56. When libcurl sends CURLOPT_POSTQUOTE commands when connected to a SFTP

  server using the multi interface, the commands are not being sent correctly
  and instead the connection is "cancelled" (the operation is considered done)
  prematurely. There is a half-baked (busy-looping) patch provided in the bug
  report but it cannot be accepted as-is. See
  http://curl.haxx.se/bug/view.cgi?id=2006544