Cart does not work

**Alfa1** · November 2, 2014

I cant add another license to my cart, because the price is always set to 1000000.

**pegasus** · November 2, 2014

Is there a specific browser you're using? I can't reproduce any problem using your cart in Chrome.

**Alfa1** · November 2, 2014

Firefox. Doesnt occur in Opera.
Also: I am being logged out from vw.org every time I leave the site.

**pegasus** · November 3, 2014

I've been looking at the logs for the cart. I think I've fixed the issue at hand.

When generating a new transaction at the Review Order page, the cart was correctly checking for an existing transaction to update and resubmit (in case you had canceled your payment and wanted to make changes to the cart).

However, when actually clicking the Checkout via PayPal button, the cart was not checking if the existing transaction contained the same info as the current cart contents before passing it to PayPal, but rather only checked if it was submitted by the same cart session.

It should have been possible to notice this on PayPal's own order review widget, but I think at the point that screen shows, most users just ignore it.

This is really a fringe case because it requires that at some point in the past you did the following:

1. Submitted an order to PayPal through our cart.
2. Instead of using PayPal's cancel link, you used the browser's Back button to return to the site.
3. Due to the Back button being used, the browser showed a cached version of the cart. Returning to the cart in the normal way (clicking a link to it) would have shown that the cart was empty because the cart was already submitted for payment.
4. In the cached cart, you clicked either Update Cart or Review Order.
5. You did not resubmit the order at that time.

The above process would result in 2 copies of the same cart session. After making updates to your cart later you would have 2 carts with the same session ID that contained 2 different sets of contents.

The Fix:
Now instead of just checking cart session IDs, our payment system also checks a hash of the cart contents to determine if the transaction being submitted is the same as what you are seeing in your cart.

Please note that it was never possible to use this technique as a hack to purchase items for a lower price. You would always be charged the correct price for the items that were actually received.

**hollosch** · November 10, 2014

License renewal doesn't work :-((

Transaction refused because of an invalid argument. See additional error messages for details.. The totals of the cart item amounts do not match order amounts.

**pegasus** · November 10, 2014

This occurred only when visiting the cart using the fake forum language "English (Translations)" rather than the site default "English (US)". The "English (Translations)" language did not have a decimal point character defined, which was causing prices in the cart to have 2 extra zeros at the end.

PayPal was rejecting carts submitted in this language because 60 == 60.00 but 60 != 6000 (decimal missing). This is now fixed for the "English (Translations)" language, so you should be able to proceed through checkout normally.

**hollosch** · November 12, 2014

It doesn't work...
I tested all available languages

Transaction refused because of an invalid argument. See additional error messages for details.. The totals of the cart item amounts do not match order amounts.