Bug 176963 Subquery's resultSetExpressions is not consistent between generate and present time.
In generate time, subquery will add the parent query's column binding to its own resultSetExpressions. While in present time, it only has the ones of itself.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/PreparedQuery.java
}
	}
	/**
	 * Colon a script expression, however do not populate the "AggregateOn" field. All the column binding that inherit
	 * from parent query by sub query should have no "AggregateOn" field, for they could not be aggregations. However, 
	 * if an aggregateOn field is set to an expression without aggregation, we should also make it inheritable by sub query
	 * for the expression actually involves no aggregations.
	 * 
	 * @param expr
	 * @return
	 */
	private ScriptExpression copyScriptExpr( IBaseExpression expr )
	{
		ScriptExpression se = new ScriptExpression( ( (IScriptExpression) expr ).getText( ),
				( (IScriptExpression) expr ).getDataType( ) );
		return se;
	}
	
	/**
	 * @param trans
	 * @param groupLevel
	 * @param cx
	 * @throws DataException
	 */
	private void prepareGroup( IBaseQueryDefinition baseQuery, int groupLevel,
			Context cx ) throws DataException
	{
		IBaseTransform trans = baseQuery;
		String groupName = IBaseExpression.GROUP_OVERALL;