Reported by an operator whose node sends little: nothing for two minutes, then a
reconnect — losing the login, the filters, and any spot that arrived during the
gap.
The read had a 120 s deadline and ANY error ended the session, a timeout
included. That reads a silence as a verdict on the link. It is not: a cluster on
a dead band legitimately says nothing for minutes.
Only a real error ends a session now. A genuinely dead peer is still caught, and
by the mechanism meant for it — TCP keepalive probes an idle connection and its
failure surfaces as an error on Read, not as a timeout. The dialer sets it
explicitly rather than inheriting a default, since it is now what the design
depends on.
One trap the advice this came from did not mention: ReadString returns the bytes
it HAD read along with the timeout. Discarding them would lose the first half of
any spot line straddling a deadline, so the partial is carried over.
Tested: a listener that goes silent past the deadline and then sends a spot —
the spot arrives on the ORIGINAL connection, and the listener never accepts a
second one. The tick is a var so that test runs in four seconds instead of
sixty; a slow test is a test that gets skipped.
rouggy
72fee7a090