FIX: incorrect edit notification in user stream

FIX: missing edit notifications when post edited by multiple users

app/models/post_alert_observer.rb

@@ -46,7 +46,13 @@ class PostAlertObserver < ActiveRecord::Observer
     return if post.topic.private_message?
     return if SiteSetting.disable_edit_notifications && post_revision.user_id == Discourse::SYSTEM_USER_ID
 
-    alerter.create_notification(post.user, Notification.types[:edited], post, display_username: post_revision.user.username)
+    alerter.create_notification(
+      post.user,
+      Notification.types[:edited],
+      post,
+        display_username: post_revision.user.username,
+        post_revision: post_revision
+    )
   end
 
 

app/models/user_action_observer.rb

@@ -33,7 +33,7 @@ class UserActionObserver < ActiveRecord::Observer
     end
   end
 
-  def self.log_notification(post, user, notification_type)
+  def self.log_notification(post, user, notification_type, acting_user_id = nil)
     action =
       case notification_type
         when Notification.types[:quoted]
@@ -52,7 +52,7 @@ class UserActionObserver < ActiveRecord::Observer
     row = {
         action_type: action,
         user_id: user.id,
-        acting_user_id: (action == UserAction::EDIT) ? post.last_editor_id : post.user_id,
+        acting_user_id: acting_user_id || post.user_id,
         target_topic_id: post.topic_id,
         target_post_id: post.id
     }

app/services/post_alerter.rb

@@ -90,7 +90,14 @@ class PostAlerter
     return if TopicUser.get(post.topic, user).try(:notification_level) == TopicUser.notification_levels[:muted]
 
     # Don't notify the same user about the same notification on the same post
-    return if user.notifications.exists?(notification_type: type, topic_id: post.topic_id, post_number: post.post_number)
+    existing_notification = user.notifications
+                                .order("notifications.id desc")
+                                .find_by(notification_type: type, topic_id: post.topic_id, post_number: post.post_number)
+
+    if(existing_notification)
+       return unless existing_notification.notification_type == Notification.types[:edited] &&
+                     existing_notification.data_hash["display_username"] = opts[:display_username]
+    end
 
     collapsed = false
 
@@ -116,7 +123,7 @@ class PostAlerter
       opts[:display_username] = I18n.t('embed.replies', count: count) if count > 1
     end
 
-    UserActionObserver.log_notification(original_post, user, type)
+    UserActionObserver.log_notification(original_post, user, type, opts[:post_revision].try(:user_id))
 
     # Create the notification
     user.notifications.create(notification_type: type,

spec/models/user_action_spec.rb

@@ -90,6 +90,17 @@ describe UserAction do
       # duplicate should not exception out
       log_test_action
 
+
+      # recategorize belongs to the right user
+      category2 = Fabricate(:category)
+      admin = Fabricate(:admin)
+      public_topic.acting_user = admin
+      public_topic.change_category_to_id(category2.id)
+
+      action = UserAction.stream(user_id: public_topic.user_id, guardian: Guardian.new)[0]
+      action.acting_user_id.should == admin.id
+      action.action_type.should == UserAction::EDIT
+
     end
   end