Twenty Twenty-One: Check if anchor exists before triggering in-page navigation.

This prevents JavaScript errors when using hash in URLs without matching them to any existing anchor in the page.

Props rixeo, sabernhardt, pbearne.
Fixes #53619.

Built from https://develop.svn.wordpress.org/trunk@52213


git-svn-id: http://core.svn.wordpress.org/trunk@51805 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-content/themes/twentytwentyone/assets/js/primary-navigation.js

@@ -180,7 +180,9 @@ function twentytwentyoneExpandSubMenu( el ) { // jshint ignore:line
 				// Wait 550 and scroll to the anchor.
 				setTimeout(function () {
 					var anchor = document.getElementById(event.target.hash.slice(1));
+					if ( anchor ) {
 						anchor.scrollIntoView();
+					}
 				}, 550);
 			}
 		} );

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.9-alpha-52212';
+$wp_version = '5.9-alpha-52213';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.