Program: 20729
Project: 20729
Buggy source:
@Override public void handleFree(DownloadLink downloadLink) throws Exception {
  requestFileInformation(downloadLink);
  if (br.containsHTML("String_Node_Str"))   throw new PluginException(LinkStatus.ERROR_IP_BLOCKED,15 * 60 * 1000l);
  if (br.containsHTML("String_Node_Str"))   throw new PluginException(LinkStatus.ERROR_FATAL,JDL.L("String_Node_Str","String_Node_Str"));
  String wait=br.getRegex("String_Node_Str").getMatch(0);
  int waittime=0;
  if (wait != null)   waittime=Integer.parseInt(wait.trim());
  if (waittime > 90 && (longwait == null || longwait == true)) {
    longwait=true;
    sleep(waittime * 1000l,downloadLink);
  }
 else {
    if (longwait == null)     longwait=false;
    if (waittime > 90 && longwait == false) {
      throw new PluginException(LinkStatus.ERROR_IP_BLOCKED,waittime * 1000l);
    }
 else {
      if (br.getRegex("String_Node_Str").getMatch(0) == null) {
        sleep(waittime * 1000l,downloadLink);
      }
    }
  }
  String id=br.getRegex("String_Node_Str").getMatch(0);
  if (br.containsHTML("String_Node_Str"))   throw new PluginException(LinkStatus.ERROR_IP_BLOCKED,60 * 60 * 1000l);
  if (id == null)   br.getPage(downloadLink.getDownloadURL());
  if (br.containsHTML("String_Node_Str"))   throw new PluginException(LinkStatus.ERROR_IP_BLOCKED,15 * 60 * 1000l);
  int tries=0;
  while (true) {
    tries++;
    id=br.getRegex("String_Node_Str").getMatch(0);
    if (id == null)     throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    Browser rcBr=br.cloneBrowser();
    rcBr.setFollowRedirects(true);
    rcBr.getPage("String_Node_Str" + id);
    String challenge=rcBr.getRegex("String_Node_Str").getMatch(0);
    String server=rcBr.getRegex("String_Node_Str").getMatch(0);
    if (challenge == null || server == null) {
      logger.severe("String_Node_Str" + br.getHttpConnection());
      throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    }
    String captchaAddress=server + "String_Node_Str" + challenge;
    File cf=getLocalCaptchaFile();
    Browser.download(cf,rcBr.openGetConnection(captchaAddress));
    Form form=null;
    Form[] allForms=br.getForms();
    if (allForms == null || allForms.length == 0)     throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    for (    Form singleForm : allForms)     if (singleForm.containsHTML("String_Node_Str") && !singleForm.containsHTML("String_Node_Str")) {
      form=singleForm;
      break;
    }
    if (form == null)     throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    String code=getCaptchaCode("String_Node_Str",cf,downloadLink);
    form.put("String_Node_Str",challenge);
    form.put("String_Node_Str",Encoding.urlEncode(code));
    br.setFollowRedirects(true);
    dl=jd.plugins.BrowserAdapter.openDownload(br,downloadLink,form,true,1);
    if (!dl.getConnection().isContentDisposition()) {
      br.followConnection();
      if (br.containsHTML("String_Node_Str"))       throw new PluginException(LinkStatus.ERROR_IP_BLOCKED,15 * 60 * 1000l);
      if (br.containsHTML("String_Node_Str")) {
        if (tries <= 5) {
          continue;
        }
 else {
          throw new PluginException(LinkStatus.ERROR_CAPTCHA);
        }
      }
      throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    }
    break;
  }
  downloadLink.setFinalFileName(Encoding.htmlDecode(getFileNameFromHeader(dl.getConnection())));
  dl.startDownload();
}

Fixed version (ground truth):
@Override public void handleFree(DownloadLink downloadLink) throws Exception {
  requestFileInformation(downloadLink);
  URLConnectionAdapter con=br.openGetConnection(downloadLink.getDownloadURL());
  br.setCookie("String_Node_Str","String_Node_Str","String_Node_Str");
  if (con.getResponseCode() == 503)   throw new PluginException(LinkStatus.ERROR_FILE_NOT_FOUND);
  br.followConnection();
  if (br.containsHTML("String_Node_Str"))   throw new PluginException(LinkStatus.ERROR_FILE_NOT_FOUND);
  if (br.containsHTML("String_Node_Str"))   throw new PluginException(LinkStatus.ERROR_IP_BLOCKED,15 * 60 * 1000l);
  if (br.containsHTML("String_Node_Str"))   throw new PluginException(LinkStatus.ERROR_FATAL,JDL.L("String_Node_Str","String_Node_Str"));
  String wait=br.getRegex("String_Node_Str").getMatch(0);
  int waittime=0;
  if (wait != null)   waittime=Integer.parseInt(wait.trim());
  if (waittime > 90 && (longwait == null || longwait == true)) {
    longwait=true;
    sleep(waittime * 1000l,downloadLink);
  }
 else {
    if (longwait == null)     longwait=false;
    if (waittime > 90 && longwait == false) {
      throw new PluginException(LinkStatus.ERROR_IP_BLOCKED,waittime * 1000l);
    }
 else {
      if (br.getRegex("String_Node_Str").getMatch(0) == null) {
        sleep(waittime * 1000l,downloadLink);
      }
    }
  }
  String id=br.getRegex("String_Node_Str").getMatch(0);
  if (br.containsHTML("String_Node_Str"))   throw new PluginException(LinkStatus.ERROR_IP_BLOCKED,60 * 60 * 1000l);
  if (id == null)   br.getPage(downloadLink.getDownloadURL());
  if (br.containsHTML("String_Node_Str"))   throw new PluginException(LinkStatus.ERROR_IP_BLOCKED,15 * 60 * 1000l);
  int tries=0;
  while (true) {
    tries++;
    id=br.getRegex("String_Node_Str").getMatch(0);
    if (id == null)     throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    Browser rcBr=br.cloneBrowser();
    rcBr.setFollowRedirects(true);
    rcBr.getPage("String_Node_Str" + id);
    String challenge=rcBr.getRegex("String_Node_Str").getMatch(0);
    String server=rcBr.getRegex("String_Node_Str").getMatch(0);
    if (challenge == null || server == null) {
      logger.severe("String_Node_Str" + br.getHttpConnection());
      throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    }
    String captchaAddress=server + "String_Node_Str" + challenge;
    File cf=getLocalCaptchaFile();
    Browser.download(cf,rcBr.openGetConnection(captchaAddress));
    Form form=null;
    Form[] allForms=br.getForms();
    if (allForms == null || allForms.length == 0)     throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    for (    Form singleForm : allForms)     if (singleForm.containsHTML("String_Node_Str") && !singleForm.containsHTML("String_Node_Str")) {
      form=singleForm;
      break;
    }
    if (form == null)     throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    String code=getCaptchaCode("String_Node_Str",cf,downloadLink);
    form.put("String_Node_Str",challenge);
    form.put("String_Node_Str",Encoding.urlEncode(code));
    br.setFollowRedirects(true);
    dl=jd.plugins.BrowserAdapter.openDownload(br,downloadLink,form,true,1);
    if (!dl.getConnection().isContentDisposition()) {
      br.followConnection();
      if (br.containsHTML("String_Node_Str"))       throw new PluginException(LinkStatus.ERROR_IP_BLOCKED,15 * 60 * 1000l);
      if (br.containsHTML("String_Node_Str")) {
        if (tries <= 5) {
          continue;
        }
 else {
          throw new PluginException(LinkStatus.ERROR_CAPTCHA);
        }
      }
      throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    }
    break;
  }
  downloadLink.setFinalFileName(Encoding.htmlDecode(getFileNameFromHeader(dl.getConnection())));
  dl.startDownload();
}