Replace define_method with alias_method in Omniauth Controllers

app/controllers/ldap/omniauth_callbacks_controller.rb

@@ -2,23 +2,21 @@ class Ldap::OmniauthCallbacksController < OmniauthCallbacksController
   extend ::Gitlab::Utils::Override
 
   def self.define_providers!
-    if Gitlab::Auth::LDAP::Config.enabled?
-      Gitlab::Auth::LDAP::Config.available_servers.each do |server|
-        define_method server['provider_name'] do
-          ldap
-        end
-      end
+    return unless Gitlab::Auth::LDAP::Config.enabled?
+
+    Gitlab::Auth::LDAP::Config.available_servers.each do |server|
+      alias_method server['provider_name'], :ldap
     end
   end
 
-  define_providers!
-
   # We only find ourselves here
   # if the authentication to LDAP was successful.
   def ldap
     sign_in_user_flow(Gitlab::Auth::LDAP::User)
   end
 
+  define_providers!
+
   override :set_remember_me
   def set_remember_me(user)
     user.remember_me = params[:remember_me] if user.persisted?

app/controllers/omniauth_callbacks_controller.rb

@@ -4,10 +4,12 @@ class OmniauthCallbacksController < Devise::OmniauthCallbacksController
 
   protect_from_forgery except: [:kerberos, :saml, :cas3]
 
+  def handle_omniauth
+    omniauth_flow(Gitlab::Auth::OAuth)
+  end
+
   Gitlab.config.omniauth.providers.each do |provider|
-    define_method provider['name'] do
-      handle_omniauth
-    end
+    alias_method provider['name'], :handle_omniauth
   end
 
   # Extend the standard implementation to also increment
@@ -70,10 +72,6 @@ class OmniauthCallbacksController < Devise::OmniauthCallbacksController
 
   private
 
-  def handle_omniauth
-    omniauth_flow(Gitlab::Auth::OAuth)
-  end
-
   def omniauth_flow(auth_module, identity_linker: nil)
     if current_user
       log_audit_event(current_user, with: oauth['provider'])

lib/gitlab/auth/ldap/user.rb

@@ -49,7 +49,7 @@ module Gitlab
         end
 
         def valid_sign_in?
-          allowed?
+          allowed? && super
         end
 
         def ldap_config