WXR unnecessarily includes all post authors

[johnbillion]

If you're exporting just one post type (from Tools -> Export), the resulting WXR file still includes all authors from the posts table, regardless if they are the author of a post of the post type being exported. This can be particularly noticable for Pages (which are often only authored by a small number of different users on the site) and for custom post types.

This means when you subsequently import the file you'll be asked to map a complete list of all authors from the exported site, even if they have no posts in the WXR file being imported.

Patch to only include relevant post authors in the WXR export.

I really like this idea. It makes sense to export all of the data based on the selected parameters.

It may make more sense to reuse the $post_ids array so that the query for distinct post authors mirrors the results from the main posts query. Restricting it to post_type could cause the same issue with extra authors for some taxonomies, etc...

The updated patch attached uses the $post_ids array instead.

Updated patch using $post_ids

Even better!