can't login after upgrade

$base_url = 'http://domain.tld/forum'

// Login
if (isset($_POST['form_sent']) && empty($action))
{
    $form_username = forum_trim($_POST['req_username']);
    $form_password = forum_trim($_POST['req_password']);
    $save_pass = isset($_POST['save_pass']);

    ($hook = get_hook('li_login_form_submitted')) ? eval($hook) : null;

    // Get user info matching login attempt
    $query = array(
        'SELECT'    => 'u.id, u.group_id, u.password, u.salt',
        'FROM'        => 'users AS u'
    );

    if (in_array($db_type, array('mysql', 'mysqli', 'mysql_innodb', 'mysqli_innodb')))
        $query['WHERE'] = 'username=\''.$forum_db->escape($form_username).'\'';
    else
        $query['WHERE'] = 'LOWER(username)=LOWER(\''.$forum_db->escape($form_username).'\')';

    ($hook = get_hook('li_login_qr_get_login_data')) ? eval($hook) : null;
    $result = $forum_db->query_build($query) or error(__FILE__, __LINE__);
    list($user_id, $group_id, $db_password_hash, $salt) = $forum_db->fetch_row($result);

    $authorized = false;
    if (!empty($db_password_hash))
    {
        $sha1_in_db = (strlen($db_password_hash) == 40) ? true : false;
        $form_password_hash = forum_hash($form_password, $salt);

        if ($sha1_in_db && $db_password_hash == $form_password_hash)
            $authorized = true;
        else if ((!$sha1_in_db && $db_password_hash == md5($form_password)) || ($sha1_in_db && $db_password_hash == sha1($form_password)))
        {
            $authorized = true;

            $salt = random_key(12);
            $form_password_hash = forum_hash($form_password, $salt);

            // There's an old MD5 hash or an unsalted SHA1 hash in the database, so we replace it
            // with a randomly generated salt and a new, salted SHA1 hash
            $query = array(
                'UPDATE'    => 'users',
                'SET'        => 'password=\''.$form_password_hash.'\', salt=\''.$forum_db->escape($salt).'\'',
                'WHERE'        => 'id='.$user_id
            );

            ($hook = get_hook('li_login_qr_update_user_hash')) ? eval($hook) : null;
            $forum_db->query_build($query) or error(__FILE__, __LINE__);
        }
    }

    ($hook = get_hook('li_login_pre_auth_message')) ? eval($hook) : null;

    if (!$authorized)
        $errors[] = sprintf($lang_login['Wrong user/pass']);

    // Did everything go according to plan?
    if (empty($errors))
    {
        // Update the status if this is the first time the user logged in
        if ($group_id == FORUM_UNVERIFIED)
        {
            $query = array(
                'UPDATE'    => 'users',
                'SET'        => 'group_id='.$forum_config['o_default_user_group'],
                'WHERE'        => 'id='.$user_id
            );

            ($hook = get_hook('li_login_qr_update_user_group')) ? eval($hook) : null;
            $forum_db->query_build($query) or error(__FILE__, __LINE__);

            // Remove cache file with forum stats
            if (!defined('FORUM_CACHE_FUNCTIONS_LOADED'))
            {
                require FORUM_ROOT.'include/cache.php';
            }

            clean_stats_cache();
        }

        // Remove this user's guest entry from the online list
        $query = array(
            'DELETE'    => 'online',
            'WHERE'        => 'ident=\''.$forum_db->escape(get_remote_address()).'\''
        );

        ($hook = get_hook('li_login_qr_delete_online_user')) ? eval($hook) : null;
        $forum_db->query_build($query) or error(__FILE__, __LINE__);

        $expire = ($save_pass) ? time() + 1209600 : time() + $forum_config['o_timeout_visit'];
        forum_setcookie($cookie_name, base64_encode($user_id.'|'.$form_password_hash.'|'.$expire.'|'.sha1($salt.$form_password_hash.forum_hash($expire, $salt))), $expire);

        ($hook = get_hook('li_login_pre_redirect')) ? eval($hook) : null;

        redirect(forum_htmlencode($_POST['redirect_url']).((substr_count($_POST['redirect_url'], '?') == 1) ? '&' : '?').'login=1', $lang_login['Login redirect']);
    }
}

// Generates a salted, SHA-1 hash of $str
function forum_hash($str, $salt)
{
    $return = ($hook = get_hook('fn_forum_hash_start')) ? eval($hook) : null;
    if ($return != null)
        return $return;

    return sha1($salt.sha1($str));
}