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
* support JDT's explorations into grouping by working sets, which requires
	 * viewers to support multiple equal elements. See bug 76482 for more
	 * details. This support will likely be removed in Eclipse 3.2 in favour of
	 * proper support for multiple equal elements.
	 * </p>
	 * 
	 * @param elementsOrPaths
	 *            the elements or element paths to remove
	 * @since 3.1
	 */
	protected void internalRemove(Object[] elementsOrPaths) {
		Object input = getInput();
		
		
		CustomHashtable parentItems = new CustomHashtable(5);
		for (int i = 0; i < elementsOrPaths.length; ++i) {
			Object element = elementsOrPaths[i];
			if (equals(element, input)) {
				setInput(null);
				return;
			}
			Widget[] childItems = internalFindItems(element);
			for (int j = 0; j < childItems.length; j++) {
				Widget childItem = childItems[j];
				if (childItem instanceof Item) {
					Item parentItem = getParentItem((Item) childItem);
					if (parentItem != null) {
						parentItems.put(parentItem, parentItem);
					}
					disassociate((Item) childItem);