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
MElementContainer<MUIElement> pscModel = (MElementContainer<MUIElement>) parent;
				if (UIEvents.UIElement.CONTAINERDATA.equals(event
						.getProperty(UIEvents.EventTags.ATTNAME))) {
					addModelToUpdate(pscModel);
				}
			}
		};
		visibilityHandler = new EventHandler() {
			public void handleEvent(Event event) {
				
				MUIElement element = (MUIElement) event
						.getProperty(UIEvents.EventTags.ELEMENT);
				MUIElement parent = element.getParent();
				if (!(parent instanceof MPartSashContainer)
						|| parent.getRenderer() != SashRenderer.this)
					return;
				MElementContainer<MUIElement> pscModel = (MElementContainer<MUIElement>) parent;
				if (UIEvents.UIElement.VISIBLE.equals(event
						.getProperty(UIEvents.EventTags.ATTNAME))) {
					if (element.isVisible())
						addModelToUpdate(pscModel);
				}
			}
		};
		eventBroker.subscribe(UIEvents.buildTopic(UIEvents.UIElement.TOPIC,
				UIEvents.UIElement.VISIBLE), visibilityHandler);
	}
	@PreDestroy
	void preDestroy() {
		eventBroker.unsubscribe(sashOrientationHandler);