FIX: suggested topics showing up when last post not loaded

New fix means that was show suggested

1. If all posts are loaded
2. If we are in the process of loading 1 more post due to message bus

app/assets/javascripts/discourse/controllers/topic.js.es6

@@ -15,7 +15,7 @@ export default Ember.Controller.extend(SelectedPostsCount, BufferedContent, {
   selectedPosts: null,
   selectedReplies: null,
   queryParams: ['filter', 'username_filters', 'show_deleted'],
-  loadedAllPosts: false,
+  loadedAllPosts: Em.computed.or('model.postStream.loadedAllPosts', 'model.postStream.loadingLastPost'),
   enteredAt: null,
   firstPostExpanded: false,
   retrying: false,
@@ -36,22 +36,6 @@ export default Ember.Controller.extend(SelectedPostsCount, BufferedContent, {
     }
   }.observes('model.title', 'category'),
 
-  postStreamLoadedAllPostsChanged: function() {
-    // semantics of loaded all posts are slightly diff at topic level,
-    // it just means that we "once" loaded all posts, this means we don't
-    // keep re-rendering the suggested topics when new posts zoom in
-    let loaded = this.get('model.postStream.loadedAllPosts');
-
-    if (loaded) {
-      this.set('model.loadedTopicId', this.get('model.id'));
-    } else {
-      loaded = this.get('model.loadedTopicId') === this.get('model.id');
-    }
-
-    this.set('loadedAllPosts', loaded);
-
-  }.observes('model.postStream', 'model.postStream.loadedAllPosts'),
-
   @computed('model.postStream.summary')
   show_deleted: {
     set(value) {

app/assets/javascripts/discourse/models/post-stream.js.es6

@@ -464,7 +464,12 @@ const PostStream = RestModel.extend({
 
     if (this.get('stream').indexOf(postId) === -1) {
       this.get('stream').addObject(postId);
-      if (loadedAllPosts) { this.appendMore(); }
+      if (loadedAllPosts) {
+        this.set('loadingLastPost', true);
+        this.appendMore().finally(
+            ()=>this.set('loadingLastPost', true)
+        );
+      }
     }
   },