Program: 3219
Project: 3219
Buggy source:
/** 
 * Start the authentication process. This packages up the request that led to authentication being required, and then invokes the site-specific authentication method. If it returns true, the user was authenticated without any redirection (e.g. by an X.509 certificate or other implicit method) so the process that called this can continue and send its own response. A "false" result means this method has sent its own redirect.
 * @param context current DSpace context
 * @param request current HTTP request - the one that prompted authentication
 * @param response current HTTP response
 * @return true if authentication is already finished (implicit method)
 */
public static boolean startAuthentication(Context context,HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
  HttpSession session=request.getSession();
  if (AuthenticationManager.authenticateImplicit(context,null,null,null,request) == AuthenticationMethod.SUCCESS) {
    loggedIn(context,request,context.getCurrentUser());
    log.info(LogManager.getHeader(context,"String_Node_Str","String_Node_Str"));
    return true;
  }
 else {
    response.addDateHeader("String_Node_Str",1);
    response.addHeader("String_Node_Str","String_Node_Str");
    response.addHeader("String_Node_Str","String_Node_Str");
    RequestInfo info=new RequestInfo(request);
    session.setAttribute("String_Node_Str",info);
    session.setAttribute("String_Node_Str",UIUtil.getOriginalURL(request));
    Iterator ai=AuthenticationManager.authenticationMethodIterator();
    AuthenticationMethod am;
    int count=0;
    String url=null;
    while (ai.hasNext()) {
      String s;
      am=(AuthenticationMethod)ai.next();
      s=am.loginPageURL(context,request,response);
      if (s != null) {
        url=s;
        ++count;
      }
    }
    if (count == 1) {
      response.sendRedirect(url);
    }
 else {
      JSPManager.showJSP(request,response,"String_Node_Str");
    }
  }
  return false;
}

Fixed version (ground truth):
/** 
 * Start the authentication process. This packages up the request that led to authentication being required, and then invokes the site-specific authentication method. If it returns true, the user was authenticated without any redirection (e.g. by an X.509 certificate or other implicit method) so the process that called this can continue and send its own response. A "false" result means this method has sent its own redirect.
 * @param context current DSpace context
 * @param request current HTTP request - the one that prompted authentication
 * @param response current HTTP response
 * @return true if authentication is already finished (implicit method)
 */
public static boolean startAuthentication(Context context,HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
  HttpSession session=request.getSession();
  if (AuthenticationManager.authenticateImplicit(context,null,null,null,request) == AuthenticationMethod.SUCCESS) {
    loggedIn(context,request,context.getCurrentUser());
    log.info(LogManager.getHeader(context,"String_Node_Str","String_Node_Str"));
    if (context.getCurrentUser() != null) {
      Authenticate.resumeInterruptedRequest(request,response);
      return false;
    }
 else {
      return true;
    }
  }
 else {
    response.addDateHeader("String_Node_Str",1);
    response.addHeader("String_Node_Str","String_Node_Str");
    response.addHeader("String_Node_Str","String_Node_Str");
    RequestInfo info=new RequestInfo(request);
    session.setAttribute("String_Node_Str",info);
    session.setAttribute("String_Node_Str",UIUtil.getOriginalURL(request));
    Iterator ai=AuthenticationManager.authenticationMethodIterator();
    AuthenticationMethod am;
    int count=0;
    String url=null;
    while (ai.hasNext()) {
      String s;
      am=(AuthenticationMethod)ai.next();
      s=am.loginPageURL(context,request,response);
      if (s != null) {
        url=s;
        ++count;
      }
    }
    if (count == 1) {
      response.sendRedirect(url);
    }
 else {
      JSPManager.showJSP(request,response,"String_Node_Str");
    }
  }
  return false;
}