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

[Pierre Téchoueyres]

Emacs 26 is unable to restore an previously saved eieio object.
Same receipt work fine in emacs 25.3

emacs-26 --batch -l eieio-fail.el produces:
Wrong number of arguments: #<subr stringp>, 3

where emacs 25.3
Loading /usr/share/emacs/site-lisp/site-start.d/autoconf-init.el (source)...
Loading /usr/share/emacs/site-lisp/site-start.d/cmake-init.el (source)...
Loading /usr/share/emacs/site-lisp/site-start.d/desktop-entry-mode-init.el 
(source)...
Loading /usr/share/emacs/site-lisp/site-start.d/git-init.el (source)...
Loading /usr/share/emacs/site-lisp/site-start.d/rpmdev-init.el (source)...
Loading /usr/share/emacs/site-lisp/site-start.d/systemtap-init.el (source)...
[eieio-class-tag--eieio-fail "tmp-25.3.1" nil nil #s(hash-table size 65 test 
eql rehash-size 1.5 rehash-threshold 0.8 data

;;; -*- lexical-binding: t -*-
(require 'eieio)
(require 'eieio-base)

(defclass eieio-fail (eieio-persistent eieio-named)
  ((version :initarg :version :initform nil)
   (version-constant :allocation :class)
   (entries :initarg :entries :initform (make-hash-table))))

(let ((ef (make-instance 'eieio-fail :file "tmp")))
  (eieio-persistent-save ef (concat "tmp-" emacs-version)))

(let ((ef (eieio-persistent-read (concat "tmp-" emacs-version) 'eieio-fail t)))
  (pp ef))


In GNU Emacs 26.0.90 (build 1, x86_64-fc26-linux-gnu, GTK+ Version 3.22.21)
 of 2017-11-08 built on killashandra.ballybran.fr
Repository revision: a215be999454b8f0118141d4e4f6cf58298f79e0
Windowing system distributor 'Fedora Project', version 11.0.11903000
Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.

Configured using:
 'configure --prefix=/usr/local --with-xwidgets --with-modules
 --host=x86_64-fc26-linux-gnu --with-mailutils --with-gconf
 host_alias=x86_64-fc26-linux-gnu'

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GCONF GSETTINGS
NOTIFY ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11 MODULES XWIDGETS LIBSYSTEMD LCMS2

Important settings:
  value of $LC_CTYPE: fr_FR.UTF-8
  value of $LANG: fr_FR.UTF-8
  value of $XMODIFIERS: @im=none
  locale-coding-system: utf-8-unix

Major mode: Emacs-Lisp

Minor modes in effect:
  diff-auto-refine-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message rmc puny seq byte-opt gv
bytecomp byte-compile cconv cl-loaddefs cl-lib dired dired-loaddefs
format-spec rfc822 mml mml-sec password-cache epa derived epg epg-config
gnus-util rmail rmail-loaddefs mm-decode mm-bodies mm-encode mail-parse
rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045
ietf-drums mm-util mail-prsvr mail-utils vc-git diff-mode easymenu
easy-mmode elec-pair time-date mule-util tooltip eldoc electric uniquify
ediff-hook vc-hooks lisp-float-type mwheel term/x-win x-win
term/common-win x-dnd tool-bar dnd fontset image regexp-opt fringe
tabulated-list replace newcomment text-mode elisp-mode lisp-mode
prog-mode register page menu-bar rfn-eshadow isearch timer select
scroll-bar mouse jit-lock font-lock syntax facemenu font-core
term/tty-colors frame cl-generic cham georgian utf-8-lang misc-lang
vietnamese tibetan thai tai-viet lao korean japanese eucjp-ms cp51932
hebrew greek romanian slovak czech european ethiopic indian cyrillic
chinese composite charscript charprop case-table epa-hook jka-cmpr-hook
help simple abbrev obarray minibuffer cl-preloaded nadvice loaddefs
button faces cus-face macroexp files text-properties overlay sha1 md5
base64 format env code-pages mule custom widget hashtable-print-readable
backquote dbusbind inotify lcms2 dynamic-setting system-font-setting
font-render-setting xwidget-internal move-toolbar gtk x-toolkit x
multi-tty make-network-process emacs)

Memory information:
((conses 16 99040 11809)
 (symbols 48 21157 1)
 (miscs 40 53 130)
 (strings 32 29949 1299)
 (string-bytes 1 792306)
 (vectors 16 14803)
 (vector-slots 8 509702 10218)
 (floats 8 53 175)
 (intervals 56 265 20)
 (buffers 992 13))