Moved ActionMailer and ActionController railties options to inherited hook

This change is needed, because we must take namespace into account and if
controller's/mailer's class is namespaced, engine's paths should be set
instead of application's ones.

The nice side effect of this is removing unneeded logic in
ActionController::Base.inherited - now the helpers_path should be set
correctly even for engine's controllers, so helper(:all) will always
include correct helpers.

actionmailer/lib/action_mailer/railtie.rb

 require "action_mailer"
 require "rails"
 require "abstract_controller/railties/routes_helpers"
+require "action_mailer/railties/paths"
 
 module ActionMailer
   class Railtie < Rails::Railtie
@@ -11,17 +12,13 @@ class Railtie < Rails::Railtie
     end
 
     initializer "action_mailer.set_configs" do |app|
-      paths   = app.config.paths
       options = app.config.action_mailer
 
-      options.assets_dir      ||= paths.public.to_a.first
-      options.javascripts_dir ||= paths.public.javascripts.to_a.first
-      options.stylesheets_dir ||= paths.public.stylesheets.to_a.first
-
       ActiveSupport.on_load(:action_mailer) do
         include AbstractController::UrlFor
-        extend ::AbstractController::Railties::RoutesHelpers.with(app.routes)
         include app.routes.mounted_helpers(:app)
+        extend ::AbstractController::Railties::RoutesHelpers.with(app.routes)
+        extend ::ActionMailer::Railties::Paths.with(app)
         options.each { |k,v| send("#{k}=", v) }
       end
     end

actionmailer/lib/action_mailer/railties/paths.rb

+module ActionMailer
+  module Railties
+    module Paths
+      def self.with(_app)
+        Module.new do
+          define_method(:inherited) do |klass|
+            super(klass)
+            if namespace = klass.parents.detect {|m| m.respond_to?(:_railtie) }
+              app = namespace._railtie
+            else
+              app = _app
+            end
+
+            paths   = app.config.paths
+            options = app.config.action_mailer
+
+            options.assets_dir      ||= paths.public.to_a.first
+            options.javascripts_dir ||= paths.public.javascripts.to_a.first
+            options.stylesheets_dir ||= paths.public.stylesheets.to_a.first
+            options.each { |k,v| klass.send("#{k}=", v) }
+          end
+        end
+      end
+    end
+  end
+end

actionpack/lib/action_controller/base.rb

@@ -223,11 +223,7 @@ def self.without_modules(*modules)
 
     def self.inherited(klass)
       super
-      if namespace = klass.parents.detect {|m| m.respond_to?(:_railtie) }
-        klass.helper(all_helpers_from_path(namespace._railtie.config.paths.app.helpers.to_a))
-      else
-        klass.helper :all if klass.superclass == ActionController::Base
-      end
+      klass.helper :all if klass.superclass == ActionController::Base
     end
 
     ActiveSupport.run_load_hooks(:action_controller, self)

actionpack/lib/action_controller/railtie.rb

@@ -5,6 +5,7 @@
 require "active_support/deprecation/proxy_wrappers"
 require "active_support/deprecation"
 require "abstract_controller/railties/routes_helpers"
+require "action_controller/railties/paths"
 
 module ActionController
   class Railtie < Rails::Railtie
@@ -41,19 +42,10 @@ class Railtie < Rails::Railtie
     end
 
     initializer "action_controller.set_configs" do |app|
-      paths   = app.config.paths
-      options = app.config.action_controller
-
-      options.assets_dir           ||= paths.public.to_a.first
-      options.javascripts_dir      ||= paths.public.javascripts.to_a.first
-      options.stylesheets_dir      ||= paths.public.stylesheets.to_a.first
-      options.page_cache_directory ||= paths.public.to_a.first
-      options.helpers_path         ||= paths.app.helpers.to_a
-
       ActiveSupport.on_load(:action_controller) do
-        extend ::AbstractController::Railties::RoutesHelpers.with(app.routes)
         include app.routes.mounted_helpers(:app)
-        options.each { |k,v| send("#{k}=", v) }
+        extend ::AbstractController::Railties::RoutesHelpers.with(app.routes)
+        extend ::ActionController::Railties::Paths.with(app)
       end
     end
 

actionpack/lib/action_controller/railties/paths.rb

+module ActionController
+  module Railties
+    module Paths
+      def self.with(_app)
+        Module.new do
+          define_method(:inherited) do |klass|
+            super(klass)
+            if namespace = klass.parents.detect {|m| m.respond_to?(:_railtie) }
+              app = namespace._railtie
+            else
+              app = _app
+            end
+
+            paths   = app.config.paths
+            options = app.config.action_controller
+
+            options.assets_dir           ||= paths.public.to_a.first
+            options.javascripts_dir      ||= paths.public.javascripts.to_a.first
+            options.stylesheets_dir      ||= paths.public.stylesheets.to_a.first
+            options.page_cache_directory ||= paths.public.to_a.first
+            options.helpers_path         ||= paths.app.helpers.to_a
+            options.each { |k,v| klass.send("#{k}=", v) }
+          end
+        end
+      end
+    end
+  end
+end