Bug 141950 Selection of select value in data set filter is error
Details: Selection of select value in data set filter is error Step: 1.New a report design. 2.Create a sample datasource and dataset. 3.Switch to filter. 4.Select a value in expression. 5.Drop the list of the value1 and select <select value...> Actual result: No value is appear and pop up an error. It said that "An expression has not been set"
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/data/ui/util/DataSetProvider.java
{
			while ( iter.hasNext( ) )
			{
				ColumnHintHandle hint = (ColumnHintHandle) iter.next( );
				
				for ( int n = 0; n < columns.length; n++ )
				{
					
					
					
					String columnName = columns[n].getName( );
					if ( columnName == null
							|| columnName.trim( ).length( ) == 0 )
					{
						Iterator resultIter = resultSetColumnHandle.iterator( );
						if ( resultIter != null )
						{
							while ( resultIter.hasNext( ) )
							{
								ResultSetColumnHandle column = (ResultSetColumnHandle) resultIter.next( );
								if ( column.getPosition( ).intValue( ) == n + 1 )
								{
									columnName = column.getColumnName( );
									break;
								}
							}
						}
						if ( columnName == null )
						{
							columnName = "";