Don't map id to primary key in raw_write_attribute

The `raw_write_attribute` method is used to update a record's attributes
to reflect the new state of the database in `update_columns`. The hash
provided to `update_columns` is turned into an UPDATE query directly,
which means passing an `id` key results in an update to the `id` column,
even if the model uses a different attribute as its primary key. When
updating the record, we don't want to apply the `id` column change to
the primary key attribute, since that's not what happened in the query.

Without the code to handle this case, `write_attribute_with_type_cast`
no longer contains any logic shared between `raw_write_attribute` and
`write_attribute`, so we can inline the code into those two methods.

activerecord/lib/active_record/attribute_methods/write.rb

@@ -35,11 +35,15 @@ module ActiveRecord
           attr_name.to_s
         end
 
-        write_attribute_with_type_cast(name, value, true)
+        name = self.class.primary_key if name == "id".freeze && self.class.primary_key
+        @attributes.write_from_user(name, value)
+        value
       end
 
       def raw_write_attribute(attr_name, value) # :nodoc:
-        write_attribute_with_type_cast(attr_name, value, false)
+        name = attr_name.to_s
+        @attributes.write_cast_value(name, value)
+        value
       end
 
       private
@@ -47,19 +51,6 @@ module ActiveRecord
         def attribute=(attribute_name, value)
           write_attribute(attribute_name, value)
         end
-
-        def write_attribute_with_type_cast(attr_name, value, should_type_cast)
-          attr_name = attr_name.to_s
-          attr_name = self.class.primary_key if attr_name == "id" && self.class.primary_key
-
-          if should_type_cast
-            @attributes.write_from_user(attr_name, value)
-          else
-            @attributes.write_cast_value(attr_name, value)
-          end
-
-          value
-        end
     end
   end
 end

activerecord/test/cases/primary_keys_test.rb

@@ -80,6 +80,12 @@ class PrimaryKeysTest < ActiveRecord::TestCase
     assert_equal 1, subscriber.update_count
   end
 
+  def test_update_columns_with_non_primary_key_id_column
+    subscriber = Subscriber.first
+    subscriber.update_columns(id: 1)
+    assert_not_equal 1, subscriber.nick
+  end
+
   def test_string_key
     subscriber = Subscriber.find(subscribers(:first).nick)
     assert_equal(subscribers(:first).name, subscriber.name)