gorhill/Javascript-Voronoi — pull request #14 by mbostock (2013-09-22 20:34:23+00:00)
Title: Fix initial duplicate detection.

When detecting coincident points, the previous site [xsitex, xsitey] should be initialized to an illegal value (different from any potential valid input site). But [Number.MIN_VALUE, Number.MIN_VALUE] is a valid site, so use [undefined, undefined] instead.