From 3874d40910efb100fecdb975fe700b6e7b4f1ed6 Mon Sep 17 00:00:00 2001
From: Guo Xiang Tan <tgx_world@hotmail.com>
Date: Wed, 18 Jul 2018 10:21:54 +0800
Subject: [PATCH] Prepare to drop `EmailLog#topic_id`.

---
 app/models/email_log.rb              | 4 +++-
 lib/email/receiver.rb                | 2 +-
 lib/email/sender.rb                  | 8 +++-----
 spec/components/email/sender_spec.rb | 2 +-
 4 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/app/models/email_log.rb b/app/models/email_log.rb
index ee57d0db19f..10240f8bc70 100644
--- a/app/models/email_log.rb
+++ b/app/models/email_log.rb
@@ -1,6 +1,8 @@
 require_dependency 'distributed_mutex'
 
 class EmailLog < ActiveRecord::Base
+  self.ignored_columns = %w{topic_id}
+
   CRITICAL_EMAIL_TYPES ||= Set.new %w{
     account_created
     admin_login
@@ -14,7 +16,7 @@ class EmailLog < ActiveRecord::Base
 
   belongs_to :user
   belongs_to :post
-  belongs_to :topic
+  has_one :topic, through: :post
 
   validates :email_type, :to_address, presence: true
 
diff --git a/lib/email/receiver.rb b/lib/email/receiver.rb
index 50735806d2d..ae8da1a36f6 100644
--- a/lib/email/receiver.rb
+++ b/lib/email/receiver.rb
@@ -634,7 +634,7 @@ module Email
     def forwarded_reply_key?(email_log, user)
       incoming_emails = IncomingEmail
         .joins(:post)
-        .where('posts.topic_id = ?', email_log.topic_id)
+        .where('posts.topic_id = ?', email_log.topic.id)
         .addressed_to(email_log.reply_key)
         .addressed_to_user(user)
         .pluck(:to_addresses, :cc_addresses)
diff --git a/lib/email/sender.rb b/lib/email/sender.rb
index f36b9496924..7dca1fa8550 100644
--- a/lib/email/sender.rb
+++ b/lib/email/sender.rb
@@ -77,11 +77,9 @@ module Email
       # always set a default Message ID from the host
       @message.header['Message-ID'] = "<#{SecureRandom.uuid}@#{host}>"
 
-      if topic_id.present?
-        email_log.topic_id = topic_id
-
-        post = Post.find_by(id: post_id)
-        topic = Topic.find_by(id: topic_id)
+      if topic_id.present? && post_id.present?
+        post = Post.find_by(id: post_id, topic_id: topic_id)
+        topic = post.topic
         first_post = topic.ordered_posts.first
 
         topic_message_id = first_post.incoming_email&.message_id.present? ?
diff --git a/spec/components/email/sender_spec.rb b/spec/components/email/sender_spec.rb
index 65838ab1d06..5fad20d13b2 100644
--- a/spec/components/email/sender_spec.rb
+++ b/spec/components/email/sender_spec.rb
@@ -316,7 +316,7 @@ describe Email::Sender do
       it 'should create the right log' do
         email_sender.send
         expect(email_log.post_id).to eq(post.id)
-        expect(email_log.topic_id).to eq(topic.id)
+        expect(email_log.topic.id).to eq(topic.id)
       end
     end