This is a report of the downstream bug
https://bugzilla.redhat.com/show_bug.cgi?id=1028766
======
Version-Release number of selected component:
xfwm4-4.10.1-1.fc19

Additional info:
reporter:       libreport-2.1.9
backtrace_rating: 4
cmdline:        xfwm4 --display :0.0 --sm-client-id 21434d81f-b1b6-4884-9354-5dc8c765f699
crash_function: strcmp
executable:     /usr/bin/xfwm4
kernel:         3.11.7-200.fc19.x86_64
runlevel:       N 5
type:           CCpp
uid:            1000

Truncated backtrace:
Thread no. 1 (4 frames)
 #0 strcmp at ../sysdeps/x86_64/multiarch/strcmp-sse42.S:164
 #1 clientTerminate at client.c:2582
 #2 terminateProcessIO at terminate.c:82
 #7 gtk_main at gtkmain.c:1257
======

Another downstream bug report has a way to reproduce this -
https://bugzilla.redhat.com/show_bug.cgi?id=949631#c6

Take also note that this might be a duplicate of bug #10365.