another unhelpful backtrace from redisplay-internal

[Madhu]

I have a sure recipe for a crash in recent emacs but the configuration
is complex and I'm afraid I don't have a simple test case. I'm posting
the initial backtrace here in case anyone can suggest things I should
look for, or some ways I could narrow it down.


Thread 1 "emacs" hit Breakpoint 1, terminate_due_to_signal
(sig=sig@entry=6,
    backtrace_limit=backtrace_limit@entry=40) at ../../src/emacs.c:371
371       signal (sig, SIG_DFL);
(gdb) back
#0  terminate_due_to_signal (sig=sig@entry=6,
    backtrace_limit=backtrace_limit@entry=40) at ../../src/emacs.c:371
#1  0x000000000041f740 in emacs_abort () at ../../src/sysdep.c:2448
#2  0x000000000041d051 in select_window (window=XIL(0x1165305),
    norecord=XIL(0x30), inhibit_point_swap=<optimized out>)
    at ../../src/lisp.h:780
#3  0x0000000000458f20 in gui_consider_frame_title (
    frame=frame@entry=XIL(0x1123255)) at ../../src/lisp.h:1048
#4  0x0000000000472394 in redisplay_window (window=XIL(0x1165305),
    just_this_one_p=<optimized out>) at ../../src/xdisp.c:18940
#5  0x0000000000476b9b in redisplay_window_0 (
    window=window@entry=XIL(0x1165305)) at ../../src/xdisp.c:16179
#6  0x000000000056c114 in internal_condition_case_1 (
    bfun=bfun@entry=0x476b70 <redisplay_window_0>,
    arg=arg@entry=XIL(0x1165305), handlers=<optimized out>,
    hfun=hfun@entry=0x43a0d0 <redisplay_window_error>) at
    ../../src/eval.c:1379
#7  0x0000000000443554 in redisplay_windows (window=XIL(0x1165305))
    at ../../src/xdisp.c:16159
#8  0x0000000000462e1d in redisplay_internal () at
../../src/xdisp.c:15627
#9  0x00000000005040f7 in read_char (commandflag=1, map=XIL(0x2bca3b3),
    prev_event=XIL(0), used_mouse_menu=0x7fffffffd9cb, end_time=0x0)
    at ../../src/keyboard.c:2493

#10 0x0000000000506a6e in read_key_sequence (keybuf=<optimized out>,
    prompt=XIL(0), dont_downcase_last=<optimized out>,
    can_return_switch_frame=true, fix_current_buffer=true,
    prevent_redisplay=<optimized out>) at ../../src/keyboard.c:9549
#11 0x00000000005080ee in command_loop_1 () at ../../src/lisp.h:1048
#12 0x000000000056c087 in internal_condition_case (
    bfun=bfun@entry=0x507f10 <command_loop_1>,
    handlers=handlers@entry=XIL(0x90), hfun=hfun@entry=0x4ff120
    <cmd_error>)
    at ../../src/eval.c:1355
#13 0x00000000004f9f2c in command_loop_2 (ignore=ignore@entry=XIL(0))
    at ../../src/lisp.h:1048
#14 0x000000000056bfe1 in internal_catch (tag=tag@entry=XIL(0xd4d0),
    func=func@entry=0x4f9f10 <command_loop_2>, arg=arg@entry=XIL(0))
    at ../../src/eval.c:1116
#15 0x00000000004f9ed4 in command_loop () at ../../src/lisp.h:1048
#16 0x00000000004fed36 in recursive_edit_1 () at
../../src/keyboard.c:714
#17 0x00000000004ff060 in Frecursive_edit () at ../../src/keyboard.c:786
#18 0x00000000004259c9 in main (argc=7, argv=<optimized out>)
    at ../../src/emacs.c:2059

Lisp Backtrace:
"redisplay_internal (C function)" (0x0)


The crash happens when quitting a sly-db-mode buffer in its own window
which has popped up in a frame.  The window being redisplayed is the
window which is selected after the sly-db window quits.

Emacs is compiled with -g3 -O2, and I'm not sure if all the info to
debug this is available.

Any suggestions please?
--Madhu


(gdb) up
#1  0x000000000041f740 in emacs_abort () at ../../src/sysdep.c:2448
2448      terminate_due_to_signal (SIGABRT, 40);
(gdb) up
#2  0x000000000041d051 in select_window (window=XIL(0x1165305),
    norecord=XIL(0x30), inhibit_point_swap=<optimized out>)
    at ../../src/lisp.h:780
780       lisp_h_CHECK_TYPE (ok, predicate, x);
(gdb) up
#3  0x0000000000458f20 in gui_consider_frame_title (
    frame=frame@entry=XIL(0x1123255)) at ../../src/lisp.h:1048
1048      return make_lisp_symbol (&lispsym(index));
(gdb) p &lispsym(index)
$1 = (struct Lisp_Symbol *) 0x17fffe29037f80
(gdb) pp &lispsym(index)
#<INVALID_LISP_OBJECT 0x17fffe29037f80>
(gdb) pp lispsym(index)
Cannot access memory at address 0x17fffe29037f80
(gdb) up
#4  0x0000000000472394 in redisplay_window (window=XIL(0x1165305),
    just_this_one_p=<optimized out>) at ../../src/xdisp.c:18940
18940         gui_consider_frame_title (w->frame);
(gdb) pp window
#<window 3 on 1.l>
(gdb) up
#5  0x0000000000476b9b in redisplay_window_0 (
    window=window@entry=XIL(0x1165305)) at ../../src/xdisp.c:16179
16179       redisplay_window (window, false);
(gdb) up
#6  0x000000000056c114 in internal_condition_case_1 (
    bfun=bfun@entry=0x476b70 <redisplay_window_0>,
    arg=arg@entry=XIL(0x1165305), handlers=<optimized out>,
    hfun=hfun@entry=0x43a0d0 <redisplay_window_error>) at
    ../../src/eval.c:1379
1379          Lisp_Object val = bfun (arg);
(gdb) up
#7  0x0000000000443554 in redisplay_windows (window=XIL(0x1165305))
    at ../../src/xdisp.c:16159
16159             internal_condition_case_1 (redisplay_window_0, window,
(gdb) up
#8  0x0000000000462e1d in redisplay_internal () at
../../src/xdisp.c:15627
15627                     redisplay_windows (FRAME_ROOT_WINDOW (f));