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
if ((foundDescriptor = foundExtension.getDescriptor()).getOverriddenDescriptor() != null) {
			return findStyledText(contentService.getExtension(foundDescriptor.getOverriddenDescriptor()), anElement);
		}  
		return null;
	}
	
	private String makeSmallString(Object obj) {
		String str = obj.toString();
		int len = str.length();
		return str.substring(0, len < 50 ? len : 49);
	}
	
	/**
	 * Search for image and take overrides into account. 
	 * Uses only simple ITreeContentProvider.getParent() style semantics. 
	 */
	private Image findImage(NavigatorContentExtension foundExtension, Object anElement, int aColumn) { 
		Image image = null;
		INavigatorContentDescriptor foundDescriptor;  
		ICommonLabelProvider provider = foundExtension.getLabelProvider();
		if (provider instanceof ITableLabelProvider && aColumn >= 0)
			image = ((ITableLabelProvider)provider).getColumnImage(anElement, aColumn);
		else
			image = provider.getImage(anElement);
		if (image == null && (foundDescriptor = foundExtension.getDescriptor()).getOverriddenDescriptor() != null) {
			return findImage(contentService.getExtension(foundDescriptor.getOverriddenDescriptor()), anElement, aColumn);
		}  
		return image;
	}