Bug 164989 [Viewers] ColumnViewer#getColumnViewerOwner() doesn't respects column count
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/TreeViewer.java
treePath = getTreePathFromItem(item);
			if (currentChildCount == 0) {
				
				((ILazyTreePathContentProvider) getContentProvider())
						.updateHasChildren(treePath);
			} else {
				((ILazyTreePathContentProvider) getContentProvider())
						.updateChildCount(treePath, currentChildCount);
			}
		} else {
			((ILazyTreeContentProvider) getContentProvider()).updateChildCount(item.getData(), currentChildCount);
		}
	}
	private boolean internalIsInputOrEmptyPath(final Object elementOrTreePath) {
		if (elementOrTreePath.equals(getInput()))
			return true;
		if (!(elementOrTreePath instanceof TreePath))
			return false;
		return ((TreePath) elementOrTreePath).getSegmentCount() == 0;
	}
	
	protected void disassociate(Item item) {
		if (contentProviderIsLazy) {
			
			item.setText(" "); 
		}
		super.disassociate(item);
	}
}