x11: Fix XWindowAttributes
x11: Fix XWindowAttributes

Fixes bug 597068.

kamanashisroy/aroop,Distrotech/vala,tjol/vala-tjol,flobrosch/vala-fixes,phako/vala,rvu95/vala,spidermonkdust/vala,frida/vala,xdave/pvala,severinh/vala,spidermonkdust/vala,flobrosch/vala-fixes,frida/vala,kamanashisroy/aroop,GNOME/vala,jessevdk/vala,Jc2k/vala,GNOME/vala,spidermonkdust/vala,playya/vala,flobrosch/vala-fixes,GNOME/vala,jessevdk/vala,kamanashisroy/aroop,phako/vala,tjol/vala-tjol,frida/vala,severinh/vala,rvu95/vala,lovebug356/vala,Distrotech/vala,Jc2k/vala,themiwi/vala,Distrotech/vala,severinh/vala,tjol/vala-tjol,lovebug356/vala,playya/vala,themiwi/vala,rvu95/vala,themiwi/vala,GNOME/vala,jessevdk/vala,frida/vala,frida/vala,playya/vala