[dcc2] SIDs and connections to self.

[myndzi]

> Yes, this looks really as a special case. The cleanest way I can think of to
> handle it is to use a message counter (MID=<count>) token.
> In this way you are always able to detect if an incoming message is odd or
> even in a negotiation.

In another post I mentioned giving each stage a distinct name. That
would apply here as well. However, I like the idea of a counter
better, as you can just increment it each time and compare (count > N,
abort).

-myndzi