Notifications error for deleted users

[Marc Farré]

When a user of a conversation is deleted, I get the following error in the log:

Could not send notification e-mail to: deleted-3198. Error:foreach()
argument must be of type array|object, null given
in
/var/www/humhub/protected/modules/mail/models/MessageNotification.php:63
in
/var/www/humhub/protected/modules/mail/models/MessageNotification.php:44
in
/var/www/humhub/protected/modules/mail/models/MessageEntry.php:51

$_POST = [
'ReplyForm' => [
'message' => 'The message'
]
]

'REQUEST_URI' => '/mail/mail/reply?id=4699'

Perhaps, in Message::getUsers() (here) we could add:

->where(['user.status' => User::STATUS_ENABLED])

But I'm not quite sure if it solves the bug, as the error is foreach() argument must be of type array|object, null given. I don't understand why. It seams to be in MessageNotification::notifyAll() (here) that $this->message->users is returning null instead of an array.
I've checked in the DB, and I have 5 active users for this conversion and 1 deleted user.

[Yuriy Bakhtin]

@luke- @marc-farre Fixed in PR #359, the problem was in that a deleted user has email === NULL but the method yii\symfonymailer\Message::setTo() exptects array or string.

[Marc Farré]

@yurabakhtin Thanks!