Small tidy up on Rails::Engine.

railties/lib/rails/engine.rb

@@ -288,7 +288,6 @@ def endpoint(endpoint = nil)
       end
 
       def namespace(mod)
-        # TODO: extract that into a module
         engine_name(generate_railtie_name(mod))
 
         _railtie = self
@@ -386,7 +385,7 @@ def config
     # per engine and get the engine as a block parameter
     initializer :set_autoload_paths, :before => :bootstrap_hook do |app|
       ActiveSupport::Dependencies.autoload_paths.unshift(*_all_autoload_paths)
-      ActiveSupport::Dependencies.autoload_once_paths.unshift(*config.autoload_once_paths)
+      ActiveSupport::Dependencies.autoload_once_paths.unshift(*_all_autoload_once_paths)
 
       # Freeze so future modifications will fail rather than do nothing mysteriously
       config.autoload_paths.freeze
@@ -419,11 +418,9 @@ def config
 
     initializer :add_view_paths do
       views = paths.app.views.to_a
-      ActiveSupport.on_load(:action_controller) do
-        prepend_view_path(views)
-      end
-      ActiveSupport.on_load(:action_mailer) do
-        prepend_view_path(views)
+      unless views.empty?
+        ActiveSupport.on_load(:action_controller){ prepend_view_path(views) }
+        ActiveSupport.on_load(:action_mailer){ prepend_view_path(views) }
       end
     end
 
@@ -433,7 +430,7 @@ def config
     end
 
     initializer :append_asset_paths do
-      config.asset_path = "/#{engine_name}%s" unless config.asset_path
+      config.asset_path ||= "/#{engine_name}%s"
 
       public_path = config.paths.public.to_a.first
       if config.compiled_asset_path && File.exist?(public_path)
@@ -479,6 +476,10 @@ def default_middleware_stack
       ActionDispatch::MiddlewareStack.new
     end
 
+    def _all_autoload_once_paths
+      config.autoload_once_paths
+    end
+
     def _all_autoload_paths
       @_all_autoload_paths ||= (config.autoload_paths + config.eager_load_paths + config.autoload_once_paths).uniq
     end