Description

I've noticed that registering a block template with a slug matching exactly page even if not applied (so the meta _wp_page_template does not exist) will be applied if and only if I click on the Template within the editor.

The template is applied only to the Editor.

Below is the code I've used

namespace Plugin\Templates;

function load_template(string $templateName): string {
	ob_start();
	include plugin_dir_path(__FILE__) . '/templates/' . $templateName . '.php';
	return ob_get_clean();
}

add_action( 'init', static function() {
	wp_register_block_template(
		'templates//page',
		[
			'title' => 'My Single Page',
			'description' => 'This is my single template',
			'content' => load_template('page'),
			'post_types' => [ 'page' ],
		]
	);
} );

Step-by-step reproduction instructions

1. Register a new block template using a slug including '//page' as part of the template name
2. Open the Sample Page Edit page
3. On Page Panel, click Pages near the right of the Template label

Screenshots, screen recording, code snippet

Environment info

WordPress Version: 6.7-alpha-59076
Gutenberg Version: 19.3.0-rc.1

Please confirm that you have searched existing issues in the repo.

• Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

• Yes