For completeness, here is the backtrace at breakpoint on
XSetInputFocus, on Debian unstable with debug symbols (before
launching gdb, export DEBUGINFOD_URLS="https://debuginfod.debian.net";
).
(gdb) bt full
#0 XSetInputFocus (dpy=0x5555555fda90, focus=focus@entry=41943047,
revert_to=revert_to@entry=2, time=time@entry=0) at
../../src/SetIFocus.c:41
req = <optimized out>
#1 0x00007ffff7f3678f in gdk_x11_window_focus (window=<optimized
out>, timestamp=0) at ../../../gdk/x11/gdkwindow-x11.c:2326
display = 0x5555556110f0 [GdkX11Display]
__func__ = "gdk_x11_window_focus"
#2 0x00007ffff798cfeb in gtk_window_present_with_time
(window=0x5555556e47c0 [XScreenSaverWindow], timestamp=0) at
../../../gtk/gtkwindow.c:10611
priv = <optimized out>
widget = 0x5555556e47c0 [XScreenSaverWindow]
gdk_window = 0x55555595ac30 [GdkX11Window]
__func__ = "gtk_window_present_with_time"
#3 0x000055555557009d in xscreensaver_app_activate
(app=0x5555555da0f0 [XScreenSaverApp]) at demo-Gtk.c:5321
win = 0x5555556e47c0 [XScreenSaverWindow]
debug_p = 1
dpy = 0x5555555fda90
#4 0x00007ffff70f55a9 in _g_closure_invoke_va
(closure=closure@entry=0x5555555d4400,
return_value=return_value@entry=0x0,
instance=instance@entry=0x5555555da0f0,
args=args@entry=0x7fffffffdc30, n_params=0, param_types=0x0) at
../../../gobject/gclosure.c:895
marshal = 0x7ffff70f3b60 <g_type_class_meta_marshalv>
marshal_data = 0x90
in_marshal = 0
real_closure = 0x5555555d43e0
__func__ = "_g_closure_invoke_va"
#5 0x00007ffff710ebbf in g_signal_emit_valist
(instance=0x5555555da0f0, signal_id=8, detail=<optimized out>,
var_args=var_args@entry=0x7fffffffdc30) at
../../../gobject/gsignal.c:3456
return_accu = <optimized out>
accu = {g_type = 0x0, data = {{v_int = 0, v_uint = 0, v_long =
0, v_ulong = 0, v_int64 = 0, v_uint64 = 0, v_float = 0, v_double = 0,
v_pointer = 0x0}, {v_int = 0, v_uint = 0, v_long = 0, v_ulong = 0,
v_int64 = 0, v_uint64 = 0, v_float = 0, v_double = 0, v_pointer =
0x0}}}
accumulator = 0x0
emission = {next = 0x0, instance = 0x5555555da0f0, ihint =
{signal_id = 8, detail = 0, run_type = (G_SIGNAL_RUN_LAST |
G_SIGNAL_ACCUMULATOR_FIRST_RUN)}, state = EMISSION_RUN, chain_type =
0x5555555d2640 [XScreenSaverApp/GtkApplication/GApplication]}
instance_type = <optimized out>
emission_return = {g_type = 0x0, data = {{v_int = 0, v_uint =
0, v_long = 0, v_ulong = 0, v_int64 = 0, v_uint64 = 0, v_float = 0,
v_double = 0, v_pointer = 0x0}, {v_int = 0, v_uint = 0, v_long = 0,
v_ulong = 0, v_int64 = 0, v_uint64 = 0, v_float = 0, v_double = 0,
v_pointer = 0x0}}}
rtype = 0x4 [void]
static_scope = 0
fastpath_handler = <optimized out>
closure = <optimized out>
run_type = <optimized out>
hlist = <optimized out>
l = <optimized out>
fastpath = <optimized out>
instance_and_params = <optimized out>
signal_return_type = <optimized out>
param_values = <optimized out>
node = <optimized out>
i = <optimized out>
n_params = <optimized out>
__func__ = "g_signal_emit_valist"
#6 0x00007ffff710edbf in g_signal_emit
(instance=instance@entry=0x5555555da0f0, signal_id=<optimized out>,
detail=detail@entry=0) at ../../../gobject/gsignal.c:3606
var_args = {{gp_offset = 24, fp_offset = 48, overflow_arg_area
= 0x7fffffffdd10, reg_save_area = 0x7fffffffdc50}}
#7 0x00007ffff74ff0c3 in g_application_activate
(application=application@entry=0x5555555da0f0 [XScreenSaverApp]) at
../../../gio/gapplication.c:2312
__func__ = "g_application_activate"
#8 0x00007ffff74ff438 in g_application_real_local_command_line
(application=0x5555555da0f0 [XScreenSaverApp],
arguments=0x7fffffffdd78, exit_status=0x7fffffffdd74) at
../../../gio/gapplication.c:1148
error = 0x0
options = 0x5555555dbfa0
n_args = 1
#9 0x00007ffff74ff5c6 in g_application_run
(application=0x5555555da0f0 [XScreenSaverApp], argc=<optimized out>,
argv=<optimized out>) at ../../../gio/gapplication.c:2542
arguments = 0x5555555db710
status = -1
context = 0x5555555db770
acquired_context = <optimized out>
__func__ = "g_application_run"
#10 0x000055555557040b in main (argc=2, argv=0x7fffffffdf18) at demo-Gtk.c:5398
s = 0x7fffffffe2a6 "/xscreensaver-settings"
(gdb) c
Note that if I install an empty command (command 1, continue, end) at
the breakpoint, the crash doesn't happen. So it is timing sensitive. I
don't even know if the backtrace corresponds to the request in the
crash, it is the only occurrence of XSetInputFocus when I have a
breakpoint, but maybe it is different without. On another system I see
two occurrences before the window comes up finished.
