Private posts skipped in single post navigation

[blogan]

A private post that appears on my main page when logged in does not appear in the next/previous navigation of a single post.

[valendesigns]

The issue is with the query in the get_adjacent_post() functions that only allows for published posts.

WHERE p.post_date $op %s AND p.post_type = %s AND p.post_status = 'publish'

Changing it to the following could solve this, but I don't know if it's as straight forward as that because there's no logged in check and I'm fairly certain we don't want to run this altered query for every user.

WHERE p.post_date $op %s AND p.post_type = %s AND p.post_status = IN ('publish', 'private')

[boonebgorges]

The issue is with the query in the get_adjacent_post() functions that only allows for published posts.

Correct. The post_status = 'publish' clause has been hardcoded since at least 1.5. See [1557].

I don't know if it's as straight forward as that because there's no logged in check and I'm fairly certain we don't want to run this altered query for every user.

It definitely is not this straightforward, for these very reasons :) The purpose of the 'private' post status is to hide a post from all members but the author of the post. WP_Query accounts for this, but get_adjacent_post() does not use WP_Query (see #26937). I suppose mirroring the logic here too would be fine, but I'd like to see a patch + unit tests.

[bswatson]

Add private posts for current user to get_adjacent_post

[bswatson]

Unit Tests for get_adjacent_post

[bswatson]

Patch and unit tests added to include private posts in get_adjacent_post

[boonebgorges]

bswatson - Thanks! This looks great. I'm going to do some minor cleanup.

[boonebgorges]

In 31302:

In get_adjacent_post(), return private post if the current user has the capacity to read it.

This mirrors the check that happens post-query in WP_Query. See #30911.

Props bswatson.
Fixes #30287.