FIX: invited staged users would sometimes not get notified of replies

app/models/topic_user.rb

@@ -38,26 +38,19 @@ class TopicUser < ActiveRecord::Base
     end
 
     def auto_notification(user_id, topic_id, reason, notification_level)
-      if TopicUser.where("user_id = :user_id AND topic_id = :topic_id AND (notifications_reason_id IS NULL OR
+      should_change = TopicUser
-        (notification_level < :notification_level AND notification_level > :normal_notification_level))",
+        .where(user_id: user_id, topic_id: topic_id)
-                           user_id: user_id, topic_id: topic_id, notification_level: notification_level,
+	.where("notifications_reason_id IS NULL OR (notification_level < :min AND notification_level > :max)", min: notification_level, max: notification_levels[:regular])
-                           normal_notification_level: notification_levels[:regular]).exists?
+        .exists?
-        change(user_id, topic_id,
+
-          notification_level: notification_level,
+      change(user_id, topic_id, notification_level: notification_level, notifications_reason_id: reason) if should_change
-          notifications_reason_id: reason
-        )
-      end
     end
 
-    def auto_notification_for_staging(user_id, topic_id, reason)
+    def auto_notification_for_staging(user_id, topic_id, reason, notification_level=notification_levels[:watching])
-      topic_user = TopicUser.find_or_initialize_by(user_id: user_id, topic_id: topic_id)
+      change(user_id, topic_id, notification_level: notification_level, notifications_reason_id: reason)
-      topic_user.notification_level = notification_levels[:watching]
-      topic_user.notifications_reason_id = reason
-      topic_user.save
     end
 
     def unwatch_categories!(user, category_ids)
-
       track_threshold = user.user_option.auto_track_topics_after_msecs
 
       sql = <<SQL

app/services/post_alerter.rb

@@ -93,7 +93,7 @@ class PostAlerter
         DiscourseEvent.trigger(:before_create_notifications_for_users, users, post)
         users.each do |user|
           notification_level = TopicUser.get(post.topic, user).try(:notification_level)
-          if notified.include?(user) || notification_level == TopicUser.notification_levels[:watching]
+          if notified.include?(user) || notification_level == TopicUser.notification_levels[:watching] || user.staged?
             create_notification(user, Notification.types[:private_message], post)
           end
         end

lib/email/receiver.rb

@@ -692,7 +692,7 @@ module Email
       if result.post
         @incoming_email.update_columns(topic_id: result.post.topic_id, post_id: result.post.id)
         if result.post.topic && result.post.topic.private_message?
-          add_other_addresses(result.post.topic, user)
+          add_other_addresses(result.post, user)
         end
       end
 
@@ -707,7 +707,7 @@ module Email
       html
     end
 
-    def add_other_addresses(topic, sender)
+    def add_other_addresses(post, sender)
       %i(to cc bcc).each do |d|
         if @mail[d] && @mail[d].address_list && @mail[d].address_list.addresses
           @mail[d].address_list.addresses.each do |address_field|
@@ -718,13 +718,14 @@ module Email
               next unless email["@"]
               if should_invite?(email)
                 user = find_or_create_user(email, display_name)
-                if user && can_invite?(topic, user)
+                if user && can_invite?(post.topic, user)
-                  topic.topic_allowed_users.create!(user_id: user.id)
+                  post.topic.topic_allowed_users.create!(user_id: user.id)
-                  topic.add_small_action(sender, "invited_user", user.username)
+                  TopicUser.auto_notification_for_staging(user.id, post.topic_id, TopicUser.notification_reasons[:auto_watch])
+                  post.topic.add_small_action(sender, "invited_user", user.username)
                 end
                 # cap number of staged users created per email
                 if @staged_users.count > SiteSetting.maximum_staged_users_per_email
-                  topic.add_moderator_post(sender, I18n.t("emails.incoming.maximum_staged_user_per_email_reached"))
+                  post.topic.add_moderator_post(sender, I18n.t("emails.incoming.maximum_staged_user_per_email_reached"))
                   return
                 end
               end

lib/post_creator.rb

@@ -508,12 +508,9 @@ class PostCreator
 
     if @user.staged
       TopicUser.auto_notification_for_staging(@user.id, @topic.id, TopicUser.notification_reasons[:auto_watch])
-    elsif @user.user_option.notification_level_when_replying === NotificationLevels.topic_levels[:watching]
-      TopicUser.auto_notification(@user.id, @topic.id, TopicUser.notification_reasons[:created_post], NotificationLevels.topic_levels[:watching])
-    elsif @user.user_option.notification_level_when_replying === NotificationLevels.topic_levels[:regular]
-      TopicUser.auto_notification(@user.id, @topic.id, TopicUser.notification_reasons[:created_post], NotificationLevels.topic_levels[:regular])
     else
-      TopicUser.auto_notification(@user.id, @topic.id, TopicUser.notification_reasons[:created_post], NotificationLevels.topic_levels[:tracking])
+      notification_level = @user.user_option.notification_level_when_replying || NotificationLevels.topic_levels[:tracking]
+      TopicUser.auto_notification(@user.id, @topic.id, TopicUser.notification_reasons[:created_post], notification_level)
     end
   end
 

spec/components/email/receiver_spec.rb

@@ -419,9 +419,13 @@ describe Email::Receiver do
 
     it "invites everyone in the chain but emails configured as 'incoming' (via reply, group or category)" do
       expect { process(:cc) }.to change(Topic, :count)
-      emails = Topic.last.allowed_users.joins(:user_emails).pluck(:"user_emails.email")
+
-      expect(emails.size).to eq(3)
+      topic = Topic.last
-      expect(emails).to include("someone@else.com", "discourse@bar.com", "wat@bar.com")
+
+      emails = topic.allowed_users.joins(:user_emails).pluck(:"user_emails.email")
+      expect(emails).to contain_exactly("someone@else.com", "discourse@bar.com", "wat@bar.com")
+
+      expect(topic.topic_users.count).to eq(3)
     end
 
     it "cap the number of staged users created per email" do