Merge pull request #22395 from avokhmin/becomes-errors-base-2

`ActiveRecord::Base#becomes` should copy the errors

2 files changed, 21 insertions, 2 deletions

diff --git a/activerecord/lib/active_record/persistence.rb b/activerecord/lib/active_record/persistence.rb
index 9e566031b8..522c35252f 100644
--- a/activerecord/lib/active_record/persistence.rb
+++ b/activerecord/lib/active_record/persistence.rb
@@ -215,7 +215,7 @@ module ActiveRecord
       became.instance_variable_set("@changed_attributes", attributes_changed_by_setter)
       became.instance_variable_set("@new_record", new_record?)
       became.instance_variable_set("@destroyed", destroyed?)
-      became.instance_variable_set("@errors", errors)
+      became.errors.copy!(errors)
       became
     end
 
diff --git a/activerecord/test/cases/persistence_test.rb b/activerecord/test/cases/persistence_test.rb
index b2e59e3970..af15e63d9c 100644
--- a/activerecord/test/cases/persistence_test.rb
+++ b/activerecord/test/cases/persistence_test.rb
@@ -19,6 +19,8 @@ require 'models/person'
 require 'models/pet'
 require 'models/ship'
 require 'models/toy'
+require 'models/admin'
+require 'models/admin/user'
 require 'rexml/document'
 
 class PersistenceTest < ActiveRecord::TestCase
@@ -161,7 +163,24 @@ class PersistenceTest < ActiveRecord::TestCase
     assert !company.valid?
     original_errors = company.errors
     client = company.becomes(Client)
-    assert_equal original_errors, client.errors
+    assert_equal original_errors.keys, client.errors.keys
+  end
+
+  def test_becomes_errors_base
+    child_class = Class.new(Admin::User) do
+      store_accessor :settings, :foo
+
+      def self.name; 'Admin::ChildUser'; end
+    end
+
+    admin = Admin::User.new
+    admin.errors.add :token, :invalid
+    child = admin.becomes(child_class)
+
+    assert_equal [:token], child.errors.keys
+    assert_nothing_raised do
+      child.errors.add :foo, :invalid
+    end
   end
 
   def test_dupd_becomes_persists_changes_from_the_original