Description:
------------
When testing against Sybase AS 12, varchar columns are described as unknown.

Test script:
---------------
#!~/src/php-src/sapi/cli/php
<?php

putenv("TDSDUMP=/home/stanley/src/freetds.log");

include("login.php");

$pdo=new PDO('dblib:host=localhost:2638;dbname=test;charset=UTF-8',$user,$pass);
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

$stmt = $pdo->query("SELECT cast('foo' as varchar(32)) as foo");
print_r($stmt->getColumnMeta(0));


?>


Expected result:
----------------
Array
(
    [max_length] => 32
    [precision] => 0
    [scale] => 0
    [column_source] => foo
    [native_type] => varchar
    [name] => foo
    [len] => 32
    [pdo_type] => 2
)


Actual result:
--------------
Array
(
    [max_length] => 0
    [precision] => 0
    [scale] => 0
    [column_source] => foo
    [native_type] => unknown
    [name] => foo
    [len] => 0
    [pdo_type] => 2
)