Bug 283340 NPE is thrown when last child of stack is removed
1. Close the 'Outline' view. 2. That stack is now gone. An NPE is logged. java.lang.NullPointerException at org.eclipse.e4.workbench.ui.renderers.swt.StackModelFactory.childRemoved(StackModelFactory.java:315) at org.eclipse.e4.workbench.ui.renderers.swt.StackModelFactory$2.notifyChanged(StackModelFactory.java:265) at org.eclipse.emf.common.notify.impl.BasicNotifierImpl.eNotify(BasicNotifierImpl.java:280) at org.eclipse.e4.ui.model.internal.application.MPartImpl.setVisible(MPartImpl.java:457) at org.eclipse.e4.workbench.ui.renderers.swt.StackModelFactory$5.close(StackModelFactory.java:344) at org.eclipse.swt.custom.CTabFolder.onMouse(CTabFolder.java:2199) at org.eclipse.swt.custom.CTabFolder$1.handleEvent(CTabFolder.java:327)
bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/workbench/ui/renderers/swt/SWTPartRenderer.java
}
		if (!(widgetObject instanceof Composite)) {
			return null;
		}
		composite = (Composite) widgetObject;
		if (composite.getLayout() instanceof RowLayout) {
			RowLayout rl = (RowLayout) composite.getLayout();
			orientation = rl.type;
		}
		ToolBarManager manager = new ToolBarManager(SWT.FLAT | orientation);
		ToolBar swtToolBar = manager.createControl(composite);
		swtToolBar.setData(AbstractPartRenderer.OWNING_ME, toolbar);
		EList<MToolBarItem> items = toolbar.getItems();
		if (items != null && items.size() > 0) {
			for (MToolBarItem toolBarItem : toolbar.getItems()) {
				createToolBarItem(part, manager, toolBarItem);
			}
		}
		manager.update(true);
		return swtToolBar;
	}
	private void createToolBarItem(MPart<?> part, ToolBarManager manager,
			final MToolBarItem toolBarItem) {
		manager.add(new HandledContributionItem(toolBarItem, context));
	}
	private void createMenuItem(MPart<?> part, final MenuManager manager,
			final MHandledItem handledItem) {
		if (handledItem instanceof MMenuItemRenderer) {
			final IContributionItem renderer = (IContributionItem) ((MMenuItemRenderer) handledItem)
					.getRenderer();