bug#51277: 27.1; menu-set-font not loading correct font

[Eli Zaretskii <eliz@gnu.org>]

> Date: Mon, 18 Oct 2021 18:08:48 -0400
> From: Jesse Sheidlower <jester@panix.com>
> 
> emacs -Q
> 
> M-x menu-set-font
> 
> [navigate the menu to choose 'Operator Mono SSm Book'; the font then
> changes to a bold font, not to Operator Mono SSm Book]
> 
> M-x describe-font
> 
> [The "name" and "full name" fields show that I have selected a 'normal'
> font; however, the "file name" field shows that Emacs has loaded
> OperatorMonoSSm-Bold.otf, i.e. the "bold" version, even though the
> "book" version is available on the system and was in fact rendered
> correctly in the menu displayed by menu-set-font.]

What happens if you invoke Emacs like this:

  emacs -Q -fn 'Operator Mono SSm'

and then type this:

  M-x (set-face-attribute 'default nil :weight 'book) RET

Does that produce the expected effect?

> There is a description of this bug, with pictures of the process, at
> https://www.reddit.com/r/emacs/comments/kykma4/menusetfont_not_loading_correct_font/
> 
> Another user reported the same problem.

Sounds like some problem with that font.  Does this work correctly
with other fonts that have the "book" variant?