When a user includes commas in a text options field, an error results in shopping_cart.php, which expects commas to be delimiters of product id's.

After many hours trying to isolate the problem, I solved it by changing the function get_product_id_list() in classes/shopping_cart.php

Zip file includes the modified function only. All I did was take the true product ID to the product ID list, not the entire string, which contains attribute information, and in the case that a user has entered commas in text fields, commas.

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