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.

1 files changed, 2 insertions, 3 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