What I would like to see:

I buy a product of category 60, get all products of category 59 with a discount of 35%.

So I need this:

$this->add_cat_to_cat(60, 59, "%", 35);

But then I only get one product of cat 59 with discount. I would like to see a discount on

*all*products I buy from category 59.

So I changed:

$bt_one_to_many = false;

to

$bt_one_to_many = true;

Now I can buy two

*different*products from cat 59 and get discount, but I still can't buy more than one of the

*same*products.

So I get the right amount of discount when I buy something from cat 60 and say, one of products a,b,c and d from cat 59, but if I buy something from cat 60 and want to buy 5 products a, 5 products b I only get the discount for one of the products a and for one of the products b.

It's a bit hard to explain, but I hope you understand it.

How can I solve this problem?