From a0f59a55ccc75678703e34748b58d9531f4254e1 Mon Sep 17 00:00:00 2001
From: Krzysztof Kotlarek <kotlarek.krzysztof@gmail.com>
Date: Tue, 31 Mar 2020 16:19:47 +1100
Subject: [PATCH] FIX: when a post is moved copy notifications level (#9311)

This is a revert of https://github.com/discourse/discourse/commit/2c011252f1c0443965ca5317169550083a43c657

More information on meta: https://meta.discourse.org/t/when-a-reply-is-moved-to-a-new-topic-the-followers-of-the-previous-topic-are-automatically-follower-of-the-new-topic-as-well/130025
---
 app/models/post_mover.rb       | 23 +++++++++--------------
 spec/models/post_mover_spec.rb |  4 ++--
 2 files changed, 11 insertions(+), 16 deletions(-)

diff --git a/app/models/post_mover.rb b/app/models/post_mover.rb
index 1037c3ff00e..0e36834ac88 100644
--- a/app/models/post_mover.rb
+++ b/app/models/post_mover.rb
@@ -332,8 +332,7 @@ class PostMover
       old_topic_id: original_topic.id,
       new_topic_id: destination_topic.id,
       old_highest_post_number: destination_topic.highest_post_number,
-      old_highest_staff_post_number: destination_topic.highest_staff_post_number,
-      default_notification_level: NotificationLevels.topic_levels[:regular]
+      old_highest_staff_post_number: destination_topic.highest_staff_post_number
     }
 
     DB.exec(<<~SQL, params)
@@ -342,9 +341,13 @@ class PostMover
                               notifications_changed_at, notifications_reason_id)
       SELECT tu.user_id,
              :new_topic_id                               AS topic_id,
-             CASE
-               WHEN p.user_id IS NULL THEN FALSE
-               ELSE TRUE END                             AS posted,
+               EXISTS(
+                 SELECT 1
+                 FROM posts p
+                 WHERE p.topic_id = :new_topic_id
+                   AND p.user_id = tu.user_id
+                 LIMIT 1
+               )                                         AS posted,
              (
                SELECT MAX(lr.new_post_number)
                FROM moved_posts lr
@@ -365,19 +368,11 @@ class PostMover
              )                                           AS last_emailed_post_number,
              GREATEST(tu.first_visited_at, t.created_at) AS first_visited_at,
              GREATEST(tu.last_visited_at, t.created_at)  AS last_visited_at,
-             CASE
-               WHEN p.user_id IS NOT NULL THEN tu.notification_level
-               ELSE :default_notification_level END      AS notification_level,
+             tu.notification_level,
              tu.notifications_changed_at,
              tu.notifications_reason_id
       FROM topic_users tu
            JOIN topics t ON (t.id = :new_topic_id)
-           LEFT OUTER JOIN
-           (
-             SELECT DISTINCT user_id
-             FROM posts
-             WHERE topic_id = :new_topic_id
-           ) p ON (p.user_id = tu.user_id)
       WHERE tu.topic_id = :old_topic_id
         AND GREATEST(
                 tu.last_read_post_number,
diff --git a/spec/models/post_mover_spec.rb b/spec/models/post_mover_spec.rb
index d198e2d33cd..aebfefe12d0 100644
--- a/spec/models/post_mover_spec.rb
+++ b/spec/models/post_mover_spec.rb
@@ -470,7 +470,7 @@ describe PostMover do
                       last_read_post_number: 2,
                       highest_seen_post_number: 2,
                       last_emailed_post_number: 2,
-                      notification_level: TopicUser.notification_levels[:regular],
+                      notification_level: TopicUser.notification_levels[:tracking],
                       posted: false
                     )
               expect(TopicUser.find_by(topic: new_topic, user: user2))
@@ -486,7 +486,7 @@ describe PostMover do
                       last_read_post_number: 1,
                       highest_seen_post_number: 2,
                       last_emailed_post_number: 2,
-                      notification_level: TopicUser.notification_levels[:regular],
+                      notification_level: TopicUser.notification_levels[:watching],
                       posted: false
                     )
             end