display weirdness: show cursor where it shouldn't be after scroll-left

[Miguel V. S. Frasson]

Hi

In lenghty lines, using scroll-left and scroll-right in some
combination (how to reproduce bellow) results that the display shows
the middle of the line, I see the cursor there in the middle, but
point is in beginning of line.

If one should be prepared to see cursor where the point isn't, then
this is not a bug.

How to reproduce:

1) emacs -Q

2) define the following kbd macro
    C-x (
    C-x C-k TAB   ; insert kmacro counter
    C-q TAB       ; insert a tab
    C-x )

3) repeat it 50 times
    C-u 50 C-x e
  you should see a long line displayed with about 3 display lines
  using fringles.

4) go to beginning of line
    C-a
   after this point, point will be always at beginning of line and buffer.

5) type
    C-next !   ; C-PgDn in my keyboard
  to scroll-left, enabling in this session all disabled commands;
  I see in the display numbers from 10 to 19, and *no cursor*

6) type
    C-next   ; 2nd time
  I see numbers from 20 to 29 and *no cursor*

7) type
    C-next   ; 3rd time
  I see numbers from 30 to 39 and *cursor is there, blinking*

8) type
    C-next   ; 4th time
  I see numbers from 39 to 48 and *cursor is there, blinking*

9) type
    C-next   ; 5th time
  I see numbers 49 and 50 and *no cursor*

10) coming back with C-proir some times, I see the cursor present or
   absent in the same cases as above.

If emacs crashed, and you have the emacs process in the gdb debugger,
please include the output from the following gdb commands:
   `bt full' and `xbacktrace'.
If you would like to further debug the crash, please read the file
/usr/local/share/emacs/22.0.50/etc/DEBUG for instructions.


In GNU Emacs 22.0.50.4 (i686-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
of 2006-05-18 on miguel
X server distributor `The X.Org Foundation', version 11.0.60802000
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: en_US.UTF-8
 locale-coding-system: utf-8
 default-enable-multibyte-characters: t

Major mode: Lisp Interaction

Minor modes in effect:
 tooltip-mode: t
 auto-compression-mode: t
 tool-bar-mode: t
 mouse-wheel-mode: t
 menu-bar-mode: t
 file-name-shadow-mode: t
 global-font-lock-mode: t
 font-lock-mode: t
 blink-cursor-mode: t
 unify-8859-on-encoding-mode: t
 utf-translate-cjk-mode: t
 line-number-mode: t

Recent input:
C-x ( C-x C-k <tab> C-q <tab> C-x ) C-u 5 0 C-x e C-a
<C-next> ! <C-next> <C-next> <C-next> <C-next> <C-prior>
<C-prior> <C-prior> <C-prior> <C-prior> M-x r e p o
r t - e m <tab> <return>

Recent messages:
New macro counter value: 1 (1)
Keyboard macro defined
Loading edmacro...done
(Type e to repeat macro)
Loading novice...done
Loading help-mode...done
Type y, n, ! or SPC (the space bar):
Loading emacsbug...
Loading regexp-opt...done
Loading emacsbug...done

--
Miguel Vinicius Santini Frasson
address@hidden