Bug 339573 Splitting the shared area with a part doesn't remove stale placeholders
The current code only looks for the addition of an MPlaceholder in the shared area as the hint to remove locals. When you split the area the element that gets added is the new MPartSashContainer...
bundles/org.eclipse.e4.ui.workbench.swt/src/org/eclipse/e4/ui/internal/workbench/swt/PartRenderingEngine.java
prevCtrl = (Control) kid.getWidget();
			}
		}
	}
	/**
	 * Initialize a part renderer from the extension point.
	 * 
	 * @param context
	 *            the context for the part factories
	 */
	@PostConstruct
	void initialize(IEclipseContext context) {
		this.appContext = context;
		
		KeyFormatterFactory.setDefault(SWTKeySupport
				.getKeyFormatterForPlatform());
		
		context.set(IPresentationEngine.class.getName(), this);
		IRendererFactory factory = null;
		IContributionFactory contribFactory = context
				.get(IContributionFactory.class);
		try {
			factory = (IRendererFactory) contribFactory.create(factoryUrl,
					context);
		} catch (Exception e) {
			logger.warn(e, "Could not create rendering factory");
		}
		
		if (factory == null) {
			try {