Full-site editing theme warning about missing header.php

[Iulia Cazan]

When using a theme compatible with full site editing, I get this warning from time to time when the page is redirecting. This can be replicated also in WordPress 6.3-RC2-56310 running Twenty Twenty-Three theme.

Deprecated: File Theme without header.php is deprecated since version 3.0.0 with no alternative available. Please include a header.php template in your theme. in /public/wp-includes/functions.php on line 5653

[rajinsharwar]

I think, twenty twenty-three is a block theme. Can you check if using the below code resolves the warning you are getting?

if( wp_is_block_theme() ) {
    block_template_part('header');
}

if( wp_is_block_theme() ) {
    block_template_part('footer');
}

[Iulia Cazan]

Replying to rajinsharwar:

I think, twenty twenty-three is a block theme. Can you check if using the below code resolves the warning you are getting?

if( wp_is_block_theme() ) {
    block_template_part('header');
}

if( wp_is_block_theme() ) {
    block_template_part('footer');
}

Not sure I understand what you meant by that.

The theme itself does not have a header.php file at all, this is the theme structure. ​https://imgur.com/45G7OkU

To me, this looks like a bug, to get a warning about the theme not having a header.php file when the official theme does not have one. What am I missing?