Ticket #21099: 21099.2.patch

wp-includes/class-wp-theme.php

@@ -1071 +1071 @@
          * @return array Array of stylesheet names.
          */
         public static function get_allowed( $blog_id = null ) {
-                return self::get_allowed_on_network() + self::get_allowed_on_site( $blog_id );
+                $allowed_on_network = (array) apply_filters( 'allowed_themes', self::get_allowed_on_network() );
+                $allowed_on_site = (array) apply_filters( 'site_allowed_themes', self::get_allowed_on_site( $blog_id ), $blog_id );
+                return $allowed_on_network + $allowed_on_site;
         }
 
         /**