Ticket #28577: 28577.5.patch

src/wp-admin/js/language-chooser.js

@@ -40 +40 @@
                 $(this).find('.step .spinner').css('visibility','visible');
         });
 
+        var hits = 0,
+                row_height = $('.language-chooser').find('label').height();
+                max = $fieldset.find('input').length - parseInt( $fieldset.height() / row_height, 10 );
+        $(document).keydown(function(e) {
+                if ( e.which !== 38 && e.which !== 40 ) {
+                        return;
+                }
+
+                // Hits should be positive value, shouldn't be more than inputs count
+                if ( hits >= 0 && hits <= max ) {
+                        if ( e.which == 38 ) { // Up
+                                hits--;
+                        }
+                        else { // Down
+                                hits++;
+                        }
+
+                        // Fix limit values
+                        hits = hits < 1 ? 0 : hits;
+                        hits = hits > max ? max : hits;
+
+                        $fieldset.scrollTop( row_height * hits );
+                }
+        });
+
 })(jQuery);