bug#6026: 23.1.96; Cursor drawing problems with the Khmer script

[Eli Zaretskii <eliz@gnu.org>]

Type "C-h H" in "emacs -Q", then go to the line of the Khmer greeting
and move cursor.  Both forward and backward movement has problems:
with forward movement, the cursor sometimes disappears (or maybe
degenerates into very small bitmap), and backward movement leaves
strange artifacts on the screen.

This problem exists in Emacs 23.1 as well.


In GNU Emacs 23.1.96.1 (i386-mingw-nt5.1.2600)
 of 2010-04-20 on HOME-C4E4A596F7
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
  value of $XMODIFIERS: nil
  locale-coding-system: cp1255
  default enable-multibyte-characters: t

Major mode: Mail

Minor modes in effect:
  diff-auto-refine-mode: t
  shell-dirtrack-mode: t
  flyspell-mode: t
  desktop-save-mode: t
  show-paren-mode: t
  display-time-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-encryption-mode: t
  auto-compression-mode: t
  temp-buffer-resize-mode: t
  line-number-mode: t
  abbrev-mode: t

Recent input:
<M-backspace> t r <tab> s r <tab> C h a n g <tab> <return> 
<up> <up> <up> <up> <right> C-SPC <down> <down> <down> 
C-w <down> <down> <down> <down> <down> <down> <up> 
<up> <up> <up> <up> <up> C-y C-/ <down> <down> <down> 
<down> <down> <down> C-k C-k <down> <down> C-k C-k 
C-x C-s <help-echo> <switch-frame> <help-echo> <help-echo> 
<help-echo> <switch-frame> <M-end> C-x k <return> <help-echo> 
<M-home> <up> <up> <up> <up> <up> <up> <up> <up> C-SPC 
<down> <down> <down> <down> M-w <M-end> <help-echo> 
<help-echo> C-y <delete> C-x C-x <return> <up> F D 
<backspace> i x SPC c u r s o r SPC m o t i o n SPC 
a t SPC e n d SPC o f SPC l i n e SPC t h a t SPC e 
n d s SPC i n SPC a SPC c o m p o s i t e SPC c h a 
r a c t e r . <return> <C-left> <C-left> <C-right> 
<backspace> <backspace> <backspace> e d <down> <right> 
<delete> <delete> <down> <delete> SPC <down> <delete> 
SPC <down> <delete> SPC <down> C-x C-s C-x # <help-echo> 
<help-echo> <switch-frame> p p p p p p p d p p p r 
<C-home> <down> <right> <right> <right> <right> C-SPC 
<down> C-w <C-end> C-c C-y C-x C-x <down> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <C-end> C-w <return> F i x SPC i t , SPC I S-SPC 
t h i n k SPC ( r e v n o SPC 1 0 0 0 2 5 ) . <return> 
<right> C-c C-s <help-echo> <switch-frame> o <return> 
p p p p p p n d p p p p p p n p p <M-home> <C-end> 
<M-end> <switch-frame> M-x r e p o r t - e m <tab> 
<return>

Recent messages:
Mark set
Saving file d:/usr/tmp/bzr_log.uvwh-x...
Wrote d:/usr/tmp/bzr_log.uvwh-x
Mark set [5 times]
call-interactively: End of buffer
Sending...
Added to d:/usr/eli/rmail/SENT.MAIL
Sending...done
Added to d:/usr/eli/rmail/BIDI.rmail
Mark set

Load-path shadows:
None found.

Features:
(vc-dispatcher smerge-mode diff-mode thai-util thai-word mule-util
lao-util rmailmm gud shell rmailedit find-func shadow emacsbug
multi-isearch help-mode view texinfo auth-source message ecomplete
rfc822 mml mml-sec password-cache mm-decode mm-bodies mm-encode
mailcap mail-parse rfc2231 rfc2047 rfc2045 qp ietf-drums nnheader
gnus-util netrc mm-util mail-prsvr gmm-utils wid-edit mailheader
canlock hashcash smtpmail dabbrev mailalias mailabbrev sendmail
rmailout conf-mode newcomment ld-script sh-script executable dired-x
dired-aux dired tcl generic parse-time nxml-uchnm rng-xsd xsd-regexp
rng-cmpct rng-nxml rng-valid rng-loc rng-uri rng-parse nxml-parse
rng-match rng-dt rng-util rng-pttrn nxml-ns nxml-mode nxml-outln
nxml-rap nxml-util nxml-glyph nxml-enc xmltok sgml-mode arc-mode
archive-mode make-mode python-21 python comint ring jka-compr vc-cvs
info add-log flyspell ispell org-wl org-w3m org-vm org-rmail org-mhe
org-mew org-irc org-jsinfo org-infojs org-html org-exp org-exp-blocks
org-agenda org-info org-gnus org-bibtex org-bbdb org byte-opt bytecomp
byte-compile advice help-fns advice-preload org-footnote org-src
org-list org-faces org-compat org-macs time-date noutline outline
easy-mmode vc-bzr sha1 hex-util cc-mode cc-fonts easymenu cc-menus
cc-cmds cc-styles cc-align cc-engine cc-vars cc-defs regexp-opt
rmailsum rmail mail-utils desktop server filecache saveplace generic-x
paren battery time tooltip ediff-hook vc-hooks lisp-float-type mwheel
dos-w32 disp-table ls-lisp w32-win w32-vars tool-bar dnd fontset image
fringe lisp-mode register page menu-bar rfn-eshadow timer select
scroll-bar mldrag 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 loaddefs button minibuffer faces
cus-face files text-properties overlay md5 base64 format env
code-pages mule custom widget hashtable-print-readable backquote
make-network-process multi-tty emacs)