code: function copyArrayIgnoringAttributesWithoutValue(dst, src)
  {
    if (!src) return;
    for (var i = src.length - 1; i >= 0; --i) {
      // this test will pass so long as the attribute has a non-empty string
      // value, even if that value is "false", "0", "undefined", etc.
      if (src[i].nodeValue) {
        dst.push(src[i]);
      }
    }
  }
docs: This is an optimization for copying attribute lists in IE. IE includes many
  extraneous properties in its DOM attribute lists, which take require
  significant extra processing when evaluating attribute steps. With this
  function, we ignore any such attributes that has an empty string value.