[wp-trac] [WordPress Trac] #50019: remove_meta_box triggers warning in PHP 7.4

[WordPress Trac]

#50019: remove_meta_box triggers warning in PHP 7.4
-------------------------------+-----------------------------
 Reporter:  coolmann           |      Owner:  (none)
     Type:  defect (bug)       |     Status:  new
 Priority:  normal             |  Milestone:  Awaiting Review
Component:  Posts, Post Types  |    Version:  5.4
 Severity:  major              |   Keywords:  needs-patch
  Focuses:  ui                 |
-------------------------------+-----------------------------
 After updating my local sandbox to PHP 7.4, I started seeing errors on my
 Edit Page screen for my custom post type:

 Notice: Trying to access array offset on value of type bool in /[..]/wp-
 admin/includes/template.php on line 1079, 1080, 1081

 After some research, I narrowed down the issue to a call in one of my
 plugin, which removes one of the metaboxes on that screen:

 remove_meta_box( 'profile_rolediv', 'people', 'normal' );

 Everything had been working fine in earlier versions. Looking at the code
 in template.php, it looks like remove_meta_box just sets values to false,
 instead of removing the entry:

 function remove_meta_box( $id, $screen, $context ) {
   .
   .
   $wp_meta_boxes[ $page ][ $context ][ $priority ][ $id ] = false;
   .
   .
 }

 which then causes this line in template.php to fail:

 $title = $wp_meta_boxes[ $page ][ $a_context ][ $a_priority ][ $id
 ]['title'];

 Changing line 1078 in wp-admin/includes/template.php fixes the issue:

 } elseif ( 'sorted' == $priority && is_array( $wp_meta_boxes[ $page ][
 $a_context ][ $a_priority ][ $id ] ) ) {

 Thank you,
 Jason

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/50019>
WordPress Trac <https://core.trac.wordpress.org/>
WordPress publishing platform