No Slug Conflicts with Trash

NOTE: WordPress 4.5 incorporated the functionality of this plugin and thus it is no longer needed unless you’re still running an older version of WP.

This plugin implements the belief that a trashed page or post should not in any way conflict with a new page or post when it comes to slugs. In essence, a new page or post should take precedence over anything in the trash. After all, the page/post is in the trash for a reason.

By default, WordPress takes into consideration posts and pages that have been trashed when deciding if the slug for a new post is already in use. Obviously, in general, WordPress should not allow duplicate slugs because that could interfere with permalinks. The thinking behind WordPress’s handling of the situation is that trashed posts/pages are still technically present, just inaccessible. It is possible that an author or admin would choose to restore a post from the trash, which WordPress feels should then occupy that same permalink as before it was trashed.

If what WordPress does is unclear, here’s an example to help clarify things:

• WordPress ships with a page called “About” with the slug of “about”. The page’s URL would be http://yoursite/about/
• Let’s say you trash that page and start a new page with the name “About”.
• Due to a trashed page having the slug that would normally have been assigned to the new page (“about”), the new page gets the slug of “about-2”, resulting in the page’s URL being http://yoursite/about-2/

With this plugin, for this example, the new “About” page would get the slug “about” as one would hope.

That said, the plugin tries its best to restore untrashed posts to their original slug. The only time it fails to do so is if a new page or post has claimed the trashed post’s original slug, in which case the untrashed post is assigned a new slug.

See other sections of the documentation for more insight into the plugin’s functionality. See WP core ticket #11863 for discussion on the matter.

Links: Plugin Homepage | Plugin Directory Page | Author Homepage

The Solution Explained

An overview of the approach employed by the plugin to resolve the issue of slugs potentially conflicting with posts in the trash.

What WordPress does

In order to understand the crux of the implemented solution, a quick refresher on unique slug handling by WP:

Before published use, a desired slug is passed to wp_unique_post_slug() and a safe slug is returned. The safe slug may differ from the desired slug if any existing post (including a trashed post) has that slug (or, less likely, is invalid for permalink reasons such as feeds or date archives).