Index: NormalizedEntityPersister.java
===================================================================
RCS file: /cvsroot/hibernate/Hibernate2/src/net/sf/hibernate/persister/NormalizedEntityPersister.java,v
retrieving revision 1.32.2.44
diff -u -r1.32.2.44 NormalizedEntityPersister.java
--- NormalizedEntityPersister.java	25 Jan 2004 03:54:15 -0000	1.32.2.44
+++ NormalizedEntityPersister.java	9 Feb 2004 10:13:18 -0000
@@ -1094,8 +1094,14 @@
 			
 			return new String[] { discriminatorFragment(alias).toFragmentString() };
 		}
-		
-		int tab = ( (Integer) tableNumberByPropertyPath.get(property) ).intValue();
+
+		Integer tableNum = ( (Integer) tableNumberByPropertyPath.get(property) );
+		if (null == tableNum)
+		{
+			throw new QueryException("TODO: what does it mean? for property = "+property);
+		}
+
+		int tab = tableNum.intValue();
 		
 		return super.toColumns( alias(alias, tab), property );
 	}