Dear developers,

Since its version 42, GNOME allows to globally set a dark theme, with a
different background thanks to the dconf key
/org/gnome/desktop/background/picture-uri-dark.

This key is not set in
/usr/share/glib-2.0/schemas/10_desktop-base.gschema.override, resulting
in the background reverting to the default GNOME one if the user selects
the a dark theme, instead of keeping the Debian one.

Without creating dark versions of the Debian backgrounds, a simple
solution consists in setting the Debian background also in the
picture-uri-dark dconf key.

Here is a simple patch to do this.

I think this simple bugfix can't do any harm, and I hope it can be
backported to both Trixie and Bookworm through proposed-updates.

Regards,