Description:
------------
If PDO is using ERRMODE_EXCEPTION, the errorInfo property of PDOException is not filled with the driver specific errorinformation.

A patch is available at http://www.phpschlampe.de/pdo_dbh.patch

Reproduce code:
---------------
<?php
$sql    =   new PDO         ("mysql:host=localhost;dbname=test","foo","bar");
$sql    ->  setAttribute    (PDO::ATTR_ERRMODE,PDO::ERRMODE_EXCEPTION);
try{
    $sql    ->  query           ("INSERT INTO test.nonexistent (id) VALUES (1)");
}catch(PDOException $e){
    echo $e->getMessage();
    print_r($e->errorInfo);
}
?>

Expected result:
----------------
Output of the errormessage and a filled errorInfo-Array

Actual result:
--------------
errormessage is ok, but errorInfo is NULL