FIX: If last post was deleted the gap was not displayed

app/assets/javascripts/discourse/components/scrolling-post-stream.js.es6

@@ -28,6 +28,7 @@ export default MountWidget.extend({
     return this.getProperties('posts',
                               'canCreatePost',
                               'multiSelect',
+                              'gaps',
                               'selectedQuery',
                               'selectedPostsCount',
                               'searchService');

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

@@ -280,6 +280,7 @@ export default RestModel.extend({
     if (idx !== -1) {
       stream.pushObjects(gap);
       return this.appendMore().then(() => {
+        delete this.get('gaps.after')[postId];
         this.get('stream').enumerableContentDidChange();
       });
     }

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

@@ -15,7 +15,7 @@ export default createWidget('post-stream', {
     const result = [];
 
     const before = attrs.gaps && attrs.gaps.before ? attrs.gaps.before : {};
-    const after = attrs.gaps && attrs.gaps.before ? attrs.gaps.after : {};
+    const after = attrs.gaps && attrs.gaps.after ? attrs.gaps.after : {};
 
     let prevPost;
     let prevDate;