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
public void handleEvent(Event event) {
				
				Object element = event.getProperty(UIEvents.EventTags.ELEMENT);
				if (!(element instanceof MPartSashContainer)) {
					return;
				}
				if (UIEvents.GenericTile.HORIZONTAL.equals(event
						.getProperty(UIEvents.EventTags.ATTNAME))) {
					Boolean horizontal = (Boolean) event
							.getProperty(UIEvents.EventTags.NEW_VALUE);
					MPartSashContainer container = (MPartSashContainer) element;
					SashForm sashForm = (SashForm) container.getWidget();
					sashForm.setOrientation(horizontal.booleanValue() ? SWT.HORIZONTAL
							: SWT.VERTICAL);
				}
			}
		};
		eventBroker.subscribe(UIEvents.buildTopic(UIEvents.GenericTile.TOPIC,
				UIEvents.GenericTile.HORIZONTAL), sashOrientationHandler);
		sashWeightHandler = new EventHandler() {
			public void handleEvent(Event event) {
				if (ignoreWeightUpdates)
					return;
				
				MUIElement element = (MUIElement) event
						.getProperty(UIEvents.EventTags.ELEMENT);
				MUIElement parent = element.getParent();
				if (!(parent instanceof MPartSashContainer)
						|| parent.getRenderer() != SashRenderer.this)
					return;