You cannot attack players riding the same boat or camel as you

The Bug:

You cannot attack players riding the same boat or camel as you.

Steps to Reproduce:

1. Get two players and label them "Player A" and "Player B".
2. Get "Player A" to enter a boat and have "Player B" enter the same boat.
3. Get "Player B" to attempt to attack "Player A".
4. Take note as to whether or not you can attack players riding the same boat or camel as you.

Observed Behavior:

You cannot attack players riding the same boat or camel as you.

Expected Behavior:

You would be able to attack players riding the same boat or camel as you.