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
CachedMetaDataHandle metaHandle = dataSet.getCachedMetaDataHandle( );
		if ( metaHandle == null )
		{
			try
			{
				metaHandle = DataSetUIUtil.getCachedMetaDataHandle( dataSet );
			}
			catch ( SemanticException e )
			{
				ExceptionHandler.handle( e );
				return new String[0];
			}
		}
		if ( metaHandle == null || metaHandle.getResultSet( ) == null )
		{
			return new String[0];
		}
		ArrayList valueList = new ArrayList( );
		for ( Iterator iter = metaHandle.getResultSet( ).iterator( ); iter.hasNext( ); )
		{
			ResultSetColumnHandle columnHandle = (ResultSetColumnHandle) iter.next( );
			if ( !needFilter || matchDataType( handle, columnHandle ) )
			{
				valueList.add( columnHandle.getColumnName( ) );
			}
		}
		return (String[]) valueList.toArray( new String[0] );
	}
	private DataSetHandle getDataSet( ScalarParameterHandle handle )
	{