While a Connect awaits its Accept, only an Accept the client honours retires it. An Ack that names the Connect (a server's reply to a repeat or a stale copy) no longer wedges the client with nothing to resend. The Connect payload lives on the session, so a fresh attempt can always be built. The fresh attempt uses the abandoned sequence plus the receive window less one (serial), so a late copy of the abandoned Connect stays inside the new one's stale window; only a session's first Connect draws at random.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
A frame at or before the seeded watermark is a duplicate of an earlier generation and is acknowledged, never delivered again (serial compare within the receive window). A Connect that precedes the current generation's within the window is a stale copy of an earlier attempt: it is answered like a repeat (Accept owed or Ack), changes no state and does not refresh liveness. A Connect unanswered for 3 s is replaced by a fresh Connect with a newly drawn sequence and the same payload. In server mode a Connect from another endpoint is always a new generation. The initial sequence is unset by default and each session draws its own; the public random helper is removed.
An accepted peer now stamps its liveness on accept, so one that goes silent times out.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
A bounded session whose queue still held an unacknowledged Accept for a peer
that vanished refused the next Connect; the old server-mode path reset before
accepting, so this would have been a regression. accept_connect and
create_connect now end the generation first in every runtime, and a test per
runtime holds a one-slot queue to it.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Two rules the first mutation pass found undefended in every runtime: a new
Connect on a session that had a peer clears the old peer's received window (a
restarted server's sequences overlap the old ones), and ending a session
abandons its pending Connect. The cultmesh-py server test now counts the
server's own data packets by sequence, so a peer replaced on a retransmitted
Connect is seen, and asserts a restarted client inherits no subscription.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
