Program: 188218
Project: 188218
Buggy source:
/** 
 * Create a new panel to view a notification
 */
public ShowNotification(Notification notification){
  initWidget(uiBinder.createAndBindUi(this));
  notificationId.setText(notification.getId());
  notificationSubject.setText(notification.getSubject());
  notificationBody.setHTML(notification.getBody());
  notificationSentOn.setText(DateTimeFormat.getFormat(PredefinedFormat.DATE_TIME_MEDIUM).format(notification.getSentOn()));
  notificationFromUser.setText(notification.getFromUser());
  notificationIsAcknowledged.setText(messages.isAcknowledged(Boolean.toString(notification.isAcknowledged()).toLowerCase()));
  acknowledgedUsersKey.setVisible(false);
  notAcknowledgedUsersKey.setVisible(false);
  List<String> recipientUsers=new ArrayList<>(notification.getRecipientUsers());
  for (  String user : notification.getAcknowledgedUsers().keySet()) {
    String ackDate=notification.getAcknowledgedUsers().get(user);
    acknowledgedUsersKey.setVisible(true);
    acknowledgedUsersValue.setHTML(SafeHtmlUtils.fromSafeConstant(acknowledgedUsersValue.getHTML() + "String_Node_Str" + user+ "String_Node_Str"+ ackDate+ "String_Node_Str"));
    recipientUsers.remove(user);
  }
  for (  String user : recipientUsers) {
    notAcknowledgedUsersKey.setVisible(true);
    notAcknowledgedUsersValue.setHTML(SafeHtmlUtils.fromSafeConstant(notAcknowledgedUsersValue.getHTML() + "String_Node_Str" + user+ "String_Node_Str"));
  }
  stateValue.setHTML(HtmlSnippetUtils.getNotificationStateHTML(notification.getState()));
  stateLabel.setVisible(notification.getState() != null);
  stateValue.setVisible(notification.getState() != null);
}

Fixed version (ground truth):
/** 
 * Create a new panel to view a notification
 */
public ShowNotification(Notification notification){
  initWidget(uiBinder.createAndBindUi(this));
  notificationId.setText(notification.getId());
  notificationSubject.setText(notification.getSubject());
  notificationBody.setHTML(notification.getBody());
  notificationSentOn.setText(Humanize.formatDateTime(notification.getSentOn()));
  notificationFromUser.setText(notification.getFromUser());
  notificationIsAcknowledged.setText(messages.isAcknowledged(Boolean.toString(notification.isAcknowledged()).toLowerCase()));
  acknowledgedUsersKey.setVisible(false);
  notAcknowledgedUsersKey.setVisible(false);
  List<String> recipientUsers=new ArrayList<>(notification.getRecipientUsers());
  for (  String user : notification.getAcknowledgedUsers().keySet()) {
    String ackDate=notification.getAcknowledgedUsers().get(user);
    acknowledgedUsersKey.setVisible(true);
    acknowledgedUsersValue.setHTML(SafeHtmlUtils.fromSafeConstant(acknowledgedUsersValue.getHTML() + "String_Node_Str" + user+ "String_Node_Str"+ ackDate+ "String_Node_Str"));
    recipientUsers.remove(user);
  }
  for (  String user : recipientUsers) {
    notAcknowledgedUsersKey.setVisible(true);
    notAcknowledgedUsersValue.setHTML(SafeHtmlUtils.fromSafeConstant(notAcknowledgedUsersValue.getHTML() + "String_Node_Str" + user+ "String_Node_Str"));
  }
  stateValue.setHTML(HtmlSnippetUtils.getNotificationStateHTML(notification.getState()));
  stateLabel.setVisible(notification.getState() != null);
  stateValue.setVisible(notification.getState() != null);
}