The following code invokes func() in the empty-if case, and it shouldn't:

public class Test {
    static boolean func()
    {
        System.out.println("Func called");
        return true;
    }

    public static void main(String args[]) {
        boolean val = true;

        if (val || func()) {
        }

        System.out.println("Not Prevented");

        if (val || func()) {
            System.out.println("Prevented");
        }
    }
}

The output is:

Func called
Not Prevented
Prevented