Description of feature: The current state save of mod_muc on shutdown is great, it lets the admin restart Prosody in a way that is almost invisible to participants. If Prosody isn’t aware it is going to shutdown though, this mechanism isn’t used and participants will have to discover by themselves they aren’t present anymore, either the next time they reconnect, or by implementing XEP-0410. It would be neat if Prosody would always keep the state of the MUC saved on disk, to be ready for this event. It would consume more IO but on most deployments it isn’t a problem anyway, and the frequency could be tweaked or even this feature could be disabled if it becomes a bother. Another solution could be to store only the list of current participants, and on a restart after a crash to notify these people with an error, so they can come back on their own, but I think the first solution is better. Motivation: (Why?) Prosody or the computer it is running on can crash, and it makes MUCs seem unstable to people, as they don’t get notified they aren’t in anymore.