anchor.diff:      }
   
       if (rebuildIndex) {
  -        archiveIndexer.rebuildIndex();
  +        if (archiveIndexer.rebuildIndex() == null) {
  +            errors.put("rebuildIndex", "");
  +            errorMessage = "Archive Index rebuild failed.";
  +        }
       }
   
       // Update the session kick policy if requested
  -    Map errors = new HashMap();
  -    String errorMessage = "";
       if (update) {
           // New settings for message archiving.
           boolean metadataArchiving = request.getParameter("metadataArchiving") != null;
  
positive.code:         else {
              var rebuildProgress = document.getElementById('rebuildProgress');
              rebuildProgress.innerHTML = "100";
              Effect.Fade('rebuildElement');
          }
      }
  </script>
  
negative.code:     Cookie csrfCookie = CookieUtils.getCookie(request, "csrf");
      String csrfParam = ParamUtils.getParameter(request, "csrf");
  
      Map errors = new HashMap();
      String errorMessage = "";
  
      if (csrfCookie == null || csrfParam == null || !csrfCookie.getValue().equals(csrfParam)) {
          rebuildIndex = false;
          update = false;
          errors.put("csrf", "");
          errorMessage = "Archive Index rebuild failed.";
      }
      csrfParam = StringUtils.randomString(16);
      CookieUtils.setCookie(request, response, "csrf", csrfParam, -1);
  