eliminate alias_method_chain from ActiveRecord

1 files changed, 10 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/attribute_methods.rb b/activerecord/lib/active_record/attribute_methods.rb
index 3a9a67e3a2..c117271c71 100644
--- a/activerecord/lib/active_record/attribute_methods.rb
+++ b/activerecord/lib/active_record/attribute_methods.rb
@@ -18,10 +18,19 @@ module ActiveRecord
       def instance_method_already_implemented?(method_name)
         method_name = method_name.to_s
         @_defined_class_methods         ||= ancestors.first(ancestors.index(ActiveRecord::Base)).sum([]) { |m| m.public_instance_methods(false) | m.private_instance_methods(false) | m.protected_instance_methods(false) }.map {|m| m.to_s }.to_set
-        @@_defined_activerecord_methods ||= (ActiveRecord::Base.public_instance_methods(false) | ActiveRecord::Base.private_instance_methods(false) | ActiveRecord::Base.protected_instance_methods(false)).map{|m| m.to_s }.to_set
+        @@_defined_activerecord_methods ||= defined_activerecord_methods
         raise DangerousAttributeError, "#{method_name} is defined by ActiveRecord" if @@_defined_activerecord_methods.include?(method_name)
         @_defined_class_methods.include?(method_name)
       end
+
+      def defined_activerecord_methods
+        active_record = ActiveRecord::Base
+        super_klass   = ActiveRecord::Base.superclass
+        methods =  active_record.public_instance_methods - super_klass.public_instance_methods
+        methods += active_record.private_instance_methods - super_klass.private_instance_methods
+        methods += active_record.protected_instance_methods - super_klass.protected_instance_methods
+        methods.map {|m| m.to_s }.to_set
+      end
     end
 
     def method_missing(method_id, *args, &block)