1 files changed, 38 insertions, 11 deletions
diff --git a/activerecord/lib/active_record/attribute_methods/write.rb b/activerecord/lib/active_record/attribute_methods/write.rb
index cd33494cc3..c853fc0917 100644
--- a/activerecord/lib/active_record/attribute_methods/write.rb
+++ b/activerecord/lib/active_record/attribute_methods/write.rb
@@ -1,6 +1,21 @@
+require 'active_support/core_ext/module/method_transplanting'
+
 module ActiveRecord
   module AttributeMethods
     module Write
+      WriterMethodCache = Class.new(AttributeMethodCache) {
+        private
+
+        def method_body(method_name, const_name)
+          <<-EOMETHOD
+          def #{method_name}(value)
+            name = ::ActiveRecord::AttributeMethods::AttrNames::ATTR_#{const_name}
+            write_attribute(name, value)
+          end
+          EOMETHOD
+        end
+      }.new
+
       extend ActiveSupport::Concern
 
       included do
@@ -10,17 +25,29 @@ module ActiveRecord
       module ClassMethods
         protected
 
-        # See define_method_attribute in read.rb for an explanation of
-        # this code.
-        def define_method_attribute=(name)
-          safe_name = name.unpack('h*').first
-          generated_attribute_methods.module_eval <<-STR, __FILE__, __LINE__ + 1
-            def __temp__#{safe_name}=(value)
-              write_attribute(AttrNames::ATTR_#{safe_name}, value)
-            end
-            alias_method #{(name + '=').inspect}, :__temp__#{safe_name}=
-            undef_method :__temp__#{safe_name}=
-          STR
+        if Module.methods_transplantable?
+          # See define_method_attribute in read.rb for an explanation of
+          # this code.
+          def define_method_attribute=(name)
+            method = WriterMethodCache[name]
+            generated_attribute_methods.module_eval {
+              define_method "#{name}=", method
+            }
+          end
+        else
+          def define_method_attribute=(name)
+            safe_name = name.unpack('h*').first
+            ActiveRecord::AttributeMethods::AttrNames.set_name_cache safe_name, name
+
+            generated_attribute_methods.module_eval <<-STR, __FILE__, __LINE__ + 1
+              def __temp__#{safe_name}=(value)
+                name = ::ActiveRecord::AttributeMethods::AttrNames::ATTR_#{safe_name}
+                write_attribute(name, value)
+              end
+              alias_method #{(name + '=').inspect}, :__temp__#{safe_name}=
+              undef_method :__temp__#{safe_name}=
+            STR
+          end
         end
       end