bug#36633: Scrolling by pixels: visible stretch glyphs overwrite header-line.

[Stefan Kangas]

Eli Zaretskii <eliz@gnu.org> writes:

> > Date: Fri, 12 Jul 2019 19:10:44 -0700
> > From: Keith David Bershatsky <esq@lawlist.com>
> >
> > Step 1:  Launch Emacs 26.
> >
> > Step 2:  Evaluate the following code.
> >
> > (progn
> >   (find-library "simple")
> >   (pixel-scroll-mode 1)
> >   (re-search-forward "\t\t\t\t\t" nil t)
> >   (set-window-start (selected-window) (match-beginning 0))
> >   (setq header-line-format "hello-world")
> >   (setq buffer-display-table (make-display-table))
> >   (aset buffer-display-table
> >         ?\t
> >         (vector (make-glyph-code ?\u00BB 'font-lock-warning-face)
> >                 (make-glyph-code ?\t 'highlight)))
> >   (setq tab-width 8))
> >
> > Step 3:  Move the mousewheel downward one time; i.e., one ratchet.
> >
> > Step 4:  Observe the visible stretch glyphs overwriting the header-line.
>
> This doesn't happen to me on MS-Windows, so I think this is
> Darwin-specific.
>
> Can someone try reproducing this on GNU/Linux and report?

I can't reproduce this here.

In GNU Emacs 26.2 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.22.11)
 of 2019-04-13 built on joffe
Windowing system distributor 'The X.Org Foundation', version 11.0.11902000
System Description:    Debian GNU/Linux 9.9 (stretch)

Thanks,
Stefan Kangas