emacs 21.1, linux 2.4.12-3.5G, core dump in set_point_both()

emacs 21.1, linux 2.4.12-3.5G, core dump in set_point_both()

[Quentin Fennessy]

In GNU Emacs 21.1.1 (i686-pc-linux-gnu, X toolkit)
 of 2002-02-19 on go002
configured using `configure  --prefix=/tool/pandora/.package/emacs-21.1'
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
  locale-coding-system: iso-latin-1
  default-enable-multibyte-characters: t

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:

While I was editing a mail message (wide reply from gnus) in modes: Message,
SC, MML and Abbrev I found nulls at the end of the buffer. I tried C-U
several times and could not remove them. While trying several C-U emacs
crashed and left a core file.

I have been unable to reproduce this failure.

Here is the back trace:

: qf@odin003:~; gdb /tool/pandora/bin/emacs core
GNU gdb 5.1
Copyright 2001 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "i686-pc-linux-gnu"...
Core was generated by `emacs'.
Program terminated with signal 6, Aborted.
Error while mapping shared library sections:
/lib/i686/libm.so.6: No such file or directory.
Error while mapping shared library sections:
/lib/i686/libc.so.6: No such file or directory.
Reading symbols from /tool/pandora/.package/X11-R6.3/lib/libXaw.so.6...done.
Loaded symbols for /tool/pandora/.package/X11-R6.3/lib/libXaw.so.6
Reading symbols from /tool/pandora/.package/X11-R6.3/lib/libXmu.so.6...done.
Loaded symbols for /tool/pandora/.package/X11-R6.3/lib/libXmu.so.6
Reading symbols from /tool/pandora/.package/X11-R6.3/lib/libXt.so.6...done.
Loaded symbols for /tool/pandora/.package/X11-R6.3/lib/libXt.so.6
Reading symbols from /tool/pandora/.package/X11-R6.3/lib/libSM.so.6...done.
Loaded symbols for /tool/pandora/.package/X11-R6.3/lib/libSM.so.6
Reading symbols from /tool/pandora/.package/X11-R6.3/lib/libICE.so.6...done.
Loaded symbols for /tool/pandora/.package/X11-R6.3/lib/libICE.so.6
Reading symbols from /tool/pandora/.package/X11-R6.3/lib/libXext.so.6...done.
Loaded symbols for /tool/pandora/.package/X11-R6.3/lib/libXext.so.6
Reading symbols from /usr/lib/libtiff.so.3...done.
Loaded symbols for /usr/lib/libtiff.so.3
Reading symbols from /usr/lib/libjpeg.so.62...done.
Loaded symbols for /usr/lib/libjpeg.so.62
Reading symbols from /usr/lib/libpng.so.2...done.
Loaded symbols for /usr/lib/libpng.so.2
Reading symbols from /usr/lib/libz.so.1...done.
Loaded symbols for /usr/lib/libz.so.1
Error while reading shared library symbols:
/lib/i686/libm.so.6: No such file or directory.
Reading symbols from /usr/lib/libungif.so.4...done.
Loaded symbols for /usr/lib/libungif.so.4
Reading symbols from /tool/pandora/.package/X11-R6.3/lib/libXpm.so.4...done.
Loaded symbols for /tool/pandora/.package/X11-R6.3/lib/libXpm.so.4
Reading symbols from /tool/pandora/.package/X11-R6.3/lib/libX11.so.6...done.
Loaded symbols for /tool/pandora/.package/X11-R6.3/lib/libX11.so.6
Reading symbols from /usr/lib/libncurses.so.4...done.
Loaded symbols for /usr/lib/libncurses.so.4
Error while reading shared library symbols:
/lib/i686/libc.so.6: No such file or directory.
---Type <return> to continue, or q <return> to quit---
Reading symbols from /lib/ld-linux.so.2...done.

Loaded symbols for /lib/ld-linux.so.2
Reading symbols from /lib/libnss_dns.so.2...done.
Loaded symbols for /lib/libnss_dns.so.2
Reading symbols from /lib/libresolv.so.2...done.
Loaded symbols for /lib/libresolv.so.2
Reading symbols from /lib/libnss_files.so.2...done.
Loaded symbols for /lib/libnss_files.so.2
Reading symbols from /lib/libnss_nis.so.2...done.
Loaded symbols for /lib/libnss_nis.so.2
Reading symbols from /lib/libnsl.so.1...done.
Loaded symbols for /lib/libnsl.so.1
#0  0x4ad5a801 in ?? ()
(gdb) bt
#0  0x4ad5a801 in ?? ()
#1  0x4ad5a648 in ?? ()
#2  0x0815a848 in set_point_both (buffer=0x921ed90, charpos=1248, bytepos=1301)
    at intervals.c:1895
#3  0x08102a66 in Fvertical_motion (lines=31, window=1224097232)
    at indent.c:2007
#4  0x081258af in Ffuncall (nargs=3, args=0xdfffe078) at eval.c:2658
#5  0x0814c14c in Fbyte_code (bytestr=944925764, vector=1213388560, maxdepth=5)
    at bytecode.c:716
#6  0x08125e8b in funcall_lambda (fun=1213388704, nargs=1, 
    arg_vector=0xdfffe194) at eval.c:2847
#7  0x081259f1 in Ffuncall (nargs=2, args=0xdfffe190) at eval.c:2712
#8  0x0814c14c in Fbyte_code (bytestr=944926228, vector=1213384936, maxdepth=3)
    at bytecode.c:716
#9  0x08125e8b in funcall_lambda (fun=1213385072, nargs=1, 
    arg_vector=0xdfffe2a4) at eval.c:2847
#10 0x081259f1 in Ffuncall (nargs=2, args=0xdfffe2a0) at eval.c:2712
#11 0x0814c14c in Fbyte_code (bytestr=941542832, vector=1209978364, maxdepth=5)
    at bytecode.c:716
#12 0x08125e8b in funcall_lambda (fun=1209978228, nargs=3, 
    arg_vector=0xdfffe3c4) at eval.c:2847
#13 0x081259f1 in Ffuncall (nargs=4, args=0xdfffe3c0) at eval.c:2712
#14 0x0814c14c in Fbyte_code (bytestr=944926244, vector=1213385136, maxdepth=4)
---Type <return> to continue, or q <return> to quit---
    at bytecode.c:716
#15 0x08125e8b in funcall_lambda (fun=1213385280, nargs=1, 
    arg_vector=0xdfffe4f4) at eval.c:2847
#16 0x081259f1 in Ffuncall (nargs=2, args=0xdfffe4f0) at eval.c:2712
#17 0x081255ff in call1 (fn=408076748, arg1=1218486800) at eval.c:2452
#18 0x080641c7 in prepare_menu_bars () at xdisp.c:7310
#19 0x08065c34 in redisplay_internal (preserve_echo_area=0) at xdisp.c:8433
#20 0x080655e4 in redisplay () at xdisp.c:8231
#21 0x080d3135 in read_char (commandflag=1, nmaps=3, maps=0xdfffeb50, 
    prev_event=405197564, used_mouse_menu=0xdfffeb98) at keyboard.c:2272
#22 0x080d9bdf in read_key_sequence (keybuf=0xdfffeca0, bufsize=30, 
    prompt=405197564, dont_downcase_last=0, can_return_switch_frame=1, 
    fix_current_buffer=1) at keyboard.c:8180
#23 0x080d1ce4 in command_loop_1 () at keyboard.c:1440
#24 0x08123d77 in internal_condition_case (bfun=0x80d19f0 <command_loop_1>, 
    handlers=405293884, hfun=0x80d1628 <cmd_error>) at eval.c:1267
#25 0x080d18c8 in command_loop_2 () at keyboard.c:1245
#26 0x08123903 in internal_catch (tag=405255492, 
    func=0x80d18a4 <command_loop_2>, arg=405197564) at eval.c:1030
#27 0x080d1872 in command_loop () at keyboard.c:1224
#28 0x080d13cd in recursive_edit_1 () at keyboard.c:950
#29 0x080d1500 in Frecursive_edit () at keyboard.c:1006
#30 0x080d0391 in main (argc=1, argv=0xdffff264, envp=0xdffff26c)
---Type <return> to continue, or q <return> to quit---
    at emacs.c:1547
#31 0x4ad49177 in ?? ()


This input is from the current emacs run -- it core dumped
and so I don't have the recent input.


Recent input:
SPC a n d SPC i t SPC f a i l e d SPC o n <backspace> 
<backspace> t h e <return> s a m e SPC w a y . SPC 
o d i n 0 0 4 SPC M-b p e p e SPC s <backspace> r u 
n s SPC l i n u x SPC 2 . 4 . 1 2 , SPC a n d SPC C-e 
r u n s SPC 2 . 4 . 1 6 . C-h i n M-x r e p o r t - 
e m <tab> <return>

Recent messages:
Loading supercite...done
Ref header 0 [0 lines]: (sc-no-header)
Ref header 0 [38 lines]: (sc-no-header)
Mark set
Auto-saving...done
kill-line: End of buffer [2 times]
mml-minibuffer-read-file: Quit
Type C-x 1 to remove help window.  C-M-v to scroll the help.
Undo! [2 times]
Loading emacsbug...done

Re: emacs 21.1, linux 2.4.12-3.5G, core dump in set_point_both()

[Richard Stallman]

Thanks for the bug report.

I suspect that ZV and ZV_BYTE got out of sync, that they do not
correspond to each other properly given the current buffer contents.
Or perhaps some other pair of pointers that are supposed to match up
as character count and byte count.  If this is true, it would be due
to a bug in some C primitives.

The way to find out more would be to carefully study the data structures
using GDB.  It is not easy, but it is the only way.