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
* Recursively collects all expanded items from the given widget.
	 * 
	 * @param result
	 *            a list (element type: <code>Item</code>) into which to
	 *            collect the elements
	 * @param widget
	 *            the widget
	 */
	private void internalCollectExpandedItems(List result, Widget widget) {
		Item[] items = getChildren(widget);
		for (int i = 0; i < items.length; i++) {
			Item item = items[i];
			if (getExpanded(item)) {
				result.add(item);
			}
			internalCollectExpandedItems(result, item);
		}
	}
	/**
	 * Tries to create a path of tree items for the given element or tree path.
	 * This method recursively walks up towards the root of the tree and in the
	 * case of an element (rather than a tree path) assumes that
	 * <code>getParent</code> returns the correct parent of an element.
	 * 
	 * @param elementOrPath
	 *            the element
	 * @param expand
	 *            <code>true</code> if all nodes on the path should be
	 *            expanded, and <code>false</code> otherwise
	 * @return Widget