Somewhere between revisions 111524 and 111617, auto-revert-tail-mode
stopped working (on this system, at least).


Recipe: visit a nonempty file from `emacs -Q' and enable
`auto-revert-tail-mode'. Append to the file from outside emacs using
"cmd.exe", "echo" and ">>".


Expected result: the buffer auto-reverts within a short time.


Actual results for revisions of bzr trunk emacs:
  r111524 (latest good): as expected.
  r111617 (earliest bad): failure (buffer doesn't auto-revert).
  r111794 (recent): failure.


(These aren't tight bounds but random revisions for which I happen to have builds lying around.)




In GNU Emacs 24.3.50.1 (i386-mingw-nt6.2.9200)
 of 2013-02-15 on MACHINE
Bzr revision: 111794 acm@muc.de-20130215200151-sgpb907deac5n7qd
Windowing system distributor `Microsoft Corp.', version 6.2.9200
Configured using:
 `configure --with-gcc (4.7) --cflags -I c:/gnuwin32/include --ldflags
 -L c:/gnuwin32/lib'


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


Major mode: Text


Minor modes in effect:
  auto-revert-tail-mode: t
  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
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t


Recent input:
M-x a - r - t - m o d e <return> <help-echo> M-x r 
e p o r t - e m a c s - b u g <return>


Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
Auto-Revert-Tail mode enabled


Load-path shadows:
None found.


Features:
(shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml
easymenu 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 autorevert time-date tooltip ediff-hook
vc-hooks lisp-float-type mwheel dos-w32 ls-lisp w32-common-fns
disp-table w32-win w32-vars tool-bar dnd fontset image regexp-opt fringe
tabulated-list newcomment lisp-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 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 w32notify w32 multi-tty emacs)