Furnace creates wrong items

Furnaces will turn items into wrong items

Raw Porkchop is turned into Raw Salmon
Raw Beef is turned into Cooked Chicken
Raw Fish is turned into Cooked Salmon
Raw Salmon is turned into Melon
Iron Ore is turned into Stick

Note that the result is not always wrong. Raw Mutton becomes Cooked Mutton and Birch Wood becomes Charcoal.