Bug 292322 [Viewers] Tree view is removing + indicator when one of multiple children is removed.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/TreeViewer.java
virtualMaterializeItem((TreeItem) widget);
				
				element = widget.getData();
			}
			if (element ==  null) {
				
				return;
			}
			Item[] children = getChildren(widget);
			if (children.length == 1 && children[0].getData() == null) {
				
				virtualLazyUpdateChildCount(widget, children.length);
				children = getChildren(widget);
			}
			
			for (int i = 0; i < children.length; i++) {
				if (children[i].getData() == null) {
					virtualLazyUpdateWidget(widget, i);
				}
			}
			return;
		}
		super.createChildren(widget);
	}
	protected void internalAdd(Widget widget, Object parentElement,
			Object[] childElements) {
		if (contentProviderIsLazy) {
			if (widget instanceof TreeItem) {
				TreeItem ti = (TreeItem) widget;
				int count = ti.getItemCount() + childElements.length;