Refactor redirect_guess_404_permalink to use WP_Query instead of raw SQL

[spacedmonkey]

The current implementation of the redirect_guess_404_permalink() function uses a direct SQL query to retrieve post IDs when attempting to guess the correct URL for a 404 request based on query variables. While this approach works, it bypasses WordPress’s built-in query abstraction layer and associated benefits.

This change proposes replacing the raw SQL with a WP_Query implementation. Doing so will improve maintainability, consistency, and performance through native WordPress features such as:

• Query caching – Utilises WordPress’s object caching layer, reducing redundant database queries.
• Filtering and extensibility – Enables the use of hooks and filters that developers may rely on to modify query behaviour.
• Security and readability – Removes the need for manual SQL sanitisation and improves code clarity.
• Future compatibility – Ensures the function remains aligned with core WordPress query handling and schema changes.

The refactor should maintain the same functional behaviour — guessing the most appropriate redirect target for a 404 request — while ensuring no regression in performance or accuracy.

The redirect_guess_404_permalink() function in src/wp-includes/canonical.php has been refactored to replace direct SQL queries with WordPress's native WP_Query abstraction layer.

Trac ticket: https://core.trac.wordpress.org/ticket/64250

[altf4falt]

I've refactored the function to use WP Query instead of direct SQL queries.

PR Link: ​https://github.com/WordPress/wordpress-develop/pull/10531

@westonruter I've resolved the comments. Seeking clarification on one comment and requesting for a re-review

Trac ticket:

@westonruter @anandrajaram21 I have put together a little PR to use WP_Query without a filter. ​https://github.com/WordPress/wordpress-develop/pull/10590/commits/4c87073adeed8643d01d8a5934d7c8c5c00cf889. Completely untested, but this is how I think this should work.

@spacedmonkey Clever. So you're leveraging the search capabilities of WP_Query to implement fuzzy redirect guessing, specifically via restricting the search_columns to just include the post_name.

Full diff from base: ​https://github.com/WordPress/wordpress-develop/compare/33c8d7efa3d96ddd9a87168dfe15e771fb81d29c...4c87073adeed8643d01d8a5934d7c8c5c00cf889

In looking at ​https://github.com/WordPress/wordpress-develop/pull/10590 which has the aforementioned commit, unit tests are failing.

@spacedmonkey This approach makes sense. I'll try this out, however as @westonruter mentioned, the tests do not pass, so I'll try making the tests pass while keeping the core idea in mind. Thanks for the input!

@anandrajaram21 Here is the full changeset Full diff from base:
​https://github.com/WordPress/wordpress-develop/compare/33c8d7efa3d96ddd9a87168dfe15e771fb81d29c...ff81f8864ce2277b9c2c3596315af4e55942960b

I had to make some more tweaks to WP_Query, but it seems to be working. It needs unit tests and testing.