Merge pull request #18349 from jdelStrother/primarykeyless

Fix rollback of primarykey-less tables

activerecord/lib/active_record/transactions.rb

@@ -378,7 +378,7 @@ def restore_transaction_record_state(force = false) #:nodoc:
           thaw unless restore_state[:frozen?]
           @new_record = restore_state[:new_record]
           @destroyed  = restore_state[:destroyed]
-          write_attribute(self.class.primary_key, restore_state[:id])
+          write_attribute(self.class.primary_key, restore_state[:id]) if self.class.primary_key
         end
       end
     end

activerecord/test/cases/transactions_test.rb

@@ -650,6 +650,28 @@ def test_transactions_state_from_commit
     assert transaction.state.committed?
   end
 
+  def test_transaction_rollback_with_primarykeyless_tables
+    connection = ActiveRecord::Base.connection
+    connection.create_table(:transaction_without_primary_keys, force: true, id: false) do |t|
+       t.integer :thing_id
+    end
+    
+    klass = Class.new(ActiveRecord::Base) do
+      self.table_name = 'transaction_without_primary_keys'
+      after_commit { } # necessary to trigger the has_transactional_callbacks branch
+    end
+
+    assert_no_difference(-> { klass.count }) do
+      ActiveRecord::Base.transaction do
+        klass.create!
+        raise ActiveRecord::Rollback
+      end
+    end
+    
+  ensure
+    connection.execute("DROP TABLE IF EXISTS transaction_without_primary_keys")
+  end
+
   private
 
   %w(validation save destroy).each do |filter|