Description:
------------
infinite results and huge CPU usage

Test script:
---------------
<?php

$pdo = new \PDO('mysql:host=localhost;dbname=test', 'test', 'test');
$db  = new db( $pdo );
class db
{
    public function __construct(\PDO &$pdo = null, array $options = []) { $this->pdo = $pdo; }
    public function query( $sql, array $bind = [], array $options = [])
    {
        $stmt = $this->pdo->prepare($sql);
        $stmt->execute($bind);
        return $stmt;
    }
}
$sql = "SELECT change_id as id FROM ac_changelog LIMIT 10";
while( $row = $db->query( $sql )->fetch() )
{
    echo $row['id'] . PHP_EOL;
}

?>



Expected result:
----------------
10 results returned.

Actual result:
--------------
infinite results and huge CPU usage and until the process is killed.

changing code to 

$stmt = $db->query( $sql );

while( $row = $stmt->fetch() )
{
    echo $row['id'] . PHP_EOL;
}

fixes the problem.