Fix namespaced redirects [#4389 state:resolved]

Signed-off-by: José Valim <jose.valim@gmail.com>

actionpack/lib/action_dispatch/routing/mapper.rb

@@ -55,7 +55,7 @@ module ActionDispatch
               path = args.first
             end
 
-            if @scope[:module] && options[:to]
+            if @scope[:module] && options[:to] && !options[:to].is_a?(Proc)
               if options[:to].to_s.include?("#")
                 options[:to] = "#{@scope[:module]}/#{options[:to]}"
               elsif @scope[:controller].nil?

actionpack/test/dispatch/routing_test.rb

@@ -300,6 +300,11 @@ class TestRoutingMapper < ActionDispatch::IntegrationTest
         match '/' => 'mes#index'
       end
 
+      namespace :private do
+        root :to => redirect('/private/index')
+        match "index", :to => 'private#index'
+      end
+
       match "whatever/:controller(/:action(/:id))"
 
       resource :profile do
@@ -421,6 +426,15 @@ class TestRoutingMapper < ActionDispatch::IntegrationTest
     end
   end
 
+  def test_namespace_redirect
+    with_test_routes do
+      get '/private'
+      assert_equal 301, @response.status
+      assert_equal 'http://www.example.com/private/index', @response.headers['Location']
+      assert_equal 'Moved Permanently', @response.body
+    end
+  end
+
   def test_session_singleton_resource
     with_test_routes do
       get '/session'