the sample renders the Button fully within the screen.