Remove support for OAUTH_REDIRECT_AT_SIGN_IN (#17287)

Fixes #15959

Introduced in #6540, OAUTH_REDIRECT_AT_SIGN_IN allowed skipping the log-in form
to instead redirect to the external OmniAuth login provider.

However, it did not prevent the log-in form on /about introduced by #10232 from
appearing, and completely broke with the introduction of #15228.

As I restoring that previous log-in flow without introducing a security
vulnerability may require extensive care and knowledge of how OmniAuth works,
this commit removes support for OAUTH_REDIRECT_AT_SIGN_IN instead for the time
being.

1 files changed, 0 insertions, 16 deletions

diff --git a/app/controllers/auth/sessions_controller.rb b/app/controllers/auth/sessions_controller.rb
index 3337a43c4..4d2695bf5 100644
--- a/app/controllers/auth/sessions_controller.rb
+++ b/app/controllers/auth/sessions_controller.rb
@@ -13,14 +13,6 @@ class Auth::SessionsController < Devise::SessionsController
   before_action :set_instance_presenter, only: [:new]
   before_action :set_body_classes
 
-  def new
-    Devise.omniauth_configs.each do |provider, config|
-      return redirect_to(omniauth_authorize_path(resource_name, provider)) if config.strategy.redirect_at_sign_in
-    end
-
-    super
-  end
-
   def create
     super do |resource|
       # We only need to call this if this hasn't already been
@@ -87,14 +79,6 @@ class Auth::SessionsController < Devise::SessionsController
     end
   end
 
-  def after_sign_out_path_for(_resource_or_scope)
-    Devise.omniauth_configs.each_value do |config|
-      return root_path if config.strategy.redirect_at_sign_in
-    end
-
-    super
-  end
-
   def require_no_authentication
     super