make CURLOPT_PROXYUSERPWD sort of deprecated. The primary motive for adding
  these new options is that they have no problems with the colon separator
  that the CURLOPT_PROXYUSERPWD option does.

  curl_easy_setopt: CURLOPT_USERNAME and CURLOPT_PASSWORD that sort of
  deprecates the good old CURLOPT_USERPWD since they allow applications to set
  the user name and password independently and perhaps more importantly allow
  both to contain colon(s) which CURLOPT_USERPWD doesn't fully support.

request.

Detect cases where an upload must be sent chunked and the server supports
only HTTP 1.0 and return CURLE_UPLOAD_FAILED.

  CURLOPT_POST301 (but adds a define for backwards compatibility for you who
  don't define CURL_NO_OLDIES). This option allows you to now also change the
  libcurl behavior for a HTTP response 302 after a POST to not use GET in the
  subsequent request (when CURLOPT_FOLLOWLOCATION is enabled). I edited the
  patch somewhat before commit. The curl tool got a matching --post302
  option. Test case 1076 was added to verify this.

  enabling this feature with CURLOPT_CERTINFO for a request using SSL (HTTPS
  or FTPS), libcurl will gather lots of server certificate info and that info
  can then get extracted by a client after the request has completed with
  curl_easy_getinfo()'s CURLINFO_CERTINFO option. Linus Nielsen Feltzing
  helped me test and smoothen out this feature.

  Unfortunately, this feature currently only works with libcurl built to use
  OpenSSL.

  This feature was sponsored by networking4all.com - thanks!

  parser to allow numerical IPv6-addresses to be specified with the scope
  given, as per RFC4007 - with a percent letter that itself needs to be URL
  escaped. For example, for an address of fe80::1234%1 the HTTP URL is:
  "http://[fe80::1234%251]/"

and OS/2.

CURLINFO_APPCONNECT_TIME. This is set with the "application layer"
handshake/connection is completed (typically SSL, TLS or SSH). By using this
you can figure out the application layer's own connect time. You can extract
the time stamp using curl's -w option and the new variable named
'time_appconnect'. This feature was sponsored by Lenny Rachitsky at NeuStar.

  OpenSSL, NSS and GnuTLS-built libcurls.

  OpenSSL, NSS and GnuTLS-built libcurls.

  curl_easy_getinfo. It returns a pointer to a string with the most recently
  used IP address. Modified test case 500 to also verify this feature. The
  implementing of this feature was sponsored by Lenny Rachitsky at NeuStar.

  redirections and thus cannot use CURLOPT_FOLLOWLOCATION easily, we now
  introduce the new CURLINFO_REDIRECT_URL option that lets applications
  extract the URL libcurl would've redirected to if it had been told to. This
  then enables the application to continue to that URL as it thinks is
  suitable, without having to re-implement the magic of creating the new URL
  from the Location: header etc. Test 1029 verifies it.

a single state variable to make the code easier to follow and understand.

  better control at the exact state of the connection's SSL status so that we
  know exactly when it has completed the SSL negotiation or not so that there
  won't be accidental re-uses of connections that are wrongly believed to be
  in SSL-completed-negotiate state.

  such as the CURLOPT_SSL_CTX_FUNCTION one treat that as if it was a Location:
  following. The patch that introduced this feature was done for 7.11.0, but
  this code and functionality has been broken since about 7.15.4 (March 2006)
  with the introduction of non-blocking OpenSSL "connects".

  It was a hack to begin with and since it doesn't work and hasn't worked
  correctly for a long time and nobody has even noticed, I consider it a very
  suitable subject for plain removal. And so it was done.

  use of the "is_in_pipeline" struct field.

  the SingleRequest one to make pipelining better. It is a bit tricky to keep
  them in the right place, to keep things related to the actual request or to
  the actual connection in the right place.

that it is bad anyway. Starting now, removing a handle that is in used in a
pipeline will break the pipeline - it'll be set back up again but still...

previously had a number of flaws, perhaps most notably when an application
fired up N transfers at once as then they wouldn't pipeline at all that
nicely as anyone would think... Test case 530 was also updated to take the
improved functionality into account.

The signalling of that a global DNS cache is wanted is done by setting the
option but the setting of the internal variable that it is in use must not be
done until it finally actually gets used!

NOTE and WARNING: I noticed that you can't actually switch off the global dns
cache with CURLOPT_DNS_USE_GLOBAL_CACHE but you couldn't do that previously
either and the option is very clearly and loudly documented as DO NOTE USE so
I won't bother to fix this bug now.

silly code left from when we switched to let the multi handle "hold" the dns
cache when using the multi interface... Of course this only triggered when a
certain function call returned error at the correct moment.

obvious ways. Give an explicit error.

libcurl to seek in a given input stream. This is particularly important when
doing upload resumes when there's already a huge part of the file present
remotely. Before, and still if this callback isn't used, libcurl will read
and through away the entire file up to the point to where the resuming
begins (which of course can be a slow opereration depending on file size,
I/O bandwidth and more). This new function will also be preferred to get
used instead of the CURLOPT_IOCTLFUNCTION for seeking back in a stream when
doing multi-stage HTTP auth with POST/PUT.

and the write callbacks that now can make a connection's reading and/or
writing get paused.

code to instead introduce support for a new proxy type called
CURLPROXY_SOCKS5_HOSTNAME that is used to send the host name to the proxy
instead of IP address and there's thus no longer any need for a new
curl_easy_setopt() option.

The default SOCKS5 proxy is again back to sending the IP address to the
proxy.  The new curl command line option for enabling sending host name to a
SOCKS5 proxy is now --socks5-hostname.

proxy do the host name resolving and only if --socks5ip (or
CURLOPT_SOCKS5_RESOLVE_LOCAL) is used we resolve the host name locally and
pass on the IP address only to the proxy.

the appending of the "type=" thing on FTP URLs when they are passed to a
HTTP proxy. Some proxies just don't like that appending (which is done
unconditionally in 7.17.1), and some proxies treat binary/ascii transfers
better with the appending done!

is inited at the start of the DO action. I removed the Curl_transfer_keeper
struct completely, and I had to move out a few struct members (that had to
be set before DO or used after DONE) to the UrlState struct. The SingleRequest
struct is accessed with SessionHandle->req.

One of the biggest reasons for doing this was the bunch of duplicate struct
members in HandleData and Curl_transfer_keeper since it was really messy to
keep track of two variables with the same name and basically the same purpose!

the same state struct as the host auth, so both could never be used at the
same time! I fixed it (without being able to check) to use two separate
structs to allow authentication using Negotiate on host and proxy
simultanouesly.

do_init() and do_complete() which now are called first and last in the DO
function. It simplified the flow in multi.c and the functions got more
sensible names!

persistent connection. Mentioned by Immanuel Gregoire on the mailing list.

out that SFTP requests didn't use persistent connections. Neither did SCP
ones.  I gave the SSH code a good beating and now both SCP and SFTP should
use persistent connections fine. I also did a bunch for indent changes as
well as a bug fix for the "keyboard interactive" auth.

connectdata struct. This will in theory enable us to do persistent connections
with SCP+SFTP, but currently the state machine always (and wrongly) cleanup
everything in the 'done' action instead of in 'disconnect'. Also did a bunch
of indent fixes, if () => if() and a few other source cleanups like added
comments etc.

https://bugzilla.novell.com/show_bug.cgi?id=332917 about a HTTP redirect to
FTP that caused memory havoc. His work together with my efforts created two
fixes:

#1 - FTP::file was moved to struct ftp_conn, because is has to be dealt with
     at connection cleanup, at which time the struct HandleData could be
     used by another connection.
     Also, the unused char *urlpath member is removed from struct FTP.

#2 - provide a Curl_reset_reqproto() function that frees
     data->reqdata.proto.* on connection setup if needed (that is if the
     SessionHandle was used by a different connection).