Re: always put Customizations in `custom-file', never in `user-init-file'

[Lennart Borgman (gmail)]

Stephen J. Turnbull wrote:
> Lennart Borgman (gmail) writes:
>
>  > Drew Adams wrote:
>  > > I think it was probably a mistake ever to have put Customize customizations
>  > > into a file intended for editing. That can confuse users, and it's just
>  > > asking for trouble. Now that we have a good alternative (`custom-file'), I
>  > > think that should be used exclusively.
>  > ...
>  > > WDOT?
>
> Be very careful.  In particular, the natural idea of migrating by
> loading the init file and using Custom to save its internal state to a
> custom-file caused no end of pain to users when it was implemented in
> XEmacs.  If there is any error in the init file, you can lose all
> customizations.

Then it might be best to avoid automatic migration, but to give a 
command to migrate custom data to custom-file.

>  > Great. And I guess custom-file should be run after .emacs, since that 
>  > makes it possible to chose another custom-file.
>
> Experience in XEmacs showed that users often want to use information
> in the custom-file in their init files.  There were issues (maybe
> XEmacs-specific) with initial values for faces, too.  After the init
> file was run was too late.  It's easy enough to load the custom-file
> late for those users for whom that matters: don't use the default
> name.  Something like
>
> (defvar custom-file "custom.el")
> (defvar default-custom-file-loaded-p nil)
> (progn
>   (do-emacs-early-initializations)
>   (when (file-readable-p custom-file)
>     (load custom-file))
>   (load user-init-file)
>   (when (and (not default-custom-file-loaded-p)
>              (file-readable-p custom-file))
>     (load custom-file)))

Yes, you are of course right.