Merge pull request #2549 from trek/RoutingErrorForMissingControllers

When a route references a missing controller, raise ActionController::RoutingError with clearer message

actionpack/lib/action_dispatch/routing/route_set.rb

@@ -663,9 +663,13 @@ def recognize_path(path, environment = {})
             dispatcher = dispatcher.app
           end
 
-          if dispatcher.is_a?(Dispatcher) && dispatcher.controller(params, false)
-            dispatcher.prepare_params!(params)
-            return params
+          if dispatcher.is_a?(Dispatcher)
+            if dispatcher.controller(params, false)
+              dispatcher.prepare_params!(params)
+              return params
+            else
+              raise ActionController::RoutingError, "A route matches #{path.inspect}, but references missing controller: #{params[:controller].camelize}Controller"
+            end
           end
         end
 

actionpack/test/controller/routing_test.rb

@@ -1037,6 +1037,16 @@ def test_route_constraints_with_options_method_condition_is_valid
     end
   end
 
+  def test_route_error_with_missing_controller
+    set.draw do
+      get    "/people" => "missing#index"
+    end
+    
+    assert_raise(ActionController::RoutingError) {
+      set.recognize_path("/people", :method => :get)
+    }
+  end
+
   def test_recognize_with_encoded_id_and_regex
     set.draw do
       get 'page/:id' => 'pages#show', :id => /[a-zA-Z0-9\+]+/