Subject: bug#42406: Mouse-wheel scrolling can be flickering

From: martin rudalics <[email-masked]>
Date: Fri, 18 Dec 2020 00:19:29 +0100

>     if (WINDOWP (fselected_window) && XWINDOW (fselected_window) == w)
 > -    update_mode_lines = 42;
 > +    {
 > +      update_mode_lines = 2;
 > +      fset_redisplay (XFRAME (WINDOW_FRAME (w)));
 > +    }
 >     else
 >       w->update_mode_line = true;

Why penalize people with >= 2 windows per selected frame when scrolling
one of them by updating all the others' mode, header, tab lines?

martin