Template Hierarchy: Custom 404 pages for CPTs

[ramiy]

Currently theme developers can customize only one error page they can design - using the 404.php file. We can't create custom 404 pages based on CPT's. Let's change that!

WordPress template hierarchy supports CPT's with single CPT pages single-{post-type}.php, archive CPT pages archive-{post-type}.php and embed pages embed-{post-type}.php. It's missing the option to create custom 404 pages for CPTs in a form of 404-{post-type}.php.

Let's extend the 404 pages with a new template file path:

• 404-{post-type}.php
• 404.php
• index.php

[johnbillion]

Thanks for the suggestion. This is already being worked on in #23049.