Comment 3 for bug 1061556

StacktraceTop:
 __assert_fail_base (fmt=<optimized out>, assertion=0x7fd06db35cc7 "!xcb_xlib_unknown_seq_number", file=0x7fd06db35c92 "../../src/xcb_io.c", line=<optimized out>, function=<optimized out>) at assert.c:94
 __GI___assert_fail (assertion=assertion@entry=0x7fd06db35cc7 "!xcb_xlib_unknown_seq_number", file=file@entry=0x7fd06db35c92 "../../src/xcb_io.c", line=line@entry=160, function=function@entry=0x7fd06db35de0 "append_pending_request") at assert.c:103
 append_pending_request (dpy=dpy@entry=0x1ef9de0, sequence=4037) at ../../src/xcb_io.c:158
 _XReply (dpy=dpy@entry=0x1ef9de0, rep=rep@entry=0x7fff36337620, extra=extra@entry=0, discard=discard@entry=1) at ../../src/xcb_io.c:584
 XQueryExtension (dpy=dpy@entry=0x1ef9de0, name=name@entry=0x7fd06264f8b2 <Address 0x7fd06264f8b2 out of bounds>, major_opcode=major_opcode@entry=0x7fff36337684, first_event=first_event@entry=0x7fff36337688, first_error=first_error@entry=0x7fff3633768c) at ../../src/QuExt.c:48