has_many :old_nodes, :class_name => "OldWayNode", :foreign_key => [:way_id, :version]
has_many :old_tags, :class_name => "OldWayTag", :foreign_key => [:way_id, :version]
- validates :changeset, :presence => true, :associated => true
+ validates :changeset, :associated => true
validates :timestamp, :presence => true
validates :visible, :inclusion => [true, false]