Description:
seahorse crashes on close, on an XFCE4 system.

Additional info:
Package versions:
- seahorse3.20.0+288+gce2340dc-1
- gnome-keyring 1:3.28.2-1
- libgnome-keyring 3.12.0-2
- glib2 2.56.1-1
- gtk2 2.24.32-1
- gtk3 3.22.30-1
- xfce4-session 4.12.1-8
- xfwm4 4.12.4-1
- linux 4.16.11-1

Console messages:
$ seahorse
seahorse-Message: 13:12:43.339: DNS-SD initialization failed: Daemon not running
(seahorse:3461): Gtk-WARNING **: 13:12:43.465: (gtkicontheme.c:5497):gtk_icon_theme_lookup_by_gicon_for_scale: runtime check failed: ((flags & GTK_ICON_LOOKUP_GENERIC_FALLBACK) == 0)
(seahorse:3461): Gtk-WARNING **: 13:12:43.465: (gtkicontheme.c:2226):gtk_icon_theme_choose_icon_for_scale: runtime check failed: ((flags & GTK_ICON_LOOKUP_GENERIC_FALLBACK) == 0)
(seahorse:3461): Gtk-WARNING **: 13:12:43.465: (gtkicontheme.c:5497):gtk_icon_theme_lookup_by_gicon_for_scale: runtime check failed: ((flags & GTK_ICON_LOOKUP_GENERIC_FALLBACK) == 0)
(seahorse:3461): Gtk-WARNING **: 13:12:43.465: (gtkicontheme.c:2226):gtk_icon_theme_choose_icon_for_scale: runtime check failed: ((flags & GTK_ICON_LOOKUP_GENERIC_FALLBACK) == 0)
(seahorse:3461): GLib-GObject-CRITICAL **: 13:12:44.401: g_object_ref: assertion 'object->ref_count > 0' failed
[1] 3461 segmentation fault (core dumped) seahorse

journal:
May 28 13:26:12 thoughtpad kernel: seahorse[4091]: segfault at 0 ip 00007f36adab4f79 sp 00007ffe537c9580 error 4 in libgobject-2.0.so.0.5600.1[7f36adaa7000+52000]
May 28 13:26:12 thoughtpad systemd[1]: Started Process Core Dump (PID 4115/UID 0).
-- Subject: Unit systemd-coredump@3-4115-0.service has finished start-up
-- Defined-By: systemd
-- Support: https://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit systemd-coredump@3-4115-0.service has finished starting up.
--
-- The start-up result is RESULT.
May 28 13:26:13 thoughtpad systemd-coredump[4116]: Process 4091 (seahorse) of user 1000 dumped core.

Stack trace of thread 4091:
#0 0x00007f36adab4f79 n/a (libgobject-2.0.so.0)
#1 0x00007f36adab6a4d g_closure_invoke (libgobject-2.0.so.0)
#2 0x00007f36adac9bca n/a (libgobject-2.0.so.0)
#3 0x00007f36adad26f6 g_signal_emit_valist (libgobject-2.0.so.0)
#4 0x00007f36adad3130 g_signal_emit (libgobject-2.0.so.0)
#5 0x0000562ea64d99cd n/a (seahorse)
#6 0x00007f36adabbb05 g_object_unref (libgobject-2.0.so.0)
#7 0x0000562ea650f4ad n/a (seahorse)
#8 0x00007f36adabba95 g_object_unref (libgobject-2.0.so.0)
#9 0x0000562ea64e6be8 n/a (seahorse)
#10 0x00007f36adabbb05 g_object_unref (libgobject-2.0.so.0)
#11 0x0000562ea648f8b4 main (seahorse)
#12 0x00007f36ae0350eb __libc_start_main (libc.so.6)
#13 0x0000562ea648f8ea _start (seahorse)

Stack trace of thread 4109:
#0 0x00007f36ae0fe609 __poll (libc.so.6)
#1 0x00007f36add47523 n/a (libglib-2.0.so.0)
#2 0x00007f36add4763e g_main_context_iteration (libglib-2.0.so.0)
#3 0x00007f3697df9f4e n/a (libdconfsettings.so)
#4 0x00007f36add6fa2a n/a (libglib-2.0.so.0)
#5 0x00007f36ae3d3015 start_thread (libpthread.so.0)
#6 0x00007f36ae108bef __clone (libc.so.6)

Stack trace of thread 4113:
#0 0x00007f36ae1037e9 syscall (libc.so.6)
#1 0x00007f36add8e52d g_cond_wait_until (libglib-2.0.so.0)
#2 0x00007f36add19903 n/a (libglib-2.0.so.0)
#3 0x00007f36add70436 n/a (libglib-2.0.so.0)
#4 0x00007f36add6fa2a n/a (libglib-2.0.so.0)
#5 0x00007f36ae3d3015 start_thread (libpthread.so.0)
#6 0x00007f36ae108bef __clone (libc.so.6)

Stack trace of thread 4092:
#0 0x00007f36ae0fe609 __poll (libc.so.6)
#1 0x00007f36add47523 n/a (libglib-2.0.so.0)
#2 0x00007f36add4763e g_main_context_iteration (libglib-2.0.so.0)
#3 0x00007f36add47692 n/a (libglib-2.0.so.0)
#4 0x00007f36add6fa2a n/a (libglib-2.0.so.0)
#5 0x00007f36ae3d3015 start_thread (libpthread.so.0)
#6 0x00007f36ae108bef __clone (libc.so.6)

Stack trace of thread 4093:
#0 0x00007f36ae0fe609 __poll (libc.so.6)
#1 0x00007f36add47523 n/a (libglib-2.0.so.0)
#2 0x00007f36add478e2 g_main_loop_run (libglib-2.0.so.0)
#3 0x00007f36ad7d7348 n/a (libgio-2.0.so.0)
#4 0x00007f36add6fa2a n/a (libglib-2.0.so.0)
#5 0x00007f36ae3d3015 start_thread (libpthread.so.0)
#6 0x00007f36ae108bef __clone (libc.so.6)
-- Subject: Process 4091 (seahorse) dumped core
-- Defined-By: systemd
-- Support: https://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- Documentation: man:core(5)
--
-- Process 4091 (seahorse) crashed and dumped core.
--
-- This usually indicates a programming error in the crashing program and
-- should be reported to its vendor as a bug.

Steps to reproduce:
Run seahorse from terminal, close once open.