Php 8.1 compatibility: unreliable (tons of errors)

Hello!

Subject: bug report

Severity: minor

Context: WordPress 6.1.1 (latest stable), mysql 10.3.36-mariaDB, on a Debian buster server, webmin+virtualmin. Wp-discuz 5.3.6.

Details: I’m testing the switch of my hosting from php7.4.33 (as it’s not maintained anymore), to php8.1.13 (as it’s the future, but, damn, so much old stuff has awkward compatibility.)

And I notice a TON of error messages in my apache error log, related to wp-discuz, I thought you guys may be interested in hearing about them.

Quoting, they’re all similar depending on whether it’s the home page of the plugin options page that are visited:

[Wed Jan 04 18:13:16.935455 2023] [fcgid:warn] [pid 16853:tid 140157650982656] [client xxx] mod_fcgid: stderr: PHP Warning: Trying to access array offset on value of type null in /home/ xxx /public_html/testphp8test/wp-content/plugins/wpdiscuz.5.3.6/class.WpdiscuzCore.php on line 975, referer: https:// xxx /testphp8test/wp-admin/edit-comments.php?page=wpdiscuz_options_page

[Wed Jan 04 18:13:19.180527 2023] [fcgid:warn] [pid 16902:tid 140157357369088] [client xxx] mod_fcgid: stderr: PHP Warning: Trying to access array offset on value of type null in /home/ xxx /public_html/testphp8test/wp-content/plugins/wpdiscuz.5.3.6/class.WpdiscuzCore.php on line 942, referer: https:// xxx /testphp8test/wp-admin/themes.php

Commenting still works, but that doesn’t look too healthy, so I thought you guys might be interesting in knowing, in case you didn’t yet.