From 0393b9262dcf1b8302d35a8a470e14837ca1300b Mon Sep 17 00:00:00 2001
From: Takayuki Hirayama <hirayama@atama.plus>
Date: Fri, 4 Jun 2021 00:32:55 +0900
Subject: [PATCH] Fixed #32812 -- Restored immutability of named values from
 QuerySet.values_list().

Regression in 981a072dd4dec586f8fc606712ed9a2ef116eeee.

Thanks pirelle for the report.
---
 django/db/models/utils.py       |  6 +++++-
 docs/releases/3.2.5.txt         |  4 +++-
 tests/model_utils/__init__.py   |  0
 tests/model_utils/tests.py      | 10 ++++++++++
 tests/prefetch_related/tests.py |  7 +++++++
 5 files changed, 25 insertions(+), 2 deletions(-)
 create mode 100644 tests/model_utils/__init__.py
 create mode 100644 tests/model_utils/tests.py

diff --git a/django/db/models/utils.py b/django/db/models/utils.py
index 764ca5888b..a8bd20fba7 100644
--- a/django/db/models/utils.py
+++ b/django/db/models/utils.py
@@ -45,4 +45,8 @@ def create_namedtuple_class(*names):
     def __reduce__(self):
         return unpickle_named_row, (names, tuple(self))
 
-    return type('Row', (namedtuple('Row', names),), {'__reduce__': __reduce__})
+    return type(
+        'Row',
+        (namedtuple('Row', names),),
+        {'__reduce__': __reduce__, '__slots__': ()},
+    )
diff --git a/docs/releases/3.2.5.txt b/docs/releases/3.2.5.txt
index f7b1d1e87b..b782985ca1 100644
--- a/docs/releases/3.2.5.txt
+++ b/docs/releases/3.2.5.txt
@@ -9,4 +9,6 @@ Django 3.2.5 fixes several bugs in 3.2.4.
 Bugfixes
 ========
 
-* ...
+* Fixed a regression in Django 3.2 that caused a crash of
+  ``QuerySet.values_list(…, named=True)`` after ``prefetch_related()``
+  (:ticket:`32812`).
diff --git a/tests/model_utils/__init__.py b/tests/model_utils/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/tests/model_utils/tests.py b/tests/model_utils/tests.py
new file mode 100644
index 0000000000..be4dd4300b
--- /dev/null
+++ b/tests/model_utils/tests.py
@@ -0,0 +1,10 @@
+from django.db.models.utils import create_namedtuple_class
+from django.test import SimpleTestCase
+
+
+class NamedTupleClassTests(SimpleTestCase):
+    def test_immutability(self):
+        row_class = create_namedtuple_class('field1', 'field2')
+        row = row_class('value1', 'value2')
+        with self.assertRaises(AttributeError):
+            row.field3 = 'value3'
diff --git a/tests/prefetch_related/tests.py b/tests/prefetch_related/tests.py
index e21bd5ec23..cba1897fc5 100644
--- a/tests/prefetch_related/tests.py
+++ b/tests/prefetch_related/tests.py
@@ -309,6 +309,13 @@ class PrefetchRelatedTests(TestDataMixin, TestCase):
                     list(Book.objects.prefetch_related(relation))
                     self.assertEqual(add_q_mock.call_count, 1)
 
+    def test_named_values_list(self):
+        qs = Author.objects.prefetch_related('books')
+        self.assertCountEqual(
+            [value.name for value in qs.values_list('name', named=True)],
+            ['Anne', 'Charlotte', 'Emily', 'Jane'],
+        )
+
 
 class RawQuerySetTests(TestDataMixin, TestCase):
     def test_basic(self):