WP 6.3-RC3: it is not possible to trash patterns with draft status in post editor

[bvlgn]

Description

If you add a new pattern in the post editor you will not get the row action option to trash the pattern.

This seems to be caused by map_meta_cap mapping delete_post cap to delete_blocks.(@line 153 in capabilities.php).
It looks this is not a default cap assigned to the administrator role, therefor administrators are not allowed to trash draft patterns. Which of course is a bug. See screenshot.

Step-by-step reproduction instructions

1. Add a pattern in the post editor (wp-admin/edit.php?post_type=wp_block)
2. Save it in draft status
3. Go back to the list table
4. Try to trash the pattern (the row action will not be there)

Screenshots, screen recording, code snippet

So $cap = 'delete_blocks', which is not in $capabilities:

Environment info

WP 6.3 RC3

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes

[glendaviesnz]

Thanks @bvlgn, I was able to replicate this, but I could also replicate it with reusable blocks on 6.2.2 so given it is an existing bug not introduced by the pattern changes in 6.3 I don't think we need to prioritise it for 6.3 - but it would be good to get this sorted, so have added to the patterns project board.

[ramonjd]

Would something like this be an interim plugin fix?

• Patterns: add delete_posts to the wp_block (patterns) capabilities #53405

If so I can then add a WP backport patch to add delete_posts to the register_post_type args.