Re: Fedora Core 3: File mode specification error

[email protected] writes:

> I just installed Fedora Core 3 (and ran "yum update") and the latest
> auctex rpm for fedora (auctex-emacs-11.54-2.fedora.noarch.rpm) from
> http://ftp.gnu.org/pub/gnu/auctex/.  It appears that the rpm puts a
> file (auctex-init.el) in /usr/share/emacs/site-lisp/site-start.d which
> is loaded by site-start.el and contains the requisite "(require
> 'tex-site)", but auctex is not working for me on what is practically a
> virgin FC3/emacs/auctex install with no .emacs file.
>
> When I try to load a (la)tex file (new or existing), I get the
> following error message:
>
> (New file)
> Loading tex...
> Loading advice...done
> Loading tex...done
> Loading latex...done
> Loading font-latex...done
> File mode specification error: (error "Variable binding depth exceeds max-specpdl-size")
>
> and the resulting buffer is in "Fundamental" mode rather than tex or
> latex.

[...]

> Backtrace:
>
> Debugger entered--Lisp error: (error "Variable binding depth exceeds max-specpdl-size")
>   regexp-opt-group(nil t t)
>   regexp-opt-group(nil t t)

[...]

>   regexp-opt-group(nil t t)
>   regexp-opt-group(nil nil)
>   regexp-opt(nil)
>   font-latex-set-syntactic-keywords()
>   font-latex-setup()
>   VirTeX-common-initialization()
>   LaTeX-common-initialization()
>   latex-mode()
> * call-interactively(latex-mode)
>   execute-extended-command(nil)
>   call-interactively(execute-extended-command)

Uh, what?  I am completely stumped.  At both my standard FC3 Emacs as
well as the development version of Emacs, (regexp-opt nil) returns ""
for me.  And that is because of the definition of regexp-opt-group:

(defun regexp-opt-group (strings &optional paren lax)
[...]
  (let* ((open-group (cond ((stringp paren) paren) (paren "\\(?:") (t "")))
	 (close-group (if paren "\\)" ""))
	 (open-charset (if lax "" open-group))
	 (close-charset (if lax "" close-group)))
    (cond
     ;;
     ;; If there are no strings, just return the empty string.
     ((= (length strings) 0)
      "")
     ;;
     ;; If there is only one string, just return it.
[...]

It complete escapes me how, with arguments nil nil, regexp-opt-group
should be tempted to recurse on itself.

Can you check your definition of regexp-opt-group?  And maybe do a
edebug-defun on its definition, and then see what happens when calling
(regexp-opt nil)
?


-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum