Prevent an editor to move the front page / posts page to trash

[benoitchantre]

When an admin choose to use static pages for the front page and the posts page in the reading settings, an editor should not be able to unpublish them.

[SergeyBiryukov]

Related: #17470, #21665, #30190.

[helen]

I almost wonder if we shouldn't allow those pages to be unpublished by anybody while they're still set for those options, but certainly it seems to make sense not to allow somebody to alter that unless they have the capability to edit the setting.

[mrahmadawais]

Started working on it.

[mrahmadawais]

I have the logic ready, just unable to figure out where to add it.
Can't do it in wp-admin/edit.php.
Reviewed wp-admin/includes/class-wp-post-list-table.php and added the check and it works, but an editor can always go inside the page and trash it from there.

So, I figured the better way to stop editor from deleting a page which is being used as front page should be editing the user's capability of

delete_pages

Now unable to figure it out where to do that. Looking inside /wp-admin/includes/schema.php but I think it's not right. Looking for pointers.

[mrahmadawais]

prevent_front_page_delete_by_editor function added to wp-includes/pluggable.php

[mrahmadawais]

I have added a function to prevent the editor user role from deleting any page which has been selected as the front page.
Awaiting review.

[benoitchantre]

An improvement for Wordpress 4.3 ?

[jorbin]

I wonder if it might be simpler to add this into the delete_post section of map_meta_cap

[johnbillion]

Closing in favour of #37580 as it has a cleaner approach and tests.