Program: 20877
Project: 20877
Buggy source:
public void doFree(DownloadLink downloadLink) throws Exception, PluginException {
  if (brbefore.contains("String_Node_Str"))   throw new PluginException(LinkStatus.ERROR_FATAL,JDL.L("String_Node_Str","String_Node_Str"));
  br.setFollowRedirects(true);
  Form DLForm0=br.getForm(0);
  if (DLForm0 == null)   throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
  DLForm0.remove("String_Node_Str");
  br.submitForm(DLForm0);
  doSomething();
  checkErrors(downloadLink);
  String ttt=br.getRegex("String_Node_Str").getMatch(0);
  if (ttt == null)   ttt=br.getRegex("String_Node_Str").getMatch(0);
  int tt=60;
  if (ttt != null && Integer.parseInt(ttt) < 100) {
    logger.info("String_Node_Str" + ttt.trim() + "String_Node_Str");
    tt=Integer.parseInt(ttt);
  }
  sleep(tt * 1001,downloadLink);
  String passCode=null;
  if (br.containsHTML("String_Node_Str")) {
    PluginForHost recplug=JDUtilities.getPluginForHost("String_Node_Str");
    jd.plugins.hoster.DirectHTTP.Recaptcha rc=((DirectHTTP)recplug).getReCaptcha(br);
    rc.parse();
    rc.load();
    File cf=rc.downloadCaptcha(getLocalCaptchaFile());
    String c=getCaptchaCode(cf,downloadLink);
    if (br.containsHTML("String_Node_Str")) {
      if (downloadLink.getStringProperty("String_Node_Str",null) == null) {
        passCode=Plugin.getUserInput("String_Node_Str",downloadLink);
      }
 else {
        passCode=downloadLink.getStringProperty("String_Node_Str",null);
      }
      rc.getForm().put("String_Node_Str",passCode);
    }
    rc.setCode(c);
  }
 else {
    Form dlForm=br.getFormbyProperty("String_Node_Str","String_Node_Str");
    if (dlForm == null)     throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    if (br.containsHTML("String_Node_Str")) {
      if (downloadLink.getStringProperty("String_Node_Str",null) == null) {
        passCode=Plugin.getUserInput("String_Node_Str",downloadLink);
      }
 else {
        passCode=downloadLink.getStringProperty("String_Node_Str",null);
      }
      dlForm.put("String_Node_Str",passCode);
    }
    br.submitForm(dlForm);
  }
  doSomething();
  if (brbefore.contains("String_Node_Str") || brbefore.contains("String_Node_Str")) {
    logger.warning("String_Node_Str");
    downloadLink.setProperty("String_Node_Str",null);
    throw new PluginException(LinkStatus.ERROR_CAPTCHA);
  }
  if (passCode != null) {
    downloadLink.setProperty("String_Node_Str",passCode);
  }
  String dllink=br.getRegex("String_Node_Str").getMatch(0);
  if (dllink == null)   throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
  jd.plugins.BrowserAdapter.openDownload(br,downloadLink,dllink,false,1);
  dl.startDownload();
}

Fixed version (ground truth):
public void doFree(DownloadLink downloadLink) throws Exception, PluginException {
  if (brbefore.contains(ONLY4PREMIUMERROR0) || brbefore.contains(ONLY4PREMIUMERROR1))   throw new PluginException(LinkStatus.ERROR_FATAL,JDL.L("String_Node_Str","String_Node_Str"));
  br.setFollowRedirects(true);
  Form DLForm0=br.getForm(0);
  if (DLForm0 == null)   throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
  DLForm0.remove("String_Node_Str");
  br.submitForm(DLForm0);
  doSomething();
  checkErrors(downloadLink);
  String ttt=br.getRegex("String_Node_Str").getMatch(0);
  if (ttt == null)   ttt=br.getRegex("String_Node_Str").getMatch(0);
  int tt=60;
  if (ttt != null && Integer.parseInt(ttt) < 100) {
    logger.info("String_Node_Str" + ttt.trim() + "String_Node_Str");
    tt=Integer.parseInt(ttt);
  }
  sleep(tt * 1001,downloadLink);
  String passCode=null;
  if (br.containsHTML("String_Node_Str")) {
    PluginForHost recplug=JDUtilities.getPluginForHost("String_Node_Str");
    jd.plugins.hoster.DirectHTTP.Recaptcha rc=((DirectHTTP)recplug).getReCaptcha(br);
    rc.parse();
    rc.load();
    File cf=rc.downloadCaptcha(getLocalCaptchaFile());
    String c=getCaptchaCode(cf,downloadLink);
    if (br.containsHTML("String_Node_Str")) {
      if (downloadLink.getStringProperty("String_Node_Str",null) == null) {
        passCode=Plugin.getUserInput("String_Node_Str",downloadLink);
      }
 else {
        passCode=downloadLink.getStringProperty("String_Node_Str",null);
      }
      rc.getForm().put("String_Node_Str",passCode);
    }
    rc.setCode(c);
  }
 else {
    Form dlForm=br.getFormbyProperty("String_Node_Str","String_Node_Str");
    if (dlForm == null)     throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    if (br.containsHTML("String_Node_Str")) {
      if (downloadLink.getStringProperty("String_Node_Str",null) == null) {
        passCode=Plugin.getUserInput("String_Node_Str",downloadLink);
      }
 else {
        passCode=downloadLink.getStringProperty("String_Node_Str",null);
      }
      dlForm.put("String_Node_Str",passCode);
    }
    br.submitForm(dlForm);
  }
  doSomething();
  if (brbefore.contains("String_Node_Str") || brbefore.contains("String_Node_Str")) {
    logger.warning("String_Node_Str");
    downloadLink.setProperty("String_Node_Str",null);
    throw new PluginException(LinkStatus.ERROR_CAPTCHA);
  }
  if (passCode != null) {
    downloadLink.setProperty("String_Node_Str",passCode);
  }
  String dllink=br.getRegex("String_Node_Str").getMatch(0);
  if (dllink == null)   throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
  jd.plugins.BrowserAdapter.openDownload(br,downloadLink,dllink,false,1);
  dl.startDownload();
}