bug#66765: 30.0.50; Building emacs with xinput2 breaks receiving XSendEvent events

[Eli Zaretskii]

> Cc: 66765-done@debbugs.gnu.org
> Date: Fri, 27 Oct 2023 08:32:44 +0800
> From:  Po Lu via "Bug reports for GNU Emacs,
>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
> 
> When the X input extension is in use, both Emacs and the X server ignore
> core events.  It's also impossible to send extension events, so this
> extension renders external event delivery effectively impossible.
> 
> This isn't a bug we can fix, sorry; but the XTEST extension is capable
> of simulating real key presses, so I suggest whatever tools send Emacs
> events be rewritten to make use of that extension.
> 
> The same issue can be observed in programs written to use version 3 or 4
> of the GTK toolkit.

Can you please add something to etc/PROBLEMS about this issue?

How widely is this mechanism used in the wild?  If it is used widely
enough, perhaps we should tell people not to build with XInput2 if
they have vested interests in those methods?

Also, maybe submitting bug reports to the respective developers would
cause them to improve the situation?