Bug 327033 Workbench doesn't relayout after a stack disappears
If you close all the views of a stack, you just get an empty rectangle of space now. Resizing your window will adjust the layout properly. Note that reopening the views don't help, you still have to resize something to force a layout.
bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/ui/workbench/renderers/swt/PerspectiveRenderer.java
@Override
	public void childRendered(MElementContainer<MUIElement> parentElement,
			MUIElement element) {
		
		super.childRendered(parentElement, element);
		Composite comp = (Composite) parentElement.getWidget();
		SashLayout sl = (SashLayout) comp.getLayout();
		sl.setRootElemenr(element);
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.e4.ui.internal.workbench.swt.AbstractPartRenderer#getUIContainer
	 * (org.eclipse.e4.ui.model.application.ui.MUIElement)
	 */
	@Override
	public Object getUIContainer(MUIElement element) {
		if (!(element instanceof MWindow))
			return super.getUIContainer(element);
		MPerspective persp = (MPerspective) ((EObjectImpl) element)
				.eContainer();
		if (persp.getWidget() instanceof Composite) {
			Composite comp = (Composite) persp.getWidget();
			return comp.getShell();
		}
		return null;
	}
}