mongoid/mongoid — pull request #3561 by knapo (2014-03-13 14:41:21+00:00)
Title: Fix uniqueness validation for inherited models.

The uniqueness validation for inherited models is currently broken. The spec example doesn't represent real-world situation, when subclasses contain all superclass validators - it dynamically defines validation on superclass when subclasses were already loaded and it's why it was passing.