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/impl/QueryExecutor.java
for ( int i = 0; it.hasNext( ); i++ )
			{
				IGroupDefinition src = (IGroupDefinition) it.next( );
				if ( ( src.getKeyColumn( ) == null || src.getKeyColumn( )
						.trim( )
						.length( ) == 0 )
						&& ( src.getKeyExpression( ) == null || src.getKeyExpression( )
								.trim( )
								.length( ) == 0 ) )
					throw new DataException( ResourceConstants.BAD_GROUP_EXPRESSION );
				
				
				String expr = getGroupKeyExpression( src );
				String groupName = "";
				if ( expr.trim( ).equalsIgnoreCase( "row[0]" )
						|| expr.trim( )
								.equalsIgnoreCase( "row._rowPosition" )
						|| expr.trim( ).equalsIgnoreCase( "dataSetRow[0]" )
						|| expr.trim( )
								.equalsIgnoreCase( "dataSetRow._rowPosition" ) )
				{
					groupName = "_{$TEMP_GROUP_" + i + "ROWID$}_";
				}
				else
				{
					groupName = "_{$TEMP_GROUP_" + i + "$}_";
				}
				
				if ( ( src.getInterval( ) != IGroupDefinition.NO_INTERVAL )
						&& ( src.getIntervalRange( ) != 0 ) )