The empty check is to make sure we don't save a group with a blank name, which I think this method would let through. The text edit dialog will give you a blank string, not null, if you type in nothing.

Thinking about this some more, since we're saving the configuration anyway at the end of this method, the check for the difference between the old and new name doesn't really do anything. I'll just leave the check for a non-empty string and remove the other one.