Bug 324230 NPE thrown when unrendering an MPartSashContainer that contains unrendered children
java.lang.NullPointerException at org.eclipse.e4.ui.workbench.renderers.swt.SashRenderer.hideChild(SashRenderer.java:317) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.removeGui(PartRenderingEngine.java:517) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.removeGui(PartRenderingEngine.java:528)
bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/ui/workbench/renderers/swt/SashRenderer.java
eventBroker.unsubscribe(sashWeightHandler);
		eventBroker.unsubscribe(visibilityHandler);
	}
	public Widget createWidget(MUIElement element, Object parent) {
		if (!(element instanceof MPartSashContainer)
				|| !(parent instanceof Composite))
			return null;
		Widget parentWidget = (Widget) parent;
		MPartSashContainer psc = (MPartSashContainer) element;
		int orientation = psc.isHorizontal() ? SWT.HORIZONTAL : SWT.VERTICAL;
		SashForm newSash = new SashForm((Composite) parentWidget, SWT.SMOOTH
				| orientation);
		bindWidget(element, newSash);
		newSash.setVisible(true);
		return newSash;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.e4.ui.workbench.renderers.swt.SWTPartRenderer#childAdded(
	 * org.eclipse.e4.ui.model.application.MPart,
	 * org.eclipse.e4.ui.model.application.MPart)
	 */
	@Override
	public void childRendered(MElementContainer<MUIElement> parentElement,
			MUIElement element) {
		super.childRendered(parentElement, element);
		if (!(parentElement.getWidget() instanceof SashForm))
			return;