KeyRelease event, serial 37, synthetic NO, window 0x1800001,
    root 0x2a4, subw 0x1800002, time 13754426, (22,51), root:(1512,497),
    state 0x18, keycode 108 (keysym 0xffea, Alt_R), same_screen YES,
    XLookupString gives 0 bytes:
    XFilterEvent returns: False