bug#50534: 28.0.50; Toolbar shows despite tool-bar-mode being disabled on macOS

[Alan Third]

On Sun, Sep 12, 2021 at 06:40:55PM +0200, Kirill A. Korinsky via Bug reports 
for GNU Emacs, the Swiss army knife of text editors wrote:
> this one works,

Turns out it doesn't, it just prevents the toolbar from appearing at
all.

What's the value of (frame-parameter nil 'tool-bar-lines) once the
frame has loaded with the toolbar visible?
-- 
Alan Third