LogService::prune_logs removes old posts from custom post type

[soup-bowl]

From the plugin forums posted by @odkr:

https://wordpress.org/support/topic/logservice-prune_logs-removes-old-posts-from-custom-post-type/

There is a proven concern that the post cleanup scheduler has the possibility to delete posts that aren't from the CPT of the plugin.

[odkr]

I had some time to think about this since I opened the issue, and it would seem to me that it comes down to is that the expectation that a WP_Query returns the posts that the query was for, while reasonable, may not hold up in the real world, for three reasons:

1. is_home(), is_blog() have counter-intuitive edge cases; in my case, that is_home() holds true for any query made using get_posts, even if it is made in a cron job. Moreover, plugins may run arbitrary queries and modify them in arbitrary ways that are not covered by conditional tags to begin with (e.g., plugins for plugins).

2. The WP Codex offers little normative guidance what to use pre_get_posts, parse_query, query, etc. for and how to use them, so any query may be modified. In fairness, it does say that functions that hook into pre_get_posts should use is_main_query(). I forgot about that because it's counter-intuitive to me that is_home() == true does not imply is_main_query() == true.

3. There are people, like me 😄 , whose intuitions do not fit WordPress' API.

So, I'd still recommend to check the post type before calling wp_delete_post(). The cron job can delete a lot of posts (in our case, it deleted roughly 2,000 posts that pre-dated the installation of WP Simple SMTP), and some people don't make backups (or so I've been told). What is more, because it only deletes old posts, the deletion may go unnoticed for a while (it took us some days to notice, so we couldn't just revert to the backup from two hours ago, but had to merge backups with the content added since then).