Description:
------------
PDO MySQL not allow create multi connections from one PHP session

Test script:
---------------
#!/usr/bin/php
<?php
error_reporting(E_ALL);
ini_set('display_errors','On');

$dsn = 'mysql:dbname=test;unix_socket=/var/lib/mysql/mysql.sock';
$user = 'root';
$pass = '';



$connection1 = new PDO(	$dsn,
						$user,
						$pass,
						array(	PDO::ATTR_PERSISTENT => true,
								PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8",
								PDO::MYSQL_ATTR_USE_BUFFERED_QUERY => false,
								PDO::ATTR_AUTOCOMMIT => false,
								PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION
							)
					);

$connection2 = new PDO(	$dsn,
						$user,
						$pass,
						array(	PDO::ATTR_PERSISTENT => true,
								PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8",
								PDO::MYSQL_ATTR_USE_BUFFERED_QUERY => false,
								PDO::ATTR_AUTOCOMMIT => false,
								PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION
							)
					);

$sth1 = $connection1->query('select 1');
$sth2 = $connection2->query('select 2');

unset($connection1);
unset($connection2);

echo("It's works");
?>


Expected result:
----------------
I am expected that I can send first query for connection1 and second query for connection2.

But I see what still uses one connection :(

Actual result:
--------------
We have
Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[HY000]: General error: 2014 Cannot execute queries while other unbuffered queries are active.  Consider using PDOStatement::fetchAll().  Alternatively, if your code is only ever going to run against mysql, you may enable query buffering by setting the PDO::MYSQL_ATTR_USE_BUFFERED_QUERY attribute.' in /home/crmdev/www/bes/mysql_multi_connection_bug.php:35