emacs -nw segfaults toggling menu bar mode

emacs -nw segfaults toggling menu bar mode

[Thien-Thi Nguyen]

with a 2005-04-06 cvs update, and configured w/ no options,
i built and then started emacs like so:

  emacs -nw -q --no-site-file

then i did:

  M-x menu-bar-mode

this turned off the menu bar as expected.  then i did:

  M-x menu-bar-mode

this segfaulted.  poking around w/ gdb, i eventually came up w/ the
following patch, which prevents the segfault.  could someone review it
(i'm not very familiar w/ this area of emacs) and let me know how to
improve it?

thi

________________________________________________________________
diff -c -r1.343 dispnew.c
*** dispnew.c	17 Mar 2005 23:39:12 -0000	1.343
--- dispnew.c	6 Apr 2005 23:14:17 -0000
***************
*** 3165,3178 ****
  		  int m2_from;
  
  		  w2 = frame_row_to_window (root, frame_from);
! 		  m2 = w2->current_matrix;
! 		  m2_from = frame_from - m2->matrix_y;
! 		  copy_row_except_pointers (m->rows + window_to,
! 					    m2->rows + m2_from);
! 
! 		  /* If frame line is empty, window line is empty, too.  */
! 		  if (!retained_p[copy_from[i]])
! 		    m->rows[window_to].enabled_p = 0;
  		  sync_p = 1;
  		}
  	      else if (from_inside_window_p)
--- 3165,3184 ----
  		  int m2_from;
  
  		  w2 = frame_row_to_window (root, frame_from);
!                   /* Apparently, when turning on the menu bar using "emacs
!                      -nw", `from_frame' does not yield an associated window.
!                      This check avoids a segfault.  */
!                   if (w2)
!                     {
!                       m2 = w2->current_matrix;
!                       m2_from = frame_from - m2->matrix_y;
!                       copy_row_except_pointers (m->rows + window_to,
!                                                 m2->rows + m2_from);
! 
!                       /* If frame line is empty, window line is empty, too.  */
!                       if (!retained_p[copy_from[i]])
!                         m->rows[window_to].enabled_p = 0;
!                     }
  		  sync_p = 1;
  		}
  	      else if (from_inside_window_p)

Re: emacs -nw segfaults toggling menu bar mode

[Marcelo Toledo]

I couldn't reproduce this.

Thien-Thi Nguyen <ttn@surf.glug.org> writes:

> with a 2005-04-06 cvs update, and configured w/ no options,
> i built and then started emacs like so:
>
>   emacs -nw -q --no-site-file
>
> then i did:
>
>   M-x menu-bar-mode
>
> this turned off the menu bar as expected.  then i did:
>
>   M-x menu-bar-mode
>
> this segfaulted.  poking around w/ gdb, i eventually came up w/ the
> following patch, which prevents the segfault.  could someone review it
> (i'm not very familiar w/ this area of emacs) and let me know how to
> improve it?

-- 
Marcelo Toledo
marcelo@marcelotoledo.org
http://www.marcelotoledo.org
Mobile: 55 71 9116-1101

Re: emacs -nw segfaults toggling menu bar mode

[Richard Stallman]

Although someone else said he could not reproduce this,
it could be that sometimes W2 is null.  Your change can't hurt
anything.  So I installed it.

Re: emacs -nw segfaults toggling menu bar mode

[Thien-Thi Nguyen]

   From: Richard Stallman <rms@gnu.org>
   Date: Sat, 09 Apr 2005 21:55:23 -0400

   Although someone else said he could not reproduce this,
   it could be that sometimes W2 is null.  Your change can't
   hurt anything.  So I installed it.

thank you.

i have not investigated further, but anyway append for the
archives some X resources i use, in case they play a part in
the crash.

thi

_________________________________
Emacs*menuBar: off
Emacs*toolBar: 0
Emacs*verticalScrollBars: off

Re: emacs -nw segfaults toggling menu bar mode

[Lute Kamstra]

Richard Stallman <rms@gnu.org> writes:

> Although someone else said he could not reproduce this,
> it could be that sometimes W2 is null.  Your change can't hurt
> anything.  So I installed it.

I could reproduce the crash and the patch fixes it for me.

Lute.