Problem with if statements containing && or || expressions

[mikma . bird]

Hello,

I'm having problems with if statements containing &&, or ||. Why do the 
config file below cause the following error?

$ ./bird -d -l
bird: filters, line 8: Argument 2 of AND must be of type bool, got type int
bird: bird.conf:15:12 Runtime error while evaluating expression; see log 
for details

# bird.conf
function dummy()
{
        return 1;
}

function test()
{
        if (dummy() != 0) && true then {
                print "Success";
        }

        return 0;
}

eval test();

protocol device {
        interface "*";
}

/Mikael