diff --git a/app/assets/javascripts/discourse/controllers/topic_controller.js b/app/assets/javascripts/discourse/controllers/topic_controller.js
index da9a63c7345..c6bdf654fac 100644
--- a/app/assets/javascripts/discourse/controllers/topic_controller.js
+++ b/app/assets/javascripts/discourse/controllers/topic_controller.js
@@ -400,7 +400,7 @@ Discourse.TopicController = Discourse.ObjectController.extend(Discourse.Selected
       if (data.type === "revised" || data.type === "acted"){
         // TODO we could update less data for "acted"
         // (only post actions)
-        postStream.triggerChangedPost(data.id, data.updated_at);
+        postStream.triggerChangedPost(data.id, data.updated_at, data.type);
         return;
       }
 
diff --git a/app/assets/javascripts/discourse/models/post.js b/app/assets/javascripts/discourse/models/post.js
index 7d06c66dfa7..7517a0e9589 100644
--- a/app/assets/javascripts/discourse/models/post.js
+++ b/app/assets/javascripts/discourse/models/post.js
@@ -284,9 +284,30 @@ Discourse.Post = Discourse.Model.extend({
     var post = this;
     Object.keys(otherPost).forEach(function (key) {
       var value = otherPost[key];
-      if (typeof value !== "function") {
-        post.set(key, value);
+      var oldValue = post.get(key);
+
+      if(!value) {
+        value = null;
       }
+
+      if(!oldValue) {
+        oldValue = null;
+      }
+
+      var skip = false;
+
+      if (typeof value !== "function" && oldValue !== value) {
+
+        // wishing for an identity map
+        if(key === "reply_to_user") {
+          skip = Em.get(value, "username") === Em.get(oldValue, "username");
+        }
+
+        if(!skip) {
+          post.set(key, value);
+        }
+      }
+
     });
   },
 
diff --git a/app/assets/javascripts/discourse/models/post_stream.js b/app/assets/javascripts/discourse/models/post_stream.js
index 4179812ffc5..1340683864a 100644
--- a/app/assets/javascripts/discourse/models/post_stream.js
+++ b/app/assets/javascripts/discourse/models/post_stream.js
@@ -504,7 +504,7 @@ Discourse.PostStream = Em.Object.extend({
     }
   },
 
-  triggerChangedPost: function(postId, updatedAt) {
+  triggerChangedPost: function(postId, updatedAt, type) {
     if (!postId) { return; }
 
     var postIdentityMap = this.get('postIdentityMap'),
diff --git a/app/controllers/posts_controller.rb b/app/controllers/posts_controller.rb
index efee6a1ceeb..f3c00de750f 100644
--- a/app/controllers/posts_controller.rb
+++ b/app/controllers/posts_controller.rb
@@ -218,6 +218,8 @@ class PostsController < ApplicationController
   def render_post_json(post)
     post_serializer = PostSerializer.new(post, scope: guardian, root: false)
     post_serializer.add_raw = true
+    post_serializer.topic_slug = post.topic.slug if post.topic.present?
+
     counts = PostAction.counts_for([post], current_user)
     if counts && counts = counts[post.id]
       post_serializer.post_actions = counts
diff --git a/app/models/user.rb b/app/models/user.rb
index c10f36b4513..738e05d5edc 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -41,6 +41,7 @@ class User < ActiveRecord::Base
   has_one :user_stat, dependent: :destroy
   has_one :single_sign_on_record, dependent: :destroy
   belongs_to :approved_by, class_name: 'User'
+  belongs_to :primary_group, class_name: 'Group'
 
   has_many :group_users, dependent: :destroy
   has_many :groups, through: :group_users
diff --git a/app/serializers/post_serializer.rb b/app/serializers/post_serializer.rb
index f82f4af9edf..35b3951ef06 100644
--- a/app/serializers/post_serializer.rb
+++ b/app/serializers/post_serializer.rb
@@ -78,8 +78,13 @@ class PostSerializer < BasicPostSerializer
   end
 
   def primary_group_name
-    return nil unless object.user && @topic_view
-    return @topic_view.primary_group_names[object.user.primary_group_id] if object.user.primary_group_id
+    return nil unless object.user && object.user.primary_group_id
+
+    if @topic_view
+      @topic_view.primary_group_names[object.user.primary_group_id]
+    else
+      object.user.primary_group.name if object.user.primary_group
+    end
   end
 
   def link_counts
diff --git a/spec/controllers/posts_controller_spec.rb b/spec/controllers/posts_controller_spec.rb
index 735a88f9822..4b5474e5856 100644
--- a/spec/controllers/posts_controller_spec.rb
+++ b/spec/controllers/posts_controller_spec.rb
@@ -62,6 +62,17 @@ describe PostsController do
       let(:action) { :show }
       let(:params) { {id: post.id} }
     end
+
+    it 'gets all the expected fields' do
+      # non fabricated test
+      new_post = create_post
+      xhr :get, :show, {id: new_post.id}
+      parsed = JSON.parse(response.body)
+      parsed["topic_slug"].should == new_post.topic.slug
+      parsed["moderator"].should == false
+      parsed["username"].should == new_post.user.username
+      parsed["cooked"].should == new_post.cooked
+    end
   end
 
   describe 'by_number' do