Always use meta caps directly instead of going through the post_type_object->caps array

[markjaquith]

When using post-related meta caps in core, we should use their meta cap name instead of manually digging into the post object looking for the cap.

e.g.

Do this:

if ( ! current_user_can( 'edit_post', $post_id ) ) {
  // ...
}

Instead of this:

$post_type = get_post_type_object( get_post_type( $post_id ) );
if ( ! current_user_can( $post_type->cap->edit_post, $post_id ) ) {
  // ...
}

Our meta caps resolve custom caps for the meta caps (if someone has been foolish enough to use them), and we should be consistent about doing it that way so people know that's the right way to do it.

[nacin]

I've been meaning to do this for a while as a first step to cleaning up meta capabilities for post types. +1.

[scribu]

To clarify: that's the correct way, even if register_post_type() has 'map_meta_cap' => false, right?

[markjaquith]

Replying to scribu:

To clarify: that's the correct way, even if register_post_type() has 'map_meta_cap' => false, right?

Right. Our post-related meta caps all have this block of code:

if ( ! $post_type->map_meta_cap ) {
	$caps[] = $post_type->cap->$cap;

So it essentially does that digging for us.

[markjaquith]

First swing. Passes existing unit tests. Where possible, I removed the associated get_post_type_object() call — that is, if it was only being used in the cap check. I could probably use a double-check where that happened.

[markjaquith]

Assigning to nacin for review, as map_meta_cap is near and dear to him.

[kovshenin]

Found a couple more in query.php, fixed in 23226.2.diff​

[nacin]

In 24593:

Use meta caps edit_post, read_post, and delete_post directly, rather than consulting the post type object. map_meta_cap() handles that for us. props markjaquith, kovshenin. fixes #23226.

[ocean90]

In 47850:

Role/Capability: Use meta caps edit_post, read_post, and delete_post directly.

Rather than consulting the post type object, let map_meta_cap() handle that for us.

Props peterwilsoncc, ocean90.
Fixes #50128.
See #23226.