[feature suggestion] Duplicate registration of the same account should be rejected with an informative message

[yurivict]

Some people might copy the account files and run it on different devices (no multi-device support yet). In such case devices chaotically register/unregister, possibly kicking each other out. Other users see such account as going online/offline many times. I observed this behavior before, and again today (qTox/qTox#3525).

I suggest Tox should reject the duplicate account registrations with the message to user, possibly stating the IP address/time/any available information about the previous registration. Such condition may be caused by lost/stolen account/device, or simply by the copied account.

Rejecting the duplicate registration with an informative message is much better and safer behavior rather than what happens now. User will also know that something is wrong, vs. probably not noticing the problem as it is now.

[GrayHatter]

Doing so would prohibit you from reconnecting if you have a spotty internet connection

[LittleVulpix]

I do agree that this is an issue because if it happens, you generally have no way of telling the user to sort it out - because they will constantly flap between offline and online; and if any messages do get through, they will arrive on random of the two clients. A difficult thing to solve indeed...

[yurivict]

Maybe DHT should keep a state for a while and ban reregistration when done from the same host over and over again within seconds, but allow reregistration from the new IP.