bug#53916: 29.0.50; pgtk: Gtk-WARNING with popup menu

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

Lars Ingebrigtsen <larsi@gnus.org> writes:

> Po Lu via "Bug reports for GNU Emacs, the Swiss army knife of text
> editors" <bug-gnu-emacs@gnu.org> writes:
>
>> That warning is harmless, though we could make it go away by installing
>> a log handler.  Someone else should chime in at this point to decide
>> whether or not that's worth it, since such a filter might end up
>> obscuring legitimate problems in the future.
>
> My impression is that most of these warnings from GTK are harmless, so
> perhaps having a log handler (and defaulting it to "off") would be good.
> (But there should be a user option to switch them on.)

I'm okay with doing that for this particular warning, and the
appropriate option already exists (the G_DEBUG environment variable can
be set to `fatal-warnings', which will cause GLib to abort upon
encoutering such a warning, even if we filter it out.)

But I don't know whether or not it's okay to treat all warnings that
way.  For example, bug#53900 is a serious bug that got caught by someone
noticing a warning emitted by GTK, and presumably wouldn't have been
reported if the warning had been filtered out.

Thanks.