HTTP3 quiche and http_version

[monwolf]

We are starting to test http3 in our proxies and I found curl doesn't have the same behaviour when printing http_version variable.

When we do it with http/1.1:

$ docker run -it --rm --network test_network $curl curl -sk  https://usvc-ingress:1443/nginx_status -o/dev/null -w '%{http_version}\n'
1.1

If we do the same with http/3, it's empty:

$ docker run -it --rm --network test_network $curl curl -sk  --http3 https://usvc-ingress:1443/nginx_status -o/dev/null -w '%{http_version}\n'

The request is working fine with http/3:

$ docker run -it --rm --network test_network $curl curl -sk --http3 https://usvc-ingress:1443/nginx_status -i
HTTP/3 200
server: nginx
date: Mon, 29 Nov 2021 15:17:31 GMT
content-type: text/plain
content-length: 97
vary: accept-encoding
alt-svc: h3=":1443"
quic-status: quic

Active connections: 2
server accepts handled requests
 9 9 9
Reading: 0 Writing: 1 Waiting: 0

I compiled curl from sources using the versions:

ARG CURL_VERSION=curl-7_80_0
ARG QUICHE_VERSION=0.10.0

From curl -V:

$ docker run -it --rm --network test_network $curl curl -V
curl 7.80.0-DEV (x86_64-pc-linux-gnu) libcurl/7.80.0-DEV BoringSSL nghttp2/1.40.0 quiche/0.10.0
Release-Date: [unreleased]
Protocols: dict file ftp ftps gopher gophers http https imap imaps mqtt pop3 pop3s rtsp smb smbs smtp smtps telnet tftp
Features: alt-svc AsynchDNS HSTS HTTP2 HTTP3 HTTPS-proxy IPv6 Largefile NTLM NTLM_WB SSL UnixSockets