A connection drops before any response is read. What does RFC 9110 require of an intermediary proxy regarding retries?
A proxy MAY retry any request once, since the response was never seen
A proxy MUST NOT retry any request, idempotent or not
A proxy MUST NOT automatically retry non-idempotent requests✓Правильный ответ
A proxy MUST retry idempotent requests on the client's behalf
Объяснение
The prohibition on automatic retry of non-idempotent requests is absolute for proxies (MUST NOT), while a client only gets a SHOULD NOT and may retry when it has other grounds to believe the request is safe to repeat. Retrying idempotent requests is permitted, not required.