bug#2833: 23.0.92; Bug in Directory Variables

I think there's a bug in direcotry variables code, that is, changing the
directory variables would require a restart of Emacs for them to take
effect.

A recipe to reproduce:

  1. Create a dir and write the following to file .dir-locals in the dir
     created:

((latex-mode . ((fill-column . 78)
                (coding . "latin-1"))))

  2. Open or create a .tex file in that dir

  3. C-h v fill-column RET to check the value 

  4. Change 78 to another value say 75

  5. Re-open the .tex file and you will see fill-column has a value 78
     NOT 75

In my view, this makes the `Directory Variables' feature much less
useful. Any fix?


In GNU Emacs 23.0.92.1 (i386-mingw-nt5.1.2600) of 2009-03-31 on BREPNB
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (3.4)'

Important settings:
  value of $LC_ALL: nil
  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: ENG
  value of $XMODIFIERS: nil
  locale-coding-system: cp1252
  default-enable-multibyte-characters: t

Major mode: LaTeX/P

Minor modes in effect:
  reftex-mode: t
  TeX-PDF-mode: t
  dired-omit-mode: t
  recentf-mode: t
  icomplete-mode: t
  savehist-mode: t
  display-time-mode: t
  xterm-mouse-mode: t
  delete-selection-mode: t
  global-auto-revert-mode: t
  minibuffer-depth-indicate-mode: t
  which-function-mode: t
  show-paren-mode: t
  rcirc-track-minor-mode: t
  shell-dirtrack-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  global-auto-composition-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
<left> <left> <left> C-x C-f . d i <return> <backspace> 
8 C-x C-s C-h i m e m a <tab> <return> m f i l e SPC 
v a r <tab> <tab> <return> <down> <down> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> <up> 
<return> SPC SPC SPC l <down> <return> SPC l ^ <down> 
<return> <down> <down> <down> <down> <down> <down> 
q <right> <backspace> 8 C-x C-s C-x k <return> <down> 
<down> <down> <down> <down> <down> <down> M-x r e p 
o r <tab> <return>

Recent messages:
Applying style hooks... done
Type "q" to delete this window.
Applying style hooks... done
Type "q" to delete this window.
Composing main Info directory...done
Reverting buffer `.dir-locals.el'.