… true as the second param
Since ActiveModel::Errors instance keeps all error messages as hash we should duplicate this object as well. Previously ActiveModel::Errors was a subclass of ActiveSupport::OrderedHash, which results in different behavior on dup, this may result in regression for people relying on it. Because Rails 3.2 stills supports Ruby 1.8.7 in order to properly fix this regression we need to backport #initialize_dup.
… use delegation
… commit while porting to the rails repo)