`join_to_delete` is same as `join_to_update`

activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb

@@ -344,18 +344,12 @@ def sanitize_limit(limit)
       # The default strategy for an UPDATE with joins is to use a subquery. This doesn't work
       # on MySQL (even when aliasing the tables), but MySQL allows using JOIN directly in
       # an UPDATE statement, so in the MySQL adapters we redefine this to do that.
-      def join_to_update(update, select) #:nodoc:
-        key = update.key
+      def join_to_update(update, select, key) # :nodoc:
         subselect = subquery_for(key, select)
 
         update.where key.in(subselect)
       end
-
-      def join_to_delete(delete, select, key) #:nodoc:
-        subselect = subquery_for(key, select)
-
-        delete.where key.in(subselect)
-      end
+      alias join_to_delete join_to_update
 
       protected
 

activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb

@@ -432,7 +432,7 @@ def exec_rollback_db_transaction #:nodoc:
       # In the simple case, MySQL allows us to place JOINs directly into the UPDATE
       # query. However, this does not allow for LIMIT, OFFSET and ORDER. To support
       # these, we must use a subquery.
-      def join_to_update(update, select) #:nodoc:
+      def join_to_update(update, select, key) # :nodoc:
         if select.limit || select.offset || select.orders.any?
           super
         else

activerecord/lib/active_record/relation.rb

@@ -371,11 +371,11 @@ def update_all(updates)
 
       stmt.set Arel.sql(@klass.send(:sanitize_sql_for_assignment, updates))
       stmt.table(table)
-      stmt.key = table[primary_key]
 
       if joins_values.any?
-        @klass.connection.join_to_update(stmt, arel)
+        @klass.connection.join_to_update(stmt, arel, table[primary_key])
       else
+        stmt.key = table[primary_key]
         stmt.take(arel.limit)
         stmt.order(*arel.orders)
         stmt.wheres = arel.constraints