mbostock/d3 — pull request #1067 by ZJONSSON (2013-02-07 14:10:45+00:00)
Title: Rebind returns target when the source returns itself

The logic is as follows: If a rebound function returns the source object, we should return the target object, even when no arguments were supplied.

Example: If I rebind a dispatch object to a target object and call a dispatch function with no argument, it will return the target, not the dispatch object, allowing for proper chaining.