alt-svc protocol not support "h3"

[Cering]

I did this

curl -v -o /dev/null --alt-svc ./altsvc.txt "https://www.google.com"

I expected the following

• when curl parsing alt-svc header, the log shows that Unknown alt-svc protocol "h3", skipping

< HTTP/3 200
< date: Fri, 16 Sep 2022 10:19:13 GMT
< expires: -1
< cache-control: private, max-age=0
< content-type: text/html; charset=ISO-8859-1
< p3p: CP="This is not a P3P policy! See g.co/p3phelp for more info."
< server: gws
< x-xss-protection: 0
< x-frame-options: SAMEORIGIN
< set-cookie: 1P_JAR=2022-09-16-10; expires=Sun, 16-Oct-2022 10:19:13 GMT; path=/; domain=.google.com; Secure
< set-cookie: AEC=AakniGMc-ZdeohAySBgKAjYlOvo5pNY9dzD8EIcJZ-9EOeHDSpnxocFiKgs; expires=Wed, 15-Mar-2023 10:19:13 GMT; path=/; domain=.google.com; Secure; HttpOnly; SameSite=lax
< set-cookie: NID=511=MtDg8vS6WMcbLheQpqz2F039f1B9KfbGNos52NvUFKp6C3xhhpucrPpFkQ9YX0x7cakBYfy89KGulFXsK9DEKCgHmb8NPXjN3RVyF3v2tXmzYNGzKAck-gqYkGfFx-4hNTnxPoyvLRAfrloZ2d2UhQmLN9wVEcAGuyv1YPoEbFY; expires=Sat, 18-Mar-2023 10:19:13 GMT; path=/; domain=.google.com; HttpOnly
* Unknown alt-svc protocol "h3", skipping.
* Added alt-svc: www.google.com:443 over h3-29
* Unknown alt-svc protocol "h3-Q050", skipping.
* Unknown alt-svc protocol "h3-Q046", skipping.
* Unknown alt-svc protocol "h3-Q043", skipping.
* Unknown alt-svc protocol "quic", skipping.
< alt-svc: h3=":443"; ma=2592000,h3-29=":443"; ma=2592000,h3-Q050=":443"; ma=2592000,h3-Q046=":443"; ma=2592000,h3-Q043=":443"; ma=2592000,quic=":443"; ma=2592000; v="46,43"
< accept-ranges: none
< vary: Accept-Encoding

• my curl's http3 is based on quiche, and quiche already Support for QUIC v1 (RFC 8999, 9000, 9001, 9002) since 0.9.0, that is "h3" in alt-svc header
• "h3" and "h3-29" are the major quic version online now, can curl support both in alt-svc header?

curl/libcurl version

curl 7.83.0 (x86_64-pc-linux-gnu) libcurl/7.83.0 BoringSSL zlib/1.2.7 brotli/1.0.9 nghttp2/1.41.0 quiche/0.12.0
Release-Date: 2022-04-27
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 brotli Debug HSTS HTTP2 HTTP3 HTTPS-proxy IPv6 Largefile libz NTLM NTLM_WB SSL TrackMemory UnixSockets

operating system

Linux mylinux 3.10.0-957.el7.x86_64 #1 SMP Thu Nov 8 23:39:32 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

[bagder]

That code is clearly lagging behind. I see no reason why this shouldn't just use h3 always.