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
this.groupProcessor.getGroupCalculationUtil( )
					.sortGroupBoundaryInfos( groupArray );
			OrderingInfo odInfo = this.groupProcessor.getGroupCalculationUtil( )
					.getGroupInformationUtil( )
					.getOrderingInfo( groupArray );
			this.populator.reSetSmartCacheUsingOrderingInfo( odInfo );
		}
	}
	/**
	 * 
	 * @param expressionList
	 * @param groupLevels
	 */
	void populateGroupSortExpressions( List expressionList, List groupLevels )
	{
		for ( int i = 0; i < this.populator.getQuery( ).getGrouping( ).length; i++ )
		{
			List groupSorts = this.populator.getQuery( ).getGrouping( )[i].getSorts( );
			if ( groupSorts == null )
				continue;
			for ( int j = 0; j < groupSorts.size( ); j++ )
			{
				expressionList.add( ( (ISortDefinition) groupSorts.get( j ) ).getExpression( ) );
				groupLevels.add( new Integer( i + 1 ) );
			}
		}
	}
	/**
	 * Populate the sortings in GroupBoundaryInfos instance. Each
	 * GroupBoundaryInfos instance consists of several GroupBoundaryInfo