used during the FTP connection phase (after the actual TCP connect), while
  it of course should be. I also made the speed check get called correctly so
  that really slow servers will trigger that properly too.

  QUOTE commands and the request used the same path as the connection had
  already changed to, it would decide that no commands would be necessary for
  the "DO" action and that was not handled properly but libcurl would instead
  hang.

- Introduced a SYST-based test to properly set-up name format when dealing  with the OS/400 FTP server.
- Fixed an ftp_readresp() bug preventing detection of failing control socket  and causing FTP client to loop forever.

  (http://curl.haxx.se/bug/view.cgi?id=2835196), fixing a few compiler
  warnings when mixing ints and bools.

  CURLOPT_PREQUOTE) now accept a preceeding asterisk before the command to
  send when using FTP, as a sign that libcurl shall simply ignore the response
  from the server instead of treating it as an error. Not treating a 400+ FTP
  response code as an error means that failed commands will not abort the
  chain of commands, nor will they cause the connection to get disconnected.

  setting a file descriptor non-blocking. Used by the functionality Eric
  himself brough on June 15th.

Markus Koetter provided a patch to avoid getnameinfo() usage which broke a couple of both IPv4 and IPv6 autobuilds.

to use the "standard" ENABLE_IPV6 one. Also, if port number cannot be figured
out to connect to after a name resolve (due to it not being IPv4 or IPv6),
that particular address will now simply be skipped.

  range if given colon-separated after the host name/address part. Like
  "192.168.0.1:2000-10000"

With the curl memory tracking feature decoupled from the debug build feature,
CURLDEBUG and DEBUGBUILD preprocessor symbol definitions are used as follows:

CURLDEBUG used for curl debug memory tracking specific code (--enable-curldebug)

DEBUGBUILD used for debug enabled specific code (--enable-debug)

  https://bugzilla.redhat.com/show_bug.cgi?id=427966 which was libcurl closing
  a bad file descriptor when closing down the FTP data connection.  Caolan
  McNamara seems to be the original author of it.

thinking straight.

badness in the code flow even for the socks case.

  well. See change 28 Apr 2009.

  Chen pointed out how curl couldn't upload with resume when reading from a
  pipe.

  This ended up with the introduction of a new return code for the
  CURLOPT_SEEKFUNCTION callback that basically says that the seek failed but
  that libcurl may try to resolve the situation anyway. In our case this means
  libcurl will attempt to instead read that much data from the stream instead
  of seeking and that way curl can now upload with resume when data is read
  from a stream!

  how it occurs (http://curl.haxx.se/mail/lib-2009-04/0289.html). The
  conclusion was that if an error is detected and Curl_done() is called for
  the connection, ftp_done() could at times return another error code that
  then would take precedence and that new code confused existing logic that
  works for the first error code (CURLE_SEND_ERROR) only.

  proxy. libcurl would then wrongly close the connection after each
  request. In his case it had the weird side-effect that it killed NTLM auth
  for the proxy causing an inifinite loop!

  I added test case 1098 to verify this fix. The test case does however not
  properly verify that the transfers are done persistently - as I couldn't
  think of a clever way to achieve it right now - but you need to read the
  stderr output after a test run to see that it truly did the right thing.

  strdup() call failed.

  FTP with the multi interface: when a transfer fails, like when aborted by a
  write callback, the control connection was wrongly closed and thus not
  re-used properly.

  This change is also an attempt to cleanup the code somewhat in this area, as
  now the FTP code attempts to keep (better) track on pending responses
  necessary to get read in ftp_done().

FTP downloads (i.e.: RETR) ending with code 550 now return error CURLE_REMOTE_FILE_NOT_FOUND instead of CURLE_FTP_COULDNT_RETR_FILE.

  plain FTP connections, and it will then allow MKD to fail once and retry the
  CWD afterwards. This is especially useful if you're doing many simultanoes
  connections against the same server and they all have this option enabled,
  as then CWD may first fail but then another connection does MKD before this
  connection and thus MKD fails but trying CWD works! The numbers can
  (should?) now be set with the convenience enums now called
  CURLFTP_CREATE_DIR and CURLFTP_CREATE_DIR_RETRY.

  Tests has proven that if you're making an application that uploads a set of
  files to an ftp server, you will get a noticable gain in speed if you're
  using multiple connections and this option will be then be very useful.

  the condition in the previous request was unmet. This is typically a time
  condition set with CURLOPT_TIMECONDITION and was previously not possible to
  reliably figure out. From bug report #2565128
  (http://curl.haxx.se/bug/view.cgi?id=2565128)

  version 1.1 instead of 1.0 like before. This change also introduces the new
  proxy type for libcurl called 'CURLPROXY_HTTP_1_0' that then allows apps to
  switch (back) to CONNECT 1.0 requests. The curl tool also got a --proxy1.0
  option that works exactly like --proxy but sets CURLPROXY_HTTP_1_0.

  I updated all test cases cases that use CONNECT and I tried to do some using
  --proxy1.0 and some updated to do CONNECT 1.1 to get both versions run.

the problem.

clarity.  This does fix one problem that causes ;type=i FTP URLs
to fail in the Turkish locale when CURLOPT_PROXY_TRANSFER_MODE is
used (test case 561)

Added tests 561 and 1092 through 1094 to test various combinations
of ;type= and ;mode= URLs that could potentially fail in the Turkish
locale.

  now has an improved ability to do right when the multi interface (both
  "regular" and multi_socket) is used for SCP and SFTP transfers. This should
  result in (much) less busy-loop situations and thus less CPU usage with no
  speed loss.

  particular state for the control connection like it did before for implicit
  FTPS (libcurl assumed such control connections to be encrypted while some
  FTPS servers such as FileZilla assumes such connections to be clear
  mode). Use the CURLOPT_USE_SSL option to set your desired level.

  researching it, it turned out he got a 550 response back from a SIZE command
  and then I fell over the text in RFC3659 that says:

   The presence of the 550 error response to a SIZE command MUST NOT be taken
   by the client as an indication that the file cannot be transferred in the
   current MODE and TYPE.

  In other words: the change I did on September 30th 2008 and that has been
  included in the last two releases were a regression and a bad idea. We MUST
  NOT take a 550 response from SIZE as a hint that the file doesn't exist.