No - I think you misunderstood what I was asking.
If there are 10 in stock of an item and I add 15 to the cart. It changes the quantity added to 10, but it does not show the message that only 10 have been added. It only shows this message if I go back and try to add more or if I change the quantity and press update cart.
Here is an example on the demo store.
Products_Detail.php?ProductID=16
On the above link, try to add a quantity of 110 to the cart. It will change the quantity to 100 but will not let you know that it is doing that.