2 files changed, 10 insertions, 11 deletions
diff --git a/actionpack/lib/abstract_controller/base.rb b/actionpack/lib/abstract_controller/base.rb
index af5de815bb..a84ed17bd4 100644
--- a/actionpack/lib/abstract_controller/base.rb
+++ b/actionpack/lib/abstract_controller/base.rb
@@ -114,6 +114,11 @@ module AbstractController
       end
     end
 
+    # Define some internal variables that should not be propagated to the view.
+    def self.default_protected_instance_vars
+      []
+    end
+
     abstract!
 
     # Calls the action going through the entire action dispatch stack.
diff --git a/actionpack/lib/abstract_controller/rendering.rb b/actionpack/lib/abstract_controller/rendering.rb
index 5a5c47eb3b..41f19fba78 100644
--- a/actionpack/lib/abstract_controller/rendering.rb
+++ b/actionpack/lib/abstract_controller/rendering.rb
@@ -13,13 +13,8 @@ module AbstractController
   module Rendering
     extend ActiveSupport::Concern
 
-    included do
-      class_attribute :protected_instance_variables
-      self.protected_instance_variables = []
-    end
-
-    def default_protected_instance_vars
-      [:@_action_name, :@_response_body, :@_formats, :@_prefixes, :@_config]
+    def self.default_protected_instance_vars
+      super.concat [:@_action_name, :@_response_body, :@_formats, :@_prefixes, :@_config]
     end
 
     # Raw rendering of a template to a string.
@@ -57,10 +52,9 @@ module AbstractController
     # :api: public
     def view_assigns
       hash = {}
-      variables  = instance_variables
-      variables -= protected_instance_variables
-      variables -= default_protected_instance_vars
-      variables.each { |name| hash[name[1..-1]] = instance_variable_get(name) }
+      (instance_variables - self.class.default_protected_instance_vars).each do |name|
+        hash[name[1..-1]] = instance_variable_get(name)
+      end
       hash
     end