Ticket #23085: 23085.3.patch

wp-includes/wp-db.php

@@ -1670 +1670 @@
                         $this->last_error = mysql_error( $this->dbh );
                 }
 
-                if ( $this->last_error ) {
+                if ( is_resource( $this->dbh ) && $this->last_error ) {
                         // Clear insert_id on a subsequent failed insert.
                         if ( $this->insert_id && preg_match( '/^\s*(insert|replace)\s/i', $query ) )
                                 $this->insert_id = 0;