QuicConnection.onTokensLost(tokens) closes the loop between loss
detection (step 5) and writer drain (step 4). For each lost token:
- Ack: ignored (RFC 9000 §13.2.1: ACK frames not retransmittable)
- MaxStreamsUni: pendingMaxStreamsUni := token.maxStreams
iff token.maxStreams == advertisedMaxStreamsUni
- MaxStreamsBidi / MaxData: same shape, against their advertised cap
- MaxStreamData: pendingMaxStreamData[streamId] := maxData iff
stream exists AND token.maxData == stream.receiveLimit
The supersede check (`lost == advertised`) mirrors neqo's
`fc.rs::frame_lost` line 322. If a higher extension has gone out
since, the older lost frame is irrelevant — the newer value
covers the receiver's grant. Without the check we'd resurrect
stale extensions and waste wire bandwidth re-emitting values the
peer already has.
Wired into the parser's AckFrame handler immediately after
detectAndRemoveLost: walk each lost packet's tokens and call
onTokensLost. Caller already holds the connection lock.
Tests added (8, all pass):
- ackToken_doesNotPopulateAnyPending
- lostMaxStreamsUni_matchingAdvertised_setsPending
- lostMaxStreamsUni_supersededByHigherEmit_isDropped (the
supersede-check invariant from neqo's fc.rs:322)
- lostMaxStreamsBidi_matchingAdvertised_setsPending
- lostMaxData_matchingAdvertised_setsPending
- lostMaxData_supersededIsDropped
- lostMaxStreamData_unknownStream_dropped (defensive)
- multipleLostTokens_dispatchAll (one packet's worth of mixed
tokens dispatched in one call)
- lostTokensFromMultiplePackets_unionInPending (sequential
dispatch across multiple lost packets — older stale, newer
valid; the valid one survives)
Mirror of neqo's `streams.rs::lost` dispatch + the
`no_max_allowed_frame_after_old_loss` and
`set_max_active_equal_does_not_set_frame_pending` tests from
`fc.rs` deferred from step 4 per the plan.
Full :quic test suite + nestsClient moq-lite tests pass.
https://claude.ai/code/session_01PYYez8a6sjiakyjAxsfCEQ
Claude
15a6bfcc84