This patch chooses different approach to integrate HTTP2 into HTTP curl
stack. The idea is that we insert HTTP2 layer between HTTP code and
socket(TLS) layer. When HTTP2 is initialized (either in NPN or Upgrade),
we replace the Curl_recv/Curl_send callbacks with HTTP2's, but keep the
original callbacks in http_conn struct. When sending serialized data by
nghttp2, we use original Curl_send callback. Likewise, when reading data
from network, we use original Curl_recv callback. In this way we can
treat both TLS and non-TLS connections.
With this patch, one can transfer contents from https://twitter.com and
from nghttp2 test server in plain HTTP as well.
The code still has rough edges. The notable one is I could not figure
out how to call nghttp2_session_send() when underlying socket is
writable.
Check the NPN result before preparing an HTTP request and switch into
HTTP/2.0 mode if necessary. This is a work in progress, the actual code
to prepare and send the request using nghttp2 is still missing from
Curl_http2_send_request().
the number of elements in the 'nghttp2_session_callbacks' structure is
now reduced by 2 in version 0.3.0 (I'm not sure when the change
happened, but checking for ver 0.3.0 work for me).
Something is wrong in 'userp' for the HTTP2 recv_callback(). The
session is created using bogus user-data; '&conn' and not 'conn'.
I noticed this since the socket-value in Curl_read_plain() was set to a
impossible high value.
Using the first little merge of nghttp2 into libcurl, I stumbeled on the
missing 'snprintf' in MSVCRT. Isn't this how we do it for other libcurl
files? I.e. use 'curl_msnprintf' and not 'snprintf' directly:
