Ticket #33926: 33926-db.patch

src/wp-includes/wp-db.php

@@ -1541 +1541 @@
          */
         public function check_connection( $allow_bail = true ) {
                 if ( $this->use_mysqli ) {
-                        if ( @mysqli_ping( $this->dbh ) ) {
+                        if ( !empty( $this->dbh ) && @mysqli_ping( $this->dbh ) ) {
                                 return true;
                         }
                 } else {
-                        if ( @mysql_ping( $this->dbh ) ) {
+                        if ( !empty( $this->dbh ) && @mysql_ping( $this->dbh ) ) {
                                 return true;
                         }
                 }
@@ -1651 +1651 @@
                 // Keep track of the last query for debug..
                 $this->last_query = $query;
 
+                // Try to reconnect if the db handle is empty to avoid catchable fatal error.
+                if ( empty( $this->dbh ) && !$this->check_connection() ) {
+                        $this->insert_id = 0;
+                        return false;
+                }
+
                 $this->_do_query( $query );
 
                 // MySQL server has gone away, try to reconnect