Sonarqube not analyzing super class equals and potentially throwing a false positive for NPE

Question

Here is an example:

public class A{
    public boolean equals(Object a){
        if(a == null)
            return false;
         // Some Implementation
    }

}

public class B extends A {
    public boolean equals(Object obj){
        if(this == obj)
            return true;
        if(!super.equals(obj)) // null check for obj is already there in super.equals
            return false;
        if(getClass() != obj.getClass())
            return false;
        // Some Implementation
    }

}

The rule for the issue observed is A "NullPointerException" could be thrown; "obj" is nullable here. My question is, what's the best way to handle such scenarios? Wouldn't the analysis not be able to always to identify the null check in super.equals(obj) ?

Answer 1

Your comments indicate that the two classes are in separate files. That's why the issue is not suppressed; cross-file analysis just isn't available in SonarJava.

Your best course is to mark this a False Positive and move on.