Bug 153405 Null parameter value is inconsistent between designer and preview
Description: Null parameter value is inconsistent between designer and preview Steps to reproduce: 1. New a report parameter, list-box, tick AllowNull. 2. Click New button, click OK without input anything. 3. Drag the parameter to Layout and preview Actual result: After step2, display text is "Null" and value is empty. However, when preview, the display text is "Null Value". Expected result: Display text and value should be consistent between Edit Parameter Dialog in Layout and Parameter dialog during preview.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
{
					text = format( choice.getValue( ) );
				}
			}
			if ( text == null )
			{
				text = ""; 
			}
			return text;
		}
		public void addListener( ILabelProviderListener listener )
		{
		}
		public void dispose( )
		{
		}
		public boolean isLabelProperty( Object element, String property )
		{
			return false;
		}
		public void removeListener( ILabelProviderListener listener )
		{
		}
	};
	private final ITableAreaModifier tableAreaModifier = new ITableAreaModifier( ) {
		public boolean editItem( final Object element )
		{
			final SelectionChoice choice = (SelectionChoice) element;
			boolean isDefault = isDefaultChoice( choice );
			SelectionChoiceDialog dialog = new SelectionChoiceDialog( Messages.getString( "ParameterDialog.SelectionDialog.Edit" ) );