Direct evidence from aioquic interop qlog:
packet_sent PN=0 frames=[crypto] (ClientHello)
packet_sent PN=1 frames=[ping] (PTO probe — bare PING)
packet_received frames=[connection_close]
reason="Packet contains no CRYPTO frame"
aioquic strictly rejects pre-handshake Initials that contain no
CRYPTO frame. Our PTO probe was a bare PING, not a CRYPTO retransmit.
Agent 2's c9e036f72 implemented the right behavior: on PTO, the
driver requeues all inflight CRYPTO at the highest pre-application
level, so the next drain emits a fresh CRYPTO frame at the original
offset. The pendingPing flag stays as a fallback only used when no
CRYPTO is available to retransmit. That logic was wiped during the
qlog observer merge — driver's PTO branch only set pendingPing,
nothing requeued anything, probe was always bare PING.
Restored. Should fix the post-flush-fix regression where aioquic
went 1/7 (only transfer green) — once a packet was dropped or PTO
fired, the next probe was bare PING, aioquic closed with
"no CRYPTO frame", the test failed. Sequential tests on the same
matrix invocation likely intermittently passed/failed depending on
whether PTO fired before the response arrived.
The :quic helpers requeueAllInflightCrypto + highestPreApplicationLevel
already exist on the branch — just the driver call wasn't wired.
https://claude.ai/code/session_01HcvfQq1ttPV9PkRoJb4nyT
Claude
c0d7b6031a