Furnace creates an infinite number of experience orbs

Steps to Reproduce:

1. Place a furnace, blast furnace, or smoker and open its UI.
2. With the UI open, place any quantity of any output item from a furnace recipe in slot 3 of your hotbar. It can be any furnace recipe, not necessarily one that's valid for a blast furnace or smoker if you're using one of those.
3. Remove any number of items from slot #3 of the hotbar. You can put them back and remove them as many times as you like.

Observed Results:

• An experience orb will be generated for each removal.
• The amount of experience is proportional to (presumably, equal to) the XP that would be earned by taking those items from the output slot.

Expected Results:

• Removing items from the hotbar does not create experience orbs.

Speculation:
A furnace, blast furnace, or smoker's output slot is designated as #3. The game must be detecting items removed from slot #3 but failing to check whether the slot belongs to the furnace.