bug#45806: 26.3; `menu-bar-separator'

[Drew Adams <drew.adams@oracle.com>]

> Sorry, this name is with us for too long to rename it now.

Not a great reason not to rename and alias.

> > How is it actually used?  Is it used only in (some?) toolkits?
> 
> Look at menu-bar.el (obviously), it's used all over there.  On all the
> toolkits and also in no-toolkit builds.

I already looked at all occurrences in the Lisp sources.

AFAICT, _none_ of those occurrences show how it's used
in the sense of explaining its effect.

I'm looking for info about its implementation and what
it actually does - info presumably available in some C
code.  HOW it does what it does.

See also the question about whether it's used only by
toolkits.  In GUI Emacs on MS Windows, for instance,
the effect of a separator is a continuous separator
line, while the effect with `emacs -nw' seems to be a
pair of hyphen chars.

> > It's a defconst (why?), so presumably you shouldn't change it.  But
> > changing it doesn't seem to have any effect anyway, in MS Windows.  If
> > this is hard-coded then why is it even needed?
> 
> See above.  If you really want to see the effect of changing it
> (why?), I think you will need to rebuild Emacs.

You think so?  How about having the doc specify that,
or whatever the actual behavior is.

FWIW, this bug report is a result of seeing this user
question:

"Is it possible to change the menu separator?"

https://emacs.stackexchange.com/q/62717/105