Ticket #59987: 59987.patch

src/wp-admin/includes/class-wp-upgrader-skin.php

@@ -240 +240 @@
                 if ( defined( 'IFRAME_REQUEST' ) ) {
                         echo '<script type="text/javascript">
                                         if ( window.postMessage && JSON ) {
-                                                window.parent.postMessage( JSON.stringify( { action: "decrementUpdateCount", upgradeType: "' . $type . '" } ), window.location.protocol + "//" + window.location.hostname );
+                                                window.parent.postMessage( JSON.stringify( { action: "decrementUpdateCount", upgradeType: "' . $type . '" } ), window.location.protocol + "//" + window.location.hostname + ( "" !== window.location.port ? ":" + window.location.port : "" ) );
                                         }
                                 </script>';
                 } else {