1 pointAdvice to use a file compare is good advice. Otherwise, how can anyone write an install...as almost all shopowners have different versions of osc running or have not stuck to the idea of "no core changes" and so on. Put another way; addon makers would spend all their time writing installation instructions for 1000 different shopowners...
1 pointThis add to basket button has no link to the out of stock functionality. From memory...it is just some text on the shopping_cart page that changes dependent on the setting of the "mark product out of stock". https://github.com/gburton/Responsive-osCommerce/blob/master/shopping_cart.php#L85-L92 and https://github.com/gburton/Responsive-osCommerce/blob/master/shopping_cart.php#L116-L132 It's fairly useless as is, so the question is ... what next... ideas; create a module that turns off the buy buttons based on the stock level create a module that shows a stock message on the product page create a module that reacts to zero stock when the person is checking out I'm sure you can think of more.