Bug 271744 [Viewers] [JFace] TreeViewer not closing CellEditors on Collapse
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/TreeViewer.java
paths[length] = getTreePathFromItem(item);
				item.setData(null);
				return new TreeSelection(paths, selection.getElementComparer());
			}
		}
		
		return selection;
	}
	public boolean isExpandable(Object element) {
		if (contentProviderIsLazy) {
			TreeItem treeItem = (TreeItem) internalExpand(element, false);
			if (treeItem == null) {
				return false;
			}
			virtualMaterializeItem(treeItem);
			return treeItem.getItemCount() > 0;
		}
		return super.isExpandable(element);
	}
	protected Object getParentElement(Object element) {
		boolean oldBusy = isBusy();
		setBusy(true);
		try {
			if (contentProviderIsLazy && !contentProviderIsTreeBased && !(element instanceof TreePath)) {
				ILazyTreeContentProvider lazyTreeContentProvider = (ILazyTreeContentProvider) getContentProvider();
				return lazyTreeContentProvider.getParent(element);
			}
			if (contentProviderIsLazy && contentProviderIsTreeBased && !(element instanceof TreePath)) {
				ILazyTreePathContentProvider lazyTreePathContentProvider = (ILazyTreePathContentProvider) getContentProvider();
				TreePath[] parents = lazyTreePathContentProvider