bug#65191: 29.1; -ms and -cr CL options don't work

[Po Lu via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Peter Mao <peter.mao@gmail.com>
>> Date: Wed, 9 Aug 2023 20:00:43 -0700
>> 
>> Recipe:
>> emacs-29.1 -Q -ms red -cr green &
>> 
>> - Cursor is not green; mouse pointer is not red.  "-cr" definitely worked in
>> v28.2, but "-ms" did not.
>> - This problem does not occur on MacOS -- both "-cr" and "-ms" work properly (config follows Ubuntu
>> config below)
>> - On Ubuntu, "-cr" worked in earlier versions of Emacs, but "-ms" did not.
>> - `set-cursor-color` works properly in all cases
>> - `set-mouse-color` does not work on Ubuntu, but it does work on OSX.
>> - Emacs did not crash.
>
> This works for me on MS-Windows (although the Windows build currently
> doesn't support -ms).
>
> Po Lu, can you please see why this doesn't work on X with GTK?

-ms doesn't work on GNOME systems, as a consequence of XRender cursors
being configured by default.  Those cursors aren't simple bitmaps, and
thus cannot be recolored.

I will look into -cr.