Steps to reproduce:

1. Place down 2 rails of any type connecting to each other
2. Place a boat one block away on the same line as the rails are on
3. Place a minecart on the rails
4. Push the minecart into the boat. Make sure to have enough velocity when pushing the minecart.
5. If the boat is now considered in the minecart, the bug can be produced. If not, repeat steps 1-5 until so.

Observed Result:

When you right click anywhere in the minecart's hitbox, it doesn't do anything. If you right click on the boat's hitbox (/data get entity @p RootVehicle shows that you are in the boat which is the passenger of the minecart; you can also see that you can add another entity such as a sheep as a passenger of the boat, meaning that you are in fact in the boat), you ride the boat. However, you cannot control the boat, even though you can control the boat OR a minecart when on land. Nor can you push the boat-cart thing and in certain angles you get camera bobbing if you continue to push the boat-cart thing.

Expected Result:

Either:

• The boat/minecart should be able to be pushed
• If the fact that they cannot be pushed is intended, there shouldn't be any camera bobbing