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
}
		return item;
	}
	
	public Item scrollDown(int x, int y) {
		Item current = getItem(x, y);
		if (current != null) {
			Item next = getNextItem(current, true);
			showItem(next == null ? current : next);
			return next;
		}
		return null;
	}
	
	public Item scrollUp(int x, int y) {
		Item current = getItem(x, y);
		if (current != null) {
			Item previous = getPreviousItem(current);
			showItem(previous == null ? current : previous);
			return previous;
		}
		return null;
	}
	/**
	 * Sets the auto-expand level. The value 0 means that there is no
	 * auto-expand; 1 means that top-level elements are expanded, but not their
	 * children; 2 means that top-level elements are expanded, and their
	 * children, but not grandchildren; and so on.
	 * <p>
	 * The value <code>ALL_LEVELS</code> means that all subtrees should be