Re: [jeff.dwork@amd.com: Re: customize]

[Per Abrahamsen <abraham@dina.kvl.dk>]

Richard Stallman <rms@gnu.org> writes:

> I looked at this message, and then studied custom-save-delete.
> It looks like the reason for this behavior is that custom-save-delete
> only deletes calls to custom-save-variables at top level in the file.

Yes.

> Should we try to make it find and delete calls that are inside other
> constructs? 

No.

However, I believe it would be useful to make custom-save-variables
signal an error if it is called from other places than the top-level.
If that is possible.

> To make that reliable, we would need to prevent it from
> deleting instances of `custom-save-variables' inside strings, or lists
> that have that symbol as car but are not expressions.

The problem is that Jeff's code is just a special case of the more
common:

(if (< emacs-major-version 21)
    ;; Emacs 20 customization.
    (custom-save-variables ...)
  ;; Emacs 21 customization.
  (custom-save-variables ...))

Which is impossible to make robust.  What we should encourage people
who need such functionality to do instead, is

(if (< emacs-major-version 21)
    ;; Emacs 20 customization.
    (setq custom-file "~/.custom-20.el")
  ;; Emacs 21 customization.
  (setq custom-file "~/.custom-21.el"))

(load-file custom-file)