FIX: keep first post edit history when moving/merging (#22966)

app/models/post_mover.rb

@@ -260,7 +260,13 @@ class PostMover
 
     PostAction.copy(post, new_post)
 
-    attrs_to_update = { reply_count: @reply_count[1] || 0 }
+    PostRevision.copy(post, new_post)
+
+    attrs_to_update = {
+      reply_count: @reply_count[1] || 0,
+      version: post.version,
+      public_version: post.public_version,
+    }
 
     if new_post.post_number != @move_map[post.post_number]
       attrs_to_update[:post_number] = @move_map[post.post_number]

app/models/post_revision.rb

@@ -39,6 +39,17 @@ class PostRevision < ActiveRecord::Base
   def create_notification
     PostActionNotifier.after_create_post_revision(self)
   end
+
+  def self.copy(original_post, target_post)
+    cols_to_copy = (column_names - %w[id post_id]).join(", ")
+
+    DB.exec <<~SQL
+    INSERT INTO post_revisions(post_id, #{cols_to_copy})
+    SELECT #{target_post.id}, #{cols_to_copy}
+    FROM post_revisions
+    WHERE post_id = #{original_post.id}
+    SQL
+  end
 end
 
 # == Schema Information

spec/models/post_mover_spec.rb

@@ -875,6 +875,18 @@ RSpec.describe PostMover do
             expect(TopicUser.find_by(topic: destination_topic, user: user).liked).to eq(true)
           end
 
+          it "copies the post revisions from first post to the new post" do
+            p1.revise(another_user, { raw: "A different raw content" })
+
+            moved_to = topic.move_posts(user, [p1.id], destination_topic_id: destination_topic.id)
+            new_post = moved_to.posts.last
+
+            expect(new_post.id).not_to eq(p1.id)
+            expect(new_post.version).to eq(2)
+            expect(new_post.public_version).to eq(2)
+            expect(new_post.post_revisions.size).to eq(1)
+          end
+
           context "with read state and other stats per user" do
             def create_topic_user(user, topic, opts = {})
               notification_level = opts.delete(:notification_level) || :regular
@@ -1223,6 +1235,18 @@ RSpec.describe PostMover do
             expect(new_topic.first_post.custom_fields).to eq(custom_fields)
           end
 
+          it "preserves the post revisions in the new post" do
+            p1.revise(another_user, { raw: "A different raw content" })
+
+            new_topic = topic.move_posts(user, [p1.id], title: "new testing topic name")
+            new_post = new_topic.posts.where(post_number: 1).first
+
+            expect(new_post.id).not_to eq(p1.id)
+            expect(new_post.version).to eq(2)
+            expect(new_post.public_version).to eq(2)
+            expect(new_post.post_revisions.size).to eq(1)
+          end
+
           include_examples "moves email related stuff" do
             let!(:old_post) { p1 }
           end