Description:
------------
According to http://www.php.net/manual/en/class.pdoexception.php,  PDOException::$errorInfo is string, but it is in fact an array (corresponding to PDO::errorInfo()) or NULL.


Reproduce code:
---------------
$sql = new PDO("mysql:host=localhost;dbname=mydb","john","secret");
$sql->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_EXCEPTION);
try {
  $sql->query("INSERT INTO test.nonexistent (id) VALUES (1)");
} catch(PDOException $e) {
  var_dump($e->errorInfo);
}


Actual result:
--------------
array(3) {
  [0]=>
  string(5) "42S02"
  [1]=>
  int(1146)
  [2]=>
  string(38) "Table 'test.nonexistent' doesn't exist"
}