bug#11070: 24.0.94; Large stippled images not displayed consistently

[Ivan Andrus]

Starting with emacs -Q, change the path to an image that is taller than a line 
of text.

;; Evaluate this
(face-remap-add-relative 'default
'(:stipple "/path/to/large/image.jpg"))

;; Evaluate this once
(scroll-down -3)

;; Evaluate this 3 times
(scroll-down 1)

;; Notice that the top 3 lines now are repeated using the top portion
;; of the image.

;; Now evaluate these
(scroll-down -3)

(scroll-down 3)

;; Notice that the top 3 lines are now correct.

Also, sometimes moving point (especially with
`backward-paragraph' and `forward-paragraph') will cause lines to
change which portion of the image they display.  This is a little
less predictable, but evaluating (scroll-down -3) and then
repeatedly using `backward-paragraph' will cause lines to change.
Then once the window scrolls to the top `forward-paragraph' will
cause them to change again.  

It seems it may be related to when the cursor is at then end of a line.

Thanks,
Ivan Andrus

In GNU Emacs 24.0.94.6 (i386-apple-darwin10.8.0, NS apple-appkit-1038.36)
of 2012-03-19 on oroszlan.local
Windowing system distributor `Apple', version 10.3.1038
Configured using:
`configure '--with-ns' '-C''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: UTF-8
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: nil
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default enable-multibyte-characters: t

Major mode: Emacs-Lisp

Minor modes in effect:
  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 M-q SPC t o SPC r e d i s p l a y SPC a g a i n . 
<up> C-a <C-right> <C-left> C-d C-d c h a n g e SPC 
t h e SPC i m a g <C-right> <C-backspace> <C-backspace> 
<backspace> M-q <down> C-e <C-left> <C-backspace> c 
h a n g e SPC M-q C-x C-s <C-up> <C-up> <C-up> <C-up> 
<C-up> <C-up> <C-up> <C-up> <C-up> <down> C-e SPC - 
- SPC C-x C-s <C-down> <C-down> <up> <up> <up> <up> 
<C-right> <C-right> <C-left> <left> <down> C-x C-e 
<up> <C-right> <C-right> <C-left> C-j <backspace> <left> 
C-y C-u C-u C-u C-u <C-left> <down> <down> <down> <down> 
<C-right> <C-right> <C-left> C-y C-d C-d C-d C-d C-d 
C-d C-d C-d C-d C-d C-d C-d C-d C-d C-d C-d C-d C-d 
C-d C-d C-d C-d C-d C-d C-d C-d C-d C-d C-d C-d C-d 
C-d C-d C-d C-d C-d C-d C-d C-d C-d C-d C-d C-d C-d 
C-d C-d C-d C-d C-d C-d C-d C-d C-d C-d C-d C-d C-d 
C-d C-d C-d C-d C-d C-d C-d C-d C-e C-x C-e C-/ C-/ 
C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ 
C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ 
C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ 
C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ 
C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ C-/ 
C-/ <backspace> C-x C-s <C-down> C-x C-e <C-down> C-x 
C-e <C-down> C-x C-e C-x C-e C-x C-e C-x C-e <C-down> 
<C-down> C-x C-e <C-down> C-x C-e <C-up> <C-up> <C-up> 
<C-up> <C-up> <C-up> <C-up> <C-down> <C-down> <C-down> 
<C-down> <C-down> <C-down> <C-down> <C-down> <C-down> 
C-x C-s M-x r e p o r <tab> <return>

Recent messages:
Undo! [23 times]
Auto-saving...
Undo! [45 times]
Saving file /Users/gvol/vcs/emacs/face-mapping-bug.el...
Wrote /Users/gvol/vcs/emacs/face-mapping-bug.el
(default :stipple "/Users/gvol/.emacs.d/local/pic/b-rock-grey.jpg")
nil [4 times]
eval: Beginning of buffer
nil [2 times]
(No changes need to be saved)

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 regexp-opt rfc2047 rfc2045
ietf-drums mm-util mail-prsvr mail-utils dabbrev newcomment face-remap
vc-hg time-date tooltip ediff-hook vc-hooks lisp-float-type mwheel
ns-win tool-bar dnd fontset image fringe 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 loaddefs
button faces cus-face files text-properties overlay sha1 md5 base64
format env code-pages mule custom widget hashtable-print-readable
backquote make-network-process ns multi-tty emacs)