Program: 170802
Project: 170802
Buggy source:
public void addDownload(final Download download){
  Torrent torrent=download.getTorrent();
  boolean is_decentralised=false;
  if (torrent != null) {
    is_decentralised=TorrentUtils.isDecentralised(torrent.getAnnounceURL());
  }
  if (download.getFlag(Download.FLAG_LOW_NOISE) && !is_decentralised) {
    return;
  }
  if (track_only_decentralsed) {
    if (torrent != null) {
      if (!is_decentralised) {
        return;
      }
    }
  }
  if (is_running) {
    String[] networks=download.getListAttribute(ta_networks);
    if (torrent != null && networks != null) {
      boolean public_net=false;
      for (int i=0; i < networks.length; i++) {
        if (networks[i].equalsIgnoreCase("String_Node_Str")) {
          public_net=true;
          break;
        }
      }
      if (public_net && !torrent.isPrivate()) {
        boolean our_download=torrent.wasCreatedByUs();
        long delay;
        if (our_download) {
          if (download.getCreationTime() > start_time) {
            delay=0;
          }
 else {
            delay=plugin_interface.getUtilities().getCurrentSystemTime() + INTERESTING_INIT_MIN_OURS + random.nextInt(INTERESTING_INIT_RAND_OURS);
          }
        }
 else {
          int min;
          int rand;
          if (TorrentUtils.isDecentralised(torrent.getAnnounceURL())) {
            min=INTERESTING_DHT_INIT_MIN;
            rand=INTERESTING_DHT_INIT_RAND;
          }
 else {
            min=INTERESTING_INIT_MIN_OTHERS;
            rand=INTERESTING_INIT_RAND_OTHERS;
          }
          delay=plugin_interface.getUtilities().getCurrentSystemTime() + min + random.nextInt(rand);
        }
        try {
          this_mon.enter();
          interesting_downloads.put(download,new Long(delay));
        }
  finally {
          this_mon.exit();
        }
      }
    }
    download.addAttributeListener(DHTTrackerPlugin.this,ta_networks,DownloadAttributeListener.WRITTEN);
    download.addAttributeListener(DHTTrackerPlugin.this,ta_peer_sources,DownloadAttributeListener.WRITTEN);
    download.addTrackerListener(DHTTrackerPlugin.this);
    download.addListener(DHTTrackerPlugin.this);
    checkDownloadForRegistration(download,true);
  }
 else {
    if (torrent != null && torrent.isDecentralised()) {
      download.addListener(new DownloadListener(){
        @Override public void stateChanged(        final Download download,        int old_state,        int new_state){
          int state=download.getState();
          if (state == Download.ST_DOWNLOADING || state == Download.ST_SEEDING) {
            download.setAnnounceResult(new DownloadAnnounceResult(){
              @Override public Download getDownload(){
                return (download);
              }
              @Override public int getResponseType(){
                return (DownloadAnnounceResult.RT_ERROR);
              }
              @Override public int getReportedPeerCount(){
                return (0);
              }
              @Override public int getSeedCount(){
                return (0);
              }
              @Override public int getNonSeedCount(){
                return (0);
              }
              @Override public String getError(){
                return ("String_Node_Str");
              }
              @Override public URL getURL(){
                return (download.getTorrent().getAnnounceURL());
              }
              @Override public DownloadAnnounceResultPeer[] getPeers(){
                return (new DownloadAnnounceResultPeer[0]);
              }
              @Override public long getTimeToWait(){
                return (0);
              }
              @Override public Map getExtensions(){
                return (null);
              }
            }
);
          }
        }
        @Override public void positionChanged(        Download download,        int oldPosition,        int newPosition){
        }
      }
);
      download.setScrapeResult(new DownloadScrapeResult(){
        @Override public Download getDownload(){
          return (download);
        }
        @Override public int getResponseType(){
          return (DownloadScrapeResult.RT_ERROR);
        }
        @Override public int getSeedCount(){
          return (-1);
        }
        @Override public int getNonSeedCount(){
          return (-1);
        }
        @Override public long getScrapeStartTime(){
          return (SystemTime.getCurrentTime());
        }
        @Override public void setNextScrapeStartTime(        long nextScrapeStartTime){
        }
        @Override public long getNextScrapeStartTime(){
          return (-1);
        }
        @Override public String getStatus(){
          return ("String_Node_Str");
        }
        @Override public URL getURL(){
          return (download.getTorrent().getAnnounceURL());
        }
      }
);
    }
  }
}

Fixed version (ground truth):
public void addDownload(final Download download){
  Torrent torrent=download.getTorrent();
  boolean is_decentralised=false;
  URL announce_url=torrent.getAnnounceURL();
  if (torrent != null) {
    is_decentralised=TorrentUtils.isDecentralised(announce_url);
  }
  if (download.getFlag(Download.FLAG_LOW_NOISE) && !is_decentralised) {
    if (!announce_url.getHost().endsWith("String_Node_Str")) {
      return;
    }
  }
  if (track_only_decentralsed) {
    if (torrent != null) {
      if (!is_decentralised) {
        return;
      }
    }
  }
  if (is_running) {
    String[] networks=download.getListAttribute(ta_networks);
    if (torrent != null && networks != null) {
      boolean public_net=false;
      for (int i=0; i < networks.length; i++) {
        if (networks[i].equalsIgnoreCase("String_Node_Str")) {
          public_net=true;
          break;
        }
      }
      if (public_net && !torrent.isPrivate()) {
        boolean our_download=torrent.wasCreatedByUs();
        long delay;
        if (our_download) {
          if (download.getCreationTime() > start_time) {
            delay=0;
          }
 else {
            delay=plugin_interface.getUtilities().getCurrentSystemTime() + INTERESTING_INIT_MIN_OURS + random.nextInt(INTERESTING_INIT_RAND_OURS);
          }
        }
 else {
          int min;
          int rand;
          if (TorrentUtils.isDecentralised(torrent.getAnnounceURL())) {
            min=INTERESTING_DHT_INIT_MIN;
            rand=INTERESTING_DHT_INIT_RAND;
          }
 else {
            min=INTERESTING_INIT_MIN_OTHERS;
            rand=INTERESTING_INIT_RAND_OTHERS;
          }
          delay=plugin_interface.getUtilities().getCurrentSystemTime() + min + random.nextInt(rand);
        }
        try {
          this_mon.enter();
          interesting_downloads.put(download,new Long(delay));
        }
  finally {
          this_mon.exit();
        }
      }
    }
    download.addAttributeListener(DHTTrackerPlugin.this,ta_networks,DownloadAttributeListener.WRITTEN);
    download.addAttributeListener(DHTTrackerPlugin.this,ta_peer_sources,DownloadAttributeListener.WRITTEN);
    download.addTrackerListener(DHTTrackerPlugin.this);
    download.addListener(DHTTrackerPlugin.this);
    checkDownloadForRegistration(download,true);
  }
 else {
    if (torrent != null && torrent.isDecentralised()) {
      download.addListener(new DownloadListener(){
        @Override public void stateChanged(        final Download download,        int old_state,        int new_state){
          int state=download.getState();
          if (state == Download.ST_DOWNLOADING || state == Download.ST_SEEDING) {
            download.setAnnounceResult(new DownloadAnnounceResult(){
              @Override public Download getDownload(){
                return (download);
              }
              @Override public int getResponseType(){
                return (DownloadAnnounceResult.RT_ERROR);
              }
              @Override public int getReportedPeerCount(){
                return (0);
              }
              @Override public int getSeedCount(){
                return (0);
              }
              @Override public int getNonSeedCount(){
                return (0);
              }
              @Override public String getError(){
                return ("String_Node_Str");
              }
              @Override public URL getURL(){
                return (download.getTorrent().getAnnounceURL());
              }
              @Override public DownloadAnnounceResultPeer[] getPeers(){
                return (new DownloadAnnounceResultPeer[0]);
              }
              @Override public long getTimeToWait(){
                return (0);
              }
              @Override public Map getExtensions(){
                return (null);
              }
            }
);
          }
        }
        @Override public void positionChanged(        Download download,        int oldPosition,        int newPosition){
        }
      }
);
      download.setScrapeResult(new DownloadScrapeResult(){
        @Override public Download getDownload(){
          return (download);
        }
        @Override public int getResponseType(){
          return (DownloadScrapeResult.RT_ERROR);
        }
        @Override public int getSeedCount(){
          return (-1);
        }
        @Override public int getNonSeedCount(){
          return (-1);
        }
        @Override public long getScrapeStartTime(){
          return (SystemTime.getCurrentTime());
        }
        @Override public void setNextScrapeStartTime(        long nextScrapeStartTime){
        }
        @Override public long getNextScrapeStartTime(){
          return (-1);
        }
        @Override public String getStatus(){
          return ("String_Node_Str");
        }
        @Override public URL getURL(){
          return (download.getTorrent().getAnnounceURL());
        }
      }
);
    }
  }
}