Bug 65762 [Viewers] Need to back out of change to AbstractTreeViewer.isExpandable
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
int oldCnt = -1;
		if (widget == tree)
			oldCnt = getItemCount(tree);
		Item[] items = getChildren(widget);
		
		CustomHashtable expanded = newHashtable(CustomHashtable.DEFAULT_CAPACITY); 
		for (int i = 0; i < items.length; ++i) {
			if (getExpanded(items[i])) {
				Object element = items[i].getData();
				if (element != null) {
					expanded.put(element, element);
				}
			}
		}
		int min = Math.min(elementChildren.length, items.length);
		
		
		
		
		
		for (int i = items.length; --i >= min;) {
			if (items[i].getData() != null) {
				disassociate(items[i]);
			}
			items[i].dispose();
		}