This fixes a behavior where a draft created with the same slug as an existing post would set the existing post to a 404.
`wp_unique_post_slug()` returns the same slug for 'draft' or 'pending' posts, so to ensure that a unique slug is generated, this changeset adds the post data with the 'publish' status to `wp_unique_post_slug()`.
Props Toro_Unit, h2ham, peterwilsoncc, costdev, antonvlasenko, azaozz, ironprogrammer, audrasjb, hellofromTonya.
Fixes#52422.
Built from https://develop.svn.wordpress.org/trunk@53813
git-svn-id: http://core.svn.wordpress.org/trunk@53372 1a063a9b-81f0-0310-95a4-ce76da25c4cd