message: Prevent a crash due to heap OOB write in grappler.
diff: @@ -1128,7 +1128,12 @@ class SymbolicShapeRefiner {
  GetUnknownOutputShape(node, output_port);
  InferenceContext* ctx = GetContext(node);
  if (ctx == nullptr) {
  - return errors::InvalidArgument("Missing context");
  + return errors::InvalidArgument("SetUnknownShape: Missing context");
  + }
  + if (output_port < 0 || output_port >= ctx->num_outputs()) {
  + return errors::InvalidArgument(
  + "SetUnknownShape: output_port must be in [0, ", ctx->num_outputs(),
  + ") but was ", output_port);
  }
  ctx->set_output(output_port, shape);
  return Status::OK();
  