bug#37832: internal-border face ignored in Emacs 26.3 for macOS

[Alan Third]

On Sun, Oct 20, 2019 at 05:46:41PM +0300, Eli Zaretskii wrote:
> > From: Andrea Cardaci <cyrus.and@gmail.com>
> > Date: Sun, 20 Oct 2019 15:25:54 +0200
> > 
> > The `internal-border` face is ignored and the `default` face
> > background is used instead. I'm experiencing this with Emacs 26.3
> > installed with `brew cask install emacs`.
> > 
> > Reproduce with the following `.emacs`:
> > 
> > (custom-set-variables
> >  '(default-frame-alist '((internal-border-width . 100))))
> > 
> > (custom-set-faces
> >  '(default ((t (:background "black" :foreground "white"))))
> >  '(internal-border ((t (:background "red")))))
> > 
> > Works fine on Linux version 26.1.
> 
> Sounds like a macOS specific issue, because this works fine for me on
> MS-Windows both with Emacs 26.3 and with the current master branch
> (which will eventually become Emacs 27).

Yes, for whatever reason the NS port doesn’t clear the internal border
like the other front ends, so it just uses the default background
colour.
-- 
Alan Third