Caged/d3-tip — pull request #88 by erikvullings (2014-11-17 08:44:19+00:00)
Title: Return gracefully when a node hasn't been found.

When initializing my d3 graphics, including the d3-tip function, (getSVGNode) cannot find a proper node yet, and el.tagName generates an exception. Therefore I've added a simple check to see if the svg node isn't null.
Hope you will accept it...