Segmentation fault

[jekhy]

Hi~ I found a Segmentation fault when I 'clone' a obj:

// Proto file
message Hero {
optional int32 userId = 1;
}
message User {
optional Hero heroes = 1;
}

// PHP code
$user = new User();
$hero = new Hero();
$anotherHero = clone $hero;
$anotherHero->setUserId(1);
$user->appendHeroes($hero); // Segmentation fault

my PHP version IS 5.4.13.