Comment 2 for bug 840850

StacktraceTop:
 link_before (link=0x123c108, before_this_link=0x123c0f0, list=0x7fff31e1a7a8) at ../../dbus/dbus-list.c:122
 _dbus_list_prepend (list=0x7fff31e1a7a8, data=<optimized out>) at ../../dbus/dbus-list.c:278
 _dbus_list_append (list=0x7fff31e1a7a8, data=<optimized out>) at ../../dbus/dbus-list.c:250
 _dbus_validate_signature_with_reason (type_str=<optimized out>, type_pos=<optimized out>, len=<optimized out>) at ../../dbus/dbus-marshal-validate.c:224
 validate_body_helper (reader=0x7fff31e1a9f0, byte_order=108, walk_reader_to_end=1, total_depth=2, p=0x1246492 "s", end=0x1246584 "", new_p=0x7fff31e1a968) at ../../dbus/dbus-marshal-validate.c:577