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
* Returns the widget to be selected for the given element or tree path.
	 * 
	 * @param elementOrTreePath
	 *            the element or tree path to select
	 * @return the widget to be selected, or <code>null</code> if not found
	 * 
	 * @since 3.1
	 */
	protected Widget internalGetWidgetToSelect(Object elementOrTreePath) {
		if (elementOrTreePath instanceof TreePath) {
			TreePath treePath = (TreePath) elementOrTreePath;
			if (treePath.getSegmentCount() == 0) {
				return null;
			}
			Widget[] candidates = findItems(treePath.getLastSegment());
			for (int i = 0; i < candidates.length; i++) {
				Widget candidate = candidates[i];
				if (!(candidate instanceof Item)) {
					continue;
				}
				if (treePath.equals(getTreePathFromItem((Item) candidate),
						getComparer())) {
					return candidate;
				}
			}
			return null;
		}
		return findItem(elementOrTreePath);
	}
	/**