Bug 317267 [Automation][Regression]Error is thrown out when preview gantt type chart
chart/org.eclipse.birt.chart.engine.extension/src/org/eclipse/birt/chart/extension/datafeed/GanttDataSetProcessorImpl.java
*      org.eclipse.birt.chart.model.data.DataSet)
	 */
	public final DataSet populate( Object oResultSetDef, DataSet ds )
			throws ChartException
	{
		if ( oResultSetDef instanceof IResultSetDataSet )
		{
			final IResultSetDataSet rsds = (IResultSetDataSet) oResultSetDef;
			final long lRowCount = rsds.getSize( );
			if ( lRowCount <= 0 )
			{
				throw new ChartException( ChartEngineExtensionPlugin.ID,
						ChartException.ZERO_DATASET,
						"exception.empty.dataset",
						Messages.getResourceBundle( getULocale( ) ) );
			}
			int i = 0;
			final GanttEntry[] gea = new GanttEntry[(int) lRowCount];
			while ( rsds.hasNext( ) )
			{
				Object[] oThreeComponents = rsds.next( );
				validateGanttEntryData( oThreeComponents );
				gea[i++] = new GanttEntry( oThreeComponents );
			}
			if ( ds == null )
			{
				ds = GanttDataSetImpl.create( gea );
			}
			else
			{