norman/friendly_id — pull request #368 by zx0 (2013-02-09 21:53:47+00:00)
Title: Fix wrong behavior with numeric slugs

Instead of responding with 404 on non-existent slug (e.g. '1001-qwe')
friendly_id redirects to the object with id = 1001.

It happens because of friendly_id? returning nil (True is the id is
definitely friendly, false if definitely unfriendly, else nil.), and it's not checked later.