1 files changed, 10 insertions, 0 deletions
diff --git a/actionpack/lib/action_controller/abstract/base.rb b/actionpack/lib/action_controller/abstract/base.rb
index ab9aed0b26..c9e1081b23 100644
--- a/actionpack/lib/action_controller/abstract/base.rb
+++ b/actionpack/lib/action_controller/abstract/base.rb
@@ -1,4 +1,14 @@
 module AbstractController
+  class Error < StandardError; end
+  
+  class DoubleRenderError < Error
+    DEFAULT_MESSAGE = "Render and/or redirect were called multiple times in this action. Please note that you may only call render OR redirect, and at most once per action. Also note that neither redirect nor render terminate execution of the action, so if you want to exit an action after redirecting, you need to do something like \"redirect_to(...) and return\"."
+
+    def initialize(message = nil)
+      super(message || DEFAULT_MESSAGE)
+    end
+  end  
+  
   class Base
     
     attr_internal :response_body