Program: 10108
Project: 10108
Buggy source:
@Override @SuppressWarnings("String_Node_Str") public void run(){
  while (true) {
    int newTopic;
    try {
      newTopic=newTopics.take();
    }
 catch (    InterruptedException e) {
      continue;
    }
    String lastMod=null;
    Topic oldTopic=topics.get(newTopic);
    if (oldTopic != null) {
      oldTopic.lock.readLock().lock();
      lastMod=oldTopic.getLastMod();
      oldTopic.lock.readLock().unlock();
    }
    long startTime=DateTime.now().getMillis();
    Topic topic;
    try {
      topic=sourceBoard.getThread(newTopic,lastMod);
    }
 catch (    HttpGetException e) {
      if (e.getHttpStatus() == 304) {
        pingTopic(oldTopic);
        debug(TALK,newTopic + "String_Node_Str");
        continue;
      }
 else       if (e.getHttpStatus() == 404) {
        if (oldTopic != null) {
          oldTopic.lock.writeLock().lock();
          if (oldTopic.getLastPage() < pageLimbo) {
            if (oldTopic.getAllPosts().size() > 1) {
              int op=oldTopic.getAllPosts().iterator().next();
              try {
                deletedPosts.put(op);
              }
 catch (              InterruptedException e1) {
              }
            }
            topicUpdates.add(oldTopic);
            debug(TALK,newTopic + "String_Node_Str" + oldTopic.getLastPage()+ "String_Node_Str");
          }
          topics.remove(newTopic);
          oldTopic.lock.writeLock().unlock();
        }
        continue;
      }
 else {
        pingTopic(oldTopic);
        debug(WARN,newTopic + "String_Node_Str" + e.getMessage());
        continue;
      }
    }
catch (    ContentGetException e) {
      pingTopic(oldTopic);
      debug(WARN,newTopic + "String_Node_Str" + e.getMessage());
      continue;
    }
catch (    ContentParseException e) {
      pingTopic(oldTopic);
      debug(ERROR,newTopic + "String_Node_Str" + e.getMessage());
      continue;
    }
    if (topic == null) {
      pingTopic(oldTopic);
      debug(WARN,newTopic + "String_Node_Str");
      continue;
    }
    topic.setLastHit(startTime);
    topic.lock.writeLock().lock();
    if (oldTopic != null) {
      oldTopic.lock.writeLock().lock();
      if (oldTopic.getLastHit() > startTime) {
        debug(ERROR,"String_Node_Str" + oldTopic.getNum());
        oldTopic.lock.writeLock().unlock();
        topic.lock.readLock().unlock();
        continue;
      }
      findDeleted(oldTopic,topic,true);
      topic.setLastPage(oldTopic.getLastPage());
      topic.setLastModTimestamp(oldTopic.getLastModTimestamp());
      topics.put(newTopic,topic);
      oldTopic.lock.writeLock().unlock();
    }
 else {
      topics.put(newTopic,topic);
    }
    topicUpdates.add(topic);
    topic.lock.writeLock().unlock();
    debug(TALK,newTopic + "String_Node_Str" + (oldTopic != null ? "String_Node_Str" : "String_Node_Str"));
  }
}

Fixed version (ground truth):
@Override @SuppressWarnings("String_Node_Str") public void run(){
  while (true) {
    int newTopic;
    try {
      newTopic=newTopics.take();
    }
 catch (    InterruptedException e) {
      continue;
    }
    String lastMod=null;
    Topic oldTopic=topics.get(newTopic);
    if (oldTopic != null) {
      oldTopic.lock.readLock().lock();
      lastMod=oldTopic.getLastMod();
      oldTopic.lock.readLock().unlock();
    }
    long startTime=DateTime.now().getMillis();
    Topic topic;
    try {
      topic=sourceBoard.getThread(newTopic,lastMod);
    }
 catch (    HttpGetException e) {
      if (e.getHttpStatus() == 304) {
        pingTopic(oldTopic);
        debug(TALK,newTopic + "String_Node_Str");
        continue;
      }
 else       if (e.getHttpStatus() == 404) {
        if (oldTopic != null) {
          oldTopic.lock.writeLock().lock();
          if (oldTopic.getLastPage() < pageLimbo) {
            if (oldTopic.getAllPosts().size() > 1) {
              int op=oldTopic.getAllPosts().iterator().next();
              try {
                deletedPosts.put(op);
              }
 catch (              InterruptedException e1) {
              }
            }
            topicUpdates.add(oldTopic);
            debug(TALK,newTopic + "String_Node_Str" + oldTopic.getLastPage()+ "String_Node_Str");
          }
          topics.remove(newTopic);
          oldTopic.lock.writeLock().unlock();
        }
        continue;
      }
 else {
        pingTopic(oldTopic);
        debug(WARN,newTopic + "String_Node_Str" + e.getMessage());
        continue;
      }
    }
catch (    ContentGetException e) {
      pingTopic(oldTopic);
      debug(WARN,newTopic + "String_Node_Str" + e.getMessage());
      continue;
    }
catch (    ContentParseException e) {
      pingTopic(oldTopic);
      debug(ERROR,newTopic + "String_Node_Str" + e.getMessage());
      continue;
    }
    if (topic == null) {
      pingTopic(oldTopic);
      debug(WARN,newTopic + "String_Node_Str");
      continue;
    }
    topic.setLastHit(startTime);
    topic.lock.writeLock().lock();
    if (oldTopic != null) {
      oldTopic.lock.writeLock().lock();
      if (oldTopic.getLastHit() > startTime) {
        debug(ERROR,"String_Node_Str" + oldTopic.getNum());
        oldTopic.lock.writeLock().unlock();
        topic.lock.readLock().unlock();
        continue;
      }
      findDeleted(oldTopic,topic,true);
      topic.setLastPage(oldTopic.getLastPage());
      topic.setLastModTimestamp(oldTopic.getLastModTimestamp());
      topics.put(newTopic,topic);
      oldTopic.lock.writeLock().unlock();
    }
 else {
      topics.put(newTopic,topic);
    }
    topicUpdates.add(topic);
    topic.lock.writeLock().unlock();
    debug(TALK,newTopic + "String_Node_Str" + ((oldTopic != null && oldTopic.getLastMod() != null) ? "String_Node_Str" : "String_Node_Str"));
  }
}