Am Mo., 14. Apr. 2025 um 10:55 Uhr schrieb Eli Zaretskii <eliz@gnu.org>:

> Date: Mon, 14 Apr 2025 10:08:14 +0200
> Cc: 77774@debbugs.gnu.org
> From: Johann Höchtl <johann.hoechtl@gmail.com>
>
> I do still believe it is a bug.

Please explain why.

> I changed the definition of to
>
> (set-face-attribute 'fill-column-indicator nil :background nil
> :foreground "white" :stipple '(10 1 " \x0\x0\x0\x0\x0\x0"))
>
> one blank representing a single set bit, followed by quite a few null
> string literals as I do not know what happens if I dynamically change
> font sizes. Does this influence the necessity to change the bitmap
> literal of a stipple?

I don't think stipple bitmaps are automatically extended as you change
the text scale. Po Lu, is that supposed to work automagically
somehow?

> Nonetheless, at Linux at scale level 0 a single line is shown, at some
> increases of the scale level I see two or more lines, at higher scale
> levels just one again.

What happens if you enlarge the bitmap even more?

I did and made an "absurdly" large 1 by <large> bitmap. It consistently becomes two lines at scale level +5.

For the sake of simplicity and ruling out other factors I set display scale level to 100%.

When starting at OS scale level 150%, I see already two stipple lines at emacs scale mode +0 (no scale)

So there might be a common culprit to the misbehaviour.

> Also, display-line-numbers-mode influences the position of the stipples.
> Which IMHO shouldn't be the case.

True. But that is a different problem.