;; -*-coding: emacs-mule;-*- ???

;; -*-coding: emacs-mule;-*- ???

[Stefan Reichör]

Hi!

Today I upgraded to the latest cvs version of emacs.

Now I get the unwanted behaviour, that emacs inserts the following
cookie in many files I want to save:
;; -*-coding: emacs-mule;-*-

This did not happen before.
How can I stop this again?

Stefan.

Re: ;; -*-coding: emacs-mule;-*- ???

[Sacha Chua]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset=iso-2022-jp-2, Size: 2082 bytes --]

Stefan Reich^[.A^[Nvr <xsteve@riic.at> writes:

> Today I upgraded to the latest cvs version of emacs.
> Now I get the unwanted behaviour, that emacs inserts the following
> cookie in many files I want to save:
> ;; -*-coding: emacs-mule;-*-

I noticed that local-write-file-hooks (which is supposed to be
automatically buffer-local) gets globally modified when it's
add-hooked. This interacts badly with BBDB because BBDB addsbbdb-write-file-hook-fn to local-write-file-hooks, and then this
becomes a global hook. Here's the code responsible for inserting the
cookie.

    (unless (looking-at ";; *-\\*-coding:")
      (insert-before-markers (format ";; -*-coding: %s;-*-\n"
                     bbdb-file-coding-system))))

I've written a small test script to check. If everything worked
properly, this should not produce errors. On my system (emacs -q
--no-site-file, Emacs 21.3.50), it passes the
local-variable-that-works test, but fails the local-write-file-hooks
test. I suspect that obsolete permanently local variables are not
treated as permanently local when add-hook is used.

The workaround I use is

;; Run the offending function so that the records are loaded
(bbdb-records)
;; Restore my local write file hooks to nil
(setq-default local-write-file-hooks nil)   

Here's the test script:

(progn
  (defvar local-variable-that-works nil)
  (setq local-variable-that-works nil)
  (make-variable-buffer-local 'local-variable-that-works)
  (setq-default local-write-file-hooks nil)
  (with-temp-buffer (add-hook 'local-write-file-hooks 'foo)
		    (add-hook 'local-variable-that-works 'foo))
  (when local-variable-that-works
    (error "Failed test. Even the local variable that was supposed to work was modified."))
  (when local-write-file-hooks
    (error "Failed test. local-write-file-hooks was modified in this buffer. Perhaps obsolete buffer-local variables aren't buffer-local when add-hooked?")))

Hope that helps!
-- 
Sacha Chua <sacha@free.net.ph> - Ateneo CS faculty geekette
interests: emacs, gnu/linux, wearables, teaching compsci
http://sacha.free.net.ph/

Re: ;; -*-coding: emacs-mule;-*- ???

[Stefan Monnier]

> This did not happen before.
> How can I stop this again?

You're probably using something like BBDB some other package that uses
`add-hook' to modify a variable buffer-locally but without passing the
`local' argument.

Please try and get this package fixed.  Also upgrade to the latest CVS
where the problem should be fixed,


        Stefan

Re: ;; -*-coding: emacs-mule;-*- ???

[Stefan Reichör]

Hi Stefan!

>> This did not happen before.
>> How can I stop this again?
>
> You're probably using something like BBDB some other package that uses
> `add-hook' to modify a variable buffer-locally but without passing the
> `local' argument.
>
> Please try and get this package fixed.  Also upgrade to the latest CVS
> where the problem should be fixed,
>
>
>         Stefan

You are right!
It is the bbdb package.

I have the following in my .emacs:
(setq bbdb-file-coding-system 'emacs-mule)

This yields in a call to bbdb-write-file-hook-fn every time I want to
save a buffer.

This function inserts the unwanted cookie, it is specified in bbdb-write-file-hooks

I will investigate the problem further.

Thanks for your help,

  Stefan.

Re: ;; -*-coding: emacs-mule;-*- ???

[Richard Stallman]

What change in Emacs caused the unmodified code in bbdb to start
having this effect?

Re: ;; -*-coding: emacs-mule;-*- ???

[Stefan Reichör]

Hi Richard!

> What change in Emacs caused the unmodified code in bbdb to start
> having this effect?

I think it is some change in the semantics of add-hook:

The original code in bbdb.el looks like this:

        (bbdb-mapc (lambda (ff) (add-hook 'local-write-file-hooks ff))
              bbdb-write-file-hooks)

When I change it to this, it works again:

        (bbdb-mapc (lambda (ff) (add-hook 'local-write-file-hooks ff nil t))
              bbdb-write-file-hooks)

Stefan.