Pressing number keys for item transport (1-9) while not hovering over an inventory slot causes the game to crash

By clicking a number key for item transport in the inventory GUI (1, 2, 3, 4, 5, 6, 7, 8, 9) while hovering over with your mouse on something that isn’t an inventory slot, causes the game to crash. This crash occurs even if there isn’t an item in the hotbar slot corresponding to the pressed number key.