Bug 298900 Renderer cannot handle an MMenuItem with a null label
java.lang.IllegalArgumentException: Argument cannot be null at org.eclipse.swt.SWT.error(SWT.java:4049) at org.eclipse.swt.SWT.error(SWT.java:3983) at org.eclipse.swt.SWT.error(SWT.java:3954) at org.eclipse.swt.widgets.Widget.error(Widget.java:467) at org.eclipse.swt.widgets.MenuItem.setText(MenuItem.java:1023) at org.eclipse.e4.workbench.ui.renderers.swt.MenuItemRenderer.setItemText(MenuItemRenderer.java:132) at org.eclipse.e4.workbench.ui.renderers.swt.MenuItemRenderer.createWidget(MenuItemRenderer.java:108) at org.eclipse.e4.ui.workbench.swt.internal.PartRenderingEngine.createWidget(PartRenderingEngine.java:406) at org.eclipse.e4.ui.workbench.swt.internal.PartRenderingEngine.createGui(PartRenderingEngine.java:272) at org.eclipse.e4.ui.workbench.swt.internal.PartRenderingEngine.createGui(PartRenderingEngine.java:349) at org.eclipse.e4.workbench.ui.renderers.swt.SWTPartRenderer.processContents(SWTPartRenderer.java:54) at org.eclipse.e4.ui.workbench.swt.internal.PartRenderingEngine.createGui(PartRenderingEngine.java:300) at org.eclipse.e4.workbench.ui.renderers.swt.WBWRenderer.processContents(WBWRenderer.java:375) at org.eclipse.e4.ui.workbench.swt.internal.PartRenderingEngine.createGui(PartRenderingEngine.java:300) at org.eclipse.e4.ui.workbench.swt.internal.PartRenderingEngine.createGui(PartRenderingEngine.java:349)
bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/workbench/ui/renderers/swt/MenuItemRenderer.java
if (menuItem == null)
					return;
				String attName = (String) event
						.getProperty(UIEvents.EventTags.ATTNAME);
				if (UIEvents.UILabel.LABEL.equals(attName)) {
					setItemText(itemModel, menuItem);
				} else if (UIEvents.UILabel.ICONURI.equals(attName)) {
					menuItem.setImage(getImage(itemModel));
				}
			}
		};
		eventBroker.subscribe(UIEvents.buildTopic(UIEvents.UILabel.TOPIC),
				itemUpdater);
	}
	@PreDestroy
	public void contextDisposed() {
		eventBroker.unsubscribe(itemUpdater);
	}
	public Object createWidget(final MUIElement element, Object parent) {
		if (!(element instanceof MMenuItem) || !(parent instanceof Menu))
			return null;
		MMenuItem itemModel = (MMenuItem) element;
		Menu parentMenu = (Menu) parent;
		if (itemModel.isSeparator()) {
			return new MenuItem(parentMenu, SWT.SEPARATOR);
		}
		
		int flags = SWT.PUSH;
		if (itemModel.getChildren() != null) {
			flags = SWT.CASCADE;