Minecart with a Furnace can take anything as fuel

The bug

A Minecart with a Furnace can take anything as fuel (ex. Buckets, Cobwebs, Wither Rose etc.) and be able to run.

To reproduce

1. Make a track (I did this with regular rails)
2. Place a Minecart with a Furnace
3. Use any none fuel based item (Buckets, Cobwebs, Wither Rose etc.)
   → Watch the Minecart run, and no 'fuel' is used