Bug 172019 [Viewers] Plus sign doesn't disappear when using deferred content providers
3.3 M4 Use a tree viewer with a content provider using IDeferredWorkbenchAdapter and DeferredTreeContentManager. When fetchDeferredChildren is call and no elements are reported to the element collector the plus sign of the node doesn't disappear. This work without problems under Windows and Mac/OS (e.g. the plus sign disappears).
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
if (provider instanceof ITreePathLabelProvider) {
				ITreePathLabelProvider pprov = (ITreePathLabelProvider) provider;
				buildLabel(updateLabel, path, pprov);
				return;
			}
			element = path.getLastSegment();
		} else {
			element = elementOrPath;
		}
		super.buildLabel(updateLabel, element);
	}
	
	/**
	 * Returns true if the given object is either the input or an empty tree path.
	 *
	 * @param elementOrTreePath an element which could either be the viewer's input, or a tree path
	 *
	 * @return <code>true</code> if the given object is either the input or an empty tree path,
	 * <code>false</code> otherwise.
	 * @since 3.3
	 */
	final protected boolean internalIsInputOrEmptyPath(final Object elementOrTreePath) {
		if (elementOrTreePath.equals(getInput()))
			return true;
		if (!(elementOrTreePath instanceof TreePath))
			return false;
		return ((TreePath) elementOrTreePath).getSegmentCount() == 0;
	}
}