Bug 132515 Expression like "Toltal.rank(Tolta.ave(row[a]),ture,Null,1)" is return an error
Description: Add an expression like "Toltal.rank(Tolta.ave(row[a]),ture,Null,1)" is return an error.The nesting "Toltal" seem not to be work. Step to reproduce: 1.new a datasource and dataset 2.drag the dataset to layout veiw for a table 3.set a group on the table 4.Insert a data into the group header with the expression e.g. "Toltal.rank(Tolta.ave(row[a]),ture,Null,1)" Actual result: An error was thrown out Expected result: It should work correctly in order to support some requirments
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/executor/transform/group/GroupInstanceSorter.java
* instances.
	 * 
	 * @param cx
	 * @param groupArray
	 * @throws DataException
	 */
	void populateGroupBoundaryInfosSortings( Context cx, ArrayList[] groupArray )
			throws DataException
	{
		for ( int i = 0; i < this.populator.getQuery( ).getGrouping( ).length; i++ )
		{
			
			List groupSorts = this.populator.getQuery( ).getGrouping( )[i].getSorts( );
			if ( groupSorts == null || groupSorts.size( ) == 0 )
				continue;
			this.populator.getResultIterator( ).first( 0 );
			for ( int j = 0; j < groupArray[i].size( ); j++ )
			{
				populateGroupBoundaryInfoSortings( cx, groupArray, i, j );
			}
		}
	}
	/**
	 * Add sort infos to GroupBoundaryInfo in groupArray.
	 * 
	 * @param cx
	 * @param groupArray
	 * @param groupPosition
	 *            groupPosition = groupLevel - 1; it is 0-based;
	 * @param groupIndex