LZW decompress: fix for CVE-2011-2895 From xorg/lib/Xfont commit d11ee5886e9d9ec610051a206b135a4cdc1e09a0

    Specially crafted LZW stream can crash an application using libXfont
    that is used to open untrusted font files.  With X server, this may
    allow privilege escalation when exploited