bug#11351: 24.1.50; marker does not point anywhere

[Sam Steingold <sds@gnu.org>]

On Thu, Apr 26, 2012 at 12:04, Eli Zaretskii <eliz@gnu.org> wrote:
> Start by seeing if this is reproducible in an unoptimized build,
> otherwise the backtrace and the values of variables are untrustworthy.


(gdb) where
#0  0x00007ffff4182613 in select () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x000000000053b601 in xg_select (max_fds=18, rfds=0x7fffffffa010,
wfds=0x7fffffffa090, efds=0x0, timeout=0x7fffffffa210)
    at /home/sds/src/emacs/trunk/src/xgselect.c:100
#2  0x0000000000651faf in wait_reading_process_output (time_limit=30,
microsecs=0, read_kbd=-1, do_display=1,
    wait_for_cell=12720514, wait_proc=0x0, just_wait_proc=0) at
/home/sds/src/emacs/trunk/src/process.c:4620
#3  0x000000000041bc51 in sit_for (timeout=120, reading=1,
do_display=1) at /home/sds/src/emacs/trunk/src/dispnew.c:6067
#4  0x000000000055b792 in read_char (commandflag=1, nmaps=2,
maps=0x7fffffffa6d0, prev_event=12720514,
    used_mouse_menu=0x7fffffffa818, end_time=0x0) at
/home/sds/src/emacs/trunk/src/keyboard.c:2692
#5  0x0000000000569515 in read_key_sequence (keybuf=0x7fffffffa9e0,
bufsize=30, prompt=12720514, dont_downcase_last=0,
    can_return_switch_frame=1, fix_current_buffer=1) at
/home/sds/src/emacs/trunk/src/keyboard.c:9335
#6  0x0000000000558f2a in command_loop_1 () at
/home/sds/src/emacs/trunk/src/keyboard.c:1449
#7  0x00000000005f68c5 in internal_condition_case (bfun=0x558b45
<command_loop_1>, handlers=12772754, hfun=0x55840a <cmd_error>)
    at /home/sds/src/emacs/trunk/src/eval.c:1448
#8  0x0000000000558834 in command_loop_2 (ignore=12720514) at
/home/sds/src/emacs/trunk/src/keyboard.c:1160
#9  0x00000000005f627c in internal_catch (tag=12842178, func=0x55880e
<command_loop_2>, arg=12720514)
    at /home/sds/src/emacs/trunk/src/eval.c:1205
#10 0x0000000000558798 in command_loop () at
/home/sds/src/emacs/trunk/src/keyboard.c:1125
#11 0x0000000000557f4e in recursive_edit_1 () at
/home/sds/src/emacs/trunk/src/keyboard.c:759
#12 0x00000000005580f1 in Frecursive_edit () at
/home/sds/src/emacs/trunk/src/keyboard.c:823
#13 0x00000000005f9bf9 in Ffuncall (nargs=1, args=0x7fffffffaf30) at
/home/sds/src/emacs/trunk/src/eval.c:2932
#14 0x0000000000645f14 in exec_byte_code (bytestr=77240273,
vector=55632165, maxdepth=116, args_template=12720514, nargs=0,
    args=0x0) at /home/sds/src/emacs/trunk/src/bytecode.c:785
#15 0x00000000005fa63d in funcall_lambda (fun=75784917, nargs=2,
arg_vector=0x7fffffffb4d8)
    at /home/sds/src/emacs/trunk/src/eval.c:3166
#16 0x00000000005f9e25 in Ffuncall (nargs=3, args=0x7fffffffb4d0) at
/home/sds/src/emacs/trunk/src/eval.c:2984
#17 0x00000000005f8e17 in Fapply (nargs=2, args=0x7fffffffb5c0) at
/home/sds/src/emacs/trunk/src/eval.c:2440
#18 0x00000000005f935e in apply1 (fn=12842594, arg=55655030) at
/home/sds/src/emacs/trunk/src/eval.c:2678
#19 0x00000000005f4768 in call_debugger (arg=55655030) at
/home/sds/src/emacs/trunk/src/eval.c:227
#20 0x00000000005f75ab in maybe_call_debugger (conditions=9382454,
sig=12772754, data=55655078)
    at /home/sds/src/emacs/trunk/src/eval.c:1863
#21 0x00000000005f7087 in Fsignal (error_symbol=12772754,
data=55655078) at /home/sds/src/emacs/trunk/src/eval.c:1684
#22 0x00000000005f719a in xsignal (error_symbol=12772754,
data=55655078) at /home/sds/src/emacs/trunk/src/eval.c:1719
#23 0x00000000005f71ef in xsignal1 (error_symbol=12772754,
arg=51091057) at /home/sds/src/emacs/trunk/src/eval.c:1734
#24 0x00000000005f77ef in verror (m=0x6accc0 "Marker does not point
anywhere", ap=0x7fffffffc748)
    at /home/sds/src/emacs/trunk/src/eval.c:1932
#25 0x00000000005f788e in error (m=0x6accc0 "Marker does not point
anywhere") at /home/sds/src/emacs/trunk/src/eval.c:1944
#26 0x0000000000594f05 in marker_position (marker=36849115) at
/home/sds/src/emacs/trunk/src/marker.c:777
#27 0x0000000000583c26 in overlays_at (pos=68, extend=0,
vec_ptr=0x7fffffffca80, len_ptr=0x7fffffffca88, next_ptr=0x0,
    prev_ptr=0x0, change_req=0) at /home/sds/src/emacs/trunk/src/buffer.c:2541
#28 0x0000000000669efd in get_char_property_and_overlay (position=272,
prop=12910066, object=12748565, overlay=0x0)
    at /home/sds/src/emacs/trunk/src/textprop.c:626
#29 0x000000000066a07d in Fget_char_property (position=272,
prop=12910066, object=12748565)
    at /home/sds/src/emacs/trunk/src/textprop.c:665
#30 0x0000000000667e2d in get_local_map (position=68, buffer=0xc28710,
type=12910066)
    at /home/sds/src/emacs/trunk/src/intervals.c:2306
#31 0x0000000000568cee in read_key_sequence (keybuf=0x7fffffffce70,
bufsize=30, prompt=12720514, dont_downcase_last=0,
    can_return_switch_frame=1, fix_current_buffer=1) at
/home/sds/src/emacs/trunk/src/keyboard.c:9147
#32 0x0000000000558f2a in command_loop_1 () at
/home/sds/src/emacs/trunk/src/keyboard.c:1449
#33 0x00000000005f68c5 in internal_condition_case (bfun=0x558b45
<command_loop_1>, handlers=12772754, hfun=0x55840a <cmd_error>)
    at /home/sds/src/emacs/trunk/src/eval.c:1448
#34 0x0000000000558834 in command_loop_2 (ignore=12720514) at
/home/sds/src/emacs/trunk/src/keyboard.c:1160
#35 0x00000000005f627c in internal_catch (tag=12768498, func=0x55880e
<command_loop_2>, arg=12720514)
    at /home/sds/src/emacs/trunk/src/eval.c:1205
#36 0x00000000005587e7 in command_loop () at
/home/sds/src/emacs/trunk/src/keyboard.c:1139
#37 0x0000000000557f4e in recursive_edit_1 () at
/home/sds/src/emacs/trunk/src/keyboard.c:759
#38 0x00000000005580f1 in Frecursive_edit () at
/home/sds/src/emacs/trunk/src/keyboard.c:823
#39 0x0000000000556192 in main (argc=1, argv=0x7fffffffd758) at
/home/sds/src/emacs/trunk/src/emacs.c:1711

Lisp Backtrace:
"recursive-edit" (0xffffaf38)
"debug" (0xffffb4d8)

f 26
#26 0x0000000000594f05 in marker_position (marker=36849115) at
/home/sds/src/emacs/trunk/src/marker.c:777
777         error ("Marker does not point anywhere");
(gdb) p marker
$4 = 36849115
(gdb) up
#27 0x0000000000583c26 in overlays_at (pos=68, extend=0,
vec_ptr=0x7fffffffca80, len_ptr=0x7fffffffca88, next_ptr=0x0,
    prev_ptr=0x0, change_req=0) at /home/sds/src/emacs/trunk/src/buffer.c:2541
2541          endpos = OVERLAY_POSITION (end);
(gdb) list
2536
2537          XSETMISC (overlay, tail);
2538
2539          start = OVERLAY_START (overlay);
2540          end = OVERLAY_END (overlay);
2541          endpos = OVERLAY_POSITION (end);
2542          if (endpos < pos)
2543            {
2544              if (prev < endpos)
2545                prev = endpos;
(gdb) p end
$5 = 36849115
(gdb) p start
$6 = 36849155
(gdb) p overlay
$7 = 36849075
(gdb) p tail
$8 = (struct Lisp_Overlay *) 0x23245b0
(gdb) p *tail
$9 = {
  type = Lisp_Misc_Overlay,
  gcmarkbit = 0,
  spacer = 0,
  next = 0x0,
  start = 36849155,
  end = 36849115,
  plist = 44767590
}
(gdb) p pos
$10 = 68
(gdb) xpr overlay
Lisp_Int1
$11 = 2
(gdb) p overlay
$12 = 36849075
(gdb) xpr
Lisp_Misc
Lisp_Misc_Overlay
No symbol "Lisp_Misc_Boolfwd" in current context.
(gdb) p marker
No symbol "marker" in current context.
(gdb) p end
$13 = 36849115
(gdb) xpr
Lisp_Misc
Lisp_Misc_Marker
No symbol "Lisp_Misc_Boolfwd" in current context.
(gdb)



-- 
Sam Steingold <http://sds.podval.org> <http://www.childpsy.net/>