Subject: Re: bug#77039: 31.0.50; Flickering on macOS

From: Eli Zaretskii <[email-masked]>
Date: Sun, 23 Mar 2025 11:44:35 +0200

> From: Gerd Möllmann <[email-masked]>
> Cc: [email-masked],  [email-masked],  [email-masked]
> Date: Sun, 23 Mar 2025 10:32:29 +0100
> 
> Eli Zaretskii <[email-masked]> writes:
> 
> >> redisplay_internal has this (line numbers may differ):
> >> 
> >> xdisp.c:
> >> 17368       && (NILP (Vdisplay_line_numbers)
> >> 17369           || EQ (Vdisplay_line_numbers, Qvisual))
> >> 
> >> This means that certain redisplay optimizations that make redisplay
> >> particularly "cheap" are not tried, depending on line number display.
> >
> > See bug#54091.
> 
> Thanks, but it's still an enigma for me :-). I've never used
> hs-minor-mode and don't know how it is implemented. Is it the old
> selective display, and something the OP did that changed it that way?

No, it uses an overlay with 'invisible' property.  See hs-make-overlay
in hideshow.el.