Program: 35797
Project: 35797
Buggy source:
/** 
 * {@inheritDoc} javax.servlet.http.HttpServlet#service(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
 */
@Override protected void service(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
  String relUrl=request.getRequestURI();
  relUrl=relUrl.substring(request.getContextPath().length());
  if (request.getServletPath() != null) {
    relUrl=relUrl.substring(request.getServletPath().length());
  }
  for (  ReverseConfiguration conf : configuration) {
    Matcher m=conf.getMatchPattern().matcher(relUrl);
    if (m.matches()) {
      String originalQueryString=request.getQueryString();
      if (originalQueryString == null) {
        originalQueryString="String_Node_Str";
      }
      String newUrl=relUrl;
      if (conf.getRewrite() != null) {
        newUrl=conf.getRewrite();
      }
      String newQueryString="String_Node_Str";
      if (conf.getQueryRewrite() != null) {
        newQueryString=conf.getQueryRewrite();
      }
      newQueryString=newQueryString.replace("String_Node_Str",originalQueryString);
      for (int i=1; i < m.groupCount() + 1; i++) {
        newUrl=newUrl.replace("String_Node_Str" + i,m.group(i));
        newQueryString=newQueryString.replace("String_Node_Str" + i,m.group(i));
      }
      if (logger.isDebugEnabled()) {
        logger.debug("String_Node_Str" + relUrl + "String_Node_Str"+ newUrl+ "String_Node_Str"+ newQueryString);
      }
      try {
        DriverFactory.getInstance(conf.getProvider()).proxy(newUrl,new ReverseHttpRequest(request,newQueryString),response);
        return;
      }
 catch (      HttpErrorPage e) {
        throw new ServletException(e);
      }
    }
  }
}

Fixed version (ground truth):
/** 
 * {@inheritDoc} javax.servlet.http.HttpServlet#service(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
 */
@Override protected void service(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
  String relUrl=request.getRequestURI();
  relUrl=relUrl.substring(request.getContextPath().length());
  if (request.getServletPath() != null) {
    relUrl=relUrl.substring(request.getServletPath().length());
  }
  for (  ReverseConfiguration conf : configuration) {
    Matcher m=conf.getMatchPattern().matcher(relUrl);
    if (m.matches()) {
      String originalQueryString=request.getQueryString();
      if (originalQueryString == null) {
        originalQueryString="String_Node_Str";
      }
      String newUrl=relUrl;
      if (conf.getRewrite() != null) {
        newUrl=conf.getRewrite();
      }
      String newQueryString="String_Node_Str";
      if (conf.getQueryRewrite() != null) {
        newQueryString=conf.getQueryRewrite();
      }
      newQueryString=newQueryString.replace("String_Node_Str",originalQueryString);
      for (int i=1; i < m.groupCount() + 1; i++) {
        newUrl=newUrl.replace("String_Node_Str" + i,m.group(i));
        newQueryString=newQueryString.replace("String_Node_Str" + i,m.group(i));
      }
      if ("String_Node_Str".equals(newQueryString)) {
        newQueryString=null;
      }
      if (logger.isDebugEnabled()) {
        logger.debug("String_Node_Str" + relUrl + "String_Node_Str"+ newUrl+ "String_Node_Str"+ newQueryString);
      }
      try {
        DriverFactory.getInstance(conf.getProvider()).proxy(newUrl,new ReverseHttpRequest(request,newQueryString),response);
        return;
      }
 catch (      HttpErrorPage e) {
        throw new ServletException(e);
      }
    }
  }
}