Heartbeat: Handle race condition in wp-auth-check where heartbeat-tick may fire before DOMContentLoaded.

Developed in WordPress/wordpress-develop#10624

Follow-up to [23805], [50547].

Props westonruter, ArtZ91, siliconforks.
See #23295.
Fixes #64403.

Built from https://develop.svn.wordpress.org/trunk@61379


git-svn-id: http://core.svn.wordpress.org/trunk@60691 1a063a9b-81f0-0310-95a4-ce76da25c4cd

Author: westonruter

wp-includes/js/wp-auth-check.js

@@ -159,12 +159,23 @@
 			setShowTimeout();
 		});
 	}).on( 'heartbeat-tick.wp-auth-check', function( e, data ) {
-		if ( 'wp-auth-check' in data ) {
+		if ( ! ( 'wp-auth-check' in data ) ) {
+			return;
+		}
+
+		var showOrHide = function () {
 			if ( ! data['wp-auth-check'] && wrap.hasClass( 'hidden' ) && ! tempHidden ) {
 				show();
 			} else if ( data['wp-auth-check'] && ! wrap.hasClass( 'hidden' ) ) {
 				hide();
 			}
+		};
+
+		// This is necessary due to a race condition where the heartbeat-tick event may fire before DOMContentLoaded.
+		if ( wrap ) {
+			showOrHide();
+		} else {
+			$( showOrHide );
 		}
 	});
 

wp-includes/js/wp-auth-check.min.js

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '7.0-alpha-61377';
+$wp_version = '7.0-alpha-61379';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.