Subject: bug#29220: 26.0.90; eieio-persistent-read fail to restore saved object.

From: Stefan Monnier <[email-masked]>
Date: Tue, 05 Dec 2017 17:14:00 -0500

> Okay, the attached appears to work just fine. Pierre's recipe passes,
> as do all the tests in eieio-test-persist. Pierre, maybe you could eval
> this quickly and make sure that pcache works correctly again?

Looks good to me.

[ While looking at this code, I notice that with cl-defmethod (which can
  dispatch not only on EIEIO objects, but other object types as well)
  we can now fold eieio-override-prin1 into object-write (i.e. make one
  into an alias for the other).  ]

> If this is okay, it's going into emacs-26, right?

I think so, but we're pretty late in the pretest, so better ask Eli&John
if they think it's OK for emacs-26.

        Stefan

> diff --git a/lisp/emacs-lisp/eieio-base.el b/lisp/emacs-lisp/eieio-base.el
> index 58dcd09d7e..0241f27395 100644
> --- a/lisp/emacs-lisp/eieio-base.el
> +++ b/lisp/emacs-lisp/eieio-base.el
> @@ -354,6 +354,26 @@ eieio-persistent-validate/fix-slot-value
>  		   proposed-value))
>  		 (t
>  		  proposed-value))))
> +        ;; For hash-tables and vectors, the top-level `read' will not
> +        ;; "look inside" member values, so we need to do that
> +        ;; explicitly.
> +        ((hash-table-p proposed-value)
> +         (maphash
> +          (lambda (key value)
> +            (when (class-p (car-safe value))
> +              (setf (gethash key proposed-value)
> +                    (eieio-persistent-convert-list-to-object
> +                     value))))
> +          proposed-value)
> +         proposed-value)
> +
> +        ((vectorp proposed-value)
> +         (dotimes (i (length proposed-value))
> +           (when (class-p (car-safe (aref proposed-value i)))
> +             (aset proposed-value i
> +                   (eieio-persistent-convert-list-to-object
> +                    (aref proposed-value i)))))
> +         proposed-value)
 
>  	 ((stringp proposed-value)
>  	  ;; Else, check for strings, remove properties.
> diff --git a/lisp/emacs-lisp/eieio.el b/lisp/emacs-lisp/eieio.el
> index d0d2ff5145..ab96547f93 100644
> --- a/lisp/emacs-lisp/eieio.el
> +++ b/lisp/emacs-lisp/eieio.el
> @@ -926,6 +926,25 @@ eieio-override-prin1
>  	 (object-write thing))
>  	((consp thing)
>  	 (eieio-list-prin1 thing))
> +	((hash-table-p thing)
> +         (let ((copy (copy-hash-table thing)))
> +	   (maphash
> +	    (lambda (key val)
> +	      (setf (gethash key copy)
> +		    (read
> +		     (with-output-to-string
> +		       (eieio-override-prin1 val)))))
> +	    copy)
> +	   (prin1 copy)))
> +	((vectorp thing)
> +         (let ((copy (copy-sequence thing)))
> +	  (dotimes (i (length copy))
> +	    (aset copy i
> +		  (read
> +		   (with-output-to-string
> +		     (eieio-override-prin1
> +		      (aref copy i))))))
> +	  (prin1 copy)))
>  	((eieio--class-p thing)
>  	 (princ (eieio--class-print-name thing)))
>  	(t (prin1 thing))))