Symfony2 user switch missing ROLE_PREVIOUS_ADMIN after switch - php

Question

When I switch as admin to a user site.loc/?_switch_user=user#email.com I don't get the role ROLE_PREVIOUS_ADMIN.
I'm not sure which code I should show you..
Symfony Version: symfony2 2.2.2
User.php
/**
* #see \Serializable::serialize()
*/
public function serialize()
{
return serialize(array(
$this->email
));
}
/**
* #see \Serializable::unserialize()
*/
public function unserialize($serialized)
{
list (
$this->email
) = unserialize($serialized);
}
public function isAccountNonExpired()
{
return true;
}
public function isAccountNonLocked()
{
return true;
}
public function isCredentialsNonExpired()
{
return true;
}
public function isEnabled()
{
return $this->isActive;
}
/**
* #inheritDoc
*/
public function eraseCredentials()
{
}
public function isEqualTo(UserInterface $user)
{
return
md5($user->getUsername()) == md5($this->getUsername()) &&
md5(serialize($user->getGroups())) == md5(serialize($this->getGroups()));
}

Answer 1

You should implement EquatableInterface for User class:
class User implements UserInterface, EquatableInterface, \Serializable {
// ...
public function isEqualTo(UserInterface $user) {
return $this->username === $user->getUsername();
}
public function serialize() {
return serialize(array(
$this->id,
$this->username,
));
}
public function unserialize($serialized) {
list($this->id, $this->username) = unserialize($serialized);
}
// ...
}