bug#74312: 31.0.50; Cygw32 build break

[Eli Zaretskii]

> Date: Wed, 13 Nov 2024 01:14:54 +0900
> From: Kazuhiro Ito <kzhr@d1.dion.ne.jp>
> Cc: Eli Zaretskii <eliz@gnu.org>, Ken Brown <kbrown@cornell.edu>
> 
> > Thanks, I tried to fix those.
> 
> As far as I tested, modifying your change as below was needed.  

Thanks, installed.

> > And when it does build, please try the drag-n-drop feature, both with
> > dropping files and with dropping text on Emacs.
> 
> Dropping multiple files or text works the same as MingW build except
> files and directories with non-ascii name.  When I dragged such files
> in Emacs frame, mouse cursor changed into red NO ENTRY SIGN (U+1F6AB)
> and no response for dropping.

I guess I didn't understand how are file names dropped into a Cygwin
program encoded?  Are they in UTF-8, per chance?  I assumed that in
the Cygw32 build they will be in UTF-16, like for native Windows
programs, but maybe that is wrong?  Or maybe we should do something on
Cygwin to announce that we support dropping files?

Did dropping a file or a directory on a Cygw32 Emacs work in previous
versions when the file/directory had a non-ASCII name?