message: fix: Guard for invalid input to `fill` helper method
diff: @@ -412,6 +412,7 @@ function isSameStacktrace(stack1, stack2) {
  * @param track {optional} record instrumentation to an array
  */
  function fill(obj, name, replacement, track) {
  + if (obj == null) return;
  var orig = obj[name];
  obj[name] = replacement(orig);
  obj[name].__raven__ = true;
  