PHP Warning when attempting to login

[eduardomozart]

It doesn't happen all the time, and as I doesn't have a deeper understood how local auth works on DokuWiki, I wasn't able to track the issue. I'm using DokuWiki latest stable and I have PHP 8.2 with display_errors directive set to On, and sometimes when I access the https://wiki.example.com/doku.php?id=start after login the following message is shown on page header:

Warning: Undefined array key "user" in /home/robertinho/public_html/wiki/inc/auth.php on line 249

Warning: Cannot modify header information - headers already sent by (output started at /home/robertinho/public_html/wiki/inc/auth.php:249) in /home/robertinho/public_html/wiki/inc/auth.php on line 1262

Warning: Cannot modify header information - headers already sent by (output started at /home/robertinho/public_html/wiki/inc/auth.php:249) in /home/robertinho/public_html/wiki/inc/actions.php on line 38

It did redirect me to the https://wiki.example.com/doku.php?id=start page but when I try to access any link on the wiki I'm redirected to the login page again (it's a closed Wiki), so I login again and now I can access any Wiki link as expected.

I added the following code above the https://github.com/dokuwiki/dokuwiki/blob/master/inc/auth.php#L305:

                if($session['user'] !== $user) {
                    var_dump($session);
                }

The following output is shown when the PHP warning is triggered:

array(2) { ["buid"]=> string(64) "d9165bb75835ea4a8c09f8cd5ced2035467aadde376b5b7049da460ce113329b" ["time"]=> int(1704973941) }

For me the problem
seems to be on lines https://github.com/dokuwiki/dokuwiki/blob/master/inc/auth.php#L309-L310 because on the var_dump above it seems that $session['user'] and $session['pass'] array keys isn't set.