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
* 
	 * @param parent the parent element
	 * @param elements
	 *            the elements to remove
	 * @since 3.1
	 */
	protected void internalRemove(Object parent, Object[] elements) {
		CustomHashtable toRemove = new CustomHashtable(getComparer());
		for (int i = 0; i < elements.length; i++) {
			toRemove.put(elements[i], elements[i]);
		}
		
		
		CustomHashtable parentItems = new CustomHashtable(5);
		
		Widget[] parentItemArray = findItems(parent);
		for (int i = 0; i < parentItemArray.length; i++) {
			Widget parentItem = parentItemArray[i];
			if (parentItem instanceof Item) {
				parentItems.put(parentItem, parentItem);
			}
			
			Item[] children = getChildren(parentItem);
			for (int j = 0; j < children.length; j++) {
				Item child = children[j];
				Object data = child.getData();
				if (data != null && toRemove.containsKey(data)) {
					disassociate(child);
					child.dispose();
				}