Fix accepts_nested_attributes for child classes

Closes GH-8131

activerecord/CHANGELOG.md

@@ -1,5 +1,31 @@
 ## Rails 3.2.9 (unreleased)
 
+*   Fix issue that raises `NameError` when overriding the `accepts_nested_attributes` in child classes.
+
+    Before:
+
+        class Shared::Person < ActiveRecord::Base
+          has_one :address
+
+          accepts_nested_attributes :address, :reject_if => :all_blank
+        end
+
+        class Person < Shared::Person
+          accepts_nested_attributes :address
+        end
+
+        Person
+        #=> NameError: method `address_attributes=' not defined in Person
+
+    After:
+
+        Person
+        #=> Person(id: integer, ...)
+
+    Fixes #8131.
+
+    *Gabriel Sobrinho, Ricardo Henrique*
+
 *   Fix issue with collection associations calling first(n)/last(n) and attempting
     to set the inverse association when `:inverse_of` was used. Fixes #8087.
 

activerecord/lib/active_record/nested_attributes.rb

@@ -277,13 +277,14 @@ def accepts_nested_attributes_for(*attr_names)
 
             type = (reflection.collection? ? :collection : :one_to_one)
 
+            # remove_possible_method :pirate_attributes=
+            #
             # def pirate_attributes=(attributes)
             #   assign_nested_attributes_for_one_to_one_association(:pirate, attributes, mass_assignment_options)
             # end
             class_eval <<-eoruby, __FILE__, __LINE__ + 1
-              if method_defined?(:#{association_name}_attributes=)
-                remove_method(:#{association_name}_attributes=)
-              end
+              remove_possible_method(:#{association_name}_attributes=)
+
               def #{association_name}_attributes=(attributes)
                 assign_nested_attributes_for_#{type}_association(:#{association_name}, attributes, mass_assignment_options)
               end

activerecord/test/cases/nested_attributes_test.rb

@@ -172,6 +172,17 @@ def test_first_and_array_index_zero_methods_return_the_same_value_when_nested_at
     man.interests_attributes = [{:id => interest.id, :topic => 'gardening'}]
     assert_equal man.interests.first.topic, man.interests[0].topic
   end
+
+  def test_something
+    Pirate.accepts_nested_attributes_for(:parrot)
+
+    mean_pirate_class = Class.new(Pirate) do
+      accepts_nested_attributes_for :parrot
+    end
+    mean_pirate = mean_pirate_class.new
+    mean_pirate.parrot_attributes = { :name => "James" }
+    assert_equal "James", mean_pirate.parrot.name
+  end
 end
 
 class TestNestedAttributesOnAHasOneAssociation < ActiveRecord::TestCase