Re: find-file-hook as illustration of Custom problems

[Luc Teirlinck]

>From my previous message:

   Maybe we could avoid that additional complexity if non-preloaded code
   strictly adhered to the conventions proposed in another message and if
   preloaded code put, for all involved list-vars, all elements of the
   involved hook, list or alist, that should be user-overridable in
   custom-list-var (instead of just in list-var).  That way, these
   elements would _not_ appear in the Custom buffer as "untouchable".

The situation is somewhat more complex.  _Newly added_ (by code)
elements could be unwittingly overridden by .emacs if they were just
put into custom-list-var.  (That is one of the reasons why the
distinction between list-var and custom-list-var is needed.  I forgot
about that for a moment.)  But _maybe_ it is OK anyway.  _Essential_
elements get put in list-var, so Emacs will never malfunction as a
result of essential new code being overridden in .emacs.
Non-essential ones go in custom-list-var.  When upgrading to a new
Emacs version, the user could then do `M-x customize-changed-options'
to see what new non-essential elements were added and see whether he
likes them.

Maybe we may need special `remove-hook' and `delete' functionality,
maybe we can avoid it.  Probably the person volunteering to implement
this (if anybody) might have to decide.

Sincerely,

Luc.