anchor.diff:    var lineIndex = null;
     var classPathSpaceMethodIdIndex = null;
     var methodIdIndex = null;
  +
  +  if (groups.length === 0) {
  +    $("#allocations thead").empty();
  +    $("#allocations tbody").empty();
  +    $("#allocations-row-count").text("0 rows");
  +    if (allocations.length > 0) {
  +      $("#allocations-row-count").text("0 rows (all of the original " + allocations.length + " allocations have been filtered out.)");
  +    }
  +    return;
  +  }
  +
     for (i in headers) {
       /* i is not an integer; the first i plus 1 is "01" */
       if (headers[i] === "file" && headers[i*1 + 1] === "line") {
  
positive.code:   if ($("#filter-pwd")[0].checked) {
      filtered = filterOutPwd(filtered);
    }
    if ($("#filter-ruby")[0].checked) {
      filtered = filterOutRuby(filtered);
    }
    if ($("#filter-eval")[0].checked) {
      filtered = filterOutEval(filtered);
    }
  
negative.code:  });
  }
  
  function filterOutGems(filtered) {
   return $.grep(filtered, function(a) {
     var r = new RegExp("<GEMDIR>");
     return r.exec(a["file"]) === null;
   });
  }
  
  function filterOutEval(filtered) {
   return $.grep(filtered, function(a) {
     return a["file"] !== "(eval)";
  