If the player is disconnected from a multiplayer server while they are currently using a fishing rod, they will be able to recast their fishing rod without getting rid of the old line/bobber.

Steps to Reproduce:

1. Connect to a multiplayer server
2. Cast a fishing rod into a body of water
3. Disconnect your instance of Minecraft from the internet (Which will kick the player)
4. Reconnect your instance to the internet
5. Rejoin the server
6. Cast the fishing rod again

Observed Results:

The fishing rod will still be cast out when reconnecting, and the player will be able to cast the rod again. This will duplicate the bobber & line.

Expected Results:

The player would no longer be casting after being removed from a server.

Screenshots/Videos:

(Video from the original issue owner, please let me know if this link no longer works in the future and I will reproduce it)
https://drive.google.com/file/d/1yR-hckdZm6zC7mCvou1AjIwR8PCeUpR5/view?usp=sharing 

Notes:

1. This does not occur when the player is removed from the server via the 'kick' command.