Program: 20876
Project: 20876
Buggy source:
@Override public void handleFree(DownloadLink downloadLink) throws Exception {
  requestFileInformation(downloadLink);
  String url=null;
  Form down=null;
  Form[] allforms=br.getForms();
  if (allforms == null)   throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
  for (  Form singleform : allforms) {
    if (singleform.containsHTML("String_Node_Str")) {
      down=singleform;
      break;
    }
  }
  String captchaurl=null;
  if (down == null)   throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
  String captchaId=down.getVarsMap().get("String_Node_Str");
  if (captchaId == null)   throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
  captchaurl="String_Node_Str" + captchaId + "String_Node_Str";
  URLConnectionAdapter con=br.openGetConnection(captchaurl);
  File file=this.getLocalCaptchaFile();
  Browser.download(file,con);
  con.disconnect();
  down.setMethod(Form.MethodType.POST);
  String code=getCaptchaCode(file,downloadLink);
  down.put("String_Node_Str",code);
  down.put("String_Node_Str",captchaId);
  down.setAction("String_Node_Str");
  br.submitForm(down);
  if (!br.containsHTML("String_Node_Str"))   throw new PluginException(LinkStatus.ERROR_CAPTCHA);
  url=br.getRegex("String_Node_Str").getMatch(0);
  if (url == null || url.equals("String_Node_Str")) {
    String nextpage="String_Node_Str";
    logger.info("String_Node_Str");
    br.getPage(nextpage + "String_Node_Str");
    int waitThat=60;
    String time=br.getRegex("String_Node_Str").getMatch(0);
    if (time != null) {
      logger.info("String_Node_Str" + time + "String_Node_Str");
      waitThat=Integer.parseInt(time);
    }
    sleep((waitThat + 5) * 1001,downloadLink);
    br.getPage(nextpage);
    url=br.getRegex("String_Node_Str").getMatch(2);
    if (url == null) {
      url=br.getRegex("String_Node_Str").getMatch(0);
      if (url == null)       url=br.getRegex("String_Node_Str").getMatch(0);
    }
  }
  if (url == null || url.equals("String_Node_Str")) {
    logger.warning("String_Node_Str");
    throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
  }
  sleep(2000,downloadLink);
  dl=jd.plugins.BrowserAdapter.openDownload(br,downloadLink,url,true,1);
  con=dl.getConnection();
  if (con.getResponseCode() == 404) {
    con.disconnect();
    throw new PluginException(LinkStatus.ERROR_TEMPORARILY_UNAVAILABLE,null,5 * 60 * 1001);
  }
  if (!con.isOK()) {
    con.disconnect();
    throw new PluginException(LinkStatus.ERROR_TEMPORARILY_UNAVAILABLE);
  }
  if (con.getContentType().contains("String_Node_Str")) {
    br.followConnection();
    if (br.containsHTML("String_Node_Str"))     throw new PluginException(LinkStatus.ERROR_TEMPORARILY_UNAVAILABLE,"String_Node_Str");
    throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
  }
  dl.startDownload();
}

Fixed version (ground truth):
@Override public void handleFree(DownloadLink downloadLink) throws Exception {
  requestFileInformation(downloadLink);
  String url=null;
  Form down=null;
  Form[] allforms=br.getForms();
  if (allforms == null)   throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
  for (  Form singleform : allforms) {
    if (singleform.containsHTML("String_Node_Str")) {
      down=singleform;
      break;
    }
  }
  String captchaurl=null;
  if (down == null)   throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
  String captchaId=down.getVarsMap().get("String_Node_Str");
  if (captchaId == null)   throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
  captchaurl="String_Node_Str" + captchaId + "String_Node_Str";
  URLConnectionAdapter con=br.openGetConnection(captchaurl);
  File file=this.getLocalCaptchaFile();
  Browser.download(file,con);
  con.disconnect();
  down.setMethod(Form.MethodType.POST);
  String code=getCaptchaCode(file,downloadLink);
  down.put("String_Node_Str",code);
  down.put("String_Node_Str",captchaId);
  down.setAction("String_Node_Str");
  br.submitForm(down);
  if (!br.containsHTML("String_Node_Str"))   throw new PluginException(LinkStatus.ERROR_CAPTCHA);
  url=br.getRegex("String_Node_Str").getMatch(0);
  String nextpage="String_Node_Str";
  if (url == null || url.equals("String_Node_Str")) {
    logger.info("String_Node_Str");
    br.getPage(nextpage + "String_Node_Str");
    int waitThat=60;
    String time=br.getRegex("String_Node_Str").getMatch(0);
    if (time != null) {
      logger.info("String_Node_Str" + time + "String_Node_Str");
      waitThat=Integer.parseInt(time);
    }
    sleep((waitThat + 5) * 1001,downloadLink);
    br.getPage(nextpage);
    url=getUrl();
  }
  if (url == null || url.equals("String_Node_Str")) {
    logger.warning("String_Node_Str");
    String extraWait=br.getRegex("String_Node_Str").getMatch(0);
    if (extraWait != null) {
      logger.info("String_Node_Str");
      sleep((Integer.parseInt(extraWait) + 5) * 1001l,downloadLink);
      br.getPage(nextpage);
      url=getUrl();
    }
    if (url == null) {
      logger.warning("String_Node_Str");
      throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    }
  }
  sleep(2000,downloadLink);
  dl=jd.plugins.BrowserAdapter.openDownload(br,downloadLink,url,true,1);
  con=dl.getConnection();
  if (con.getResponseCode() == 404) {
    con.disconnect();
    throw new PluginException(LinkStatus.ERROR_TEMPORARILY_UNAVAILABLE,null,5 * 60 * 1001);
  }
  if (!con.isOK()) {
    con.disconnect();
    throw new PluginException(LinkStatus.ERROR_TEMPORARILY_UNAVAILABLE);
  }
  if (con.getContentType().contains("String_Node_Str")) {
    br.followConnection();
    if (br.containsHTML("String_Node_Str"))     throw new PluginException(LinkStatus.ERROR_TEMPORARILY_UNAVAILABLE,"String_Node_Str");
    throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
  }
  dl.startDownload();
}