Index: java/engine/org/apache/derby/impl/sql/compile/AggregateNode.java
===================================================================
--- java/engine/org/apache/derby/impl/sql/compile/AggregateNode.java	(revision 601014)
+++ java/engine/org/apache/derby/impl/sql/compile/AggregateNode.java	(working copy)
@@ -605,4 +605,14 @@
 			return "";
 		}
 	}
+
+	public boolean isConstant()
+	{
+		return false;
+	}
+	
+	public boolean constantExpression(PredicateList where)
+	{
+		return false;
+	}
 }
Index: java/testing/org/apache/derbyTesting/functionTests/tests/lang/GroupByTest.java
===================================================================
--- java/testing/org/apache/derbyTesting/functionTests/tests/lang/GroupByTest.java	(revision 601014)
+++ java/testing/org/apache/derbyTesting/functionTests/tests/lang/GroupByTest.java	(working copy)
@@ -134,5 +134,22 @@
         s.executeUpdate("DROP TABLE A2937");
         
     }
+
+	public void testDerbyOrderByOnAggregate() throws SQLException {
+		Statement s = createStatement();
+		s.executeUpdate("create table yy (a double, b double)");
+		s.executeUpdate("insert into yy values (2,4), (2, 4), (5,7), (2,3), (2,3), (2,3), (2,3), (9,7)");
+
+		ResultSet rs = s.executeQuery("select b, count(*) from yy where a=5 or a=2 group by b order by count(*) desc");
+		JDBC.assertFullResultSet(
+				rs,
+				new Object[][]{
+						{new Double(3), new Integer(4)},
+						{new Double(4), new Integer(2)},
+						{new Double(7), new Integer(1)}},
+				false);
+		s.executeUpdate("drop table yy");
+
+	}
 }