Cart Abandoned...

I've searched around for this information, but don't seem to be having much luck... is there a timeout period for purchases where the cart (or abandoned cart) contents gets put back into stock...? I have a client who will be only selling a few products, and very limited stock, and the last thing I'd want is for stock to be indicated as gone when it's actually stuck in cart-limbo. Equally, is there a graceful experience if someone adds something to their cart and tries to pay for it and the stock is no longer available (if the last item was purchased by someone else after the person added the item to their cart)...? Apologies if this is covered somewhere, but having trawled the forum and documentation I couldn't find the answers.

Thanks and keep up the great work Perch people! :)