FIX: Only hide shared draft topics from `latest` (#6737)

Previously we were hiding them from all topic lists, which can result in
topics being "stuck" in an unread state with no easy way to clear them.

lib/topic_query.rb

@@ -453,6 +453,7 @@ class TopicQuery
     result = remove_muted_topics(result, @user) unless options && options[:state] == "muted".freeze
     result = remove_muted_categories(result, @user, exclude: options[:category])
     result = remove_muted_tags(result, @user, options)
+    result = apply_shared_drafts(result, get_category_id(options[:category]), options)
 
     # plugins can remove topics here:
     self.class.results_filter_callbacks.each do |filter_callback|
@@ -694,7 +695,6 @@ class TopicQuery
 
     result = apply_ordering(result, options)
     result = result.listable_topics.includes(:category)
-    result = apply_shared_drafts(result, category_id, options)
 
     if options[:exclude_category_ids] && options[:exclude_category_ids].is_a?(Array) && options[:exclude_category_ids].size > 0
       result = result.where("categories.id NOT IN (?)", options[:exclude_category_ids].map(&:to_i)).references(:categories)

spec/components/topic_query_spec.rb

@@ -1026,5 +1026,20 @@ describe TopicQuery do
         expect(list.topics).not_to include(topic)
       end
     end
+
+    context "unread" do
+      let!(:partially_read) do
+        topic = Fabricate(:topic, category: shared_drafts_category)
+        Fabricate(:post, user: creator, topic: topic).topic
+        TopicUser.update_last_read(admin, topic.id, 0, 0, 0)
+        TopicUser.change(admin.id, topic.id, notification_level: TopicUser.notification_levels[:tracking])
+        topic
+      end
+
+      it 'does not remove topics from unread' do
+        expect(TopicQuery.new(admin).list_latest.topics).not_to include(partially_read) # Check we set up the topic/category correctly
+        expect(TopicQuery.new(admin).list_unread.topics).to include(partially_read)
+      end
+    end
   end
 end