Active Record "insert_id" MySQL

[eluser]micha8l[/eluser]
I realised insert_id was returning 0 and I found out why.

Bad

Code:

if($this->db->affected_rows() > 0)
{
     $this->session->set_userdata(array('antispam_article' => $current_time));
     return $this->db->insert_id();
}

Bad

Code:

if($this->db->affected_rows() > 0)
{
     $insert_id = $this->db->insert_id();
     $this->session->set_userdata(array('antispam_article' => $current_time));
     return $insert_id;
}

Good

Code:

if($this->db->affected_rows() > 0)
{
     $insert_id = $this->db->insert_id();
     $this->session->set_userdata(array('antispam_article' => $current_time));
     return (string) $insert_id;
}

It seems when setting session data with CI's session -- database stored -- that it'll cause the db->insert_id() to always return a value of (int) 0. Additionally if you don't return the ID as a string it also evaluates to zero.

This is intended by CI?