Program: 20923
Project: 20923
Buggy source:
@Override public void handleFree(DownloadLink downloadLink) throws Exception {
  requestFileInformation(downloadLink);
  String dllink=null;
  String fileID=new Regex(downloadLink.getDownloadURL(),"String_Node_Str").getMatch(0);
  boolean isStream=br.containsHTML("String_Node_Str");
  if (!isStream) {
    Browser brc=requestXML(br,"String_Node_Str" + fileID,null,false);
    if (brc.containsHTML("String_Node_Str")) {
      String error=brc.getRegex("String_Node_Str").getMatch(0);
      if (error == null)       throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
      if (error.contains("String_Node_Str"))       throw new PluginException(LinkStatus.ERROR_IP_BLOCKED,5 * 60 * 1000l);
      if (error.contains("String_Node_Str"))       throw new PluginException(LinkStatus.ERROR_IP_BLOCKED,30 * 60 * 1000l);
      throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    }
    if (brc.containsHTML("String_Node_Str")) {
      int waitsecs=0;
      String waittime=brc.getRegex("String_Node_Str").getMatch(0);
      if (waittime != null)       waitsecs=Integer.parseInt(waittime);
      if (waitsecs > 0)       sleep(waitsecs * 1000l,downloadLink);
      dllink=brc.getRegex("String_Node_Str").getMatch(0);
    }
  }
 else {
    br.getPage("String_Node_Str" + fileID + "String_Node_Str");
    dllink=br.getRedirectLocation();
  }
  if (dllink == null)   throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
  br.setDebug(true);
  dl=jd.plugins.BrowserAdapter.openDownload(br,downloadLink,dllink,!isStream,1);
  if (!dl.getConnection().isContentDisposition()) {
    br.followConnection();
    throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
  }
  dl.startDownload();
}

Fixed version (ground truth):
@Override public void handleFree(DownloadLink downloadLink) throws Exception {
  requestFileInformation(downloadLink);
  String dllink=null;
  String fileID=new Regex(downloadLink.getDownloadURL(),"String_Node_Str").getMatch(0);
  boolean isStream=br.containsHTML("String_Node_Str");
  if (!isStream) {
    Browser brc=requestXML(br,"String_Node_Str" + fileID,null,false);
    if (brc.containsHTML("String_Node_Str")) {
      String error=brc.getRegex("String_Node_Str").getMatch(0);
      if (error == null)       throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
      if (error.contains("String_Node_Str"))       throw new PluginException(LinkStatus.ERROR_IP_BLOCKED,5 * 60 * 1000l);
      if (error.contains("String_Node_Str"))       throw new PluginException(LinkStatus.ERROR_IP_BLOCKED,30 * 60 * 1000l);
      throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
    }
    if (brc.containsHTML("String_Node_Str")) {
      int waitsecs=0;
      String waittime=brc.getRegex("String_Node_Str").getMatch(0);
      if (waittime != null)       waitsecs=Integer.parseInt(waittime);
      if (waitsecs > 0)       sleep(waitsecs * 1000l,downloadLink);
      dllink=brc.getRegex("String_Node_Str").getMatch(0);
    }
  }
 else {
    br.getPage("String_Node_Str" + fileID + "String_Node_Str");
    dllink=br.getRedirectLocation();
  }
  if (dllink == null)   throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
  if (!dllink.contains("String_Node_Str"))   dllink="String_Node_Str" + dllink;
  br.setDebug(true);
  dl=jd.plugins.BrowserAdapter.openDownload(br,downloadLink,dllink,!isStream,1);
  if (!dl.getConnection().isContentDisposition()) {
    br.followConnection();
    if (br.containsHTML("String_Node_Str"))     throw new PluginException(LinkStatus.ERROR_TEMPORARILY_UNAVAILABLE,"String_Node_Str");
    throw new PluginException(LinkStatus.ERROR_PLUGIN_DEFECT);
  }
  dl.startDownload();
}