bug#45125: Subject: 28.0.50; defvar dynamics

[Andreas Röhler]

Recipe:

Evaluate defvar forms at bottom in order using C-x C-e, which runs 
command eval-last-sexp here.

Evaluate the message-form C-x C-e

message-form outputs "a: 2",  i.e. "a" was dynamically updated
This contradicts saying in File: elisp.info,  Node: Defining Variables:

"But if SYMBOL is not void, VALUE is not evaluated, and SYMBOL’s value 
is left unchanged."

(defvar a 0)
(defvar a 1)
(defvar a 2)

(message "a: %s" a)

---

In GNU Emacs 28.0.50 (build 1, i686-pc-linux-gnu, GTK+ Version 3.14.5, 
cairo version 1.14.0)
 of 2020-11-19
Repository revision: 3963aea4f4a22da0c1fb8ca8ca80b59c58373811
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.11604000
System Description: Debian GNU/Linux 8 (jessie)

Configured using:
 'configure --with-modules --with-mailutils'

Configured features:
XPM JPEG TIFF GIF PNG CAIRO SOUND DBUS GSETTINGS GLIB NOTIFY INOTIFY ACL
GNUTLS LIBXML2 FREETYPE LIBOTF ZLIB TOOLKIT_SCROLL_BARS GTK3 X11 XDBE
XIM MODULES THREADS PDUMPER

Important settings:
  value of $LANG: de_DE.UTF-8
  locale-coding-system: utf-8-unix

Major mode: ELisp/d

Minor modes in effect:
  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 dired dired-loaddefs
rfc822 mml easymenu mml-sec epa derived epg epg-config gnus-util rmail
rmail-loaddefs auth-source cl-seq eieio eieio-core cl-macs
eieio-loaddefs password-cache json map text-property-search time-date
subr-x seq byte-opt gv bytecomp byte-compile cconv mm-decode mm-bodies
mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader cl-loaddefs
cl-lib sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils
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 tab-bar menu-bar rfn-eshadow isearch
timer select scroll-bar mouse jit-lock font-lock syntax facemenu
font-core term/tty-colors frame minibuffer 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
cl-preloaded nadvice button loaddefs faces cus-face macroexp files
window text-properties overlay sha1 md5 base64 format env code-pages
mule custom widget hashtable-print-readable backquote threads dbusbind
inotify dynamic-setting system-font-setting font-render-setting cairo
move-toolbar gtk x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 8 146139 6477)
 (symbols 24 30198 1)
 (strings 16 65257 1523)
 (string-bytes 1 1053500)
 (vectors 8 12265)
 (vector-slots 4 176703 11288)
 (floats 8 22 41)
 (intervals 28 209 13)
 (buffers 560 11)
 (heap 1024 12583 926))