@_formats initialization should be AbstractController::Base.

actionpack/lib/abstract_controller/base.rb

@@ -86,6 +86,11 @@ module AbstractController
 
     abstract!
 
+    # Initialize controller with nil formats.
+    def initialize #:nodoc:
+      @_formats = nil
+    end
+
     # Calls the action going through the entire action dispatch stack.
     #
     # The actual method that is called is determined by calling

actionpack/lib/abstract_controller/rendering.rb

@@ -17,12 +17,6 @@ module AbstractController
       self._view_paths ||= ActionView::PathSet.new
     end
 
-    # Initialize controller with nil formats.
-    def initialize(*) #:nodoc:
-      @_formats = nil
-      super
-    end
-
     # An instance of a view class. The default view class is ActionView::Base
     #
     # The view class must have the following methods:

actionpack/lib/action_dispatch/middleware/show_exceptions.rb

@@ -14,7 +14,7 @@ module ActionDispatch
   #     ExceptionNotifier.deliver_exception(start, payload)
   #   end
   #
-  # The payload is a hash which has to pairs:
+  # The payload is a hash which has two pairs:
   #
   # * :env - Contains the rack env for the given request;
   # * :exception - The exception raised;