From a02886a868e4bdeb586658926607bdffdd65a7f2 Mon Sep 17 00:00:00 2001
From: Isabel Brison <isabel_brison@git.wordpress.org>
Date: Tue, 11 Jul 2023 05:39:33 +0000
Subject: [PATCH] Editor: opt out of Navigation fallback.

Allows developers to opt out of the auto-creation of the Navigation fallback through a filter.

Props get_dave, spacedmonkey, ramonopoly.
Fixes #58750.


git-svn-id: https://develop.svn.wordpress.org/trunk@56202 602fd350-edb4-49c9-b593-d223f7449a82
---
 .../class-wp-navigation-fallback.php          | 11 +++++++++-
 .../tests/editor/navigation-fallback.php      | 20 +++++++++++++++++++
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/src/wp-includes/class-wp-navigation-fallback.php b/src/wp-includes/class-wp-navigation-fallback.php
index 6df4993a0f..c99b71a41a 100644
--- a/src/wp-includes/class-wp-navigation-fallback.php
+++ b/src/wp-includes/class-wp-navigation-fallback.php
@@ -26,9 +26,18 @@ class WP_Navigation_Fallback {
 	 */
 	public static function get_fallback() {
 
+		/**
+		 * Filters whether or not a fallback should be created.
+		 *
+		 * @since 6.3.0
+		 *
+		 * @param bool Whether to create a fallback navigation menu. Default true.
+		 */
+		$should_create_fallback = apply_filters( 'wp_navigation_should_create_fallback', true );
+
 		$fallback = static::get_most_recently_published_navigation();
 
-		if ( $fallback ) {
+		if ( $fallback || ! $should_create_fallback ) {
 			return $fallback;
 		}
 
diff --git a/tests/phpunit/tests/editor/navigation-fallback.php b/tests/phpunit/tests/editor/navigation-fallback.php
index 3d73b72a4d..46befacc3c 100644
--- a/tests/phpunit/tests/editor/navigation-fallback.php
+++ b/tests/phpunit/tests/editor/navigation-fallback.php
@@ -56,6 +56,26 @@ class WP_Navigation_Fallback_Test extends WP_UnitTestCase {
 		$this->assertCount( 1, $navs_in_db, 'The fallback Navigation post should be the only one in the database.' );
 	}
 
+	/**
+	 * @ticket 58750
+	 *
+	 * @covers WP_REST_Navigation_Fallback_Controller::get_fallback
+	 */
+	public function test_should_not_automatically_create_fallback_if_filter_is_falsey() {
+
+		add_filter( 'wp_navigation_should_create_fallback', '__return_false' );
+
+		$data = WP_Navigation_Fallback::get_fallback();
+
+		$this->assertEmpty( $data );
+
+		$navs_in_db = $this->get_navigations_in_database();
+
+		$this->assertCount( 0, $navs_in_db, 'The fallback Navigation post should not have been created.' );
+
+		remove_filter( 'wp_navigation_should_create_fallback', '__return_false' );
+	}
+
 	/**
 	 * @ticket 58557
 	 * @covers WP_REST_Navigation_Fallback_Controller::get_fallback