Description:
------------
Hello,

When I am trying to create PDO object with the following 
dsn, i am getting the following error.
$dsn='mysql:dbname=test;host=localhost';

Connection failed
SQLSTATE[HY000] [2005] Unknown MySQL server host '.' (4)

However, if i change the dsn string to something like 
$dsn='mysql:dbname=test;host=127.0.0.1';
there seem to be no problem.

AS you can see, in the second case, i am passing the host IP address instead of string 'localhost';

my /etc/hosts file looks like below.

<root@localhost /opt/IBMIHS/htdocs/en_US> cat /etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1               localhost.localdomain localhost
127.0.0.1               localhost

I am using IHS with PHP 5.0.3 on IA32 box running with RHEL3,

I am not sure whether this is a bug, or is there any thing silly which I am missing.

Thank you,
Srini.

Reproduce code:
---------------
<?php

//$dsn='mysql:dbname=test;host=127.0.0.1';
$dsn='mysql:dbname=test;host=localhost';
$user='root';
$password='qpoiqpoi';

try {
    $dbh = new PDO($dsn, $user, $password);
    print "PDO Object has been created </br>";
} catch (PDOException $e) {
    print "Connection failed </br>" . $e->getMessage();
}
?>


Expected result:
----------------
PDO Object has been created

Actual result:
--------------
Connection failed
SQLSTATE[HY000] [2005] Unknown MySQL server host '.' (4)