problem with my CURLINFO_PRIMARY_IP fix from October 7th that caused a NULL
pointer read. I also took the opportunity to clean up this logic (storing of
the connection's IP address) somewhat as we had it stored in two different
places and ways previously and they are now unified.
and receive data over a connection previously setup with curl_easy_perform()
and its CURLOPT_CONNECT_ONLY option. The sendrecv.c example was added to
show how they can be used.
(http://curl.haxx.se/bug/view.cgi?id=1481217), with follow-ups by Michele Bini
and David Byron. libcurl previously wrongly used GetLastError() on windows to
get error details after socket-related function calls, when it really should
use WSAGetLastError() instead.
When changing to this, the former function Curl_ourerrno() is now instead
called Curl_sockerrno() as it is necessary to only use it to get errno from
socket-related functions as otherwise it won't work as intended on Windows.
counter so that the caller needs to decrease that counter when done with
the returned data.
If compiled with MALLOCDEBUG I've added some extra checking that the counter
is decreased before a handle is closed etc.
