Bug 270952 [CommonNavigator] Eclipse RCP raises nullPointerException in makeSmallString for Project Explorer
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/NavigatorContentServiceLabelProvider.java
*            A property of the given element that could be a label provider
	 * @return True if any of the extensions enabled on anElement consider aProperty a
	 *         label-changing property.
	 * @see org.eclipse.jface.viewers.IBaseLabelProvider#isLabelProperty(java.lang.Object,
	 *      java.lang.String)
	 */
	public boolean isLabelProperty(Object anElement, String aProperty) {
		boolean result = false;
		ILabelProvider[] labelProviders = contentService.findRelevantLabelProviders(anElement);
		for (int i = 0; i < labelProviders.length && !result; i++) {
			result = labelProviders[i].isLabelProperty(anElement, aProperty);
		}
		return result;
	}
	/**
	 * <p>
	 * Label provider listeners are currently supported.
	 * </p>
	 * 
	 * {@inheritDoc}
	 * @see org.eclipse.jface.viewers.IBaseLabelProvider#addListener(org.eclipse.jface.viewers.ILabelProviderListener)
	 */
	public void addListener(ILabelProviderListener aListener) {
		addListenerObject(aListener);
	}
	/**
	 * <p>
	 * Label provider listeners are currently supported.
	 * </p>
	 *