Program: 39599
Project: 39599
Buggy source:
public void queryStockByQuote(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
  User userTmp=getUser() == null ? userMgr.random() : getUser();
  String twUserName=(String)request.getParameter(QUOTE);
  twUserName=new String(twUserName.getBytes("String_Node_Str"),"String_Node_Str");
  if (twUserName != null && twUserName.length() > 0) {
    request.setAttribute(QUOTE,twUserName);
    TwitterProxy twitterProxy=null;
    Response resp=Response.create();
    twitterProxy=twitterProxyFactory.create(userTmp.getOauthToken(),userTmp.getOauthTokenSecret());
    SimpleTwitterUser twUser=null;
    ArrayList<SimpleTwitterUser> searchResultList=new ArrayList<SimpleTwitterUser>();
    if (twitterProxy != null) {
      try {
        twitter4j.User twitterUser=null;
        if (Util.isValidTwitterUserName(twUserName)) {
          twitterUser=twitterProxy.getTwUser(twUserName);
          if (twitterUser != null) {
            twUser=new SimpleTwitterUser(twitterUser);
          }
        }
        searchResultList=twitterProxy.searchUsers(twUserName);
        if (twUser == null) {
          if (searchResultList != null && searchResultList.size() > 0) {
            twUser=searchResultList.get(0);
            searchResultList.remove(0);
          }
        }
 else         if (searchResultList.size() > 0 && twUser.getScreenName().equalsIgnoreCase(searchResultList.get(0).getScreenName())) {
          searchResultList.remove(0);
        }
        request.setAttribute(OTHER_SEARCH_RESULTS,searchResultList);
      }
 catch (      TwitterException e1) {
        resp.fail().reason("String_Node_Str");
        return;
      }
      Stock stock=null;
      if (twUser != null) {
        stock=stockMgr.getStockById(twUser.getId());
        if (stock == null) {
          logger.debug("String_Node_Str" + twUserName);
          stock=new Stock();
          stock.setId(twUser.getId());
          stock.setName(twUser.getScreenName());
          stock.setTotal(twUser.getFollowerCount());
          stock.setPictureUrl(twUser.getPictureUrl());
          stock.setSold(0.0D);
          stock.setVerified(twUser.isVerified());
          stockMgr.saveStock(stock);
        }
 else {
          stockMgr.updateTwitterData(stock.getId(),twUser.getFollowerCount(),twUser.getPictureUrl(),twUser.getScreenName(),twUser.isVerified());
        }
        request.setAttribute(STOCK,stock);
        logger.debug("String_Node_Str" + stock.getName());
      }
 else {
        logger.error("String_Node_Str" + twUserName);
        request.setAttribute(RESULT,USER_NOT_FOUND);
        request.setAttribute(REASON,twUserName + "String_Node_Str");
      }
    }
 else {
      logger.error("String_Node_Str" + twUserName);
      resp.fail().reason("String_Node_Str");
    }
  }
}

Fixed version (ground truth):
public void queryStockByQuote(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
  User userTmp=(User)request.getAttribute(User.USER) == null ? userMgr.random() : (User)request.getAttribute(User.USER);
  String twUserName=(String)request.getParameter(QUOTE);
  twUserName=new String(twUserName.getBytes("String_Node_Str"),"String_Node_Str");
  if (twUserName != null && twUserName.length() > 0) {
    request.setAttribute(QUOTE,twUserName);
    TwitterProxy twitterProxy=null;
    Response resp=Response.create();
    twitterProxy=twitterProxyFactory.create(userTmp.getOauthToken(),userTmp.getOauthTokenSecret());
    SimpleTwitterUser twUser=null;
    ArrayList<SimpleTwitterUser> searchResultList=new ArrayList<SimpleTwitterUser>();
    if (twitterProxy != null) {
      try {
        twitter4j.User twitterUser=null;
        if (Util.isValidTwitterUserName(twUserName)) {
          twitterUser=twitterProxy.getTwUser(twUserName);
          if (twitterUser != null) {
            twUser=new SimpleTwitterUser(twitterUser);
          }
        }
        searchResultList=twitterProxy.searchUsers(twUserName);
        if (twUser == null) {
          if (searchResultList != null && searchResultList.size() > 0) {
            twUser=searchResultList.get(0);
            searchResultList.remove(0);
          }
        }
 else         if (searchResultList.size() > 0 && twUser.getScreenName().equalsIgnoreCase(searchResultList.get(0).getScreenName())) {
          searchResultList.remove(0);
        }
        request.setAttribute(OTHER_SEARCH_RESULTS,searchResultList);
      }
 catch (      TwitterException e1) {
        resp.fail().reason("String_Node_Str");
        return;
      }
      Stock stock=null;
      if (twUser != null) {
        stock=stockMgr.getStockById(twUser.getId());
        if (stock == null) {
          logger.debug("String_Node_Str" + twUserName);
          stock=new Stock();
          stock.setId(twUser.getId());
          stock.setName(twUser.getScreenName());
          stock.setTotal(twUser.getFollowerCount());
          stock.setPictureUrl(twUser.getPictureUrl());
          stock.setSold(0.0D);
          stock.setVerified(twUser.isVerified());
          stockMgr.saveStock(stock);
        }
 else {
          stockMgr.updateTwitterData(stock.getId(),twUser.getFollowerCount(),twUser.getPictureUrl(),twUser.getScreenName(),twUser.isVerified());
        }
        request.setAttribute(STOCK,stock);
        logger.debug("String_Node_Str" + stock.getName());
      }
 else {
        logger.error("String_Node_Str" + twUserName);
        request.setAttribute(RESULT,USER_NOT_FOUND);
        request.setAttribute(REASON,twUserName + "String_Node_Str");
      }
    }
 else {
      logger.error("String_Node_Str" + twUserName);
      resp.fail().reason("String_Node_Str");
    }
  }
}