Re: Display bug

Re: Display bug

[Richard Stallman]

It does not fail for me in the development sources.

Display bug

[Richard Stallman]

I think I fixed the display bug now with the latest changes in xdisp.c.

Re: Display bug

[Karl Eichwalder]

Richard Stallman <rms@gnu.org> writes:

> I think I fixed the display bug now with the latest changes in xdisp.c.

Thanks a lot.  I cannot reproduce the bug any longer.

-- 
ke@suse.de (work) / keichwa@gmx.net (home):              |
http://www.suse.de/~ke/                                  |      ,__o
Free Translation Project:                                |    _-\_<,
http://www.iro.umontreal.ca/contrib/po/HTML/             |   (*)/'(*)

Display bug

[Richard Stallman]

Since this happens in the CVS trunk, it should be fixed now.
Has anyone looked at this?  Please DTRT and ack.

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	autolearn=failed version=3.1.0
From: Kenichi Handa <handa@m17n.org>
To: Kenichi Handa <handa@m17n.org>
In-reply-to: <E1HOoEX-0002hK-18@etlken.m17n.org> (message from Kenichi Handa
	on Wed, 07 Mar 2007 13:58:37 +0900)
MIME-Version: 1.0 (generated by SEMI 1.14.3 - "Ushinoya")
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Date: Wed, 07 Mar 2007 14:37:39 +0900
Cc: nickrob@snap.net.nz, hongyi.zhao@gmail.com, emacs-devel@gnu.org
Subject: Display bug [Re: My Emacs unicode 2 crash again ...]

In article <E1HOoEX-0002hK-18@etlken.m17n.org>, Kenichi Handa <handa@m17n.org> writes:
> It now shows the correct place of calling abort() as below,
> and I can reproduce the bug by compiling Emacs with
> --enable-asserts.

> Breakpoint 1, abort () at emacs.c:431
> (gdb) bt full
> #0  abort () at emacs.c:431
> No locals.
> #1  0x0808a8ec in try_window_id (w=0x8867cc8) at xdisp.c:15132
[...]
>       xassert (w->window_end_bytepos >= 0);   <-- line 15132
>       IF_DEBUG (debug_method_add (w, "A"));
>     }

> I'm now trying to find what is wrong.

I found that the same bug can be reproduced even with Emacs
22 (latest CVS HEAD) when it is configured with
- --enable-asserts.  Please try to build Emacs that way, and
run this code:

(defun temp ()
  (with-temp-buffer
    (switch-to-buffer (current-buffer))
    (insert "a-\n-\nd\n")
    (let ((nbsp (string (decode-char 'ucs #xa0))))
      (while t
	(goto-char 1)
	(replace-string "-" nbsp)
	(sit-for 0.1)
	(goto-char 1)
	(replace-string nbsp "-")
	(sit-for 0.1)))))

It just swaps "-" and NBSP repeatedly.  As the logic of the
function try_window_id is quite complicated, I still don't
understand what is wrong.  Could someone help?  FYI,

(gdb) run
[...]
Breakpoint 1, abort () at emacs.c:431
(gdb) up
#1  0x08086b40 in try_window_id (w=0x85df240) at xdisp.c:14983
(gdb) pp w->buffer
#<buffer  *temp*>
(gdb) pp current_buffer->name
" *temp*"
(gdb) p *current_buffer->text
$7 = {
  beg = 0x85bf3e0 "a-\n-", 
  gpt = 5, 
  z = 8, 
  gpt_byte = 5, 
  z_byte = 8, 
  gap_size = 13, 
  modiff = 6, 
  chars_modiff = 6, 
  save_modiff = 1, 
  overlay_modiff = 1, 
  beg_unchanged = 1, 
  end_unchanged = 3, 
  unchanged_modified = 4, 
  overlay_unchanged_modified = 1, 
  intervals = 0x0, 
  markers = 0x854d948
}
(gdb) p row->end.pos
$8 = {
  charpos = 8, 
  bytepos = 10
}
(gdb) p w->window_end_bytepos
$9 = -2
(gdb) 

It seems that the buffer now contains only ASCII
(i.e. "a-\n-\nd\n"), but row points to a data containing
multibyte characters (NBSP in this case).

- ---
Kenichi Handa
handa@m17n.org


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Re: Display bug

[Chong Yidong]

Richard Stallman <rms@gnu.org> writes:

> Since this happens in the CVS trunk, it should be fixed now.
> Has anyone looked at this?  Please DTRT and ack.
>
> From: Kenichi Handa <handa@m17n.org>
> Subject: Display bug [Re: My Emacs unicode 2 crash again ...]
>
> I found that the same bug can be reproduced even with Emacs
> 22 (latest CVS HEAD) when it is configured with
> - --enable-asserts.

The following patch fixes this bug.  I'll check it in once CVS comes
back online.

*** emacs/src/xdisp.c.~1.1142.~	2007-03-09 22:37:01.000000000 -0500
--- emacs/src/xdisp.c	2007-03-13 18:10:19.000000000 -0400
***************
*** 14898,14904 ****
      sync_frame_with_window_matrix_rows (w);
  
    /* Adjust buffer positions in reused rows.  */
!   if (delta)
      increment_matrix_positions (current_matrix,
  				first_unchanged_at_end_vpos + dvpos,
  				bottom_vpos, delta, delta_bytes);
--- 14898,14904 ----
      sync_frame_with_window_matrix_rows (w);
  
    /* Adjust buffer positions in reused rows.  */
!   if (delta || delta_bytes)
      increment_matrix_positions (current_matrix,
  				first_unchanged_at_end_vpos + dvpos,
  				bottom_vpos, delta, delta_bytes);