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
*            <code>false</code> to only update labels as needed, assuming
	 *            that labels for existing elements are unchanged.
	 * @since 2.1
	 */
	private void updateChildren(Widget widget, Object parent,
			Object[] elementChildren, boolean updateLabels) {
		
		if (widget instanceof Item) {
			Item ti = (Item) widget;
			if (!getExpanded(ti)) {
				
				
				boolean needDummy = isExpandable(ti, null, parent);
				boolean haveDummy = false;
				
				Item[] items = getItems(ti);
				for (int i = 0; i < items.length; i++) {
					if (items[i].getData() != null) {
						disassociate(items[i]);
						items[i].dispose();
					} else {
						if (needDummy && !haveDummy) {
							haveDummy = true;
						} else {
							items[i].dispose();
						}
					}
				}
				if (needDummy && !haveDummy) {
					newItem(ti, SWT.NULL, -1);