I just got the following assertion failure:

   bidi.c:329: Emacs fatal error: assertion failed: UNKNOWN_BT <= type 
&& type <= NEUTRAL_ON

I wasn't doing anything at the time.  I had been away from the computer
for a couple days, tried to view an emacs window, and then noticed the
assertion failure in the terminal from which I had started emacs under
gdb.  A full backtrace is attached.  I still have the gdb session open.

Ken



In GNU Emacs 24.3.91.13 (x86_64-unknown-cygwin)
  of 2014-06-06 on moufang
Repository revision: 117213 
monnier@iro.umontreal.ca-20140606142539-5h50ienhp3mpz68z
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
  `configure --with-w32 --enable-checking=yes,glyphs 'CFLAGS=-g3 -O0''

Important settings:
   value of $LANG: en_US.UTF-8
   locale-coding-system: utf-8-unix

Major mode: Dired by date

Minor modes in effect:
   shell-dirtrack-mode: t
   show-paren-mode: t
   display-time-mode: t
   delete-selection-mode: t
   tooltip-mode: t
   electric-indent-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-composition-mode: t
   auto-encryption-mode: t
   auto-compression-mode: t
   temp-buffer-resize-mode: t
   buffer-read-only: t
   column-number-mode: t
   line-number-mode: t
   transient-mark-mode: t

Load-path shadows:
None found.

Features:
(shadow gnus-util mail-extr emacsbug message cl-macs format-spec rfc822
mml mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev
gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums mm-util
mail-prsvr mail-utils shell pcomplete comint ansi-color ring dired-aux
misearch multi-isearch server dired edmacro kmacro solar cal-dst
planner-diary cl gv diary-lib diary-loaddefs planner-publish muse-xml
planner advice help-fns cal-menu calendar cal-loaddefs sort muse-colors
muse-latex muse-html muse-xml-common cus-edit muse-publish muse-project
muse-protocols muse-regexps wid-edit cl-loaddefs cl-lib derived muse
muse-nested-tags muse-mode gap-mode-autoloads info easymenu
muse-autoloads package saveplace paren help-at-pt time delsel cus-start
cus-load time-date tooltip electric uniquify ediff-hook vc-hooks
lisp-float-type mwheel w32-common-fns disp-table w32-win w32-vars
tool-bar dnd fontset image regexp-opt fringe tabulated-list newcomment
lisp-mode prog-mode register page menu-bar rfn-eshadow timer select
scroll-bar 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 minibuffer nadvice loaddefs button faces cus-face macroexp files
text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget hashtable-print-readable backquote make-network-process
dbusbind gfilenotify w32 multi-tty emacs)

Memory information:
((conses 16 163739 4162)
  (symbols 48 25708 0)
  (miscs 40 101 217)
  (strings 32 37923 4888)
  (string-bytes 1 1024471)
  (vectors 16 17983)
  (vector-slots 8 456533 2444)
  (floats 8 437 54)
  (intervals 56 577 9)
  (buffers 960 16))