Re: input-pending-p after make-frame-visible

[Eli Zaretskii <eliz@gnu.org>]

> From: Aaron Jensen <aaronjensen@gmail.com>
> Date: Wed, 20 Oct 2021 13:47:57 -0400
> Cc: martin rudalics <rudalics@gmx.at>, Alan Third <alan@idiocy.org>, 
> 	Gregory Heytings <gregory@heytings.org>, emacs-devel@gnu.org, 
> 	YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp>
> 
> > Yes.  But the change you propose is in readable_events, a function
> > that has many more callers than just input-pending-p.  In particular,
> > one of its callers is kbd_buffer_get_event, which is the API through
> > which Emacs reads all of its input.  And now, under some
> > circumstances, that API will ignore some events.  That's scary, at
> > least for me.
> 
> AFAICT kbd_buffer_get_event calls `readable_events (0)' only, which
> will disregard any of the code I changed or added. The
> READABLE_EVENTS_FILTER_EVENTS must be set for it to come into play.
> Only input-pending-p sets that flag AFAICT.

I don't see how this helps: who will remember that no caller of
readable_events can ever use that flag without invoking this behavior
whose justification we don't understand?

> > No, that must be a variable exposed to Lisp, so users could fiddle
> > with it without rebuilding.
> 
> Ah, I believe that variable exists already and can affect everything I
> changed other than the reliance on USE_TOOLKIT_SCROLL_BARS:
> while-no-input-ignore-events

No, it must be a separate variable, because it's for people who do
have non-nil while-no-input-ignore-events.