message: Fix bug introduced in
  Potentially invalid pointers passed to GraphConstructor::Construct()
diff: @@ -1068,11 +1068,17 @@ Status ImportGraphDef(const ImportGraphDefOptions& opts, const GraphDef& gdef,
  refiner->set_graph_def_version(
  std::min(refiner->graph_def_version(), gdef.versions().producer()));
  + if (results == nullptr) {
  + return GraphConstructor::Construct(opts, gdef.node(), &gdef.versions(),
  + &gdef.library(), g, refiner, nullptr,
  + nullptr, nullptr);
  + } else {
  return GraphConstructor::Construct(
  opts, gdef.node(), &gdef.versions(), &gdef.library(), g, refiner,
  &results->return_tensors, &results->return_nodes,
  &results->unused_input_map_keys);
  }
  +}
  void CopyGraph(const Graph& src, Graph* dest) {
  for (Node* n : dest->nodes()) {
  