Full-site Editing: Themes located in a subdirectory do not load template parts

[kjellr]

If a theme is loaded from a subdirectory, then its template parts are not properly loaded into the site editor. For example, if the theme is located here:

wp-content/themes/subfolder/themename

instead of:

wp-content/themes/themename

This has come up when folks test the TT1 Blocks theme: it used to work when you copied the entire theme-experiments folder into wp-content/themes, but it no longer does. This was fixed once before in #26391.

I believe this will be fixed by #27765, but opening an issue here to track the bug.

[jffng]

Is this fixed by #28088?

[jeyip]

Is this fixed by #28088?

Almost! We need to update block themes before the issue is completely resolved. I've modified seedlet blocks here and block theme experiments here.

There's a note in the PR description for #28088 with more information, but in essence, the problem isn't fixed until we remove theme attributes from theme provided block templates.

[annezazu]

Just noting that @helen ran into this today while streaming resulting in a really jarring experience especially when trying to use the Live Preview option for block themes. When this is fixed, should confirm it works with the Live Preview option under Appearance > Themes.

[carolinan]

Template parts for themes inside subfolders are working so I am closing this issue.