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
{
				if ( dirtyProperties.containsKey( CHECKBOX_ALLOW_BLANK ) )
				{
					inputParameter.setAllowBlank( getProperty( CHECKBOX_ALLOW_BLANK ) );
				}
			}
			else
			{
				inputParameter.setProperty( ScalarParameterHandle.ALLOW_BLANK_PROP,
						null );
			}
			if ( doNotEcho.isEnabled( ) )
			{
				if ( dirtyProperties.containsKey( CHECKBOX_DO_NOT_ECHO ) )
				{
					inputParameter.setConcealValue( getProperty( CHECKBOX_DO_NOT_ECHO ) );
				}
			}
			else
			{
				inputParameter.setProperty( ScalarParameterHandle.CONCEAL_VALUE_PROP,
						null );
			}
			if ( needSort.isEnabled( ) )
			{
				if ( dirtyProperties.containsKey( CHECKBOX_SORT ) )
				{
					inputParameter.setFixedOrder( !getProperty( CHECKBOX_SORT ) );
				}
			}