[skikken]

Deleting a site leaves that site's option caches populated. alloptions, notoptions and is_blog_installed keep answering for a site whose tables no longer exist, so a deleted site continues to behave as installed. A switch_to_blog() into the deleted site succeeds without any indication that the site is gone, whereas clearing the caches surfaces the expected Table '..._options' doesn't exist error and makes the failure debuggable.

The gap is still live on trunk. clean_blog_cache() only clears the network level site, blog-details, blog-lookup and blog_meta groups. The options group is per site, and nothing in the deletion path clears it.

This clears the three keys in wp_uninitialize_site() once the site's tables have been dropped, while the function is still switched into the deleted site's context, so the per blog keys are hit directly. The whole options group is deliberately not flushed: on multisite that group holds every site's prefixed option keys, so flushing it would evict the entire network's option cache.

clean_blog_cache() is intentionally untouched. As noted in the ticket discussion, it is a network level cache cleaner, and site level clearing belongs to the site deletion routine itself. The second test pins that scope so a later change cannot widen it silently.

The alloptions half of the report is the one that reproduces most visibly: an autoloaded option is served straight from that cache, so a stale read survives the deletion of the table it came from.

Trac ticket: https://core.trac.wordpress.org/ticket/29247

Use of AI Tools

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Used for: test cases, code review

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