bug#6017: 23.1.96; savehist-printable for hash tables

[Stefan Monnier <monnier@IRO.UMontreal.CA>]

> IIUC, starting with Emacs 23.2, we can prin1 and read hash tables. If
> that's correct, then `savehist-printable' could presumably be updated to
> add this sexp to the cond: (hash-table-p value). IOW:
 
> (defun savehist-printable (value)
>   "Return non-nil if VALUE is printable."
>   (cond
>    ((stringp value))
>    ((numberp value))
>    ((symbolp value))
>    ((hash-table-p value))
>    (t
>     (with-temp-buffer
>       (condition-case nil
>    (let ((print-readably t) (print-level nil))
>    (prin1 value (current-buffer))
>    (read (point-min-marker))
>    t)
>  (error nil))))))

That won't check whether the contents of the has-table are
themsevles printable.


        Stefan