patch.rb

module Mongoid
  module Document
    def instantiate(attrs = nil, criteria_instance_id = nil)
      attributes = attrs || {}
      doc = allocate
      doc.criteria_instance_id = criteria_instance_id
      doc.instance_variable_set(:@attributes, attributes)
      doc.apply_defaults
      IdentityMap.set(doc) if identity_map_set_possible?(criteria_instance_id)
      doc.run_callbacks(:initialize) unless doc._initialize_callbacks.empty?
      doc
    end
    
    def identity_map_set_possible?(criteria_instance_id)
      (! _loading_revision?) && Threaded.selection(criteria_instance_id).nil?
    end
  end
end