The Spotify AP reset the connection (recv -1, errno 104 ECONNRESET) on
the third Ping, every 6 minutes, like clockwork. cspot answered each
Ping at once; librespot (core/src/session.rs) waits 60 s:
Ping -> 60 s -> Pong -> PongAck -> 60 s -> Ping.
- 0003-delayed-pong: record the Ping, send the Pong 60 s later from
triggerTimeout() (called on every 3 s receive timeout), through the
PR #3 connection snapshot; dropped on reconnect.
- 0002-diag-log-recv-errors: log recv's return value/errno before
"Error in read" (error path only); this is what showed the RST.
Verified: over 8+ minutes Ping/delayed Pong/PongAck every 2 min, no
reset at the 6-minute mark.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
