bug#3785: 23.0.91; Strangeness involving regexp in directory-files command used on dir of links

I have files of todo items for various projects and a directory of
links to those files.  A simple function to search those files was
skipping over links named "misc" and "emacs".  The following function
narrows the problem down.  It seems to be a true problem but maybe I'm
doing something dumb?  I use emacs-snapshot, 23.0.91.1 but checked
using emacs 22.2.1 from Debian Lenny and same problem occurs.  Also
checked with emacs-snapshot started with emacs -Q.  Problem is same.


;;; ============================================================

(defun test-links ()
  "This narrows down a problem showing in a more complex program."
  (interactive)
  (setq links (directory-files "~/programming/emacs/debug/links" t "[:word:]" t))
  (dolist (l links)
    (insert (format "File: %s\n" (file-truename l)))))


;; Recipe for duplicating strangeness.
;;
;; 1. Set up a directory containing links named: misc, reading, and emacs.
;;
;; 2. Run the  above function as follows to get corresponding results.
;;

;; With regexp = :word:
;; File: /home/loydf/daybook/tasks/reading

;; With regexp = :digit::word:
;; File: /home/loydf/daybook/tasks/misc
;; File: /home/loydf/daybook/tasks/reading

;; With regexp = :digit::word:emacs
;; File: /home/loydf/programming/emacs/debug/links/misc
;; File: /home/loydf/programming/emacs/debug/links/reading
;; File: /home/loydf/programming/emacs/debug/links/emacs

;;; ============================================================



In GNU Emacs 23.0.91.1 (i486-pc-linux-gnu, GTK+ Version 2.12.11)
 of 2009-03-21 on elegiac, modified by Debian
 (emacs-snapshot package, version 1:20090320-1~lenny1)
Windowing system distributor `The X.Org Foundation', version 11.0.10402000
configured using `configure  '--build' 'i486-linux-gnu' '--host' 'i486-linux-gnu' '--prefix=/usr' '--sharedstatedir=/var/lib' '--libexecdir=/usr/lib' '--localstatedir=/var' '--infodir=/usr/share/info' '--mandir=/usr/share/man' '--with-pop=yes' '--enable-locallisppath=/etc/emacs-snapshot:/etc/emacs:/usr/local/share/emacs/23.0.91/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/23.0.91/site-lisp:/usr/share/emacs/site-lisp' '--with-x=yes' '--with-x-toolkit=gtk' 'build_alias=i486-linux-gnu' 'host_alias=i486-linux-gnu' 'CFLAGS=-DDEBIAN -DSITELOAD_PURESIZE_EXTRA=5000 -g -O2' 'LDFLAGS=-g -Wl,--as-needed' 'CPPFLAGS=''

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: en_US.UTF-8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default-enable-multibyte-characters: t

Major mode: Daybook

Minor modes in effect:
  savehist-mode: t
  recentf-mode: t
  desktop-save-mode: t
  display-time-mode: t
  TeX-PDF-mode: t
  show-paren-mode: t
  iswitchb-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
  line-number-mode: t
  transient-mark-mode: t
  abbrev-mode: t

Recent input:
<up> <up> <up> <up> <up> <M-right> <M-right> <M-left> 
<right> M-d C-d C-d <right> <right> <right> <right> 
<right> <right> <right> s c r a p i n g SPC p a i n 
t SPC a t M-d M-d <M-right> . C-k C-x s y M-x g n u 
s <return> <return> q <return> E q <return> <return> 
SPC E q <return> <return> <help-echo> <help-echo> <down-mouse-1> 
<mouse-1> E q <return> <down> <down> <down> c y <return> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> <down> <return> c y q y <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> <down> <down> <up> C-c M-t d C-x 
s y <up> <up> <up> <up> <up> <up> <up> <up> <up> <up> 
<up> <up> <up> <up> <up> <up> C-k C-k C-k C-k <up> 
C-c M-t d C-x s y <next> <prior> <next> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <up> <up> <up> <up> <up> <up> <up> <up> <up> 
<up> <up> <up> <up> <up> <up> <up> <up> <up> <up> <up> 
<up> <up> <up> M-x g n u s <return> <return> <return> 
SPC SPC SPC SPC SPC SPC SPC SPC SPC SPC SPC SPC E q 
<return> <return> <down> <up> SPC SPC SPC SPC SPC E 
<return> SPC SPC SPC SPC SPC SPC E q <return> <return> 
SPC E q <return> E q <return> <down> <return> c y <return> 
c y q y <help-echo> M-x r e p <tab> <switch-frame> 
<down> <down> <down> <down> <down> <down> <down> <right> 
<return>

Recent messages:
No more unread newsgroups
Are you sure you want to quit reading news? (y or n) 
Destroying external MIME viewers
Saving file /home/loydf/.newsrc...
Wrote /home/loydf/.newsrc
Saving /home/loydf/.newsrc.eld...
Saving file /home/loydf/.newsrc.eld...
Wrote /home/loydf/.newsrc.eld
Saving /home/loydf/.newsrc.eld...done
Making completion list...