Ticket #41745: 41745.patch

wp-includes/query.php

@@ -25 +25 @@
  */
 function get_query_var( $var, $default = '' ) {
         global $wp_query;
+    if( ! isset( $wp_query ) || ! method_exists( $wp_query, 'get' ) ) return $default;
         return $wp_query->get( $var, $default );
 }