Tolerated it and continued. The specification permits this but does not require it; a client that rejected it would also be conformant. The client process had already exited 1252ms in, before this test's reaction point at never observed, so the silence after that is not evidence either way.
The client did what the clause requires.
What was measured
- Client
- xquic — Alibaba xquic + BoringSSL, 2060a44
- Test
- SETTINGS containing the same identifier twice —
h-duplicate-setting - Clause
- RFC 9114 §7.2.4 (MAY)
- Class
- discretionary — The RFC permits either behaviour; the report says which was chosen.
- Required behaviour
- Either reject with H3_SETTINGS_ERROR or ignore the repeat — the specification says a receiver MAY treat this as an error, so both are conformant.
- Measured
- 2026-10-27
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=$(curl -sX POST https://conformance.pqcrypta.com/session | jq -r .id)
# then drive xquic at the test URL and read the verdict:
curl -s https://conformance.pqcrypta.com/report/$SESSION.json | jq '.results["h-duplicate-setting"]'