We have this problem. Customers have 3 products in cart. Then go to checkout & log-in: after login their cart is empty! Not good for conversion.
I see some questions actually requesting this functionality- but none that address our issue. Persistent shopping cart is set to NO
Question: Is there a setting to prevent the cart from being emptied after login?
Basically what we want is that no-matter-what the situation: the cart a user is "actively" populating (read: now) is always the cart. No merging, no resetting. Just use the cart as-is