FIX: Exclude muted results when suggested related topics at random. (#11290)

We already do this for new and unread results, but not for randomly suggested topics.

lib/topic_query.rb

@@ -1085,6 +1085,7 @@ class TopicQuery
     result = result.where("topics.id NOT IN (?)", excluded_topic_ids) unless excluded_topic_ids.empty?
 
     result = remove_muted_categories(result, @user)
+    result = remove_muted_topics(result, @user)
 
     # If we are in a category, prefer it for the random results
     if topic.category_id

spec/components/topic_query_spec.rb

@@ -967,6 +967,18 @@ describe TopicQuery do
           expect(topic_query.list_suggested_for(tt).topics.length).to eq(1)
         end
 
+        it 'removes muted topics' do
+          SiteSetting.suggested_topics_max_days_old = 1365
+          tt = topic
+          TopicNotifier.new(old_topic).mute!(user)
+          clear_cache!
+
+          topics = topic_query.list_suggested_for(tt).topics
+
+          expect(topics.length).to eq(1)
+          expect(topics).not_to include(old_topic)
+        end
+
       end
 
       context 'with private messages' do