I wanted to reordner my chests and furnaces, but have forgotten to get everything out of the furnaces. as i broke those, i did not get any experience for anything inside. the furnace was not alightened anymore, so i have forgotten to check if it is empty.
to reproduce this:
1. fill in a few raw (maybe 8, like i had) chicken (or anythin else what can be smelted) and a coal in the furnance to get it hotten
2. wait for the coal to burn down
3. when the work is done, grab your pickaxe and collect the furnace. it will drop you the cooked chicken and the furnace as intended, but no experience you would get for cooking the chicken.