Program: 93620
Project: 93620
Buggy source:
/** 
 * @param dbName
 * @param collName
 * @param content
 * @param etag
 * @param patching
 * @return the HttpStatus code to retrun
 */
public static int upsertCollection(String dbName,String collName,DBObject content,ObjectId etag,boolean updating,boolean patching){
  DB db=DBDAO.getDB(dbName);
  DBCollection coll=db.getCollection(collName);
  if (patching && !updating) {
    return HttpStatus.SC_NOT_FOUND;
  }
  if (updating) {
    if (etag == null) {
      logger.warn("String_Node_Str",Headers.ETAG);
      return HttpStatus.SC_PRECONDITION_FAILED;
    }
    BasicDBObject idAndEtagQuery=new BasicDBObject("String_Node_Str","String_Node_Str");
    idAndEtagQuery.append("String_Node_Str",etag);
    if (coll.count(idAndEtagQuery) < 1) {
      return HttpStatus.SC_PRECONDITION_FAILED;
    }
  }
  ObjectId timestamp=new ObjectId();
  Instant now=Instant.ofEpochSecond(timestamp.getTimestamp());
  if (content == null) {
    content=new BasicDBObject();
  }
  content.removeField("String_Node_Str");
  if (updating) {
    content.removeField("String_Node_Str");
    content.put("String_Node_Str",timestamp);
  }
 else {
    content.put("String_Node_Str","String_Node_Str");
    content.put("String_Node_Str",now.toString());
    content.put("String_Node_Str",timestamp);
  }
  if (patching) {
    coll.update(PROPS_QUERY,new BasicDBObject("String_Node_Str",content),true,false);
    return HttpStatus.SC_OK;
  }
 else {
    DBObject old=coll.findAndModify(PROPS_QUERY,fieldsToReturn,null,false,content,false,true);
    if (old != null) {
      Object oldTimestamp=old.get("String_Node_Str");
      if (oldTimestamp == null) {
        oldTimestamp=now.toString();
        logger.warn("String_Node_Str",coll.getFullName());
      }
      BasicDBObject createdContet=new BasicDBObject("String_Node_Str","String_Node_Str" + oldTimestamp);
      createdContet.markAsPartialObject();
      coll.update(PROPS_QUERY,new BasicDBObject("String_Node_Str",createdContet),true,false);
      return HttpStatus.SC_OK;
    }
 else {
      BasicDBObject createdContet=new BasicDBObject("String_Node_Str",now.toString());
      createdContet.markAsPartialObject();
      coll.update(PROPS_QUERY,new BasicDBObject("String_Node_Str",createdContet),true,false);
      initDefaultIndexes(coll);
      return HttpStatus.SC_CREATED;
    }
  }
}

Fixed version (ground truth):
/** 
 * @param dbName
 * @param collName
 * @param content
 * @param etag
 * @param updating
 * @param patching
 * @return the HttpStatus code to retrun
 */
public static int upsertCollection(String dbName,String collName,DBObject content,ObjectId etag,boolean updating,boolean patching){
  DB db=DBDAO.getDB(dbName);
  DBCollection coll=db.getCollection(collName);
  if (patching && !updating) {
    return HttpStatus.SC_NOT_FOUND;
  }
  if (updating) {
    if (etag == null) {
      return HttpStatus.SC_PRECONDITION_FAILED;
    }
    BasicDBObject idAndEtagQuery=new BasicDBObject("String_Node_Str","String_Node_Str");
    idAndEtagQuery.append("String_Node_Str",etag);
    if (coll.count(idAndEtagQuery) < 1) {
      return HttpStatus.SC_PRECONDITION_FAILED;
    }
  }
  ObjectId timestamp=new ObjectId();
  Instant now=Instant.ofEpochSecond(timestamp.getTimestamp());
  if (content == null) {
    content=new BasicDBObject();
  }
  content.removeField("String_Node_Str");
  if (updating) {
    content.removeField("String_Node_Str");
    content.put("String_Node_Str",timestamp);
  }
 else {
    content.put("String_Node_Str","String_Node_Str");
    content.put("String_Node_Str",now.toString());
    content.put("String_Node_Str",timestamp);
  }
  if (patching) {
    coll.update(PROPS_QUERY,new BasicDBObject("String_Node_Str",content),true,false);
    return HttpStatus.SC_OK;
  }
 else {
    DBObject old=coll.findAndModify(PROPS_QUERY,fieldsToReturn,null,false,content,false,true);
    if (old != null) {
      Object oldTimestamp=old.get("String_Node_Str");
      if (oldTimestamp == null) {
        oldTimestamp=now.toString();
        logger.warn("String_Node_Str",coll.getFullName());
      }
      BasicDBObject createdContet=new BasicDBObject("String_Node_Str","String_Node_Str" + oldTimestamp);
      createdContet.markAsPartialObject();
      coll.update(PROPS_QUERY,new BasicDBObject("String_Node_Str",createdContet),true,false);
      return HttpStatus.SC_OK;
    }
 else {
      BasicDBObject createdContet=new BasicDBObject("String_Node_Str",now.toString());
      createdContet.markAsPartialObject();
      coll.update(PROPS_QUERY,new BasicDBObject("String_Node_Str",createdContet),true,false);
      initDefaultIndexes(coll);
      return HttpStatus.SC_CREATED;
    }
  }
}