bug#63187: 30.0.50; Tail of longer lines painted after end of nearby lines on macOS

[Aaron Jensen]

On Sun, Apr 30, 2023 at 9:25 AM Po Lu <luangruo@yahoo.com> wrote:
>
> Hmmm, this looks like a scrolling optimization bug.
> I can't build the NS port right now, but if you insert:
>
>   return false;
>
> right after
>
>   /* Can't scroll the display of w32 GUI frames when position of point
>      is indicated by the system caret, because scrolling the display
>      will then "copy" the pixels used by the caret.  */
> #ifdef HAVE_NTGUI
>   if (w32_use_visible_system_caret)
>     return 0;
> #endif
>
> in `scrolling_window', in dispnew.c, does the problem go away?

Thanks, I will try this out. Is there any chance that it is related to
the other bug I just reported, bug#63186? I see that Eli's fix
affected the display matrix. It seems unlikely given the fact that
that bug was a regression.

Is there anything specific to macOS that is involved in scrolling optimization?

Thanks,

Aaron