Find the bugThe case of the degrading system
time to read 2 min | 395 words

The following code contains a bug, can you spot it?  

class Program
{
    private Timer nextcheck;
    public event EventHandler ServerSigFailed;
    static void Main(string[] args)
    {
        var program = new Program();
        if(program.ValidateServerSig() == false) 
            return;
        program.DoOtherStuff();
    }

    public bool ValidateServerSig()
    {
        nextcheck = new Timer(state => ValidateServerSig());

        var response = DoRequest("http://remote-srv/signature");
        if(response.Failed)
        {
            var copy = ServerSigFailed;
            if(copy!=null) copy(this, EventArgs.Empty);
            return false;
        }
        var result = Utils.CheckPublic KeySignatureMatches(response);
        if(result.Valid)
        if(response.Failed)
        {
            var copy = ServerSigFailed;
            if(copy!=null) copy(this, EventArgs.Empty);
            return false;
        }
        
        // setup next check
        nextcheck.Change(TimeSpan.FromSeconds(15), TimeSpan.FromSeconds(15));
        return true;
    }
}

What are the implications of this bug?

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