read-file-name misbehavior

[Richard Y. Kim]

Evaluating following expression then hitting ENTER when prompted
results in incorrect value of "" rather than the expected value of
".el".  For example, emacs version 21.4 returns "*.el", but
emacs 22 that I compiled using the latest code from cvs as of today
2006/12/26 results in "".

(let ((insert-default-directory nil))
  (read-file-name "Enter [default: *.el]: " nil "*.el" nil nil))

I tracked this down after noticing that igrep.el package which I've
been using for many years on emacs 19, 20, and 21 suddenly broke when
I tried to use it on emacs 22.




In GNU Emacs 22.0.92.1 (i686-pc-linux-gnu, GTK+ Version 2.10.6)
 of 2006-12-26 on richard-laptop
X server distributor `The X.Org Foundation', version 11.0.70101000
configured using `configure  '--with-x-toolkit=gtk''

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
  locale-coding-system: utf-8
  default-enable-multibyte-characters: t

Major mode: Apropos

Minor modes in effect:
  display-time-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
  unify-8859-on-encoding-mode: t
  utf-translate-cjk-mode: t
  auto-compression-mode: t
  line-number-mode: t

Recent input:
ESC C-b ESC w ESC > <return> <return> <return> C-y 
<return> C-x C-e <return> ESC x s u b m i <tab> C-a 
C-k b u g <tab> C-a C-k e m a <tab> <tab> C-a C-k b 
u g <tab> <tab> <backspace> <backspace> <backspace> 
s u b m <tab> <tab> h C-g C-h a b u g <return> C-x 
o C-n C-n C-n C-n C-n C-n C-n C-n C-n C-v C-s s u b 
m i t C-s C-e ESC x e d e b <tab> s u b m <tab> b u 
<tab> <backspace> <backspace> <tab> <tab> <return>

Recent messages:
Mark set [2 times]
""
Mark set [3 times]
""
Making completion list...
Quit [2 times]
Loading apropos...done
Type C-x 1 to remove help window.  
Mark saved where search started
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