Adding product to newly created cart fails

[Asaf Levy]

Hello, i'm trying to add a product to a newly created cart with a method I found somewhere on these forums, it mentioned using the function $cart->updateQty();

but for some reason it just fails, it outputs no error message and no exception to catch, even the debugger just disconnects when it gets to this line.

i'm calling it like this:

$cart->updateQty($prod['qty'], (int)$prod['id']);

what am I doing wrong?

 

Thanks in advance, Asaf