Reorganize autoloads:

  * A new module (ActiveSupport::Autoload) is provide that extends
    autoloading with new behavior.
  * All autoloads in modules that have extended ActiveSupport::Autoload
    will be eagerly required in threadsafe environments
  * Autoloads can optionally leave off the path if the path is the same
    as full_constant_name.underscore
  * It is possible to specify that a group of autoloads live under an
    additional path. For instance, all of ActionDispatch's middlewares
    are ActionDispatch::MiddlewareName, but they live under 
    "action_dispatch/middlewares/middleware_name"
  * It is possible to specify that a group of autoloads are all found
    at the same path. For instance, a number of exceptions might all
    be declared there.
  * One consequence of this is that testing-related constants are not
    autoloaded. To get the testing helpers for a given component,
    require "component_name/test_case". For instance, "action_controller/test_case".
  * test_help.rb, which is automatically required by a Rails application's
    test helper, requires the test_case.rb for all active components, so
    this change will not be disruptive in existing or new applications.

3 files changed, 2 insertions, 2 deletions

diff --git a/actionpack/lib/action_controller/metal/compatibility.rb b/actionpack/lib/action_controller/metal/compatibility.rb
index 0c264fcd09..a90f798cd5 100644
--- a/actionpack/lib/action_controller/metal/compatibility.rb
+++ b/actionpack/lib/action_controller/metal/compatibility.rb
@@ -1,5 +1,5 @@
 module ActionController
-  module Rails2Compatibility
+  module Compatibility
     extend ActiveSupport::Concern
 
     class ::ActionController::ActionControllerError < StandardError #:nodoc:
diff --git a/actionpack/lib/action_controller/metal/helpers.rb b/actionpack/lib/action_controller/metal/helpers.rb
index b4325e24ad..d0402e5bad 100644
--- a/actionpack/lib/action_controller/metal/helpers.rb
+++ b/actionpack/lib/action_controller/metal/helpers.rb
@@ -52,7 +52,7 @@ module ActionController
     included do
       # Set the default directory for helpers
       extlib_inheritable_accessor(:helpers_dir) do
-        defined?(Rails) ? "#{Rails.root}/app/helpers" : "app/helpers"
+        defined?(Rails.root) ? "#{Rails.root}/app/helpers" : "app/helpers"
       end
     end
 
diff --git a/actionpack/lib/action_controller/metal/rescuable.rb b/actionpack/lib/action_controller/metal/rescue.rb
index bbca1b2179..bbca1b2179 100644
--- a/actionpack/lib/action_controller/metal/rescuable.rb
+++ b/actionpack/lib/action_controller/metal/rescue.rb