bug#47284: emacs 26/27 SEGV

[Tjernlund]

File / Revert Buffer in the menu bar over a remote display with ping > 3 ms 
gives me a SEGV:

(gdb) bt
#0  0x00007ffff7ddc594 in GetnormalGC (lw=lw@entry=0x555556999670) at 
Label.c:310
#1  0x00007ffff7ddcc92 in Initialize (request=<optimized out>, 
new=0x555556999670, args=<optimized out>, num_args=<optimized out>) at 
Label.c:401
#2  0x00007ffff7d543b9 in CallInitialize
    (class=0x7ffff7e19280 <labelClassRec>, 
req_widget=req_widget@entry=0x7fffffffb710, 
new_widget=new_widget@entry=0x555556999670, args=args@entry=0x7fffffffbb80, 
num_args=<optimized out>, num_args@entry=0x4) at 
/var/tmp/portage/x11-libs/libXt-1.2.1/work/libXt-1.2.1/src/Create.c:219
#3  0x00007ffff7d54d30 in xtCreate
    (name=name@entry=0x7ffff7e06065 "label", class=class@entry=0x0, 
widget_class=widget_class@entry=0x7ffff7e19280 <labelClassRec>, 
parent=parent@entry=0x555556999440, default_screen=0x555555e21bf0, 
args=args@entry=0x7fffffffbb80, num_args=0x4, typed_args=0x0, 
num_typed_args=<optimized out>, parent_constraint_class=0x7ffff7e18ac0 
<dialogClassRec>, post_proc=0x7ffff7d54400 <widgetPostProc>) at 
/var/tmp/portage/x11-libs/libXt-1.2.1/work/libXt-1.2.1/src/Create.c:415
#4  0x00007ffff7d55202 in _XtCreateWidget
    (name=name@entry=0x7ffff7e06065 "label", 
widget_class=widget_class@entry=0x7ffff7e19280 <labelClassRec>, 
parent=parent@entry=0x555556999440, args=args@entry=0x7fffffffbb80, 
num_args=0x4, typed_args=typed_args@entry=0x0, num_typed_args=<optimized out>) 
at /var/tmp/portage/x11-libs/libXt-1.2.1/work/libXt-1.2.1/src/Create.c:581
#5  0x00007ffff7d55582 in XtCreateManagedWidget
    (name=name@entry=0x7ffff7e06065 "label", widget_class=0x7ffff7e19280 
<labelClassRec>, parent=parent@entry=0x555556999440, 
args=args@entry=0x7fffffffbb80, num_args=<optimized out>) at 
/var/tmp/portage/x11-libs/libXt-1.2.1/work/libXt-1.2.1/src/Create.c:619
#6  0x00007ffff7ddae7f in Initialize (request=<optimized out>, 
new=0x555556999440, args=<optimized out>, num_args=<optimized out>) at 
Dialog.c:176
#7  0x00007ffff7d543b9 in CallInitialize
    (class=0x7ffff7e18ac0 <dialogClassRec>, 
req_widget=req_widget@entry=0x7fffffffbda0, 
new_widget=new_widget@entry=0x555556999440, args=args@entry=0x7fffffffc2b0, 
num_args=<optimized out>, num_args@entry=0x0) at 
/var/tmp/portage/x11-libs/libXt-1.2.1/work/libXt-1.2.1/src/Create.c:219
#8  0x00007ffff7d54d30 in xtCreate
    (name=name@entry=0x5555568f4b50 "Q2BR1", class=class@entry=0x0, 
widget_class=widget_class@entry=0x7ffff7e18ac0 <dialogClassRec>, 
parent=parent@entry=0x55555692ab30, default_screen=0x555555e21bf0, 
args=args@entry=0x7fffffffc2b0, num_args=0x0, typed_args=0x0, 
num_typed_args=<optimized out>, parent_constraint_class=0x0, 
post_proc=0x7ffff7d54400 <widgetPostProc>) at 
/var/tmp/portage/x11-libs/libXt-1.2.1/work/libXt-1.2.1/src/Create.c:415
#9  0x00007ffff7d55202 in _XtCreateWidget
    (name=name@entry=0x5555568f4b50 "Q2BR1", 
widget_class=widget_class@entry=0x7ffff7e18ac0 <dialogClassRec>, 
parent=parent@entry=0x55555692ab30, args=args@entry=0x7fffffffc2b0, 
num_args=0x0, typed_args=typed_args@entry=0x0, num_typed_args=<optimized out>) 
at /var/tmp/portage/x11-libs/libXt-1.2.1/work/libXt-1.2.1/src/Create.c:581
#10 0x00007ffff7d55582 in XtCreateManagedWidget
    (name=name@entry=0x5555568f4b50 "Q2BR1", widget_class=0x7ffff7e18ac0 
<dialogClassRec>, parent=parent@entry=0x55555692ab30, 
args=args@entry=0x7fffffffc2b0, num_args=num_args@entry=0x0) at 
/var/tmp/portage/x11-libs/libXt-1.2.1/work/libXt-1.2.1/src/Create.c:619
#11 0x0000555555774c37 in make_dialog
    (name=0x5555568f4b50 "Q2BR1", parent=<optimized out>, pop_up_p=<optimized 
out>, shell_title=0x555555798741 "Question", text_input_slot=<optimized out>, 
radio_box=<optimized out>, list=0x0, left_buttons=0x1, right_buttons=0x1, 
instance=0x5555568f4c90, icon_name=<optimized out>) at lwlib-Xaw.c:553
#12 0x00005555557758e7 in xaw_create_dialog (instance=<optimized out>) at 
lwlib-Xaw.c:731
#13 0x000055555576e867 in instantiate_widget_instance (instance=0x5555568f4c90) 
at lwlib.c:726
#14 allocate_widget_instance (pop_up_p=0x1, parent=<optimized out>, 
info=<optimized out>) at lwlib.c:223
#15 lw_make_widget (id=<optimized out>, parent=<optimized out>, 
pop_up_p=<optimized out>) at lwlib.c:770
#16 0x00005555555f5c41 in create_and_show_dialog (f=0x555555efeea0, 
first_wv=0x5555568f4ac0) at xmenu.c:1788
#17 x_dialog_show (title=<optimized out>, error_name=<synthetic pointer>, 
header=0x0, f=0x555555efeea0) at xmenu.c:1940
#18 xw_popup_dialog (f=0x555555efeea0, header=0x0, contents=<optimized out>) at 
xmenu.c:2003
#19 0x00005555556f1256 in Fyes_or_no_p (prompt=0x5555568c8ef4) at lisp.h:1027
#20 0x00005555556e6873 in Ffuncall (nargs=0x2, args=args@entry=0x7fffffffc748) 
at eval.c:2795
#21 0x0000555555717fc8 in exec_byte_code
    (bytestr=<optimized out>, vector=<optimized out>, maxdepth=<optimized out>, 
args_template=<optimized out>, nargs=<optimized out>, args=<optimized out>) at 
bytecode.c:633
#22 0x00005555556e67d7 in Ffuncall (nargs=0x3, args=args@entry=0x7fffffffcb50) 
at eval.c:2809
#23 0x0000555555717fc8 in exec_byte_code
    (bytestr=<optimized out>, vector=<optimized out>, maxdepth=<optimized out>, 
args_template=<optimized out>, nargs=<optimized out>, args=<optimized out>) at 
bytecode.c:633
#24 0x00005555556e67d7 in Ffuncall (nargs=nargs@entry=0x2, 
args=args@entry=0x7fffffffd008) at eval.c:2809
#25 0x00005555556e31e1 in Ffuncall_interactively (nargs=0x2, 
args=0x7fffffffd008) at callint.c:254
#26 0x00005555556e6873 in Ffuncall (nargs=0x3, args=0x7fffffffd000) at 
eval.c:2795
#27 0x00005555556e6c33 in Fapply (nargs=nargs@entry=0x3, 
args=args@entry=0x7fffffffd000) at eval.c:2382
#28 0x00005555556e474a in Fcall_interactively (function=0x2aaa9d3fc650, 
record_flag=0x0, keys=0x7ffff350180d) at callint.c:342
#29 0x00005555556e6873 in Ffuncall (nargs=0x4, args=args@entry=0x7fffffffd0f8) 
at eval.c:2795
#30 0x0000555555717fc8 in exec_byte_code
    (bytestr=<optimized out>, vector=<optimized out>, maxdepth=<optimized out>, 
args_template=<optimized out>, nargs=<optimized out>, args=<optimized out>) at 
bytecode.c:633
#31 0x00005555556e67d7 in Ffuncall (nargs=0x2, args=0x7fffffffd4a0) at 
eval.c:2809
#32 0x00005555556e692a in call1 (fn=fn@entry=0x4320, arg1=<optimized out>) at 
eval.c:2655
#33 0x000055555567e728 in command_loop_1 () at lisp.h:1027
#34 0x00005555556e5b07 in internal_condition_case 
(bfun=bfun@entry=0x55555567e330 <command_loop_1>, handlers=handlers@entry=0x90, 
hfun=hfun@entry=0x555555675240 <cmd_error>)
--Type <RET> for more, q to quit, c to continue without paging--
    at eval.c:1356
#35 0x000055555566ff14 in command_loop_2 (ignore=ignore@entry=0x0) at 
lisp.h:1027
#36 0x00005555556e5a61 in internal_catch (tag=tag@entry=0xd3e0, 
func=func@entry=0x55555566fef0 <command_loop_2>, arg=arg@entry=0x0) at 
eval.c:1117
#37 0x000055555566febb in command_loop () at lisp.h:1027
#38 0x0000555555674e56 in recursive_edit_1 () at keyboard.c:714
#39 0x0000555555675182 in Frecursive_edit () at keyboard.c:786
#40 0x000055555559bb1f in main (argc=0x2, argv=<optimized out>) at emacs.c:2067