Program: 20971
Project: 20971
Buggy source:
@Override public void handleFree(DownloadLink downloadLink) throws Exception {
  boolean do_download=false;
  requestFileInformation(downloadLink);
  br.setFollowRedirects(true);
  String passCode=null;
  String watchAd=br.getRegex("String_Node_Str").getMatch(0);
  if (watchAd != null) {
    downloadLink.getLinkStatus().setStatusText(JDL.L("String_Node_Str","String_Node_Str"));
    watchAd="String_Node_Str".concat(watchAd);
    br.getPage(watchAd);
    watchAd=br.getRegex("String_Node_Str").getMatch(0);
    if (watchAd == null)     throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    br.getPage(watchAd);
    watchAd=br.getRegex("String_Node_Str").getMatch(0);
    if (watchAd == null)     throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    watchAd="String_Node_Str" + watchAd;
    br.getPage(watchAd);
    String ticketTimeS=br.getRegex("String_Node_Str").getMatch(0);
    if (ticketTimeS == null)     throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    int ticketTime=Integer.parseInt(ticketTimeS) * 1000;
    this.sleep(ticketTime + 1,downloadLink);
    br.getPage(watchAd);
  }
  for (int retry=1; retry <= 5; retry++) {
    Form captchaForm=br.getFormbyProperty("String_Node_Str","String_Node_Str");
    String captchaurl=br.getRegex("String_Node_Str").getMatch(0);
    String tag=br.getRegex("String_Node_Str").getMatch(0);
    String secret=br.getRegex("String_Node_Str").getMatch(0);
    if (captchaForm == null || captchaurl == null)     throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    if (tag != null && secret != null) {
      secret=secret.substring(2);
      captchaForm.put("String_Node_Str",tag);
      InputField nv=new InputField(secret,"String_Node_Str");
      captchaForm.addInputField(nv);
    }
 else {
      secret=br.getRegex("String_Node_Str").getMatch(0);
      String name=br.getRegex("String_Node_Str").getMatch(0);
      if (name != null && secret != null) {
        secret=secret.substring(2);
        captchaForm.put(name,secret);
        captchaForm.remove("String_Node_Str");
        captchaForm.remove("String_Node_Str");
        captchaForm.remove("String_Node_Str");
        captchaForm.put("String_Node_Str","String_Node_Str");
      }
 else       throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    }
    captchaForm.setAction(br.getURL());
    String captchaCode=getCaptchaCode(captchaurl,downloadLink);
    captchaForm.put("String_Node_Str",captchaCode);
    try {
      br.submitForm(captchaForm);
    }
 catch (    Exception e) {
      br.submitForm(captchaForm);
    }
    String directLink=br.getRegex("String_Node_Str").getMatch(0);
    if (directLink == null) {
      Form pwform=br.getForm(2);
      if (pwform != null) {
        if (downloadLink.getStringProperty("String_Node_Str",null) == null) {
          passCode=Plugin.getUserInput("String_Node_Str",downloadLink);
        }
 else {
          passCode=downloadLink.getStringProperty("String_Node_Str",null);
        }
        pwform.put("String_Node_Str",passCode);
        br.submitForm(pwform);
        directLink=br.getRegex("String_Node_Str").getMatch(0);
        if (directLink == null) {
          downloadLink.setProperty("String_Node_Str",null);
          logger.info("String_Node_Str");
          throw new PluginException(LinkStatus.ERROR_RETRY);
        }
      }
    }
    if (directLink != null) {
      if (passCode != null)       downloadLink.setProperty("String_Node_Str",passCode);
      dl=jd.plugins.BrowserAdapter.openDownload(br,downloadLink,directLink,true,-2);
      do_download=true;
      break;
    }
  }
  if (!do_download) {
    throw new PluginException(LinkStatus.ERROR_CAPTCHA,JDL.L("String_Node_Str","String_Node_Str"));
  }
 else   dl.startDownload();
}

Fixed version (ground truth):
@Override public void handleFree(DownloadLink downloadLink) throws Exception {
  boolean do_download=false;
  requestFileInformation(downloadLink);
  br.setFollowRedirects(true);
  String passCode=null;
  String watchAd=br.getRegex("String_Node_Str").getMatch(0);
  if (watchAd != null) {
    downloadLink.getLinkStatus().setStatusText(JDL.L("String_Node_Str","String_Node_Str"));
    watchAd="String_Node_Str".concat(watchAd);
    br.getPage(watchAd);
    watchAd=br.getRegex("String_Node_Str").getMatch(0);
    if (watchAd == null)     throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    br.getPage(watchAd);
    watchAd=br.getRegex("String_Node_Str").getMatch(0);
    if (watchAd == null)     throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    watchAd="String_Node_Str" + watchAd;
    br.getPage(watchAd);
    String ticketTimeS=br.getRegex("String_Node_Str").getMatch(0);
    if (ticketTimeS == null)     throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    int ticketTime=Integer.parseInt(ticketTimeS) * 1000;
    this.sleep(ticketTime + 1,downloadLink);
    br.getPage(watchAd);
  }
  for (int retry=1; retry <= 5; retry++) {
    Form captchaForm=br.getFormbyProperty("String_Node_Str","String_Node_Str");
    String captchaurl=br.getRegex("String_Node_Str").getMatch(0);
    String tag=br.getRegex("String_Node_Str").getMatch(0);
    String secret=br.getRegex("String_Node_Str").getMatch(0);
    if (captchaForm == null || captchaurl == null)     throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    if (tag != null && secret != null) {
      secret=secret.substring(2);
      captchaForm.put("String_Node_Str",tag);
      InputField nv=new InputField(secret,"String_Node_Str");
      captchaForm.addInputField(nv);
    }
 else {
      secret=br.getRegex("String_Node_Str").getMatch(0);
      String name=br.getRegex("String_Node_Str").getMatch(0);
      if (name != null && secret != null) {
        secret=secret.substring(2);
        captchaForm.put(name,secret);
        captchaForm.remove("String_Node_Str");
        captchaForm.remove("String_Node_Str");
        captchaForm.remove("String_Node_Str");
        captchaForm.put("String_Node_Str","String_Node_Str");
      }
 else       throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    }
    captchaForm.setAction(br.getURL());
    String captchaCode=getCaptchaCode(captchaurl,downloadLink);
    captchaForm.put("String_Node_Str",captchaCode);
    try {
      br.submitForm(captchaForm);
    }
 catch (    Exception e) {
      br.submitForm(captchaForm);
    }
    String directLink=br.getRegex("String_Node_Str").getMatch(0);
    if (directLink == null) {
      Form pwform=br.getForm(2);
      if (pwform != null && !br.getRegex("String_Node_Str").matches()) {
        if (downloadLink.getStringProperty("String_Node_Str",null) == null) {
          passCode=Plugin.getUserInput("String_Node_Str",downloadLink);
        }
 else {
          passCode=downloadLink.getStringProperty("String_Node_Str",null);
        }
        pwform.put("String_Node_Str",passCode);
        br.submitForm(pwform);
        directLink=br.getRegex("String_Node_Str").getMatch(0);
        if (directLink == null) {
          downloadLink.setProperty("String_Node_Str",null);
          logger.info("String_Node_Str");
          throw new PluginException(LinkStatus.ERROR_RETRY);
        }
      }
    }
    if (directLink != null) {
      if (passCode != null)       downloadLink.setProperty("String_Node_Str",passCode);
      dl=jd.plugins.BrowserAdapter.openDownload(br,downloadLink,directLink,true,-2);
      do_download=true;
      break;
    }
  }
  if (!do_download) {
    throw new PluginException(LinkStatus.ERROR_CAPTCHA,JDL.L("String_Node_Str","String_Node_Str"));
  }
 else   dl.startDownload();
}