bug#10513: 23.3; vc-modify-change-comment broken in emacs-23.3-8.fc16

bug#10513: 23.3; vc-modify-change-comment broken in emacs-23.3-8.fc16

[Francis.Montagnac]

Modifying (even under emacs -q) a change log entry typing 'e' from
*VC-log* break when typing C-c C-c with the message:

  apply: Symbol's value as variable is void: backend

I found a turnaround: use a lexical-let instead of a let in
vc-modify-change-comment:

<   (let ((backend (vc-responsible-backend (car files))))
>   (lexical-let ((backend (vc-responsible-backend (car files))))
 
but I don't know if this is a proper fix.

Francis

In GNU Emacs 23.3.1 (x86_64-redhat-linux-gnu, GTK+ Version 2.24.7)
 of 2011-11-23 on x86-16.phx2.fedoraproject.org
Windowing system distributor `The X.Org Foundation', version 11.0.10905000
configured using `configure  '--build=x86_64-redhat-linux-gnu' '--host=x86_64-redhat-linux-gnu' '--program-prefix=' '--disable-dependency-tracking' '--prefix=/usr' '--exec-prefix=/usr' '--bindir=/usr/bin' '--sbindir=/usr/sbin' '--sysconfdir=/etc' '--datadir=/usr/share' '--includedir=/usr/include' '--libdir=/usr/lib64' '--libexecdir=/usr/libexec' '--localstatedir=/var' '--sharedstatedir=/var/lib' '--mandir=/usr/share/man' '--infodir=/usr/share/info' '--with-dbus' '--with-gif' '--with-jpeg' '--with-png' '--with-rsvg' '--with-tiff' '--with-xft' '--with-xpm' '--with-x-toolkit=gtk' 'build_alias=x86_64-redhat-linux-gnu' 'host_alias=x86_64-redhat-linux-gnu' 'CFLAGS=-DMAIL_USE_LOCKF -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4  -m64 -mtune=gen
 eric' 'LDFLAGS=-Wl,-z,relro ''

Important settings:
  value of $LC_ALL: C
  value of $LC_COLLATE: en_US
  value of $LC_CTYPE: en_US.UTF-8
  value of $LC_MESSAGES: en_US
  value of $LC_MONETARY: en_US
  value of $LC_NUMERIC: en_US
  value of $LC_TIME: en_US
  value of $LANG: en_US
  value of $XMODIFIERS: nil
  locale-coding-system: nil
  default enable-multibyte-characters: t

Major mode: Fundamental

Minor modes in effect:
  tooltip-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
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
c <escape> x b l i n <tab> c <tab> <return> <return> 
<return> <switch-frame> <help-echo> <down-mouse-1> 
<mouse-movement> <mouse-1> <switch-frame> <switch-frame> 
<switch-frame> C-x 2 <help-echo> <help-echo> <down-mouse-1> 
<mouse-movement> <mouse-1> C-x b * n e s s <tab> <backspace> 
<backspace> <backspace> <backspace> m e s s <tab> <backspace> 
<backspace> <backspace> <backspace> M e <tab> <return> 
C-p C-p C-p C-p C-SPC C-n <escape> w C-x o C-y C-p 
C-o C-o S u r SPC e SPC d a n s SPC V C <backspace> 
<backspace> * V C M-/ <backspace> <backspace> <backspace> 
C-x b * V C <tab> C-SPC C-a C-e C-SPC <escape> b <escape> 
b C-b C-b <escape> w C-x o C-x o C-y SPC p u i s SPC 
^ C ^ C : C-n C-n C-a SPC SPC C-e <return> <return> 
F i x SPC d a n s SPC . e m a c s . d / v c . e l <return> 
C-d C-d C-x C-s <switch-frame> C-c C-c <help-echo> 
<down-mouse-1> <mouse-movement> <mouse-1> <switch-frame> 
<down-mouse-1> <mouse-movement> <mouse-1> <escape> 
x l o a d C-_ <escape> x l o a d - f i l <tab> <return> 
. e m a c s <tab> . d <tab> v <tab> <return> <help-echo> 
<down-mouse-1> <mouse-1> C-v <switch-frame> <down-mouse-1> 
<mouse-movement> <mouse-1> C-c C-c <help-echo> <down-mouse-1> 
<mouse-movement> <mouse-1> C-x v l e C-c C-c C-x v 
l e f o o <return> C-c C-c C-x v l e C-p C-k C-c C-c 
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <menu-bar> <help-menu> 
<send-emacs-bug-report> <switch-frame> <help-echo> 
<down-mouse-1> <mouse-movement> <mouse-1> C-x C-f <switch-frame> 
~ / C-_ C-x C-f ~ / . e m a c s <tab> . d <tab> v c 
. e l <tab> <return> <help-echo> <switch-frame> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <menu-bar> <help-menu> <send-emacs-bug
-report>

Recent messages:
Enter a replacement change comment.  Type C-c C-c when done
Mark set
Press C-c C-c when you are done editing.
Enter a replacement change comment.  Type C-c C-c when done
Mark set
Press C-c C-c when you are done editing.
Enter a replacement change comment.  Type C-c C-c when done
byte-code: Command attempted to use minibuffer while in minibuffer~/
undo-start: No undo information in this buffer
Scanning for dabbrevs...99%

Load-path shadows:
/usr/share/emacs/site-lisp/site-start.d/maxima-modes hides /usr/share/emacs/site-lisp/maxima/site_start.d/maxima-modes

Features:
(shadow sort mail-extr message sendmail ecomplete rfc822 mml mml-sec
password-cache mm-decode mm-bodies mm-encode mailcap mail-parse rfc2231
rfc2047 rfc2045 qp ietf-drums mailabbrev nnheader gnus-util netrc
time-date mm-util mail-prsvr gmm-utils mailheader canlock sha1 hex-util
hashcash mail-utils emacsbug dired regexp-opt cl cl-19 jka-compr dabbrev
cus-start cus-load parse-time vc-cvs log-edit ring add-log log-view
easy-mmode wid-edit pcvs-util vc vc-dispatcher vc-rcs help-mode easymenu
view tooltip ediff-hook vc-hooks lisp-float-type mwheel x-win x-dnd
font-setting 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 system-font-setting
font-render-setting gtk x-toolkit x multi-tty emacs)

-- 
Francis.Montagnac@inria.fr, Tel: (33) 04 92 38 79 11, Bur: C113
INRIA Sophia, 2004, rte des Lucioles, B.P.93 - 06902 Sophia Antipolis Cedex

bug#10513: 23.3; vc-modify-change-comment broken in emacs-23.3-8.fc16

[Glenn Morris]

Version: 24.0.93

Francis.Montagnac@inria.fr wrote:

> Modifying (even under emacs -q) a change log entry typing 'e' from
> *VC-log* break when typing C-c C-c with the message:
>
>   apply: Symbol's value as variable is void: backend
>
> I found a turnaround: use a lexical-let instead of a let in
> vc-modify-change-comment:
>
> <   (let ((backend (vc-responsible-backend (car files))))
>>   (lexical-let ((backend (vc-responsible-backend (car files))))

Thanks for the report. I installed something similar:


*** lisp/vc/vc.el	2012-01-19 07:21:25 +0000
--- lisp/vc/vc.el	2012-01-25 00:05:40 +0000
***************
*** 1880,1886 ****
       "Enter a replacement change comment."
       "*vc-log*"
       (lambda () (vc-call-backend backend 'log-edit-mode))
!      (lexical-let ((rev rev))
         (lambda (files comment)
           (vc-call-backend backend
                            'modify-change-comment files rev comment))))))
--- 1880,1887 ----
       "Enter a replacement change comment."
       "*vc-log*"
       (lambda () (vc-call-backend backend 'log-edit-mode))
!      (lexical-let ((rev rev)
!                    (backend backend))
         (lambda (files comment)
           (vc-call-backend backend
                            'modify-change-comment files rev comment))))))