component: Create curl-http3 flavour

Required components are added, and in order to be really on the bleeding edge
for experimental and fresh features pick up recent curl version.

Allow to use --alt-svc for the http3 flavour, as it is quite imporant switch
for HTTP3 feature.

Based on https://curl.se/docs/http3.html

component/curl/buildout.cfg

@@ -10,6 +10,8 @@ extends =
   ../zstd/buildout.cfg
   ../zlib/buildout.cfg
   ../nghttp2/buildout.cfg
+  ../ngtcp2/buildout.cfg
+  ../nghttp3/buildout.cfg
   ../ca-certificates/buildout.cfg
 parts =
   curl
@@ -36,10 +38,10 @@ configure-options =
   --disable-manual
   --enable-ipv6
   --disable-sspi
-  --disable-alt-svc
+  ${:ALT-SVC}
   --with-zlib=${zlib:location}
-  --with-ssl=${openssl:location}
-  --with-ca-path=${openssl:location}/etc/ssl/certs
+  --with-ssl=${:OPENSSL}
+  --with-ca-path=${:OPENSSL}/etc/ssl/certs
   --without-gnutls
   --without-polarssl
   --without-mbedtls
@@ -60,8 +62,34 @@ configure-options =
   --without-brotli
   --with-zstd=${zstd:location}
   --without-gssapi
+  ${:WITH}
+
+ALT-SVC = --disable-alt-svc
+LDFLAGS =
+OPENSSL = ${openssl:location}
+PATH =
+PKG_CONFIG_PATH =
+WITH =
 
 environment =
-  PATH=${perl:location}/bin:${pkgconfig:location}/bin:${xz-utils:location}/bin:%(PATH)s
-  PKG_CONFIG_PATH=${openssl:location}/lib/pkgconfig:${nghttp2:location}/lib/pkgconfig
-  LDFLAGS=-Wl,-rpath=${zlib:location}/lib -Wl,-rpath=${openssl:location}/lib -Wl,-rpath=${nghttp2:location}/lib -Wl,-rpath=${zstd:location}/lib
+  PATH=${perl:location}/bin:${pkgconfig:location}/bin:${xz-utils:location}/bin:${:PATH}:%(PATH)s
+  PKG_CONFIG_PATH=${:OPENSSL}/lib/pkgconfig:${nghttp2:location}/lib/pkgconfig${:PKG_CONFIG_PATH}
+  LDFLAGS=-Wl,-rpath=${zlib:location}/lib -Wl,-rpath=${:OPENSSL}/lib -Wl,-rpath=${nghttp2:location}/lib -Wl,-rpath=${zstd:location}/lib ${:LDFLAGS}
+
+[curl-http3]
+<= curl
+url = https://shacache.nxdcdn.com/73669dd9ed7aefbb30414c6ce2dd20c39bb2f106cf420dedf7d302eb2c4147876a05b0a1458661bcb66ab1d944e7254a42802caa31070a7e43e9dd24f98320b8
+md5sum = d71d04dd7201480df1024d5c754a9613
+pre-configure =
+  autoreconf -fisv -I ${libtool:location}/share/aclocal -I ${pkgconfig:location}/share/aclocal
+  automake
+  autoconf
+
+ALT-SVC = --enable-alt-svc
+LDFLAGS = -Wl,-rpath=${nghttp3:location}/lib -Wl,-rpath=${ngtcp2:location}/lib
+OPENSSL = ${openssl-quictls:location}
+PATH = ${autoconf:location}/bin:${automake:location}/bin:${libtool:location}/bin:${m4:location}/bin
+PKG_CONFIG_PATH = :${nghttp3:location}/lib/pkgconfig:${ngtcp2:location}/lib/pkgconfig
+WITH =
+  --with-nghttp3=${nghttp3:location}
+  --with-ngtcp2=${ngtcp2:location}

component/nghttp3/buildout.cfg

+[buildout]
+extends =
+  ../automake/buildout.cfg
+  ../libtool/buildout.cfg
+  ../pkgconfig/buildout.cfg
+
+[nghttp3]
+recipe = slapos.recipe.cmmi
+shared = true
+url = https://github.com/ngtcp2/nghttp3/archive/refs/tags/v0.8.0.tar.gz
+md5sum = c6068762cdf221ae1fed2351af40b4d6
+pre-configure =
+  autoreconf -fisv -I ${libtool:location}/share/aclocal -I ${pkgconfig:location}/share/aclocal
+  automake
+  autoconf
+configure-options =
+  --enable-lib-only
+environment =
+  PATH=${autoconf:location}/bin:${automake:location}/bin:${libtool:location}/bin:${m4:location}/bin:%(PATH)s

component/ngtcp2/buildout.cfg

+[buildout]
+extends =
+  ../pkgconfig/buildout.cfg
+  ../automake/buildout.cfg
+  ../libtool/buildout.cfg
+  ../pkgconfig/buildout.cfg
+
+[ngtcp2]
+recipe = slapos.recipe.cmmi
+shared = true
+url = https://github.com/ngtcp2/ngtcp2/archive/refs/tags/v0.12.1.tar.gz
+md5sum = c826c4630689d2afb9300b97cc5e52a3
+pre-configure =
+  autoreconf -fisv -I ${libtool:location}/share/aclocal -I ${pkgconfig:location}/share/aclocal
+  automake
+  autoconf
+configure-options =
+  --enable-lib-only
+environment =
+  PATH=${autoconf:location}/bin:${automake:location}/bin:${libtool:location}/bin:${m4:location}/bin:${pkgconfig:location}/bin:%(PATH)s
+  PKG_CONFIG_PATH=${openssl-quictls:location}/lib/pkgconfig:${nghttp3:location}/lib/pkgconfig
+  LDFLAGS=-Wl,-rpath=${openssl-quictls:location}/lib -Wl,-rpath=${nghttp3:location}/lib