fail to build when this happens, and show an appropriate error.

The brave of heart can circumvect this. Defining ALLOW_MSVC6_WITHOUT_PSDK
in lib/config-win32.h, although absolutely discouraged and unsupported,
this will allow the die hard MSVC hacker to build in such a discouraged
environment.

The actually supported 'fix' is to install 'February 2003 Platform SDK'
a.k.a. 'Windows Server 2003 PSDK' which can be freely downloaded from
http://www.microsoft.com/msdownload/platformsdk/sdkupdate/psdk-full.htm

is only expanded and included once in the configure script.

due to autoconf 2.64 m4_require'ing it in _AS_SHELL_SANITIZE indirectly through
_AS_PATH_WALK.

  that now makes curl_getdate(3) actually handles RFC 822 formatted dates that
  use the "single letter military timezones".
  http://www.rfc-ref.org/RFC-TEXTS/822/chapter5.html has the details.

Check for basename() is now done the same as other function checks

  data!

(http://curl.haxx.se/bug/view.cgi?id=2873666) which identified a problem which
made libcurl loop infinitely when given incorrect credentials when using HTTP
GSS negotiate authentication.

  libcurl called NSS to close the SSL "session" it also closed the actual
  socket.

As it actually builds with gcrypt these days, but not the NSS functions.

Fix invalid file name characters handling on Windows

else ASN1_STRING_to_UTF8() returns the string length.

Fix potential out-of-bounds read

Fix compiler warning: loop without body

- Fixing out of bounds memory overwrite triggered with malformed /etc/hosts file.
- Improving parsing of /etc/hosts file.
- Validating requested address family.
- Ensuring that failures always return a NULL pointer.
- Adjusting header inclusions.

target as indicated end requested by Viktor Szakats in bug report #2872879.

  (http://curl.haxx.se/bug/view.cgi?id=2870221) that libcurl returned an
  incorrect return code from the internal trynextip() function which caused
  him grief. This is a regression that was introduced in 7.19.1 and I find it
  strange it hasn't hit us harder, but I won't persue into figuring out
  exactly why.

  SO_SNDBUF to CURL_WRITE_SIZE even if the SO_SNDBUF starts out larger.  The
  patch doesn't do a setsockopt if SO_SNDBUF is already greater than
  CURL_WRITE_SIZE. This should help folks who have set up their computer with
  large send buffers.

make errno available as a preprocessor macro.