bug#6096: 24.0.50; code error in accept-change-group

bug#6096: 24.0.50; code error in accept-change-group

[Andreas Politz]

(defun accept-change-group (handle)
  "Finish a change group made with `prepare-change-group' (which see).
This finishes the change group by accepting its changes as final."
  (dolist (elt handle)
    (with-current-buffer (car elt)
      (if (eq elt t)
	  (setq buffer-undo-list t)))))

I think this should be more like `(eq (cdr elt) t)', it should
redeactivate undo.  This test can not possibly succeed anyway.

-ap


In GNU Emacs 24.0.50.3 (x86_64-unknown-linux-gnu, GTK+ Version 2.18.9)
 of 2010-05-03 on raven
Windowing system distributor `The X.Org Foundation', version 11.0.10705000
Important settings:
  value of $LC_ALL: C
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default enable-multibyte-characters: t

Major mode: Emacs-Lisp

Minor modes in effect:
  diff-auto-refine-mode: t
  narrow-stack-mode: t
  server-mode: t
  easy-repeat-mode: t
  eldoc-mode: t
  shell-dirtrack-mode: t
  recentf-mode: t
  ido-hacks-mode: t
  window-numbering-mode: t
  which-function-mode: t
  show-paren-mode: t
  ido-everywhere: t
  icomplete-mode: t
  global-hi-lock-mode: t
  hi-lock-mode: t
  display-time-mode: t
  savehist-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
SPC n e e d SPC t o SPC ` p r e p a r e ' SPC a l l 
SPC b u f f e r s , SPC b e c a u s e SPC a SPC m a 
c r o SPC c a n SPC d o SPC a b o u t SPC a n y t h 
i n g . M-q C-h SPC t o SPC a n y SPC b u f f e r . 
M-q C-j C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n 
C-n C-n C-k C-k C-k C-k C-M-a C-M-SPC M-w C-M-e C-j 
- a p C-x h M-w C-x C-g C-x h C-w C-x b C-s <return> 
F M-> C-j C-y M-{ M-{ M-{ C-n C-n M-d t h e M-q M-f 
M-f M-f C-f C-j C-j M-q M-{ M-{ M-{ M-{ M-{ M-{ M-{ 
C-c C-c 2 x q g <return> <return> q q C-y M-y M-y M-y 
C-u C-x b <return> C-n C-M-a C-M-a C-M-e C-n C-M-l 
C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n 
C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n 
C-n C-n C-n C-n C-n C-n C-l C-p C-p C-p C-p C-p C-p 
C-p C-p C-p C-p C-p C-p C-p C-p C-p C-p C-p M-1 C-x 
b f f o o M-h <return> M-x b u f f SPC - d i <return> 
M-x C-g M-x k m M-p <return> C-/ C-/ M-2 C-M-a C-n 
C-n C-n C-n C-n C-n C-p M-f M-f C-f ( c d r SPC M-f 
) C-M-x M-1 M-x C-g C-p M-x M-p M-p <return> M-x M-p 
M-p <return> C-/ M-2 C-M-a C-M-SPC M-w M-1 M-x r e 
p o <return>

Recent messages:
Saving /home/politza/.emacs.d/gnus/.newsrc.eld...done
Mark set [4 times]
Quit
Undo!
undo-more: No further undo information
Mark set [2 times]
accept-change-group
Quit
undo-start: No undo information in this buffer
Mark set [3 times]

Load-path shadows:
/home/politza/.emacs.d/minor-modes/ido hides /home/politza/src/emacs23/lisp/ido

Features:
(canlock sha1 hex-util info-look info mailalias smtpmail sendmail shadow
emacsbug whitespace diff-mode diff browse-kill-ring apropos gnus-cite
smiley ansi-color gnus-async gnus-bcklg qp sort gnus-ml disp-table
parse-time nnfolder nnmbox utf-7 utf7 netrc starttls nnimap imap nndraft
nnmh bbdb-gnus bbdb-snarf mail-extr bbdb-com warnings nnnil gnus-agent
gnus-srvr gnus-score score-mode nnvirtual gnus-msg gnus-art mm-uu
mml2015 epg-config mm-view smime dig mailcap nntp gnus-cache gnus-sum
nnoo gnus-group gnus-undo nnmail mail-source gnus-start gnus-spec
gnus-win jka-compr find-dired cl-specs edebug newcomment thingatpt
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ido-hacks hippie-exp my-anything anything edmacro kmacro kbd-helper
derived org-install bbdb-autoloads bbdb timezone
persistent-scratch-buffer window-numbering easy-mmode cl cl-19 uniquify
winner which-func imenu paren ido icomplete grep compile comint
regexp-opt ring hi-lock time cus-start cus-load saveplace savehist
advice help-fns advice-preload tooltip ediff-hook vc-hooks
lisp-float-type mwheel x-win x-dnd tool-bar dnd fontset image fringe
lisp-mode register page menu-bar rfn-eshadow timer select scroll-bar
mldrag mouse jit-lock font-lock syntax facemenu font-core frame cham
georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao
korean japanese hebrew greek romanian slovak czech european ethiopic
indian cyrillic chinese case-table epa-hook jka-cmpr-hook help simple
abbrev loaddefs button minibuffer faces cus-face files text-properties
overlay md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote make-network-process dbusbind
dynamic-setting font-render-setting gtk x-toolkit x multi-tty emacs)

bug#6096: 24.0.50; code error in accept-change-group

[Lars Magne Ingebrigtsen]

Andreas Politz <politza@fh-trier.de> writes:

> (defun accept-change-group (handle)
>   "Finish a change group made with `prepare-change-group' (which see).
> This finishes the change group by accepting its changes as final."
>   (dolist (elt handle)
>     (with-current-buffer (car elt)
>       (if (eq elt t)
> 	  (setq buffer-undo-list t)))))
>
> I think this should be more like `(eq (cdr elt) t)', it should
> redeactivate undo.  This test can not possibly succeed anyway.

Yes, `(eq elt t)' can't possibly be true, since `elt' is a list.

`elt is something on the form

  (cons (current-buffer) buffer-undo-list)

so I think probably `(eq (cdr elt) t)' is correct, as noted.

Does anybody have any comments, or should I just apply that fix?
  
-- 
(domestic pets only, the antidote for overdose, milk.)
  bloggy blog http://lars.ingebrigtsen.no/