Ticket #38409: 38409.0.diff

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

@@ -654 +654 @@
                         this.add( 'origin', this.url() ).link( this.url ).setter( function( to ) {
                                 var urlParser = document.createElement( 'a' );
                                 urlParser.href = to;
-                                return urlParser.protocol + '//' + urlParser.hostname;
+                                return urlParser.protocol + '//' + urlParser.host;
                         });
 
                         // first add with no value