Bug 153523 OK button in parameter dialog is enabled without default value in combo-box
Description: OK button in parameter dialog is enabled without default value in combo-box Steps to reproduce: 1. New a report parameter, combo-box. 2. Click New button, input abc as value, click OK 3. Set abc as default value and close Edit Parameter dialog. 4. New a data source and dataset 5. Edit the parameter, remove abc value and import values from dataset Expected result: OK button is disabled for there is no default value. Actual result: OK button is enabled.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/CascadingParametersDialog.java
inputParameterGroup.setDataSetMode( DesignChoiceConstants.DATA_SET_MODE_SINGLE );
			}
			else
			{
				inputParameterGroup.setDataSetMode( DesignChoiceConstants.DATA_SET_MODE_MULTIPLE );
			}
		}
		catch ( SemanticException e )
		{
			ExceptionHandler.handle( e );
			refreshParameterProperties( );
			return;
		}
		setResult( inputParameterGroup );
		super.okPressed( );
	}
	private void deleteRow( )
	{
		int index = valueTable.getTable( ).getSelectionIndex( );
		ScalarParameterHandle choice = (ScalarParameterHandle) ( (IStructuredSelection) valueTable.getSelection( ) ).getFirstElement( );
		if ( choice == null )
		{
			return;
		}
		try
		{
			inputParameterGroup.getParameters( ).drop( choice );
		}
		catch ( SemanticException e )
		{