(coll) NullPointerException not thrown by AbstractCollection.retainAll/removeAll

Name: nt126004 Date: 01/13/2003


FULL PRODUCT VERSION :
java version "1.4.1"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.1-b21)
Java HotSpot(TM) Client VM (build 1.4.1-b21, mixed mode)

FULL OPERATING SYSTEM VERSION : Microsoft Windows 2000
[Version 5.00.2195]


A DESCRIPTION OF THE PROBLEM :
java.util.AbstractCollection.retainAll and removeAll
methods do not - as specified - throw a
NullPointerException when the argument is null.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. Create a non-abstract extension C of
java.util.AbstractCollection, not overriding the methods
removeAll or retainAll.
2. Create an instance X of C.
3. Invoke removeAll(null) on X.
4. Invoke retainAll(null) on X.

EXPECTED VERSUS ACTUAL BEHAVIOR :
Steps 3 and 4 should result in NullPointerExceptions
(according to the API specification). They don't.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.util.AbstractCollection;
import java.util.Iterator;
import java.util.ArrayList;

public class C extends AbstractCollection {

    ArrayList list = new ArrayList();

    public boolean remove(Object obj) {
        return list.remove(obj);
    }

    public boolean add(Object obj) {
        return list.add(obj);
    }

    public Iterator iterator() {
        return list.iterator();
    }

    public int size() {
        return list.size();
    }

    public static void main(String[] args) {
        // Should throw NullPointerException
        (new C()).removeAll(null);

        // Should throw NullPointerException
        (new C()).retainAll(null);
    }

}
---------- END SOURCE ----------

CUSTOMER WORKAROUND :
removeAll() and retainAll() should always be overridden.
(Review ID: 179274)
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