NullPointerException with 7.2.1 ResultSet

Running the following code gives:
String 0 is blah
Exception in thread "main" java.lang.NullPointerException
         at org.postgresql.jdbc2.ResultSet.next(ResultSet.java:113)
         at PostgresTest.test1(PostgresTest.java:33)
         at PostgresTest.main(PostgresTest.java:50)

Commenting out the executeUpdate() inside the for loop solves the problem.  I think a
ResultSet that is closed should throw an IllegalStateException, not just let a
NullPointerException be thrown.


/**
  * PostresTest.java
  *
  *
  * Created: Thu Apr 25 15:51:47 2002
  *
  * @author <a href="mailto:jks@selectacast.net">Joseph Shraibman</a>
  * @version
  */

import java.sql.*;

public class PostgresTest{


     private static void test1(String usr, String pwd) throws SQLException,
ClassNotFoundException{
         int fetch_size = 50;

         Class.forName("org.postgresql.Driver");
         Connection  db = DriverManager.getConnection("jdbc:postgresql:playpen", usr, pwd);
         Statement st = db.createStatement();
         st.executeUpdate("BEGIN;");
         st.executeUpdate("CREATE table ptest1 (a int, b text);");
         try{
             st.executeUpdate("INSERT into ptest1 VALUES(1, 'blah');");
             st.executeUpdate("DECLARE cname CURSOR FOR SELECT b FROM ptest1 GROUP BY b");
             st.executeUpdate("CREATE TEMP TABLE tqt (id int, bstr text);");
             while(true){
                 ResultSet rs = st.executeQuery("FETCH "+fetch_size+" FROM cname;");
                 int i = 0;
                 for ( ; rs.next() ; i++ ) {
                     String b = rs.getString(1);
                     System.out.println("String "+i+" is "+b);
                     st.executeUpdate("INSERT INTO tqt SELECT a FROM ptest1 where b =
'"+b+"';");
                     //st.executeUpdate("DELETE from tqt WHERE bstr = '"+b+"';");
                 }
                 if (i < fetch_size)
                     break;
             }
             st.executeUpdate("END;");
             st.executeUpdate("DROP TABLE tqt;");
         }finally{
             st.executeUpdate("DROP table ptest1;");
             st.executeUpdate("ABORT;");
         }
     }
     public static void main(String[] args)throws Exception{
         test1(args[0], args[1]);
     }
} // PostresTest