Ticket #39175: 39175.2.diff

src/wp-includes/js/customize-preview.js

@@ -49 +49 @@
                 history.replaceState = ( function( nativeReplaceState ) {
                         return function historyReplaceState( data, title, url ) {
                                 currentHistoryState = data;
-                                return nativeReplaceState.call( history, data, title, injectUrlWithState( url ) );
+                                return nativeReplaceState.call( history, data, title, ! _.isUndefined( url ) && null !== url ? injectUrlWithState( url ) : null );
                         };
                 } )( history.replaceState );
 
                 history.pushState = ( function( nativePushState ) {
                         return function historyPushState( data, title, url ) {
                                 currentHistoryState = data;
-                                return nativePushState.call( history, data, title, injectUrlWithState( url ) );
+                                return nativePushState.call( history, data, title, ! _.isUndefined( url ) && null !== url ? injectUrlWithState( url ) : null );
                         };
                 } )( history.pushState );