Log types are interchangeable in a furnace

If you have Birch logs(or pine) and Oak logs in you're inventory and decide to make some charcoal and you see that the Birch logs are higher in the inventory than Oak and want to put the Oak into the top of the furnace one at a time, it will one by one change a Birch log to an Oak log in the furnace. If you hold down to select more than the amount of Birch the game will crash.

Inventory:
Birch Logs*
Skip 1 or more rows (it could even be to the right of the Birch)
Oak Logs*