When viewing the player in a minecart from third person view (F5), the player's body and legs will turn from one side to the other depending on the position of the camera. The player's legs will snap from one side to the other and never face forwards.

To reproduce:
1. Create a new Superflat world
2. Unpack the zip file "MC161477-generated.zip" into the world save. It should create a new folder called "generated".
3. Place a structure block in the world and load the structure "mc161477". It will create a copy of the minecart tracks from the other zip file.
4. Place a minecart on the minecart tracks and get into the minecart.
5. Turn from side to side in the minecart -> the player's legs will snap from side to side and not face forward.