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/ParameterDialog.java
else if ( PARAM_CONTROL_LIST.equals( type ) )
			{
				displayName = DISPLAY_NAME_CONTROL_LIST;
			}
		}
		return displayName;
	}
	private String validateChoice( SelectionChoice choice, String displayLabel,
			String value )
	{
		String errorMessage = isValidValue( value );
		if ( errorMessage != null )
		{
			return errorMessage;
		}
		String newValue = convertToStandardFormat( value );
		if ( ( displayLabel == null && containValue( choice,
				newValue,
				COLUMN_DISPLAY_TEXT ) )
				|| ( containValue( choice, displayLabel, COLUMN_DISPLAY_TEXT ) ) )
		{
			return ERROR_MSG_DUPLICATED_LABEL;
		}
		if ( containValue( choice, newValue, COLUMN_VALUE ) )
		{
			return ERROR_MSG_DUPLICATED_VALUE;
		}
		return null;
	}
}