(http://curl.haxx.se/bug/view.cgi?id=2155496) pointing out an error case
  without a proper human-readable error message. When a read callback returns
  a too large value (like when trying to return a negative number) it would
  trigger and the generic error message then makes the proplem slightly
  different to track down. I've added an error message for this now.

has already been dereferenced so it is bound to be valid. Pointed out to us
by coverity.com

And on the other hand a message after setsockopt() certainly must use SOCKERRNO.

_ Update RPG binding accordingly.
_ Fix new options comments.

because the struct is declared on the stack and not all members are used so
we could just as well make struct with only struct members we actually need.

systems supporting getifaddrs(). Also fixed a problem where an IPv6
address could be chosen instead of an IPv4 one for --interface when it
involved a name lookup.

  fixed a CURLINFO_REDIRECT_URL memory leak and an additional wrong-doing:

  Any subsequent transfer with a redirect leaks memory, eventually crashing
  the process potentially.

  Any subsequent transfer WITHOUT a redirect causes the most recent redirect
  that DID occur on some previous transfer to still be reported.

  eventually identified a flaw in how the multi_socket interface in some cases
  missed to call the timeout callback when easy interfaces are removed and
  added within the same millisecond.

  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.

a fresh connection to be made in such cases and the request retransmitted.
This should fix test case 160.  Added test case 1079 in an attempt to
test a similar connection dropping scenario, but as a race condition, it's
hard to test reliably.

  the app re-used the handle to do a connection to host B and then again
  re-used the handle to host A, it would not update the info with host A's IP
  address (due to the connection being re-used) but it would instead report
  the info from host B.

  gets a 550 response back for the cases where a download (or NOBODY) is
  wanted. It still allows a 550 as response if the SIZE is used as part of an
  upload process (like if resuming an upload is requested and the file isn't
  there before the upload). I also modified the FTP test server and a few test
  cases accordingly to match this modified behavior.