FIX: incoming and outgoing emails got lost when post was moved

app/models/post_mover.rb

@@ -92,10 +92,16 @@ class PostMover
       raw: post.raw,
       topic_id: destination_topic.id,
       acting_user: user,
+      cook_method: post.cook_method,
+      via_email: post.via_email,
+      raw_email: post.raw_email,
       skip_validations: true,
       guardian: Guardian.new(user)
     )
 
+    move_incoming_emails(post, new_post)
+    move_email_logs(post, new_post)
+
     PostAction.copy(post, new_post)
     new_post.update_column(:reply_count, @reply_count[1] || 0)
     new_post.custom_fields = post.custom_fields
@@ -123,12 +129,29 @@ class PostMover
 
     post.update(update)
 
+    move_incoming_emails(post, post)
+    move_email_logs(post, post)
+
     DiscourseEvent.trigger(:post_moved, post, original_topic.id)
 
     # Move any links from the post to the new topic
     post.topic_links.update_all(topic_id: destination_topic.id)
   end
 
+  def move_incoming_emails(old_post, new_post)
+    return if old_post.incoming_email.nil?
+
+    email = old_post.incoming_email
+    email.update_columns(topic_id: new_post.topic_id, post_id: new_post.id)
+    new_post.incoming_email = email
+  end
+
+  def move_email_logs(old_post, new_post)
+    EmailLog
+      .where(post_id: old_post.id)
+      .update_all(topic_id: new_post.topic_id, post_id: new_post.id)
+  end
+
   def update_statistics
     destination_topic.update_statistics
     original_topic.update_statistics

spec/models/post_mover_spec.rb

@@ -334,6 +334,49 @@ describe PostMover do
         end
       end
 
+      shared_examples "moves email related stuff" do
+        it "moves incoming email" do
+          Fabricate(:incoming_email, user: old_post.user, topic: old_post.topic, post: old_post)
+
+          new_topic = topic.move_posts(user, [old_post.id], title: "new testing topic name")
+          new_post = new_topic.first_post
+          email = new_post.incoming_email
+
+          expect(email).to be_present
+          expect(email.topic_id).to eq(new_topic.id)
+          expect(email.post_id).to eq(new_post.id)
+
+          expect(old_post.reload.incoming_email).to_not be_present unless old_post.id == new_post.id
+        end
+
+        it "moves email log entries" do
+          old_topic = old_post.topic
+          Fabricate(:email_log, user: old_post.user, topic: old_topic, post: old_post, email_type: :mailing_list)
+          Fabricate(:email_log, user: old_post.user, topic: old_topic, post: old_post, email_type: :mailing_list)
+          Fabricate(:email_log, user: old_post.user, post: old_post, email_type: :mailing_list)
+
+          expect(EmailLog.where(topic_id: old_topic.id, post_id: old_post.id).count).to eq(2)
+          expect(EmailLog.where(topic_id: nil, post_id: old_post.id).count).to eq(1)
+
+          new_topic = old_topic.move_posts(user, [old_post.id], title: "new testing topic name")
+          new_post = new_topic.first_post
+
+          expect(EmailLog.where(topic_id: old_topic.id, post_id: old_post.id).count).to eq(0)
+          expect(EmailLog.where(topic_id: new_topic.id, post_id: new_post.id).count).to eq(3)
+        end
+
+        it "preserves post attributes" do
+          old_post.update_columns(cook_method: Post.cook_methods[:email], via_email: true, raw_email: "raw email content")
+
+          new_topic = old_post.topic.move_posts(user, [old_post.id], title: "new testing topic name")
+          new_post = new_topic.first_post
+
+          expect(new_post.cook_method).to eq(Post.cook_methods[:email])
+          expect(new_post.via_email).to eq(true)
+          expect(new_post.raw_email).to eq("raw email content")
+        end
+      end
+
       context "moving the first post" do
 
         it "copies the OP, doesn't delete it" do
@@ -390,6 +433,15 @@ describe PostMover do
           expect(new_topic.first_post.custom_fields).to eq(custom_fields)
         end
 
+        include_examples "moves email related stuff" do
+          let!(:old_post) { p1 }
+        end
+      end
+
+      context "moving replies" do
+        include_examples "moves email related stuff" do
+          let!(:old_post) { p3 }
+        end
       end
 
       context "to an existing topic with a deleted post" do