gistfile1.java

public void inboundBufferUpdated(ChannelHandlerContext ctx) {
    if (ctx.hasInboundByteBuffer()) {
        ByteBuf buf = ctx.inboundByteBuffer();
        ...
    } else {
        Queue<MyMessage> buf = ctx.inboundMessageBuffer();
        for (;;) {
            MyMessage msg = buf.poll();
            if (buf == null) {
                break;
            }
            ...
        }
    }
}

The null check should be on the "msg", not the "buf" variable. See modified gist at https://gist.github.com/3549486