PHP 8.1 is less forgiving about arrays.

[Ipstenu]

After updating to PHP 8.1.9, I ran into an issue I didn't see on PHP 7x

I have a repeating group that includes cmb2_attached_posts ( https://github.com/CMB2/cmb2-attached-posts/ -- used with minimal hacks for my custom post types and changing verbiage).

https://github.com/LezWatch/lwtv-plugin/blob/production/cpts/characters/cmb2-metaboxes.php#L184

When I use it in a repeating group, I get errors and this is in the log:

Stack trace:
#0 /home/wp-content/plugins/cmb2/includes/CMB2_Field.php(148): CMB2_Field->_set_field_defaults('lezchars_show_i...')
#1 /home/wp-content/plugins/cmb2/includes/CMB2.php(1401): CMB2_Field->__construct(Array)
#2 /home/wp-content/plugins/lwtv-plugin/plugins/cmb2/cmb2-attached-posts/init.php(640): CMB2->get_field('lezchars_show_i...', Object(CMB2_Field))
#3 /home/wp-content/plugins/lwtv-plugin/plugins/cmb2/cmb2-attached-posts/init.php(614): WDS_CMB2_Attached_Posts_Field->maybe_callback(Object(WP_Query), Array)
#4 /home/wp-includes/class-wp-hook.php(308): WDS_CMB2_Attached_Posts_Field->modify_query(Object(WP_Query))
#5 /home/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters(NULL, Array)
#6 /home/wp-includes/plugin.php(565): WP_Hook->do_action(Array)
#7 /home/wp-includes/class-wp-query.php(1833): do_action_ref_array('pre_get_posts', Array)
#8 /home/wp-includes/class-wp-query.php(3749): WP_Query->get_posts()
#9 /home/wp-includes/post.php(2415): WP_Query->query(Array)
#10 /home/wp-admin/includes/ajax-actions.php(2225): get_posts(Array)
#11 /home/wp-includes/class-wp-hook.php(308): wp_ajax_find_posts('')
#12 /home/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters('', Array)
#13 /home/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#14 /home/wp-admin/admin-ajax.php(188): do_action('wp_ajax_find_po...')
#15 {main}
  thrown in /home/wp-content/plugins/cmb2/includes/CMB2_Field.php on line 1373

I edited /includes/CMB2_Field.php to kick out WHAT the value of $args was if it was a string, and it came back with the ID name (in this case 'show').

I cannot for the life of me see where that's being passed back and muddled, but I did figure out that if I edited _set_field_defaults and moved the check for parse args ABOVE the filter, it corrected it and I didn't have that error anymore.

                // Set up blank or default values for empty ones.
                $args = wp_parse_args( $args, $defaults );

This maybe is a bug for attached posts, but since the only fix I can find is in the main plugin, it seemed like a more logical place for it.

(PS: https://github.com/CMB2/cmb2-attached-posts/ is a wonderful plugin and I would love to see it maintained)

[jtsternberg]

Can you provide the actual PHP error it's throwing? You provided the stack trace, but not the actual error.

[Ipstenu]

Whoops!

[20-Jul-2023 00:34:43 UTC] PHP Fatal error: Uncaught TypeError: Cannot access offset of type string on string in /home/wp-content/plugins/cmb2/includes/CMB2_Field.php:1371

NB: My output actually says 1375 because I had thrown some testing error_log lines in there to figure out what the heck WAS the string in question.

[Ipstenu]

FYI putting my money where my mouth is, this is my full fork of attached posts - CMB2/cmb2-attached-posts#72 - I can't really test this without the fork, since out of the box, you can only use one instance of attached-posts and ... well. Yeah. I'm your local weirdo.