What happens with socket's client scope on 'disconnect' event (server side)

So What happens with socket's client scope on 'disconnect' event?

I'm trying to avoid bad racing conditions and logic flaws in my node.js + mongoose + socket.io app.

What do I mean by scope is:

io.on('connection', function (client) { 
///CLIENT SCOPE///
//define private vars, store and operate client's session info//
//recieving and sending client's socket signals//
}

Some background: Let's say, for example, I implement some function that operates db by finding room and writing user to this room.

BUT, in the moment when the room (to be written in) found, but user yet not written in - he disconnects. On disconnect event i must pull him out of his last room in db, but i can not, it's not saved in db for this moment yet. The only way I see is to assign a bool value on 'disconnect' event against which i can check before saving guy in to the room and in the case of true don't save him at all.

What i'm confused with - would this bool survive a disconnect event, as it saved in client's scope.

What happens with the scope? is it completely wiped out on disconnect? or it's wiped out only when everything that relys on this scope is finished?

I'm using 'forceNew': true to force socket.connect(); to socket immedietly if something goes wrong (hypothetically) and socket error fired without user really leaving the site.

If user reconnects through this 'old' socket is he getting back his scope on server, or this socket's previous scope has been wiped out on his disconnection or wiped out on reconnection by on 'connection' event?