bug#26639: 26.0.50; gethash can't find value from equal key

[Damien Cassou <damien@cassou.me>]

In emacs built from master today (53f8f4bf), evaluate this in the
scratch buffer of `emacs -Q`:

(cl-defstruct foo slot1 slot2)
(setq foo1 (make-foo :slot1 "abc" :slot2 "cba"))
(setq foo2 (make-foo :slot1 "abc" :slot2 "cba"))

(equal foo1 foo2) ;; should be t

(setq hytmp (make-hash-table :test 'equal))
(puthash foo1 'foobar hytmp)

(gethash foo1 hytmp 'no) ;; should be 'foobar

(gethash foo2 hytmp 'no) ;; should be 'foobar BUT IS 'no

I'm expecting last line to return 'foobar instead of 'no.


In GNU Emacs 26.0.50 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.22.11)
 of 2017-04-24 built on luz4
Repository revision: 53f8f4bf2db097f4a2c68194c55a87c5a1176c8c
Windowing system distributor 'Fedora Project', version 11.0.11903000
System Description:	Fedora release 25 (Twenty Five)

Recent messages:
Mark set [2 times]
cl-lib
foo
#s(foo "abc" "cba") [2 times]
t
#s(hash-table size 65 test equal rehash-size 1.5 rehash-threshold 0.8125 data ( ...))
foobar [2 times]
no
GNU Emacs 26.0.50 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.22.11) of 2017-04-24
Making completion list...

Configured using:
 'configure --with-mailutils'

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

Important settings:
  value of $LC_MONETARY: fr_FR.UTF-8
  value of $LC_NUMERIC: fr_FR.UTF-8
  value of $LC_TIME: fr_FR.UTF-8
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  global-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 subr-x puny seq byte-opt
bytecomp byte-compile cconv dired dired-loaddefs format-spec rfc822 mml
easymenu 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 cl-seq cl-macs gv cl-loaddefs cl-lib
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 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
dynamic-setting system-font-setting font-render-setting move-toolbar gtk
x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 16 96944 8366)
 (symbols 48 20210 1)
 (miscs 40 48 194)
 (strings 32 17755 4844)
 (string-bytes 1 573035)
 (vectors 16 14717)
 (vector-slots 8 482626 4459)
 (floats 8 49 150)
 (intervals 56 269 33)
 (buffers 976 13))

-- 
Damien Cassou
http://damiencassou.seasidehosting.st

"Success is the ability to go from one failure to another without
losing enthusiasm." --Winston Churchill