Bug 327933 Unrendering container with invalid selectedElement can cause target element to be unrendered
bundles/org.eclipse.e4.ui.workbench.swt/src/org/eclipse/e4/ui/internal/workbench/swt/PartRenderingEngine.java
Control ctrl = (Control) changedElement.getWidget();
			MElementContainer<MUIElement> parent = changedElement.getParent();
			if (parent == null)
				return;
			AbstractPartRenderer renderer = (AbstractPartRenderer) parent
					.getRenderer();
			if (renderer == null)
				return;
			
			if (changedElement.isVisible()) {
				
				
				Composite realComp = (Composite) renderer
						.getUIContainer(changedElement);
				ctrl.setParent(realComp);
				fixZOrder(changedElement);
				renderer.childRendered(parent, changedElement);
			} else {
				
				ctrl.setParent(getLimboShell());
				renderer.hideChild(parent, changedElement);
			}
		}
	};
	private EventHandler trimHandler = new EventHandler() {
		public void handleEvent(Event event) {
			Object changedObj = event.getProperty(UIEvents.EventTags.ELEMENT);
			if (!(changedObj instanceof MTrimmedWindow))
				return;
			MTrimmedWindow window = (MTrimmedWindow) changedObj;