Index: src/wp-includes/taxonomy.php
===================================================================
--- src/wp-includes/taxonomy.php	(リビジョン 38618)
+++ src/wp-includes/taxonomy.php	(作業コピー)
@@ -2675,10 +2675,11 @@
 		 *
 		 * @since 2.9.0
 		 *
-		 * @param int   $object_id Object ID.
-		 * @param array $tt_ids    An array of term taxonomy IDs.
+		 * @param int    $object_id Object ID.
+		 * @param array  $tt_ids    An array of term taxonomy IDs.
+		 * @param string $taxonomy Taxonomy slug.
 		 */
-		do_action( 'deleted_term_relationships', $object_id, $tt_ids );
+		do_action( 'deleted_term_relationships', $object_id, $tt_ids, $taxonomy );
 
 		wp_update_term_count( $tt_ids, $taxonomy );