The bug

Minecarts make walking sounds when moving after they've been pushed off and back on rails.

How to reproduce:

1. Create a circular rail loop using both normal and some powered rails (see attached video)
2. Put a Minecart on the rails and push it so that it starts moving along the placed rails
3. Destroy a rail block and push the Minecart off the rail as soon as it arrives at the broken part
4. Push it back on the rails and place the rail again
5. Fly up / don't move and listen carefully–the Minecart will make walking sounds while moving