rails/rails — pull request #5617 by Empact (2012-03-27 19:14:07+00:00)
Title: Spring cleaning in Rails::Paths

Saw @tenderlove did some work in here, and noticed set is required unnecessarily, a RuntimeError is raised where an ArgumentError would be more appropriate, and Path wasn't enforcing its own argument expectations.

I'm assuming this is appropriate for 4.0.