Program: 11969
Project: 11969
Buggy source:
public void handle(String target,Request baseRequest,HttpServletRequest request,HttpServletResponse response) throws IOException, ServletException {
  String requestPath=request.getPathInfo().substring(1);
  String urlParam=(request.getParameter("String_Node_Str") != null) ? request.getParameter("String_Node_Str") : requestPath;
  if (urlParam.isEmpty() && requestPath.isEmpty()) {
    writeWelcome(baseRequest,response,requestPath);
    return;
  }
 else   if (requestPath.startsWith("String_Node_Str") || requestPath.startsWith("String_Node_Str")) {
    FetchResult result=null;
    try {
      result=HighLevelSimpleClientInterface.fetchURI(new FreenetURI(requestPath));
    }
 catch (    MalformedURLException e) {
      writeError(baseRequest,response,requestPath);
      return;
    }
catch (    FetchException e) {
      if (e.getMode() == FetchExceptionMode.PERMANENT_REDIRECT) {
        String newURI="String_Node_Str".concat(e.newURI.toString());
        response.sendRedirect(newURI);
      }
 else       if (e.isDNF()) {
        JSONObject jsonResponse=new JSONObject();
        response.setStatus(HttpServletResponse.SC_NOT_FOUND);
        jsonResponse.put("String_Node_Str","String_Node_Str");
        response.setContentType("String_Node_Str");
        response.getOutputStream().println(jsonResponse.toJSONString());
        baseRequest.setHandled(true);
        return;
      }
 else {
        e.printStackTrace();
        writeError(baseRequest,response,requestPath);
        return;
      }
    }
    if (result != null) {
      Bundle bundle=new Bundle(urlParam);
      bundle.setContent(result.asByteArray());
      response.setContentType(result.getMimeType());
      response.setStatus(HttpServletResponse.SC_OK);
      response.setContentType("String_Node_Str");
      JSONObject jsonResponse=new JSONObject();
      jsonResponse.put("String_Node_Str","String_Node_Str");
      jsonResponse.put("String_Node_Str",bundle.getContent());
      response.getOutputStream().println(jsonResponse.toJSONString());
    }
 else {
      writeError(baseRequest,response,requestPath);
    }
  }
 else {
    FreenetURI calculatedUSK=null;
    try {
      calculatedUSK=computeUSKfromURL(urlParam);
    }
 catch (    Exception e) {
      writeError(baseRequest,response,requestPath);
      return;
    }
    response.sendRedirect("String_Node_Str" + calculatedUSK.toString());
    baseRequest.setHandled(true);
  }
}

Fixed version (ground truth):
public void handle(String target,Request baseRequest,HttpServletRequest request,HttpServletResponse response) throws IOException, ServletException {
  String requestPath=request.getPathInfo().substring(1);
  String urlParam=(request.getParameter("String_Node_Str") != null) ? request.getParameter("String_Node_Str") : requestPath;
  if (urlParam.isEmpty() && requestPath.isEmpty()) {
    writeWelcome(baseRequest,response,requestPath);
  }
 else   if (requestPath.startsWith("String_Node_Str") || requestPath.startsWith("String_Node_Str")) {
    FetchResult result=null;
    try {
      result=HighLevelSimpleClientInterface.fetchURI(new FreenetURI(requestPath));
    }
 catch (    MalformedURLException e) {
      writeError(baseRequest,response,requestPath);
      return;
    }
catch (    FetchException e) {
      if (e.getMode() == FetchExceptionMode.PERMANENT_REDIRECT) {
        String newURI="String_Node_Str".concat(e.newURI.toString());
        response.sendRedirect(newURI);
      }
 else       if (e.isDNF()) {
        JSONObject jsonResponse=new JSONObject();
        jsonResponse.put("String_Node_Str","String_Node_Str");
        response.setStatus(HttpServletResponse.SC_NOT_FOUND);
        response.setContentType("String_Node_Str");
        response.getWriter().print(jsonResponse.toJSONString());
        baseRequest.setHandled(true);
        return;
      }
 else {
        e.printStackTrace();
        writeError(baseRequest,response,requestPath);
        return;
      }
    }
    if (result != null) {
      Bundle bundle=new Bundle(urlParam);
      bundle.setContent(result.asByteArray());
      response.setContentType(result.getMimeType());
      response.setStatus(HttpServletResponse.SC_OK);
      response.setContentType("String_Node_Str");
      JSONObject jsonResponse=new JSONObject();
      jsonResponse.put("String_Node_Str","String_Node_Str");
      jsonResponse.put("String_Node_Str",bundle.getContent());
      response.getWriter().print(jsonResponse.toJSONString());
      baseRequest.setHandled(true);
      return;
    }
 else {
      writeError(baseRequest,response,requestPath);
    }
  }
 else   if (requestPath.equals("String_Node_Str")) {
    writeNotFound(baseRequest,response,requestPath);
  }
 else {
    FreenetURI calculatedUSK=null;
    try {
      calculatedUSK=computeUSKfromURL(urlParam);
    }
 catch (    Exception e) {
      writeError(baseRequest,response,requestPath);
      return;
    }
    response.sendRedirect("String_Node_Str" + calculatedUSK.toString());
    baseRequest.setHandled(true);
  }
}