bug#9530: 24.0.50; incorrect cursor moving

[Kenichi Handa <handa@m17n.org>]

With the trunk Emacs, cursor jumps around in the following
testcase.

% emacs -Q
;; Now we are in *scratch* buffer which contains ";; This
bufffer is..." comment at the head.
ESC : (insert (propertize "\t" 'display '(space :align-to 77)) "a "(propertize "\t" 'display '(space :align-to 79)) "b") RET
;; Now the last line fo *scratch* buffer is showing "a" at
;; column 77, and showingg "b" at column 0 of the continuing line.
C-a C-f C-f
;; The cursor is at the right of character "a".  This is normal.
C-f
;; The cursor jumps to the end of the first line;
;; i.e. the right of "for List evaluation."
C-f
;; The cursor moves back to the character "b" of the
;; original line; i.e. the line inserted by the above "ESC : ... RET".

---
handa@m17n.org


In GNU Emacs 24.0.50.3 (i686-pc-linux-gnu, X toolkit)
 of 2011-09-15 on ubuntu
Windowing system distributor `The X.Org Foundation', version 11.0.10706000
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_JP.utf8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix
  default enable-multibyte-characters: t

Major mode: Shell

Minor modes in effect:
  shell-dirtrack-mode: t
  display-time-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t

Recent input:
d SPC d C-p u n d d d C-e M-b M-b M-b M-b M-b M-b M-b 
M-b M-b M-b M-b M-b M-b M-b M-b M-b M-b M-f M-b C-s 
C-w C-w C-r C-r C-a C-a a <return> C-l SPC n d d SPC 
d a <return> n d d SPC d d d d d d d d d d d d d d 
d d d SPC a <return> n d d d d d d d d d d d d d d 
d d d d d d n d p a m u s t r e <tab> a <tab> <return> 
n p n d d d d d d n d d d d d d d d d d d d d d d d 
d d d d d d SPC d d d d d d d d d d d d d d d d d d 
d d d C-x o C-h c C-h H SPC C-x o n d d d d d d SPC 
d d d d d d d d SPC d d d d d d d d d d d d d d d d 
d d d d d d d d d SPC C-x o C-n C-n C-n C-n C-n C-n 
C-e M-b M-b M-b M-b M-b M-b <return> C-x 1 C-l j C-g 
x C-x C-a C-g h <escape> > C-r m u s t r e C-a C-n 
C-n n n n C-n d d d d d d d d d d d d d d d d d s y 
SPC p C-x o C-x k <return> C-x b R M <tab> C-g C-x 
m C-x k <return> M-x r e p o r t <tab> <return>

Recent messages:
Quit [2 times]
Computing summary lines...done
Mark set
Mark saved where search started
Erase deleted messages from Rmail file? (y or n)  y
Expunging deleted messages...done
Computing summary lines...done
Saving file /home/handa/RMAIL...
Wrote /home/handa/RMAIL [2 times]
Computing summary lines...done
Quit

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