Related downstream - bug https://bugzilla.redhat.com/show_bug.cgi?id=1009874

I tried to close the Midori browser which was not responding (probably because of Flash). xfwm crashed and restarted while Midori kept running for a short period of time.

I started gdb on another ocassion on a running xfwm4 process and it gave me this:

Thread 1 (Thread 0x7f55f7990a40 (LWP 4440)):
#0  0x0000003455aeb750 in __poll_nocancel () at ../sysdeps/unix/syscall-template.S:81
No locals.
#1  0x0000003457e480f4 in g_main_context_poll (priority=2147483647, n_fds=4, fds=0x2028040, timeout=-1, context=0x1eb0cb0) at gmain.c:3995
        poll_func = 0x3457e56d50 <g_poll>
#2  g_main_context_iterate (context=0x1eb0cb0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3696
        max_priority = 2147483647
        timeout = -1
        some_ready = <optimized out>
        nfds = 4
        allocated_nfds = 4
        fds = 0x2028040
#3  0x0000003457e4855a in g_main_loop_run (loop=0x2027fb0) at gmain.c:3895
        __PRETTY_FUNCTION__ = "g_main_loop_run"
#4  0x0000003cef33fdb7 in IA__gtk_main () at gtkmain.c:1257
        tmp_list = 0x0
        functions = 0x0
        init = <optimized out>
        loop = 0x2027fb0
#5  0x000000000040b6c9 in main (argc=1, argv=0x7fff68a4a8a8) at main.c:627
        daemon_mode = 0
        version = 0
        replace_wm = 0
        context = <optimized out>
        error = 0x0
        option_entries = {{long_name = 0x43ff31 "daemon", short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_NONE, arg_data = 0x7fff68a4a68c, description = 0x43ff38 "Fork to the background", arg_description = 0x0}, {long_name = 0x43ff4f "compositor", short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_CALLBACK, arg_data = 0x423040 <compositor_callback>, description = 0x43ff5a "Set the compositor mode", arg_description = 0x43ff72 "on|off|auto"}, {long_name = 0x43ff7e "replace", short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_NONE, arg_data = 0x7fff68a4a694, description = 0x43fbd8 "Replace the existing window manager", arg_description = 0x0}, {long_name = 0x43ff86 "version", short_name = 86 'V', flags = 0, arg = G_OPTION_ARG_NONE, arg_data = 0x7fff68a4a690, description = 0x43fc00 "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}}
Continuing.
Detaching after fork from child process 4940.

Program received signal SIGSEGV, Segmentation fault.
__strcmp_sse42 () at ../sysdeps/x86_64/multiarch/strcmp-sse42.S:164
164		movdqu	(%rdi), %xmm1

Thread 1 (Thread 0x7f55f7990a40 (LWP 4440)):
#0  __strcmp_sse42 () at ../sysdeps/x86_64/multiarch/strcmp-sse42.S:164
No locals.
#1  0x000000000040e2fa in clientTerminate (c=0x201b080) at client.c:2582
        screen_info = <optimized out>
        display_info = <optimized out>
        __PRETTY_FUNCTION__ = "clientTerminate"
#2  0x0000000000437ee0 in terminateProcessIO (channel=<optimized out>, condition=<optimized out>, data=0x201b080) at terminate.c:82
        c = 0x201b080
        str = 0x2032b80 "YES=0x4200004\n"
        len = 14
        err = 0x0
        __PRETTY_FUNCTION__ = "terminateProcessIO"
#3  0x0000003457e47e06 in g_main_dispatch (context=0x1eb0cb0) at gmain.c:3054
        dispatch = 0x3457e87c10 <g_io_unix_dispatch>
        was_in_call = 0
        user_data = 0x201b080
        callback = 0x437df0 <terminateProcessIO>
        cb_funcs = 0x345812a900 <g_source_callback_funcs>
        cb_data = 0x202b320
        need_destroy = <optimized out>
        current_source_link = {data = 0x2028bc0, next = 0x0}
        source = 0x2028bc0
        current = 0x1ef55b0
        i = 0
#4  g_main_context_dispatch (context=context@entry=0x1eb0cb0) at gmain.c:3630
No locals.
#5  0x0000003457e48158 in g_main_context_iterate (context=0x1eb0cb0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3701
        max_priority = 2147483647
        timeout = -1
        some_ready = 1
        nfds = <optimized out>
        allocated_nfds = 5
        fds = 0x2028040
#6  0x0000003457e4855a in g_main_loop_run (loop=0x2027fb0) at gmain.c:3895
        __PRETTY_FUNCTION__ = "g_main_loop_run"
#7  0x0000003cef33fdb7 in IA__gtk_main () at gtkmain.c:1257
        tmp_list = 0x0
        functions = 0x0
        init = <optimized out>
        loop = 0x2027fb0
#8  0x000000000040b6c9 in main (argc=1, argv=0x7fff68a4a8a8) at main.c:627
        daemon_mode = 0
        version = 0
        replace_wm = 0
        context = <optimized out>
        error = 0x0
        option_entries = {{long_name = 0x43ff31 "daemon", short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_NONE, arg_data = 0x7fff68a4a68c, description = 0x43ff38 "Fork to the background", arg_description = 0x0}, {long_name = 0x43ff4f "compositor", short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_CALLBACK, arg_data = 0x423040 <compositor_callback>, description = 0x43ff5a "Set the compositor mode", arg_description = 0x43ff72 "on|off|auto"}, {long_name = 0x43ff7e "replace", short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_NONE, arg_data = 0x7fff68a4a694, description = 0x43fbd8 "Replace the existing window manager", arg_description = 0x0}, {long_name = 0x43ff86 "version", short_name = 86 'V', flags = 0, arg = G_OPTION_ARG_NONE, arg_data = 0x7fff68a4a690, description = 0x43fc00 "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}}