bug#21871: Emacs Lisp Mode (at least): spurious parens in column 0 don't get bold red highlighting.

[Alan Mackenzie <acm@muc.de>]

Hello, Stefan.

On Sun, Sep 19, 2021 at 15:14:18 -0700, Stefan Kangas wrote:
> Alan Mackenzie <acm@muc.de> writes:

> > Hello, Emacs.

> > In the Emacs manual page "Left Margin Paren", it says that:

> >    To help you catch violations of this convention, Font Lock mode
> >    highlights confusing opening delimiters (those that ought to be quoted)
> >    in bold red.

> > , where "this convention" is the convention of not putting opening parens
> > in column 0 when they aren't at the beginning of defuns.

> > In Emacs Lisp Mode, this highlighting isn't done.  It isn't in CC Mode,
> > either.

> The above text no longer exists, and in Emacs 27.1 or later, we no
> longer treat an unescaped ( in column zero in a docstring as the
> beginning of a defun.  (See `(elisp) Documentation Tips', final
> paragraph.)

> So should this bug be closed, or is there anything more to do here?

I would say it should definitely be closed, the fix that has been
implemented being far and away better than that anticipated by the bug
report.  :-)

> > This is either a bug in the code, or a bug in the documentation.  I
> > rather tend to the view that this bold red highlighting should be done
> > when open-paren-in-column-0-is-defun-start is non-nil.  I think it did,
> > at one stage, but searching the emacs-devel archives doesn't reveal what
> > happened.

-- 
Alan Mackenzie (Nuremberg, Germany).