bug#1501: Emacs 22 loses undo buffer

[Emerick Rogul]

Header file attached, although the problem occurs with any header file
(i.e., it's not specific to this particular file).  The trace below
contains the exact key sequence that I typed.

In GNU Emacs 22.3.1 (i386-mingw-nt5.1.2600)
 of 2008-09-06 on SOFT-MJASON
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (3.4)'

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: ENU
  locale-coding-system: cp1252
  default-enable-multibyte-characters: t

Major mode: C/l

Minor modes in effect:
  encoded-kbd-mode: t
  tooltip-mode: t
  tool-bar-mode: t
  mouse-wheel-mode: t
  menu-bar-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
  abbrev-mode: t

Recent input:
<help-echo> <help-echo> <help-echo> C-x C-f <backspace>
<backspace> <backspace> <backspace> <backspace> <backspace>
<backspace> <backspace> <backspace> <backspace> c l
r <tab> <return> C-k C-k C-k C-k C-k C-k C-k C-k C-k
C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k
C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k
C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k
C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k
C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k
C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k
C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k
C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k
C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k
C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k
C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k
C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k
C-k C-k C-k C-k C-k C-k C-/ C-/ C-/ C-/ C-/ C-/ C-/
C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/
C-/ ESC x r e p o r t - e m a <tab> <return>

Recent messages:
("C:\\emacs\\bin\\emacs.exe")
Loading encoded-kb...done
For information about GNU Emacs and the GNU system, type C-h C-a.
Loading cc-mode...done
Undo! [4 times]
undo-more: No further undo information [17 times]
Loading emacsbug...done

clrdata.h
Description: Text document