From d9de74141e8a920940f1b91ed0a3ccb835b55729 Mon Sep 17 00:00:00 2001
From: Adam Johnson <me@adamj.eu>
Date: Sat, 13 Feb 2021 08:58:24 +0000
Subject: [PATCH] Fixed #32442 -- Used converters on returning fields from
 INSERT statements.

---
 django/db/models/sql/compiler.py | 21 +++++++++++++++------
 tests/custom_pk/fields.py        | 14 +++++++++++++-
 tests/custom_pk/models.py        |  8 ++++++--
 tests/custom_pk/tests.py         | 15 +++++++++++++--
 4 files changed, 47 insertions(+), 11 deletions(-)

diff --git a/django/db/models/sql/compiler.py b/django/db/models/sql/compiler.py
index f02199d97c..11ad4fde90 100644
--- a/django/db/models/sql/compiler.py
+++ b/django/db/models/sql/compiler.py
@@ -1405,6 +1405,7 @@ class SQLInsertCompiler(SQLCompiler):
             returning_fields and len(self.query.objs) != 1 and
             not self.connection.features.can_return_rows_from_bulk_insert
         )
+        opts = self.query.get_meta()
         self.returning_fields = returning_fields
         with self.connection.cursor() as cursor:
             for sql, params in self.as_sql():
@@ -1412,13 +1413,21 @@ class SQLInsertCompiler(SQLCompiler):
             if not self.returning_fields:
                 return []
             if self.connection.features.can_return_rows_from_bulk_insert and len(self.query.objs) > 1:
-                return self.connection.ops.fetch_returned_insert_rows(cursor)
-            if self.connection.features.can_return_columns_from_insert:
+                rows = self.connection.ops.fetch_returned_insert_rows(cursor)
+            elif self.connection.features.can_return_columns_from_insert:
                 assert len(self.query.objs) == 1
-                return [self.connection.ops.fetch_returned_insert_columns(cursor, self.returning_params)]
-            return [(self.connection.ops.last_insert_id(
-                cursor, self.query.get_meta().db_table, self.query.get_meta().pk.column
-            ),)]
+                rows = [self.connection.ops.fetch_returned_insert_columns(
+                    cursor, self.returning_params,
+                )]
+            else:
+                rows = [(self.connection.ops.last_insert_id(
+                    cursor, opts.db_table, opts.pk.column,
+                ),)]
+        cols = [field.get_col(opts.db_table) for field in self.returning_fields]
+        converters = self.get_converters(cols)
+        if converters:
+            rows = list(self.apply_converters(rows, converters))
+        return rows
 
 
 class SQLDeleteCompiler(SQLCompiler):
diff --git a/tests/custom_pk/fields.py b/tests/custom_pk/fields.py
index 5bd249df3c..bc7259300b 100644
--- a/tests/custom_pk/fields.py
+++ b/tests/custom_pk/fields.py
@@ -20,7 +20,7 @@ class MyWrapper:
         return self.value == other
 
 
-class MyAutoField(models.CharField):
+class MyWrapperField(models.CharField):
 
     def __init__(self, *args, **kwargs):
         kwargs['max_length'] = 10
@@ -58,3 +58,15 @@ class MyAutoField(models.CharField):
         if isinstance(value, MyWrapper):
             return str(value)
         return value
+
+
+class MyAutoField(models.BigAutoField):
+    def from_db_value(self, value, expression, connection):
+        if value is None:
+            return None
+        return MyWrapper(value)
+
+    def get_prep_value(self, value):
+        if value is None:
+            return None
+        return int(value)
diff --git a/tests/custom_pk/models.py b/tests/custom_pk/models.py
index edfc6712f3..d9a73885f2 100644
--- a/tests/custom_pk/models.py
+++ b/tests/custom_pk/models.py
@@ -7,7 +7,7 @@ this behavior by explicitly adding ``primary_key=True`` to a field.
 
 from django.db import models
 
-from .fields import MyAutoField
+from .fields import MyAutoField, MyWrapperField
 
 
 class Employee(models.Model):
@@ -31,8 +31,12 @@ class Business(models.Model):
 
 
 class Bar(models.Model):
-    id = MyAutoField(primary_key=True, db_index=True)
+    id = MyWrapperField(primary_key=True, db_index=True)
 
 
 class Foo(models.Model):
     bar = models.ForeignKey(Bar, models.CASCADE)
+
+
+class CustomAutoFieldModel(models.Model):
+    id = MyAutoField(primary_key=True)
diff --git a/tests/custom_pk/tests.py b/tests/custom_pk/tests.py
index abb4ccd90b..cbf1fd2cb6 100644
--- a/tests/custom_pk/tests.py
+++ b/tests/custom_pk/tests.py
@@ -1,7 +1,8 @@
 from django.db import IntegrityError, transaction
-from django.test import TestCase, skipIfDBFeature
+from django.test import TestCase, skipIfDBFeature, skipUnlessDBFeature
 
-from .models import Bar, Business, Employee, Foo
+from .fields import MyWrapper
+from .models import Bar, Business, CustomAutoFieldModel, Employee, Foo
 
 
 class BasicCustomPKTests(TestCase):
@@ -230,3 +231,13 @@ class CustomPKTests(TestCase):
         with self.assertRaises(IntegrityError):
             with transaction.atomic():
                 Employee.objects.create(first_name="Tom", last_name="Smith")
+
+    def test_auto_field_subclass_create(self):
+        obj = CustomAutoFieldModel.objects.create()
+        self.assertIsInstance(obj.id, MyWrapper)
+
+    @skipUnlessDBFeature('can_return_rows_from_bulk_insert')
+    def test_auto_field_subclass_bulk_create(self):
+        obj = CustomAutoFieldModel()
+        CustomAutoFieldModel.objects.bulk_create([obj])
+        self.assertIsInstance(obj.id, MyWrapper)