FWIW I doubt HTTP 1.1 ever required support for other HTTP versions; see for instance <https://tools.ietf.org/html/rfc2068#section-19.7>.

This v2 patch adds another test that includes what I understand is a true HTTP 0.9 request (although the mock connection infrastructure closes the connection before receiving the response, so you don’t see any deadlock). This is based on <https://tools.ietf.org/html/rfc1945#page-22>, which includes only one CRLF newline. I also added an entry to the What’s New page.