Name: rmT116609 Date: 01/16/2003


FULL PRODUCT VERSION :
java version "1.4.1_01"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.1_01-b01)
Java HotSpot(TM) Client VM (build 1.4.1_01-b01, mixed mode)


FULL OPERATING SYSTEM VERSION :
Microsoft Windows 2000 [Version 5.00.2195]
(C) Copyright 1985-2000 Microsoft Corp.

A DESCRIPTION OF THE PROBLEM :
Nulls cannot be removed from TreeSet

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. Add a null to a TreeSet.
2. Try to remove it.
3. Profit!!!!

EXPECTED VERSUS ACTUAL BEHAVIOR :
Expected:
class java.util.HashSet
[null]
[]
class java.util.TreeSet
[null]
[]

Actual:
class java.util.HashSet
[null]
[]
class java.util.TreeSet
[null]
Exception in thread "main" java.lang.NullPointerException
        at java.util.TreeMap.compare(TreeMap.java:1081)
        at java.util.TreeMap.getEntry(TreeMap.java:341)
        at java.util.TreeMap.remove(TreeMap.java:500)
        at java.util.TreeSet.remove(TreeSet.java:218)
        at Test.main(Test.java:17)

ERROR MESSAGES/STACK TRACES THAT OCCUR :
Exception in thread "main" java.lang.NullPointerException
        at java.util.TreeMap.compare(TreeMap.java:1081)
        at java.util.TreeMap.getEntry(TreeMap.java:341)
        at java.util.TreeMap.remove(TreeMap.java:500)
        at java.util.TreeSet.remove(TreeSet.java:218)
        at Test.main(Test.java:17)

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.util.*;

public class Test {

    public static void main(String args[]) {
        Set set = new HashSet();
        System.out.println(set.getClass());
        set.add(null);
        System.out.println(set);
        set.remove(null);
        System.out.println(set);

        set = new TreeSet();
        System.out.println(set.getClass());
        set.add(null);
        System.out.println(set);
        set.remove(null);
        System.out.println(set);
    }

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

CUSTOMER WORKAROUND :
set = new HashSet(set);
set.remove(null);
set = new TreeSet();
(Review ID: 164182)
======================================================================