Program: 21222
Project: 21222
Buggy source:
@Override public void handlePremium(DownloadLink downloadLink,Account account) throws Exception {
  LinkStatus linkStatus=downloadLink.getLinkStatus();
  br.setCookiesExclusive(true);
  br.clearCookies(getHost());
  br.setCookie("String_Node_Str","String_Node_Str","String_Node_Str");
  String link=downloadLink.getDownloadURL().replaceAll("String_Node_Str","String_Node_Str");
  downloadLink.setUrlDownload(link);
  br.getPage(link);
  if (br.getRedirectLocation() != null) {
    link=br.getRedirectLocation().replaceAll("String_Node_Str","String_Node_Str");
    br.getPage(link);
  }
  if (br.containsHTML(FILE_NOT_FOUND)) {
    logger.severe("String_Node_Str");
    linkStatus.addStatus(LinkStatus.ERROR_FILE_NOT_FOUND);
    return;
  }
  if (br.containsHTML(DOWNLOAD_NOTALLOWED)) {
    logger.severe("String_Node_Str");
    linkStatus.addStatus(LinkStatus.ERROR_TEMPORARILY_UNAVAILABLE);
    linkStatus.setValue(20 * 60 * 1000l);
    return;
  }
  Form login=br.getFormbyValue("String_Node_Str");
  login.put("String_Node_Str",account.getUser());
  login.put("String_Node_Str",account.getPass());
  br.submitForm(login);
  if (br.containsHTML("String_Node_Str") || br.containsHTML("String_Node_Str")) {
    linkStatus.addStatus(LinkStatus.ERROR_PREMIUM);
    linkStatus.setValue(LinkStatus.VALUE_ID_PREMIUM_DISABLE);
    downloadLink.getLinkStatus().setErrorMessage("String_Node_Str");
    return;
  }
  link=br.getRegex(PATTERN_PREMIUM_REDIRECT).getMatch(0);
  br.getPage(link);
  if (br.containsHTML(PASSWORD_PROTECTED)) {
    String password=Plugin.getUserInput(JDLocale.L("String_Node_Str","String_Node_Str"),downloadLink);
    br.postPage(link,"String_Node_Str" + password);
  }
 else {
  }
  link=br.getRegex(PATTERN_PREMIUM_FINALURL).getMatch(0);
  if (link == null) {
    linkStatus.addStatus(LinkStatus.ERROR_RETRY);
    return;
  }
  dl=RAFDownload.download(downloadLink,br.createGetRequest(link),true,0);
  HTTPConnection con=dl.connect(br);
  if (br.getRedirectLocation() != null && br.getRedirectLocation().indexOf("String_Node_Str") > 0) {
    linkStatus.addStatus(LinkStatus.ERROR_RETRY);
    return;
  }
  if (Plugin.getFileNameFormHeader(con) == null || Plugin.getFileNameFormHeader(con).indexOf("String_Node_Str") >= 0) {
    linkStatus.addStatus(LinkStatus.ERROR_RETRY);
    return;
  }
  dl.startDownload();
}

Fixed version (ground truth):
@Override public void handlePremium(DownloadLink downloadLink,Account account) throws Exception {
  LinkStatus linkStatus=downloadLink.getLinkStatus();
  br.setCookiesExclusive(true);
  br.clearCookies(getHost());
  br.setCookie("String_Node_Str","String_Node_Str","String_Node_Str");
  String link=downloadLink.getDownloadURL().replaceAll("String_Node_Str","String_Node_Str");
  downloadLink.setUrlDownload(link);
  br.getPage(link);
  if (br.getRedirectLocation() != null) {
    link=br.getRedirectLocation().replaceAll("String_Node_Str","String_Node_Str");
    br.getPage(link);
  }
  if (br.containsHTML(FILE_NOT_FOUND)) {
    logger.severe("String_Node_Str");
    linkStatus.addStatus(LinkStatus.ERROR_FILE_NOT_FOUND);
    return;
  }
  if (br.containsHTML(DOWNLOAD_NOTALLOWED)) {
    logger.severe("String_Node_Str");
    linkStatus.addStatus(LinkStatus.ERROR_TEMPORARILY_UNAVAILABLE);
    linkStatus.setValue(20 * 60 * 1000l);
    return;
  }
  Form login=br.getFormbyValue("String_Node_Str");
  login.put("String_Node_Str",account.getUser());
  login.put("String_Node_Str",account.getPass());
  br.submitForm(login);
  if (br.containsHTML("String_Node_Str") || br.containsHTML("String_Node_Str")) {
    linkStatus.addStatus(LinkStatus.ERROR_PREMIUM);
    linkStatus.setValue(LinkStatus.VALUE_ID_PREMIUM_DISABLE);
    downloadLink.getLinkStatus().setErrorMessage("String_Node_Str");
    return;
  }
  link=br.getRegex(PATTERN_PREMIUM_REDIRECT).getMatch(0);
  br.getPage(link);
  if (br.containsHTML(PASSWORD_PROTECTED)) {
    String password=Plugin.getUserInput(JDLocale.L("String_Node_Str","String_Node_Str"),downloadLink);
    br.postPage(link,"String_Node_Str" + password);
  }
 else {
  }
  link=br.getRegex(PATTERN_PREMIUM_FINALURL).getMatch(0);
  if (link == null) {
    throw new PluginException(LinkStatus.ERROR_PREMIUM,LinkStatus.VALUE_ID_PREMIUM_DISABLE);
  }
  dl=RAFDownload.download(downloadLink,br.createGetRequest(link),true,0);
  HTTPConnection con=dl.connect(br);
  if (br.getRedirectLocation() != null && br.getRedirectLocation().indexOf("String_Node_Str") > 0) {
    linkStatus.addStatus(LinkStatus.ERROR_RETRY);
    return;
  }
  if (Plugin.getFileNameFormHeader(con) == null || Plugin.getFileNameFormHeader(con).indexOf("String_Node_Str") >= 0) {
    linkStatus.addStatus(LinkStatus.ERROR_RETRY);
    return;
  }
  dl.startDownload();
}