Localize with i18n for Devise::FailureApp (#2309)

This PR fixes I18n.locale for rake middlewares. Mastodon uses Devise that depends on Warden.
Warden::Manager can be found in rake middleware. It is outside of the controller.

In the case of authentication failed, warden calls throw(:warden). At the time Warden::Manager
delegates request to failure_app to generate response and flash[:alert] after catching it.
Unfortunately, I18n.locale is already reset then because I18n.with_locale is enabled only
inside the controller. If we used I18n.locale=, Devise::FailureApp could get the current locale.

2 files changed, 7 insertions, 17 deletions

diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 291895457..0c324762d 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -115,8 +115,7 @@ class ApplicationController < ActionController::Base
   end
 
   def respond_with_error(code)
-    set_locale do
-      render "errors/#{code}", layout: 'error', status: code
-    end
+    set_locale
+    render "errors/#{code}", layout: 'error', status: code
   end
 end
diff --git a/app/controllers/concerns/localized.rb b/app/controllers/concerns/localized.rb
index d9a7a7227..44762df2a 100644
--- a/app/controllers/concerns/localized.rb
+++ b/app/controllers/concerns/localized.rb
@@ -4,25 +4,16 @@ module Localized
   extend ActiveSupport::Concern
 
   included do
-    around_action :set_locale
+    before_action :set_locale
   end
 
   private
 
   def set_locale
-    locale = default_locale
-
-    if user_signed_in?
-      begin
-        locale = current_user.try(:locale) || default_locale
-      rescue I18n::InvalidLocale
-        locale = default_locale
-      end
-    end
-
-    I18n.with_locale(locale) do
-      yield
-    end
+    I18n.locale = default_locale
+    I18n.locale = current_user.locale if user_signed_in?
+  rescue I18n::InvalidLocale
+    I18n.locale = default_locale
   end
 
   def default_locale