It is fixed. Thanks.

Can you see another bug #38727. It is also Darwin-specific. It causes flicker.

在 2019年12月29日 +0800 PM6:46，Alan Third <alan@idiocy.org>，写道：
> On Sat, Dec 28, 2019 at 08:27:35PM +0200, Eli Zaretskii wrote:
> > > Date: Sat, 28 Dec 2019 11:20:13 +0000
> > > From: Alan Third <alan@idiocy.org>
> > > Cc: netjune@outlook.com, 38731@debbugs.gnu.org
> > >
> > > A minimal, and possibly correct, fix is:
> > >
> > > modified src/xdisp.c
> > > @@ -33491,7 +33491,7 @@ expose_area (struct window *w, struct glyph_row *row, const Emacs_Rectangle *r,
> > >
> > > if (area == TEXT_AREA && row->fill_line_p)
> > > /* If row extends face to end of line write the whole line. */
> > > - draw_glyphs (w, 0, row, area,
> > > + draw_glyphs (w, row->x, row, area,
> > > 0, row->used[area],
> > > DRAW_NORMAL_TEXT, 0);
> > > else
> >
> > This change LGTM, thanks. If it solves your problem, then we can
> > close this issue.
>
> Thanks. Pushed to emacs-27.
> --
> Alan Third