vue-storefront

Fix: changing the page back and forth could led to have no special price

This problem was caused by multiple problems:
 1. special_price and price could be the same
 2. special_price was compared with price and not original_price
 3. special_price from and to data where set to null (This could be
 a problem here I am not 100% sure but in other cases like telling the
 customer when the sales end would be broken with that.)

 This is most likely on a client side only bug. So when you client side
 tax calculation enabled.