2 files changed, 11 insertions, 6 deletions
diff --git a/actionpack/lib/action_dispatch/middleware/show_exceptions.rb b/actionpack/lib/action_dispatch/middleware/show_exceptions.rb
index 43440e5f7c..12a93d6a24 100644
--- a/actionpack/lib/action_dispatch/middleware/show_exceptions.rb
+++ b/actionpack/lib/action_dispatch/middleware/show_exceptions.rb
@@ -45,7 +45,17 @@ module ActionDispatch
     end
 
     def call(env)
-      @app.call(env)
+      status, headers, body = @app.call(env)
+
+      # Only this middleware cares about RoutingError. So, let's just raise
+      # it here.
+      # TODO: refactor this middleware to handle the X-Cascade scenario without
+      # having to raise an exception.
+      if headers['X-Cascade'] == 'pass'
+        raise ActionController::RoutingError, "No route matches #{env['PATH_INFO'].inspect}"
+      end
+
+      [status, headers, body]
     rescue Exception => exception
       raise exception if env['action_dispatch.show_exceptions'] == false
       render_exception(env, exception)
diff --git a/actionpack/lib/action_dispatch/routing/route_set.rb b/actionpack/lib/action_dispatch/routing/route_set.rb
index fdbff74071..0d071dd7fe 100644
--- a/actionpack/lib/action_dispatch/routing/route_set.rb
+++ b/actionpack/lib/action_dispatch/routing/route_set.rb
@@ -6,10 +6,6 @@ require 'action_dispatch/routing/deprecated_mapper'
 module ActionDispatch
   module Routing
     class RouteSet #:nodoc:
-      NotFound = lambda { |env|
-        raise ActionController::RoutingError, "No route matches #{env['PATH_INFO'].inspect}"
-      }
-
       PARAMETERS_KEY = 'action_dispatch.request.path_parameters'
 
       class Dispatcher #:nodoc:
@@ -224,7 +220,6 @@ module ActionDispatch
       def finalize!
         return if @finalized
         @finalized = true
-        @set.add_route(NotFound)
         @set.freeze
       end