Do not overwrite _railtie method on namespace while creating isolated engine or application.

In order to run Engine as standalone application, you will need
Rails::Application instance in the same namespace that engine
one. It's very important to leave _railtie bound to whatever
used "namespace" method first.

1 files changed, 20 insertions, 0 deletions

diff --git a/railties/test/railties/engine_test.rb b/railties/test/railties/engine_test.rb
index a9dd7d4c1b..17bffe05e1 100644
--- a/railties/test/railties/engine_test.rb
+++ b/railties/test/railties/engine_test.rb
@@ -643,5 +643,25 @@ module RailtiesTest
       Bukkits::Engine.load_seed
       assert Bukkits::Engine.config.bukkits_seeds_loaded
     end
+
+    test "using namespace more than once on one module should not overwrite _railtie method" do
+      @plugin.write "lib/bukkits.rb", <<-RUBY
+        module AppTemplate
+          class Engine < ::Rails::Engine
+            namespace(AppTemplate)
+          end
+        end
+      RUBY
+
+      add_to_config "namespace AppTemplate"
+
+      app_file "config/routes.rb", <<-RUBY
+        AppTemplate::Application.routes.draw do end
+      RUBY
+
+      boot_rails
+
+      assert_equal AppTemplate._railtie, AppTemplate::Engine
+    end
   end
 end