bug#42406: Mouse-wheel scrolling can be flickering

[martin rudalics]

>> Not necessarily.  If you don't see any problems there, the calls in
>> window_scroll_pixel_based could be possibly removed since that case
>> should be covered elsewhere.
>
> Sorry, no.  We will not remove those calls without a positive evidence
> that they are not needed.  It is not enough to say that someone
> doesn't see any adverse effects in his/her use patterns and Emacs
> customizations.

Agreed, obviously.  But updating the mode lines on all frames because a
user scrolls a window is pure overkill.  So if all else fails, we could
make such behavior optional.

martin