Question

I need to unset my session variables, when PayPal returns IPN.

The simplest script is the following

<?php
session_start();
unset($_SESSION['my_item']);
?>

Paypal sends IPN, all works fine, but after request my session variable save it’s value.

What can be a problem?

Thanks

UPDATE

As mentioned, when ipn sends request, it’s already another session, so i can do the following.

Before send user to paypal, set custom variable to current

session_id();

When paypal sends ipn, i can change current session to previus session, and clear it.

session_id($_POST[custom]); 
session_start(); 
session_destroy(); //works fine

Answer 1

The problem here is that the IPN notification is not associated with the correct session.

The IPN is effectively a new session – it does not present the same session cookies that your client does, because you have not set them. Sessions are unique to a client, and the paypal gateway is a different client to that of your user.

You will need to bounce this information through a database. There is no sensible, easy way to have the IPN receiver directly modify the user’s session data.