Bug 139511 [CommonNavigator] getParent() fails in certain cases
In the implementation of getParents(), clients can sometimes fail to return the correct parent with the override cases taken into account. The attached patch fixes these issues, but should be reviewed by the Team Team to ensure that it does not cause any regressions for their cases.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/NavigatorContentServiceContentProvider.java
*            The current elements to return to the viewer (should be
	 *            modifiable)
	 * @return The set of elements to return to the viewer
	 */
	private Object pipelineParent(Object anInputElement,
			NavigatorContentExtension[] theOverridingExtensions,
			Object theCurrentParent) {
		IPipelinedTreeContentProvider pipelinedContentProvider;
		NavigatorContentExtension[] overridingExtensions;
		Object aSuggestedParent = null;
		for (int i = 0; i < theOverridingExtensions.length; i++) {
			if (theOverridingExtensions[i].getContentProvider() instanceof IPipelinedTreeContentProvider) {
				pipelinedContentProvider = (IPipelinedTreeContentProvider) theOverridingExtensions[i]
						.getContentProvider();
				aSuggestedParent = pipelinedContentProvider.getPipelinedParent(
						anInputElement, aSuggestedParent);
				overridingExtensions = theOverridingExtensions[i]
						.getOverridingExtensionsForTriggerPoint(anInputElement);
				if (overridingExtensions.length > 0) {
					aSuggestedParent = pipelineParent(anInputElement,
							overridingExtensions, aSuggestedParent);
				}
			}
		}
		return aSuggestedParent != null ? aSuggestedParent : theCurrentParent;
	}
	/**
	 * <p>
	 * Used to determine of anElement should be displayed with a '+' or not.
	 * </p>