When I shift click items to smelt into a furnace exactly when another item finishes the furnace interface keeps the old smelting in it's place and doesn't display the newly smelted item. This stays in effect until the menu is closed and reopened or until one tries to move one of the shift-clicked items. Shift-clicking the invisible smelted item moves them into your inventory.
What I expected to happen:
The furnace should have updated the smelting item to the shift-clicked item and displayed the smelted item.
What actually happened:
The furnace didn't update the last smelting item or the smelted item.
Steps to reproduce:
- Open a furnace with a fuel and two different smelting items.
- Place the fuel and one of the first item into the furnace to smelt.
- At the exact moment the first item finishes smelting, shift-click the second in. (I find spam clicking to be most effective)
- Notice the furnace interface doesn't update to the new smelting item or the just-finished smelted item.
- Click on the smelted item slot, or close and reopen the furnace and the interface will display correctly.
This also affects blast furnaces and smokers, but is more difficult to reproduce, due to the increased speed.