[MC-105131] Boat get into minecart

You can put the minecart on boats

Helper edit:

In fact, boats ride the minecart.

Environment

Win 10 Java1.8 1024mb

Don't see a bug here.
A boat is an entity and Minecarts can be ridden by other entities.

But minecarts cannot be ridden by ender crystal by push the mineart.

And version 1.9.4/1.8.9 does not have this issue.

also noticed that the boats sink and cannot be ridden when on minecarts.

Resolved in favor of MC-113871 with better explanation