23.0.60; vc-git-diff: diff switches can't be customized

[Magnus Henoch <mange@freemail.hu>]

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:

I opened etc/spook.lines in the Emacs Git tree, typed C-x v l, put point
on one revision and typed d to see the diff.  The result was just:

Binary files a/etc/spook.lines and b/etc/spook.lines differ

I then added "-a" to vc-diff-switches, but this had no effect.

I then found that vc-git-diff doesn't obey _any_ of diff-switches,
vc-diff-switches and vc-git-diff-switches, though the docstring of
vc-diff-switches implies that it would.

If Emacs crashed, and you have the Emacs process in the gdb debugger,
please include the output from the following gdb commands:
    `bt full' and `xbacktrace'.
If you would like to further debug the crash, please read the file
/usr/local/share/emacs/23.0.60/etc/DEBUG for instructions.


In GNU Emacs 23.0.60.1 (powerpc-unknown-netbsd4.99.42, X toolkit, Xaw3d scroll bars)
 of 2008-05-29 on zemdatav
Windowing system distributor `The X.Org Foundation', version 11.0.10300000
configured using `configure  '--with-x-toolkit=athena' '--enable-maintainer-mod' '--without-rsvg''

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

Major mode: Emacs-Lisp

Minor modes in effect:
  eldoc-mode: t
  show-paren-mode: t
  display-time-mode: t
  jabber-activity-mode: t
  jabber-mode-line-mode: t
  iswitchb-mode: t
  icomplete-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  global-auto-composition-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
<down> <down> <down> <down> <down> <down> <down> <down> 
C-v C-v C-v C-v C-v C-v s-f s p o o k . l i n e s <down> 
<down> <down> <return> C-x v l C-h c = C-h c d C-h 
c d d M-x c u s t SPC SPC g r o <return> v c - g <tab> 
<backspace> <backspace> <tab> <return> C-x 1 C-s d 
i f f <return> <down> <down> <tab> <return> <up> <up> 
<left> <left> <left> <left> <left> <left> <left> <left> 
M-! d i f f SPC - - h e l p <return> <C-s-down> C-s 
b i n a r y <return> <C-s-up> <return> 2 <down> - a 
<tab> <tab> <return> 1 <s-right> <s-right> <s-right> 
d <C-s-up> C-h k d <C-s-down> <tab> <return> <s-down> 
<s-down> <s-down> <s-down> <s-down> <s-down> <s-down> 
<s-down> <s-down> <s-down> <s-down> <down> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> <down> <down> <down> <right> <up> 
<right> <up> <up> M-f C-c f <return> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> C-c f v c - g i t - v e r s <tab> 
<backspace> <backspace> <backspace> <backspace> d i 
<tab> f <tab> <return> <down> <down> <down> M-! g i 
t SPC d i f f - t r e e SPC - - h e l p <return> M-x 
m a n <return> g i t - d i f f - t r e e <return> <C-s-down> 
C-h v v c - c v s - d i f f <backspace> <backspace> 
<backspace> <backspace> <backspace> <backspace> <backspace> 
<backspace> g i t - d i f f C-g <C-s-up> C-M-x C-r 
g <escape> <escape> <escape> M-x r e c o <backspace> 
<backspace> p o r t SPC e m a <return>

Recent messages:
uncompressing vc.el.gz...done
Note: file is write protected
Making completion list...
uncompressing vc-git.el.gz...done
Note: file is write protected
Invoking man git-diff-tree in the background
Please wait: formatting the git-diff-tree man page...
git-diff-tree man page formatted
Quit
vc-git-diff
Quit