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
choices = new String[3];
			}
			else
			{
				choices = new String[4];
			}
		}
		else
		{
			choices = new String[2];
		}
		if ( controlTypeChooser.getItemCount( ) != choices.length )
		{
			String originalSelection = controlTypeChooser.getText( );
			if ( isStatic( ) )
			{
				if ( DesignChoiceConstants.PARAM_TYPE_BOOLEAN.equals( type ) )
				{
					choices[0] = CONTROL_TYPE_CHOICE_SET.findChoice( DesignChoiceConstants.PARAM_CONTROL_CHECK_BOX )
							.getDisplayName( );
				}
				else
				{
					choices[0] = CONTROL_TYPE_CHOICE_SET.findChoice( DesignChoiceConstants.PARAM_CONTROL_TEXT_BOX )
							.getDisplayName( );
					
					choices[1] = DISPLAY_NAME_CONTROL_COMBO;
				}
				
				choices[choices.length - 2] = DISPLAY_NAME_CONTROL_LIST;