OwnerClientId Recycling and disconnection issues

[liambilly9]

Description

currently when i disconnect a client e.g with ownerclientid 1 when another client connects instead of being assigned the disconnected id of 1 he is assigned id 2

Reproduce Steps

1. starthost
2. connectclient
3. disconnectclient
4. reconnectclient

Actual Outcome

the reconnected client gets an incremented OwnerClientID

Expected Outcome

the reconnected client should use the previous disconnected clientid

Screenshots

If applicable, add screenshots to help explain your problem.

Environment

• OS: [windows10 pro]
• Unity Version: [e.g. 2021.3]
• Netcode Version: [e.g. 1.1.0-]

Additional Context

this also causes trouble when switching scenes as the destroyed playerobject when the client disconnected the first time and a script is trying to be access it

[ShadauxCat]

We don't currently support any sort of connection ID recycling, and I don't think we will want to add that. I think it would cause more issues than it would solve. For example, if user Bob is connected with ID of 1, and disconnects, and then user Alice connects, Alice would get the ID that was assigned to Bob. If game code is considering IDs to be equivalent to people (which is reasonable) and still has data structures around that correlate ID 1 to Bob, this could cause issues.

Could you explain why you would want Alice to reuse Bob's ID in this case?

Note: We don't yet have reconnect support to allow Bob to resume a previous session. In the current version, users need to implement that at the user code level using RPCs so that a reconnecting user can send the server identifying information and allow the server to switch those data structures over to be associated with the new connection ID.

[NoelStephensUnity]

@liambilly9
Just to follow up, persisting user information and/or connection state is covered in the session management section on the NGO documentation site.

[liambilly9]

a little bit to answer this, but the reason is because, when a player disconnects, he is leaving a null value in the connectedclientsdictionary e.g alice disconnected the dictionarywill read <ulong,networkclient> 1,missing which will later cause null refferences in the game,,