W10.2d Enforcing referential integrity suggestion

[papataco14]

In section 10.2d of the notes, we want to model the above relationship, without violating referential integrity, and the following code is suggested:

public class Woman {
    private Man boyfriend;

    public void setBoyfriend(Man m) {
        if (boyfriend == m) {
            return;
        }
        if (boyfriend != null) {
            boyfriend.breakUp();
        }
        boyfriend = m;
        m.setGirlfriend(this);   # Here
    }

    public void breakUp() {
        boyfriend = null;
    }
    // ...
}

However, if null is passed into the setBoyfriend method, the last line of the method will throw a NullPointerException.
I believe changing it to the following will fix it:

if (m != null) {
    m.setGirlfriend(this);
}

Similarly for the Man class

[damithc]

Good catch @papataco14
Yes, I believe you are right.