Program: 20884
Project: 20884
Buggy source:
@Override public void handleFree(DownloadLink downloadLink) throws Exception, PluginException {
  requestFileInformation(downloadLink);
  String dllink=null;
  for (int i=0; i <= 3; i++) {
    br.setFollowRedirects(true);
    if (!br.containsHTML("String_Node_Str"))     throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    String captchaUrl="String_Node_Str";
    String code=getCaptchaCode(captchaUrl,downloadLink);
    br.postPage(downloadLink.getDownloadURL(),"String_Node_Str" + code + "String_Node_Str");
    if (!br.getURL().contains("String_Node_Str"))     continue;
    break;
  }
  if (!br.getURL().contains("String_Node_Str"))   throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
  dllink=br.getRegex("String_Node_Str").getMatch(0);
  if (dllink == null)   dllink=br.getRegex("String_Node_Str").getMatch(0);
  if (dllink == null)   throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
  String ttt=br.getRegex("String_Node_Str").getMatch(0);
  int tt=60;
  if (ttt != null) {
    logger.info("String_Node_Str" + ttt.trim() + "String_Node_Str");
    if (Integer.parseInt(ttt) < 100)     tt=Integer.parseInt(ttt);
  }
  sleep(tt * 1001,downloadLink);
  dllink="String_Node_Str" + dllink;
  dl=jd.plugins.BrowserAdapter.openDownload(br,downloadLink,dllink,true,0);
  if (dl.getConnection().getContentType().contains("String_Node_Str")) {
    br.followConnection();
    if (br.containsHTML("String_Node_Str"))     throw new PluginException(LinkStatus.ERROR_FILE_NOT_FOUND);
    throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
  }
  dl.startDownload();
}

Fixed version (ground truth):
@Override public void handleFree(DownloadLink downloadLink) throws Exception, PluginException {
  requestFileInformation(downloadLink);
  if (br.containsHTML("String_Node_Str"))   throw new PluginException(LinkStatus.ERROR_FATAL,JDL.L("String_Node_Str","String_Node_Str"));
  String dllink=null;
  for (int i=0; i <= 3; i++) {
    br.setFollowRedirects(true);
    if (!br.containsHTML("String_Node_Str"))     throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    String captchaUrl="String_Node_Str";
    String code=getCaptchaCode(captchaUrl,downloadLink);
    br.postPage(downloadLink.getDownloadURL(),"String_Node_Str" + code + "String_Node_Str");
    if (!br.getURL().contains("String_Node_Str"))     continue;
    break;
  }
  if (!br.getURL().contains("String_Node_Str"))   throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
  dllink=br.getRegex("String_Node_Str").getMatch(0);
  if (dllink == null)   dllink=br.getRegex("String_Node_Str").getMatch(0);
  if (dllink == null)   throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
  String ttt=br.getRegex("String_Node_Str").getMatch(0);
  int tt=60;
  if (ttt != null) {
    logger.info("String_Node_Str" + ttt.trim() + "String_Node_Str");
    if (Integer.parseInt(ttt) < 100)     tt=Integer.parseInt(ttt);
  }
  sleep(tt * 1001,downloadLink);
  dllink="String_Node_Str" + dllink;
  dl=jd.plugins.BrowserAdapter.openDownload(br,downloadLink,dllink,true,0);
  if (dl.getConnection().getContentType().contains("String_Node_Str")) {
    br.followConnection();
    if (br.containsHTML("String_Node_Str"))     throw new PluginException(LinkStatus.ERROR_FILE_NOT_FOUND);
    throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
  }
  dl.startDownload();
}