Ticket #19649: 19649.diff

wp-admin/js/wp-fullscreen.dev.js

@@ -727 +727 @@
                 newheight = txt.scrollHeight > 300 ? txt.scrollHeight : 300;
 
                 if ( newheight != api.oldheight ) {
-                        txt.style.height = newheight + 'px';
+                        txt.style.height = (newheight) + 'px';
                         api.oldheight = newheight;
                 }
         };