compact is better

app/assets/javascripts/discourse/controllers/search_controller.js

@@ -40,7 +40,7 @@ Discourse.SearchController = Em.ArrayController.extend(Discourse.Presence, {
             .map(function(n){
               return _(results).where({type: n}).first()
             })
-            .without(undefined)
+            .compact()
             .each(function(list){
               _.each(list.results, function(item){
                 item.index = index++;

app/assets/javascripts/discourse/models/topic_list.js

@@ -91,7 +91,7 @@ Discourse.TopicList.reopenClass({
           .map(function(id){
                   return newTopics.find(function(t){ return t.id === id; });
                 })
-          .without(undefined)
+          .compact()
           .value();
 
         defer.resolve(topics);