Trying to put a non-fuel item into a furnace fuel slot drops it in the world instead

Might be a duplicate, searched my best, sorry if so.

How to reproduce

1. Place a furnace

2. Open the interface
3. Pick up a non-fuel item like dirt onto the cursor
4. Click in the fuel slot

Expected result
Nothing should happen

Actual result
You throw the item out of your inventory, it lands on the ground