Comment # 1 on bug 1003428 from VERSINI Arnaud

Seems related to seat and user change (from an user in terminal F2 to an user
using F3 for example). This backtrace seems more usable : 

#0  0x00007f1e3ec7f799 in wl_resource_post_event
(resource=resource@entry=0xffffffffffffffe0, opcode=opcode@entry=2) at
src/wayland-server.c:194
#1  0x00007f1e48ef5de7 in meta_wayland_pointer_send_motion
(surface_y=<optimized out>, surface_x=<optimized out>, time=6397408,
resource_=0xffffffffffffffe0) at
/usr/include/wayland/wayland-server-protocol.h:3423
#2  0x00007f1e48ef5de7 in meta_wayland_pointer_send_motion (pointer=0x9629d0
[MetaWaylandPointer], event=0x28fcec0) at wayland/meta-wayland-pointer.c:339
#3  0x00007f1e48ef65da in meta_wayland_pointer_handle_event (event=0x28fcec0,
pointer=0x9629d0 [MetaWaylandPointer]) at wayland/meta-wayland-pointer.c:557
#4  0x00007f1e48ef65da in meta_wayland_pointer_handle_event (event=0x28fcec0,
pointer=0x9629d0 [MetaWaylandPointer]) at wayland/meta-wayland-pointer.c:564
#5  0x00007f1e48ef65da in meta_wayland_pointer_handle_event (pointer=0x9629d0
[MetaWaylandPointer], event=event@entry=0x28fcec0) at
wayland/meta-wayland-pointer.c:710
#6  0x00007f1e48ef9e2a in meta_wayland_seat_handle_event (seat=<optimized out>,
event=event@entry=0x28fcec0) at wayland/meta-wayland-seat.c:360
#7  0x00007f1e48eed54a in meta_wayland_compositor_handle_event
(compositor=compositor@entry=0x7f1e491702c0 <_meta_wayland_compositor>,
event=event@entry=0x28fcec0) at wayland/meta-wayland.c:208
#8  0x00007f1e48eb898f in event_callback (event=0x28fcec0, display=0xab8750
[MetaDisplay]) at core/events.c:386
#9  0x00007f1e48eb898f in event_callback (event=0x28fcec0, data=0xab8750) at
core/events.c:401
#10 0x00007f1e48242f1d in _clutter_event_process_filters
(event=event@entry=0x28fcec0) at clutter-event.c:1913
#11 0x00007f1e482557f3 in _clutter_process_event (device=0x9cb0c0
[ClutterInputDeviceEvdev], event=0x28fcec0) at clutter-main.c:2011
#12 0x00007f1e482557f3 in _clutter_process_event (context=0x7c9fa0,
event=0x28fcec0, stage=<optimized out>) at clutter-main.c:2372
#13 0x00007f1e482557f3 in _clutter_process_event (event=event@entry=0x28fcec0)
at clutter-main.c:2548
#14 0x00007f1e4826bc79 in _clutter_stage_process_queued_events (stage=0x9ce660
[MetaStage]) at clutter-stage.c:1026
#15 0x00007f1e48257979 in clutter_clock_dispatch (master_clock=0x9ed100
[ClutterMasterClockDefault], stages=<optimized out>) at
clutter-master-clock-default.c:364
#16 0x00007f1e48257979 in clutter_clock_dispatch (source=<optimized out>,
callback=<optimized out>, user_data=<optimized out>) at
clutter-master-clock-default.c:561
#17 0x00007f1e476fc677 in g_main_context_dispatch (context=0x79f000) at
gmain.c:3201
#18 0x00007f1e476fc677 in g_main_context_dispatch
(context=context@entry=0x79f000) at gmain.c:3854
#19 0x00007f1e476fc8e0 in g_main_context_iterate (context=0x79f000,
block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at
gmain.c:3927
#20 0x00007f1e476fcc02 in g_main_loop_run (loop=0x9ee570) at gmain.c:4123
#21 0x00007f1e48ebf85c in meta_run () at core/main.c:572
#22 0x00000000004023c7 in main (argc=<optimized out>, argv=<optimized out>) at
main.c:471