Created attachment 6202 
untested patch

tested with latest commit which is: 634b660757dc90fe785536f902beaf06e03deb56

Core was generated by `xfwm4 --daemon --replace'.
Program terminated with signal SIGSEGV, Segmentation fault.

(gdb) bt full
#0  update_cursor (screen_info=0x272adf0) at compositor.c:2503
        cursor = 0x0
#1  compositorHandleCursorNotify (ev=0x0, display_info=0x272adf0)
    at compositor.c:2915
        screen_info = 0x272adf0
#2  compositorHandleEvent (display_info=display_info@entry=0x2728b00, 
    ev=ev@entry=0x7fffec334980) at compositor.c:3324
        __FUNCTION__ = "compositorHandleEvent"
#3  0x000000000041d372 in handleEvent (ev=0x7fffec334980, 
    display_info=0x2728b00) at events.c:2283
        status = EVENT_FILTER_STOP
#4  xfwm4_event_filter (xevent=0x7fffec334980, data=0x2728b00) at events.c:2297
        status = EVENT_FILTER_STOP
        display_info = 0x2728b00
#5  0x000000000041997f in eventXfwmFilter (gdk_xevent=0x7fffec334980, 
    event=<optimized out>, data=<optimized out>) at event_filter.c:158
        filterelt_next = 0x2843f40
        loop = EVENT_FILTER_REMOVE
        setup = <optimized out>
        filterelt = <optimized out>
        __FUNCTION__ = "eventXfwmFilter"
#6  0x00007f62b4f814e1 in ?? () from /usr/lib/libgdk-x11-2.0.so.0
No symbol table info available.
#7  0x00007f62b4f827e4 in ?? () from /usr/lib/libgdk-x11-2.0.so.0
No symbol table info available.
#8  0x00007f62b4f841f6 in ?? () from /usr/lib/libgdk-x11-2.0.so.0
No symbol table info available.
#9  0x00007f62b4f8429e in ?? () from /usr/lib/libgdk-x11-2.0.so.0
No symbol table info available.
#10 0x00007f62b405d71d in g_main_context_dispatch ()
   from /usr/lib/libglib-2.0.so.0
No symbol table info available.
#11 0x00007f62b405da08 in ?? () from /usr/lib/libglib-2.0.so.0
No symbol table info available.
#12 0x00007f62b405dd32 in g_main_loop_run () from /usr/lib/libglib-2.0.so.0
No symbol table info available.
#13 0x00007f62b530e467 in gtk_main () from /usr/lib/libgtk-x11-2.0.so.0
No symbol table info available.
#14 0x000000000042547e in main (argc=1, argv=0x7fffec334e68) at main.c:702
        daemon_mode = 1
        version = 0
        replace_wm = 1
        context = <optimized out>
        error = 0x0
        option_entries = {{long_name = 0x444ad3 "daemon", 
            short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_NONE,
            arg_data = 0x7fffec334c4c, 
            description = 0x444ada "Fork to the background", 
            arg_description = 0x0}, {long_name = 0x444af1 "compositor", 
            short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_CALLBACK, 
            arg_data = 0x424680 <compositor_callback>, 
            description = 0x444afc "Set the compositor mode", 
            arg_description = 0x444b14 "on|off|auto"}, {
            long_name = 0x444b20 "replace", short_name = 0 '\000', flags = 0, 
            arg = G_OPTION_ARG_NONE, arg_data = 0x7fffec334c54, 
            description = 0x444ce0 "Replace the existing window manager", 
            arg_description = 0x0}, {long_name = 0x444b28 "version", 
            short_name = 86 'V', flags = 0, arg = G_OPTION_ARG_NONE, 
            arg_data = 0x7fffec334c50, 
            description = 0x444d08 "Print version information and exit", 
            arg_description = 0x0}, {long_name = 0x0, short_name = 0 '\000', 
            flags = 0, arg = G_OPTION_ARG_NONE, arg_data = 0x0, 
            description = 0x0, arg_description = 0x0}}
        __FUNCTION__ = "main"
(gdb) quit



Cheers,
E