bug#74833: 31.0.50; Copy to OS clipboard doesn't work in macOS Terminal.app with xterm-mouse-mode enabled

[Eli Zaretskii <eliz@gnu.org>]

> From: Gerd Möllmann <gerd.moellmann@gmail.com>
> Cc: Eli Zaretskii <eliz@gnu.org>,  Jared Finder <jared@finder.org>,
>   74833@debbugs.gnu.org,  shipmints@gmail.com
> Date: Mon, 16 Dec 2024 18:30:30 +0100
> 
> Mouse support by default is an important feature, IMO. It makes the menu
> bar usable, or in a future Emacs containing tty child frames tooltips
> can be shown. Not to mention setting point and what else.

I agree that mouse support is an important feature -- if it works well
and doesn't cause regressions.  Here it seems like at least some
people could see some breakage.

It is easy to turn on xterm-mouse-mode for those who want it and don't
get anything broken due to it.  Turning it on by default is only TRT
if there are no significant downsides.  IOW, we shouldn't force users
to turn off some feature that is turned on by default because the
default doesn't work or breaks something.

So I still think it is safer to turn this off on Terminal.app, if we
can detect it.