Index: src/wp-includes/wp-db.php
===================================================================
--- src/wp-includes/wp-db.php	(revision 33328)
+++ src/wp-includes/wp-db.php	(working copy)
@@ -1474,7 +1474,7 @@
 
 				if ( $attempt_fallback ) {
 					$this->use_mysqli = false;
-					$this->db_connect();
+					return $this->db_connect();
 				}
 			}
 		} else {