When QuicConnection tears down (CONNECTION_CLOSE, read-loop death,
INTERNAL_ERROR from a saturated stream channel, etc.) the per-stream
incomingChannel objects were left open, so any application coroutine
suspended on `stream.incoming.collect { … }` hung forever waiting for
a FIN that would never come. The connection-wide signal channels
(closedSignal, peerStreamSignal, incomingDatagramSignal) all closed
cleanly, but the per-stream Flows did not — surfacing in the
quic-interop-runner `multiplexing` case as 677 collectors stuck after
the connection died mid-response, so zero of the 1999 expected files
landed.
Fix: closeAllSignals() now also calls closeIncoming() on every stream
in streamsList. Channel.close() is idempotent, and consumeAsFlow drains
already-buffered chunks before honouring the close, so any bytes the
parser had already pushed are still surfaced to the collector before
the Flow terminates.
Adds MultiStreamFinDeliveryTest covering: (a) FIN delivery to N parallel
client-bidi streams, (b) connection-teardown unblocks every per-stream
Flow, (c) buffered bytes survive a teardown without an explicit FIN.
Claude
39f9ae2aab