Ticket #26396: 26396.patch

src/wp-admin/css/common.css

@@ -2064 +2064 @@
         line-height: inherit;
 }
 
-/* contain floats */
-.nav-tab-wrapper:after {
+/* modern clearfix */
+.nav-tab-wrapper:after, /* Back-compat for plugins */
+.wp-clearfix:after {
         content: "";
         display: table;
         clear: both;