bug#21590: 25.0.50; MS-Windows; fns.c:4863:21: error: 'MD5_DIGEST_SIZE' undeclared (first use in this function)

[Eli Zaretskii <eliz@gnu.org>]

> Date:  Wed, 30 Sep 2015 14:26:08 -0700
> From:  Keith David Bershatsky <esq@lawlist.com>
> Cc:  21590@debbugs.gnu.org
> 
> Eureka!  I now have a working recipe to build Emacs on WindowsXP with image support.  It ended up being a combination of mingw32, ezwinports, and xpm from GnuWin.  I will write up a current "cheat sheet" on emacs.stackexchange.com in the near future -- I opened a question there a couple of days ago.
> 
> The build fails at least a couple of ways on WindowsXP as described in this bug report #21590 when using GnuWin32, so there should probably be a strong warning (near the top) in the Emacs INSTALL readme file advising against using that resource -- and suggesting the use of ezwinports instead.  Alternatively, it may be a good idea at some point for the Emacs team to find out why Emacs fails (beyond just moving `md5.h` out of the way) to build with GnuWin32 and create a workaround in the building scripts, etc. since others will undoubtedly try to use that resource in the future.

GnuWin32 is the last resort.  If you cannot find something in other
places, you have either to look there or build your own ports.  The
latter is not something many people will consider on Windows.

And yes, some GnuWin32 need "tinkering".

> Eli:  As a feature request, please consider adding an XPM zip archive to ezwinports as this portion of the build recipe is more complicated than it needs to be.

We provide libXpm from the GNU FTP site, right near the Emacs Windows
binaries.  Building libXpm on Windows (actually, anything that lacks
X11) is not trivial, since you must hack out large parts of the code
that assume X.  At the time I decided not to port a new version of
libXpm because the new features were insignificant (or even absent, I
don't remember), whereas the existing port works very well for Emacs.

I see now that the information about libXpm availability is missing
from nt/INSTALL, so I will add it soon.

> Here is the rough outline of the recipe for building Emacs master branch on Windows XP -- thank you all for helping me to get passed several hurdles until finally reaching a working solution:

We have detailed instructions for this in nt/INSTALL.  It would be
good if you could compare your experience with what that file says,
and suggest any changes/additions.

Thanks.