preview-latex and display problem.

[Matt Hodges]

In GNU Emacs 21.3.50.1 (i686-pc-linux-gnu, GTK+ Version 2.2.4)
 of 2004-05-09 on dugong
configured using `configure '--with-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: nil
  locale-coding-system: nil
  default-enable-multibyte-characters: t

Major mode: LaTeX

Minor modes in effect:
  mouse-wheel-mode: t
  unify-8859-on-encoding-mode: t
  line-number-mode: t

I have encountered redisplay problems with recent builds when using
preview-latex, and trying to open preview overlays.

Initial buffer contents:

After preview-document (C-c C-p C-d); cursor positioned at start of
preview:

After forward-char. Expect preview to be revealed at this point; this
doesn't happen and a second cursor appears at the top of the window:

After trying to force redisplay with C-l:

Leads to error:

    Debugger entered--Lisp error: (args-out-of-range 48 48)
      recenter(nil)
      call-interactively(recenter)

This is on a Debian (unstable) system, with the auctex and
preview-latex packages installed. I used emacs -Q, and evaluated:

test.el
Description: preview-latex redisplay problem (configuration).

The LaTeX source is:

\documentclass[12pt]{article}
\begin{document}
\begin{equation}
  a + b = c
\end{equation}
\end{document}

Thanks,

Matt