msquic — No stream credit at first, then MAX_STREAMS mid-connection

Pass

Handled it: announced the block with 1 STREAMS_BLOCKED rather than opening a stream it had no credit for, which is what §4.6 recommends.

The client did what the clause requires.

What was measured

Client

msquic — .NET HttpClient + msquic, 2.7.0

Test

No stream credit at first, then MAX_STREAMS mid-connection — q-max-streams-credit

Clause

RFC 9000 §4.6 (MUST NOT)

Class

discretionary — The RFC permits either behaviour; the report says which was chosen.

Required behaviour

Wait for the credit, then open the request. This port grants no bidirectional streams in its transport parameters and issues MAX_STREAMS a moment later. §4.6 is unambiguous that a client may not jump the gun — "Endpoints MUST NOT exceed the limit set by their peer" — and announcing the wait with STREAMS_BLOCKED is a SHOULD, so a client that waits quietly is equally conformant. Giving up rather than waiting is not scored as a failure: nothing obliges a one-shot client to sit on a connection it cannot use yet, and the report says which it did.

Measured

2026-09-18

Reproduce it

The suite is the judge, so the reproduction is to point the same client at the same test and let the server report what it saw.

SESSION=$(curl -sX POST https://conformance.pqcrypta.com/session | jq -r .id)
# then drive msquic at the test URL and read the verdict:
curl -s https://conformance.pqcrypta.com/report/$SESSION.json | jq '.results["q-max-streams-credit"]'