bug#5637: 23.1.92; Cygwin Emacs hangs after completion of //

[Tetsurou Okazaki]

This bug report will be sent to the Free Software Foundation,
not to your local site managers!
Please write in English if possible, because the Emacs maintainers
usually do not have translators to read other languages for them.

Your bug report will be posted to the bug-gnu-emacs@gnu.org mailing list,
and to the gnu.emacs.bug news group.

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug.  If you can, give
a recipe starting from `emacs -Q':

  Emacs in trunk built with Cygwin environment hangs
  when you try to complete path name after double slashes.

  M-x find-file
  (In the minibuffer) //[TAB]

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'.
For information about debugging Emacs, please read the file
/usr/local/share/emacs/23.1.92/etc/DEBUG.


In GNU Emacs 23.1.92.1 (i686-pc-cygwin, GTK+ Version 2.18.6)
 of 2010-02-22 on zeroset
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: C
  value of $XMODIFIERS: nil
  locale-coding-system: nil
  default enable-multibyte-characters: t

Major mode: Lisp Interaction

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:
ESC [ > 0 ; 1 3 6 ; 0 c ESC x r e p o r t - e m a TAB 
RET

Recent messages:
("emacs")
For information about GNU Emacs and the GNU system, type C-h C-a.

Load-path shadows:
/usr/local/share/emacs/site-lisp/flim/sha1 hides 
/usr/local/share/emacs/23.1.92/lisp/sha1
/usr/local/share/emacs/site-lisp/flim/md4 hides 
/usr/local/share/emacs/23.1.92/lisp/md4
/usr/local/share/emacs/site-lisp/flim/hex-util hides 
/usr/local/share/emacs/23.1.92/lisp/hex-util
/usr/local/share/emacs/site-lisp/bitmap/po hides 
/usr/local/share/emacs/23.1.92/lisp/textmodes/po
/usr/local/share/emacs/site-lisp/flim/sasl hides 
/usr/local/share/emacs/23.1.92/lisp/net/sasl
/usr/local/share/emacs/site-lisp/flim/sasl-ntlm hides 
/usr/local/share/emacs/23.1.92/lisp/net/sasl-ntlm
/usr/local/share/emacs/site-lisp/flim/sasl-digest hides 
/usr/local/share/emacs/23.1.92/lisp/net/sasl-digest
/usr/local/share/emacs/site-lisp/flim/sasl-cram hides 
/usr/local/share/emacs/23.1.92/lisp/net/sasl-cram
/usr/local/share/emacs/site-lisp/flim/ntlm hides 
/usr/local/share/emacs/23.1.92/lisp/net/ntlm
/usr/local/share/emacs/site-lisp/flim/hmac-md5 hides 
/usr/local/share/emacs/23.1.92/lisp/net/hmac-md5
/usr/local/share/emacs/site-lisp/flim/hmac-def hides 
/usr/local/share/emacs/23.1.92/lisp/net/hmac-def
/usr/local/share/emacs/site-lisp/wl/rfc2368 hides 
/usr/local/share/emacs/23.1.92/lisp/mail/rfc2368
/usr/local/share/emacs/site-lisp/wl/utf7 hides 
/usr/local/share/emacs/23.1.92/lisp/gnus/utf7

Features:
(shadow sort mail-extr message sendmail regexp-opt 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 wid-edit mailheader canlock
sha1 sha1-el hex-util hashcash mail-utils help-mode easymenu view
emacsbug 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)