Bug 166052 [Viewers] Regression: decorator of DecoratingLabelProvider completely replaces label provider
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/DecoratingLabelProvider.java
ILabelProvider, IViewerLabelProvider, IColorProvider, IFontProvider,
		ITreePathLabelProvider {
	private ILabelProvider provider;
	private ILabelDecorator decorator;
	
	private ListenerList listeners = new ListenerList();
	private IDecorationContext decorationContext = DecorationContext.DEFAULT_CONTEXT;
	/**
	 * Creates a decorating label provider which uses the given label decorator
	 * to decorate labels provided by the given label provider.
	 * 
	 * @param provider
	 *            the nested label provider
	 * @param decorator
	 *            the label decorator, or <code>null</code> if no decorator is
	 *            to be used initially
	 */
	public DecoratingLabelProvider(ILabelProvider provider,
			ILabelDecorator decorator) {