Receiving XP from items placed in furnace slot via hopper

Put the summary of the bug you're having here

What I expected to happen was...:
Nothing.

What actually happened was...:
Received xp for the items removed from furnace

Steps to Reproduce:
1. Fill the fuel slot in the furnace
2. fill the item slot in the furnace (item to be smelted)
3. place hopper on top of furnace
4. Fill the hopper with any ingots or gems (tested with diamonds, emeralds, gold and iron)
5. remove them from the smelted item slot