Segmentation fault

[RootYQ]

类定义:

class Foo
{
    protected $relations = [];

    protected $name = 2;

    /**
     * Set the specific relationship in the model.
     *
     * @param  string  $relation
     * @param  mixed  $value
     * @return $this
     */
    public function setRelation($relation, $value)
    {
        $this->relations[$relation] = $value;

        return $this;
    }
}

序列化方法

function encode($result)
{
      $stream = new BytesIO();
      $writer = new Writer($stream, false);
      $stream->write(Tags::TagResult);
      if (0 === ResultMode::Serialized) {
          $stream->write($result);
      }
      else {
          $writer->reset();
          $writer->serialize($result);
       }

      $data = $stream->toString();

      return $data;
}

调用:

$foo = new Foo();
$foo_2 = new Foo();
$foo->setRelation('sublabel', [$foo_2]);
var_dump(encode($foo));

会触发Segmentation fault, 调试了一下,里面的循环会影响到外面循环的nInternalPointer, 没再继续研究, 求助大佬帮忙看一下……^_^
(环境: php: 7.1.6, hprose: master版本也可以复现)