GNU bug report logs - #5327
23.1; unload-feature-special-hooks add fill-nobreak-predicate

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Kevin Ryde <user42 <at> zip.com.au>
To: bug-gnu-emacs <at> gnu.org
Subject: 23.1; unload-feature-special-hooks add fill-nobreak-predicate
Date: Wed, 06 Jan 2010 10:38:11 +1100

While nosing around the unload-feature stuff I wondered if
unload-feature-special-hooks should include fill-nobreak-predicate, as
it's a hook now.

The damage from leaving an unloaded func there is limited to paragraph
filling, and is likely to be either buffer local, or be autoloaded and
then end up ok anyway.  You can see a bad effect currently for instance
with

    M-x sgml-mode
    M-x unload-feature sgml-mode
    type in a long line to be filled
    M-q
    => Symbol's function definition is void: sgml-fill-nobreak


In GNU Emacs 23.1.1 (i486-pc-linux-gnu, GTK+ Version 2.16.5)
 of 2009-09-14 on raven, modified by Debian
configured using `configure  '--build=i486-linux-gnu' '--host=i486-linux-gnu' '--prefix=/usr' '--sharedstatedir=/var/lib' '--libexecdir=/usr/lib' '--localstatedir=/var/lib' '--infodir=/usr/share/info' '--mandir=/usr/share/man' '--with-pop=yes' '--enable-locallisppath=/etc/emacs23:/etc/emacs:/usr/local/share/emacs/23.1/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/23.1/site-lisp:/usr/share/emacs/site-lisp:/usr/share/emacs/23.1/leim' '--with-x=yes' '--with-x-toolkit=gtk' '--with-toolkit-scroll-bars' 'build_alias=i486-linux-gnu' 'host_alias=i486-linux-gnu' 'CFLAGS=-DDEBIAN -g -O2' 'LDFLAGS=-g' 'CPPFLAGS=''

Message #8 received at 5327 <at> debbugs.gnu.org (full text, mbox):

From: Juanma Barranquero <lekktu <at> gmail.com>
To: Kevin Ryde <user42 <at> zip.com.au>
Cc: 5327 <at> debbugs.gnu.org
Subject: Re: bug#5327: 23.1; unload-feature-special-hooks add 
	fill-nobreak-predicate
Date: Wed, 6 Jan 2010 02:30:26 +0100

On Wed, Jan 6, 2010 at 00:38, Kevin Ryde <user42 <at> zip.com.au> wrote:

> While nosing around the unload-feature stuff I wondered if
> unload-feature-special-hooks should include fill-nobreak-predicate, as
> it's a hook now.

It's a hook or hook-like, and its name does not end in -hooks?, so yes.

As an aside, perhaps unload-feature should also remove automatically
unloaded funcs from symbols called *-functions, which would eliminate
much cruft from `unload-feature-special-hooks'. The question is
whether there are many variables called -functions which are not
really hooks.

    Juanma

Message #13 received at 5327 <at> debbugs.gnu.org (full text, mbox):

From: Kevin Ryde <user42 <at> zip.com.au>
To: Juanma Barranquero <lekktu <at> gmail.com>
Cc: 5327 <at> debbugs.gnu.org
Subject: Re: bug#5327: 23.1;
	unload-feature-special-hooks add  fill-nobreak-predicate
Date: Sat, 09 Jan 2010 08:28:10 +1100

Juanma Barranquero <lekktu <at> gmail.com> writes:
>
> The question is
> whether there are many variables called -functions which are not
> really hooks.

That'd be the dangerous bit.  I've got a defconst called -functions in
some of my code, but it wouldn't be hurt.

Those with a custom-type of 'hook or '(repeat function) could be likely.
In fact any var with that custom-type might be ok to act on.  A grep
finds me three called -functions (code below)

    find-directory-functions
    auto-coding-functions
    compile-command-default-functions

of which auto-coding-functions may be the only important one not
presently in unload-feature-special-hooks.




(pp (let (ret)
      (mapatoms (lambda (sym)
                  (and (boundp sym)
                       (get sym 'custom-type)
                       (not (memq sym unload-feature-special-hooks))
                       (string-match "-functions\\'" (symbol-name sym))
                       (push (list sym (get sym 'custom-type)) ret))))
      ret)
    (current-buffer))

Message #18 received at 5327-done <at> debbugs.gnu.org (full text, mbox):

From: Juanma Barranquero <lekktu <at> gmail.com>
To: Kevin Ryde <user42 <at> zip.com.au>
Cc: 5327-done <at> debbugs.gnu.org
Subject: Re: bug#5327: 23.1;
	unload-feature-special-hooks add fill-nobreak-predicate
Date: Mon, 11 Jul 2011 18:25:01 +0200

On Wed, Jan 6, 2010 at 00:38, Kevin Ryde <user42 <at> zip.com.au> wrote:

>    M-x sgml-mode
>    M-x unload-feature sgml-mode
>    type in a long line to be filled
>    M-q
>    => Symbol's function definition is void: sgml-fill-nobreak

`fill-nobreak-predicate' was set locally, so it would be removed when
the mode for the buffer was changed. Previously, `unload-feature'
failed to do so unless the mode package's FEATURE-unload-function,
assuming one existed, did by itself. Since revno:104702
`unload-feature' does so automatically, so the above case should work
(i.e, unloading sgml-mode will change the buffer's major mode to
text-mode).

That said, I'll add that variable and some of the others you mentioned
to `unload-feature-special-hooks' because it's better to be safe than
sorry. But, what would be nice is some way to identify hook variables
in a generic way, instead of special-casing still more of them. :-(

>   find-directory-functions
>   auto-coding-functions

OK.

>   compile-command-default-functions

I cannot find that one in the Emacs sources.

    Juanma

Message #21 received at 5327 <at> debbugs.gnu.org (full text, mbox):

From: Kevin Ryde <user42 <at> zip.com.au>
To: Juanma Barranquero <lekktu <at> gmail.com>
Cc: 5327 <at> debbugs.gnu.org
Subject: Re: bug#5327: 23.1;
	unload-feature-special-hooks add fill-nobreak-predicate
Date: Sat, 16 Jul 2011 11:52:22 +1000

Juanma Barranquero <lekktu <at> gmail.com> writes:
>
>>   compile-command-default-functions
>
> I cannot find that one in the Emacs sources.

Ah yes, sorry, that's one of my own slipped through.
(Which I jigged up to add to unload-feature-special-hooks too anyway.)


-- 
The sigfile one-line movie reviews series:
"Les Amants du Pont Neuf" -- fine sequel to Les Amants du Pont Huit.

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