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
int weight = getWeight(element);
		if (weight == UNDEFINED_WEIGHT) {
			element.setContainerData(Integer.toString(DEFAULT_WEIGHT));
		}
		
		final MElementContainer<MUIElement> psc = parentElement;
		for (MUIElement part : psc.getChildren()) {
			Control partCtrl = (Control) part.getWidget();
			if (partCtrl != null) {
				partCtrl.moveBelow(null);
			}
		}
		
		Control newCtrl = (Control) element.getWidget();
		newCtrl.addControlListener(resizeListener);
		newCtrl.addDisposeListener(new DisposeListener() {
			public void widgetDisposed(DisposeEvent e) {
				((Control) e.widget).removeControlListener(resizeListener);
			}
		});
		
		addModelToUpdate(psc);
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.e4.ui.internal.workbench.swt.AbstractPartRenderer#hideChild
	 * (org.eclipse.e4.ui.model.application.MElementContainer,