Meta: Add support for site meta in get_object_subtype()

src/wp-includes/meta.php

@@ -1789,6 +1789,7 @@ function _wp_register_meta_args_allowed_list( $args, $default_args ) {
  * Returns the object subtype for a given object ID of a specific type.
  *
  * @since 4.9.8
+ * @since 6.X.0 Added support for 'blog' object type in multisite.
  *
  * @param string $object_type Type of object metadata is for. Accepts 'blog', 'post', 'comment', 'term',
  *                            'user', or any other object type with an associated meta table.
@@ -1834,6 +1835,19 @@ function get_object_subtype( $object_type, $object_id ) {
 
 			$object_subtype = 'user';
 			break;
+
+		case 'blog':
+			if ( ! is_multisite() || $object_id <= 0 ) {
+				break;
+			}
+
+			$site = get_site( $object_id );
+			if ( ! $site ) {
+				break;
+			}
+
+			$object_subtype = 'blog';
+			break;
 	}
 
 	/**

tests/phpunit/tests/meta/registerMeta.php

@@ -8,19 +8,29 @@ class Tests_Meta_Register_Meta extends WP_UnitTestCase {
 	protected static $term_id;
 	protected static $comment_id;
 	protected static $user_id;
+	protected static $blog_id;
 
 	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
 		self::$post_id    = $factory->post->create( array( 'post_type' => 'page' ) );
 		self::$term_id    = $factory->term->create( array( 'taxonomy' => 'category' ) );
 		self::$comment_id = $factory->comment->create();
 		self::$user_id    = $factory->user->create();
+
+		if ( is_multisite() ) {
+			self::$blog_id = $factory->blog->create();
+		}
 	}
 
 	public static function wpTearDownAfterClass() {
 		wp_delete_post( self::$post_id, true );
 		wp_delete_term( self::$term_id, 'category' );
 		wp_delete_comment( self::$comment_id, true );
 		self::delete_user( self::$user_id );
+
+		if ( is_multisite() ) {
+			wp_delete_site( self::$blog_id );
+			wp_update_network_site_counts();
+		}
 	}
 
 	public function _old_sanitize_meta_cb( $meta_value, $meta_key, $meta_type ) {
@@ -1105,6 +1115,52 @@ public function data_get_types_and_subtypes() {
 		);
 	}
 
+	/**
+	 * @ticket 44387
+	 * @group ms-required
+	 */
+	public function test_get_object_subtype_for_blog_returns_blog_when_site_exists() {
+		$this->assertSame( 'blog', get_object_subtype( 'blog', self::$blog_id ) );
+	}
+
+	/**
+	 * @ticket 44387
+	 * @group ms-required
+	 */
+	public function test_get_object_subtype_for_blog_returns_empty_string_for_invalid_site() {
+		$this->assertSame( '', get_object_subtype( 'blog', 0 ) );
+		$this->assertSame( '', get_object_subtype( 'blog', 999999 ) );
+	}
+
+	/**
+	 * @ticket 44387
+	 * @group ms-required
+	 */
+	public function test_get_object_subtype_for_blog_with_registered_meta() {
+		if ( ! is_site_meta_supported() ) {
+			$this->markTestSkipped( 'Test only runs with the blogmeta database table installed.' );
+		}
+
+		$this->assertSame( 'blog', get_object_subtype( 'blog', self::$blog_id ) );
+
+		register_meta(
+			'blog',
+			'site_rating',
+			array(
+				'single'         => true,
+				'object_subtype' => 'blog',
+			)
+		);
+		add_site_meta( self::$blog_id, 'site_rating', '5' );
+
+		$meta = get_registered_metadata( 'blog', self::$blog_id, 'site_rating' );
+
+		unregister_meta_key( 'blog', 'site_rating', 'blog' );
+		delete_site_meta( self::$blog_id, 'site_rating' );
+
+		$this->assertSame( '5', $meta );
+	}
+
 	/**
 	 * Test that attempting to register meta with revisions_enabled set to true on a
 	 * post type that does not have revisions enabled fails and throws a `doing_it_wrong` notice.