4 files changed, 45 insertions, 22 deletions
diff --git a/actionpack/lib/action_dispatch/http/request.rb b/actionpack/lib/action_dispatch/http/request.rb
index a3c6f015d9..e6387768de 100644
--- a/actionpack/lib/action_dispatch/http/request.rb
+++ b/actionpack/lib/action_dispatch/http/request.rb
@@ -68,16 +68,23 @@ module ActionDispatch
       end
     end
 
+    PASS_NOT_FOUND = Class.new { # :nodoc:
+      def self.action(_); self; end
+      def self.call(_); [404, {'X-Cascade' => 'pass'}, []]; 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)
+      if params.key?(:controller)
+        controller_param = params[:controller].underscore
+        params[:action] ||= 'index'
+        const_name = "#{controller_param.camelize}Controller"
+        ActiveSupport::Dependencies.constantize(const_name)
+      else
+        PASS_NOT_FOUND
+      end
     end
 
     def key?(key)
diff --git a/actionpack/lib/action_dispatch/http/response.rb b/actionpack/lib/action_dispatch/http/response.rb
index fd92e89231..d860e00217 100644
--- a/actionpack/lib/action_dispatch/http/response.rb
+++ b/actionpack/lib/action_dispatch/http/response.rb
@@ -65,7 +65,7 @@ module ActionDispatch # :nodoc:
     CONTENT_TYPE = "Content-Type".freeze
     SET_COOKIE   = "Set-Cookie".freeze
     LOCATION     = "Location".freeze
-    NO_CONTENT_CODES = [204, 304]
+    NO_CONTENT_CODES = [100, 101, 102, 204, 205, 304]
 
     cattr_accessor(:default_charset) { "utf-8" }
     cattr_accessor(:default_headers)
@@ -265,9 +265,6 @@ module ActionDispatch # :nodoc:
     end
 
     # The location header we'll be responding with.
-    def location
-      headers[LOCATION]
-    end
     alias_method :redirect_url, :location
 
     # Sets the location header we'll be responding with.
@@ -396,6 +393,7 @@ module ActionDispatch # :nodoc:
 
       if NO_CONTENT_CODES.include?(@status)
         header.delete CONTENT_TYPE
+        header.delete 'Content-Length'
         [status, header, []]
       else
         [status, header, RackBody.new(self)]
diff --git a/actionpack/lib/action_dispatch/routing/mapper.rb b/actionpack/lib/action_dispatch/routing/mapper.rb
index c3a9422ceb..1acfb2bfe8 100644
--- a/actionpack/lib/action_dispatch/routing/mapper.rb
+++ b/actionpack/lib/action_dispatch/routing/mapper.rb
@@ -283,12 +283,16 @@ module ActionDispatch
           end
 
           def app(blocks)
-            if to.respond_to?(:call)
-              Constraints.new(to, blocks, Constraints::CALL)
-            elsif blocks.any?
-              Constraints.new(dispatcher(defaults.key?(:controller)), blocks, Constraints::SERVE)
+            if to.is_a?(Class) && to < ActionController::Metal
+              Routing::RouteSet::StaticDispatcher.new to
             else
-              dispatcher(defaults.key?(:controller))
+              if to.respond_to?(:call)
+                Constraints.new(to, blocks, Constraints::CALL)
+              elsif blocks.any?
+                Constraints.new(dispatcher(defaults.key?(:controller)), blocks, Constraints::SERVE)
+              else
+                dispatcher(defaults.key?(:controller))
+              end
             end
           end
 
diff --git a/actionpack/lib/action_dispatch/routing/route_set.rb b/actionpack/lib/action_dispatch/routing/route_set.rb
index 4e29476117..e4b8d5993e 100644
--- a/actionpack/lib/action_dispatch/routing/route_set.rb
+++ b/actionpack/lib/action_dispatch/routing/route_set.rb
@@ -27,11 +27,10 @@ module ActionDispatch
         def dispatcher?; true; end
 
         def serve(req)
-          params = req.path_parameters
-          controller = req.controller_class do
-            return [404, {'X-Cascade' => 'pass'}, []]
-          end
-          dispatch(controller, params[:action], req)
+          params     = req.path_parameters
+          controller = controller req
+          res        = controller.make_response! req
+          dispatch(controller, params[:action], req, res)
         rescue NameError => e
           if @raise_on_name_error
             raise ActionController::RoutingError, e.message, e.backtrace
@@ -42,9 +41,24 @@ module ActionDispatch
 
       private
 
-        def dispatch(controller, action, req)
-          controller.action(action).call(req.env)
+        def controller(req)
+          req.controller_class
+        end
+
+        def dispatch(controller, action, req, res)
+          controller.dispatch(action, req, res)
+        end
+      end
+
+      class StaticDispatcher < Dispatcher
+        def initialize(controller_class)
+          super(false)
+          @controller_class = controller_class
         end
+
+        private
+
+        def controller(_); @controller_class; end
       end
 
       # A NamedRouteCollection instance is a collection of named routes, and also