2 files changed, 20 insertions, 40 deletions
diff --git a/actionpack/lib/action_dispatch/http/request.rb b/actionpack/lib/action_dispatch/http/request.rb
index 1f480eec73..1189111f20 100644
--- a/actionpack/lib/action_dispatch/http/request.rb
+++ b/actionpack/lib/action_dispatch/http/request.rb
@@ -67,6 +67,18 @@ module ActionDispatch
       end
     end
 
+    def controller_class
+      check_path_parameters!
+      params = path_parameters
+      controller_param = params[:controller].underscore if params.key?(:controller)
+      params[:action] ||= 'index'
+
+      yield unless controller_param
+
+      const_name = "#{controller_param.camelize}Controller"
+      ActiveSupport::Dependencies.constantize(const_name)
+    end
+
     def key?(key)
       @env.key?(key)
     end
diff --git a/actionpack/lib/action_dispatch/routing/route_set.rb b/actionpack/lib/action_dispatch/routing/route_set.rb
index c298080ac8..35385a5d9b 100644
--- a/actionpack/lib/action_dispatch/routing/route_set.rb
+++ b/actionpack/lib/action_dispatch/routing/route_set.rb
@@ -27,41 +27,18 @@ module ActionDispatch
         def dispatcher?; true; end
 
         def serve(req)
-          req.check_path_parameters!
           params = req.path_parameters
-
-          prepare_params!(params)
-
-          controller = controller(params, @raise_on_name_error) do
+          controller = controller_reference(req) do
             return [404, {'X-Cascade' => 'pass'}, []]
           end
-
           dispatch(controller, params[:action], req)
-        end
-
-        def prepare_params!(params)
-          normalize_controller!(params)
-          merge_default_action!(params)
-        end
-
-        # If this is a default_controller (i.e. a controller specified by the user)
-        # we should raise an error in case it's not found, because it usually means
-        # a user error. However, if the controller was retrieved through a dynamic
-        # segment, as in :controller(/:action), we should simply return nil and
-        # delegate the control back to Rack cascade. Besides, if this is not a default
-        # controller, it means we should respect the @scope[:module] parameter.
-        def controller(params, raise_on_name_error=true)
-          controller_reference params.fetch(:controller) { yield }
         rescue NameError => e
-          raise ActionController::RoutingError, e.message, e.backtrace if raise_on_name_error
-          yield
+          raise ActionController::RoutingError, e.message, e.backtrace if @raise_on_name_error
         end
 
       protected
-
-        def controller_reference(controller_param)
-          const_name = "#{controller_param.camelize}Controller"
-          ActiveSupport::Dependencies.constantize(const_name)
+        def controller_reference(req, &block)
+          req.controller_class(&block)
         end
 
       private
@@ -69,14 +46,6 @@ module ActionDispatch
         def dispatch(controller, action, req)
           controller.action(action).call(req.env)
         end
-
-        def normalize_controller!(params)
-          params[:controller] = params[:controller].underscore if params.key?(:controller)
-        end
-
-        def merge_default_action!(params)
-          params[:action] ||= 'index'
-        end
       end
 
       # A NamedRouteCollection instance is a collection of named routes, and also
@@ -756,14 +725,13 @@ module ActionDispatch
           req.path_parameters = old_params.merge params
           app = route.app
           if app.matches?(req) && app.dispatcher?
-            dispatcher = app.app
-
-            dispatcher.controller(params, false) do
+            begin
+              req.controller_class
+            rescue NameError
               raise ActionController::RoutingError, "A route matches #{path.inspect}, but references missing controller: #{params[:controller].camelize}Controller"
             end
 
-            dispatcher.prepare_params!(params)
-            return params
+            return req.path_parameters
           end
         end