Infinite loop in move_it_vertically_backward

[YAMAMOTO Mitsuharu]

Emacs falls into infinite loop with:

  1. emacs -Q -D
  2. Evalulate the following expression in *scratch*.

        (progn
          (goto-char (point-min))
          (insert (string-to-multibyte "\200"))
          (goto-char (point-min))
          (recenter))

Debugger says move_it_vertically_backward in xdisp.c does not finish
because it2.method at line 6389 remains to be GET_FROM_DISPLAY_VECTOR.

6381         y-distance.  */
6382      it2 = *it;
6383      it2.max_ascent = it2.max_descent = 0;
6384      do
6385        {
6386          move_it_to (&it2, start_pos, -1, -1, it2.vpos + 1,
6387                      MOVE_TO_POS | MOVE_TO_VPOS);
6388        }
6389      while (it2.method != GET_FROM_BUFFER);
6390      xassert (IT_CHARPOS (*it) >= BEGV);

                                     YAMAMOTO Mitsuharu
                                address@hidden

In GNU Emacs 22.0.50.1 (sparc-sun-solaris2.8, X toolkit, Xaw3d scroll bars)
 of 2005-07-15 on church
X server distributor `The XFree86 Project, Inc', version 11.0.40300000
configured using `configure '--x-libraries=/usr/local/lib' 'CFLAGS=-O2 -mv8''

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: ja
  locale-coding-system: japanese-iso-8bit
  default-enable-multibyte-characters: t

Major mode: Lisp Interaction

Minor modes in effect:
  display-time-mode: t
  tool-bar-mode: t
  mouse-wheel-mode: t
  tooltip-mode: t
  auto-compression-mode: t
  menu-bar-mode: t
  blink-cursor-mode: t
  unify-8859-on-encoding-mode: t
  utf-translate-cjk-mode: t
  line-number-mode: t
  next-error-follow-minor-mode:  Fol