Program: 21175
Project: 21175
Buggy source:
@Override public void handleFree(DownloadLink downloadLink) throws Exception {
  LinkStatus linkStatus=downloadLink.getLinkStatus();
  int maxCaptchaTries=5;
  String code;
  String page=null;
  br.setCookiesExclusive(true);
  br.clearCookies("String_Node_Str");
  br.getPage(downloadLink.getDownloadURL());
  int tries=0;
  while (tries < maxCaptchaTries) {
    File captchaFile=Plugin.getLocalCaptchaFile(this,"String_Node_Str");
    Browser.download(captchaFile,br.openGetConnection("String_Node_Str"));
    code=Plugin.getCaptchaCode(captchaFile,this,downloadLink);
    page=br.postPage(downloadLink.getDownloadURL(),"String_Node_Str" + code);
    tries++;
    if (!page.contains("String_Node_Str")) {
      break;
    }
  }
  if (page != null && page.contains("String_Node_Str")) {
    linkStatus.addStatus(LinkStatus.ERROR_CAPTCHA);
    return;
  }
  if (Regex.matches(page,PATTERN_MATCHER_ERROR)) {
    String error=new Regex(page,"String_Node_Str").getMatch(0);
    logger.severe("String_Node_Str" + error);
    linkStatus.addStatus(LinkStatus.ERROR_RETRY);
    return;
  }
  br.setFollowRedirects(false);
  String wait=new Regex(br,"String_Node_Str").getMatch(0);
  if (wait != null) {
    throw new PluginException(LinkStatus.ERROR_IP_BLOCKED,new Long(wait) * 1000 * 60l);
  }
  Form[] forms=br.getForms();
  if (forms.length < 2) {
    throw new PluginException(LinkStatus.ERROR_IP_BLOCKED,60 * 1000 * 60l);
  }
  page=br.submitForm(forms[1]);
  sleep(61000,downloadLink);
  dl=RAFDownload.download(downloadLink,br.createGetRequest(null));
  dl.startDownload();
}

Fixed version (ground truth):
@Override public void handleFree(DownloadLink downloadLink) throws Exception {
  LinkStatus linkStatus=downloadLink.getLinkStatus();
  int maxCaptchaTries=5;
  String code;
  String page=null;
  br.setCookiesExclusive(true);
  br.clearCookies("String_Node_Str");
  br.getPage(downloadLink.getDownloadURL());
  int tries=0;
  while (tries < maxCaptchaTries) {
    File captchaFile=Plugin.getLocalCaptchaFile(this,"String_Node_Str");
    Browser.download(captchaFile,br.openGetConnection("String_Node_Str"));
    code=Plugin.getCaptchaCode(captchaFile,this,downloadLink);
    page=br.postPage(downloadLink.getDownloadURL(),"String_Node_Str" + code);
    tries++;
    if (!page.contains("String_Node_Str")) {
      break;
    }
  }
  if (page != null && page.contains("String_Node_Str")) {
    linkStatus.addStatus(LinkStatus.ERROR_CAPTCHA);
    return;
  }
  if (Regex.matches(page,PATTERN_MATCHER_ERROR)) {
    String error=new Regex(page,"String_Node_Str").getMatch(0);
    logger.severe("String_Node_Str" + error);
    linkStatus.addStatus(LinkStatus.ERROR_RETRY);
    return;
  }
  br.setFollowRedirects(false);
  if (br.toString().contains("String_Node_Str")) {
    throw new PluginException(LinkStatus.ERROR_TEMPORARILY_UNAVAILABLE,10 * 1000 * 60l);
  }
  String wait=new Regex(br,"String_Node_Str").getMatch(0);
  if (wait != null) {
    throw new PluginException(LinkStatus.ERROR_IP_BLOCKED,new Long(wait) * 1000 * 60l);
  }
  Form[] forms=br.getForms();
  if (forms.length < 2) {
    throw new PluginException(LinkStatus.ERROR_IP_BLOCKED,60 * 1000 * 60l);
  }
  page=br.submitForm(forms[1]);
  sleep(61000,downloadLink);
  dl=RAFDownload.download(downloadLink,br.createGetRequest(null));
  dl.startDownload();
}