1 files changed, 20 insertions, 12 deletions
diff --git a/activerecord/lib/active_record/attribute_methods/read.rb b/activerecord/lib/active_record/attribute_methods/read.rb
index 90701938e5..3c03cce838 100644
--- a/activerecord/lib/active_record/attribute_methods/read.rb
+++ b/activerecord/lib/active_record/attribute_methods/read.rb
@@ -32,21 +32,29 @@ module ActiveRecord
 
         protected
 
-        # We want to generate the methods via module_eval rather than define_method,
-        # because define_method is slower on dispatch and uses more memory (because it
-        # creates a closure).
+        # We want to generate the methods via module_eval rather than
+        # define_method, because define_method is slower on dispatch and
+        # uses more memory (because it creates a closure).
         #
-        # But sometimes the database might return columns with characters that are not
-        # allowed in normal method names (like 'my_column(omg)'. So to work around this
-        # we first define with the __temp__ identifier, and then use alias method to
-        # rename it to what we want.
-        def define_method_attribute(attr_name)
+        # But sometimes the database might return columns with
+        # characters that are not allowed in normal method names (like
+        # 'my_column(omg)'. So to work around this we first define with
+        # the __temp__ identifier, and then use alias method to rename
+        # it to what we want.
+        #
+        # We are also defining a constant to hold the frozen string of
+        # the attribute name. Using a constant means that we do not have
+        # to allocate an object on each call to the attribute method.
+        # Making it frozen means that it doesn't get duped when used to
+        # key the @attributes_cache in read_attribute.
+        def define_method_attribute(name)
+          safe_name = name.unpack('h*').first
           generated_attribute_methods.module_eval <<-STR, __FILE__, __LINE__ + 1
-            def __temp__
-              read_attribute('#{attr_name}') { |n| missing_attribute(n, caller) }
+            def __temp__#{safe_name}
+              read_attribute(AttrNames::ATTR_#{safe_name}) { |n| missing_attribute(n, caller) }
             end
-            alias_method '#{attr_name}', :__temp__
-            undef_method :__temp__
+            alias_method #{name.inspect}, :__temp__#{safe_name}
+            undef_method :__temp__#{safe_name}
           STR
         end