From d24dc88dad0577f86efbd91cb9295f957f150b2d Mon Sep 17 00:00:00 2001
From: Ryuta Kamizono <kamipo@gmail.com>
Date: Fri, 8 Jan 2021 18:06:05 +0900
Subject: [PATCH] Revert "Fix update with dirty locking column to not match
 latest object accidentally"

---
 activemodel/lib/active_model/attribute.rb     | 14 +++++-----
 .../lib/active_record/locking/optimistic.rb   |  2 +-
 activerecord/test/cases/locking_test.rb       | 27 ++-----------------
 3 files changed, 10 insertions(+), 33 deletions(-)

diff --git a/activemodel/lib/active_model/attribute.rb b/activemodel/lib/active_model/attribute.rb
index 613d188c37..7facc6cc75 100644
--- a/activemodel/lib/active_model/attribute.rb
+++ b/activemodel/lib/active_model/attribute.rb
@@ -133,13 +133,14 @@ module ActiveModel
       coder["value"] = value if defined?(@value)
     end
 
-    def original_value_for_database
-      if assigned?
-        original_attribute.original_value_for_database
-      else
-        _original_value_for_database
+    protected
+      def original_value_for_database
+        if assigned?
+          original_attribute.original_value_for_database
+        else
+          _original_value_for_database
+        end
       end
-    end
 
     private
       attr_reader :original_attribute
@@ -167,7 +168,6 @@ module ActiveModel
         def _original_value_for_database
           value_before_type_cast
         end
-        private :_original_value_for_database
       end
 
       class FromUser < Attribute # :nodoc:
diff --git a/activerecord/lib/active_record/locking/optimistic.rb b/activerecord/lib/active_record/locking/optimistic.rb
index 48eb3222f8..015562d55c 100644
--- a/activerecord/lib/active_record/locking/optimistic.rb
+++ b/activerecord/lib/active_record/locking/optimistic.rb
@@ -98,7 +98,7 @@ module ActiveRecord
             affected_rows = self.class._update_record(
               attributes_with_values(attribute_names),
               @primary_key => id_in_database,
-              locking_column => @attributes[locking_column].original_value_for_database
+              locking_column => previous_lock_value
             )
 
             if affected_rows != 1
diff --git a/activerecord/test/cases/locking_test.rb b/activerecord/test/cases/locking_test.rb
index ee55d5200b..164dfb5a74 100644
--- a/activerecord/test/cases/locking_test.rb
+++ b/activerecord/test/cases/locking_test.rb
@@ -238,37 +238,14 @@ class OptimisticLockingTest < ActiveRecord::TestCase
     end
   end
 
-  def test_update_with_dirty_locking_column
-    person = Person.find(1)
-    person.first_name = "Douglas Adams"
-    person.lock_version = 42
-
-    changes = {
-      "first_name" => ["Michael", "Douglas Adams"],
-      "lock_version" => [0, 42],
-    }
-    assert_equal changes, person.changes
-
-    assert person.save!
-    assert_empty person.changes
-  end
-
   def test_explicit_update_lock_column_raise_error
     person = Person.find(1)
 
-    person2 = Person.find(1)
-    person2.lock_version = 42
-    person2.save!
-
     assert_raises(ActiveRecord::StaleObjectError) do
       person.first_name = "Douglas Adams"
-      person.lock_version = person2.lock_version
+      person.lock_version = 42
 
-      changes = {
-        "first_name" => ["Michael", "Douglas Adams"],
-        "lock_version" => [0, 43],
-      }
-      assert_equal changes, person.changes
+      assert_predicate person, :lock_version_changed?
 
       person.save
     end