Same with MC-175090

Hoppers can delete bone meal from a composter on top if each slot of the hopper has a single item (That isn't bone meal and is not a full stack). It would be expected that the hopper would leave the bone meal in the composter and not delete it, as if all slots of the hopper were completely filled with full stacks.

To reproduce

1. Fill a hopper by placing one item in each slot (That isn't bone meal and is not a full stack)
2. Place a composter on top
3. Fill the composter up
   → At the last level, the hopper will grab the bone meal from the composter, but because each slot has an item and the hopper is not filled with full stacks, the item will be deleted