rails/rails — pull request #5702 by oscardelben (2012-04-02 13:44:08+00:00)
Title: Call undefine_attribute_methods only when defining new attributes

Every time we call `attribute_method_prefix` and related methods, we also call `undefine_attribute_methods` behind the scenes. I think it'd be more clear and possibly more efficient to just do it before we define new attributes.