Ticket #24839: 24839.diff

wp-content/themes/twentytwelve/js/navigation.js

@@ -30 +30 @@
                         menu.className += ' toggled-on';
                 }
         };
-} )();
- No newline at end of file
+} )();
+
+( function( $ ) {
+        $( '.main-navigation' ).find( 'a' ).on( 'focus blur', function() {
+                $( this ).parents().toggleClass( 'focus' );
+        } );
+} )( jQuery );  
+ No newline at end of file

wp-content/themes/twentytwelve/style.css

@@ -1517 +1517 @@
                 position: relative;
         }
         .main-navigation li ul {
-                display: none;
+                /*display: none;*/
                 margin: 0;
                 padding: 0;
                 position: absolute;
                 top: 100%;
                 z-index: 1;
+                height: 1px; 
+                width: 1px; 
+                overflow: hidden;
+                clip: rect(1px 1px 1px 1px); /* IE6, IE7 */
+                clip: rect(1px, 1px, 1px, 1px)
         }
         .main-navigation li ul ul {
                 top: 0;
                 left: 100%;
         }
-        .main-navigation ul li:hover > ul {
+        .main-navigation ul li:hover > ul, .main-navigation .focus > ul {
                 border-left: 0;
-                display: block;
+                /* display: block; */
+                clip: inherit;
+                overflow: inherit;
+                height: inherit;
+                width: inherit;         
         }
         .main-navigation li ul li a {
                 background: #efefef;