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
public void run() {
					l.treeExpanded(event);
				}
			});
		}
	}
	/**
	 * Returns the auto-expand level.
	 * 
	 * @return non-negative level, or <code>ALL_LEVELS</code> if all levels of
	 *         the tree are expanded automatically
	 * @see #setAutoExpandLevel
	 */
	public int getAutoExpandLevel() {
		return expandToLevel;
	}
	/**
	 * Returns the SWT child items for the given SWT widget.
	 * 
	 * @param widget
	 *            the widget
	 * @return the child items
	 */
	protected abstract Item[] getChildren(Widget widget);
	/**
	 * Get the child for the widget at index. Note that the default
	 * implementation is not very effecient and should be overridden if this
	 * class is implemented.
	 * 
	 * @param widget