[3.2.x] Fixed #32332 -- Fixed loss of parent with non-numeric pk when saving child after parent.

Follow up to 519016e5f2.

Backport of 7cba92ec55 from master

tests/many_to_one/tests.py

@@ -7,9 +7,9 @@ from django.test import TestCase
 from django.utils.translation import gettext_lazy
 
 from .models import (
-    Article, Category, Child, ChildNullableParent, City, Country, District,
-    First, Parent, Record, Relation, Reporter, School, Student, Third,
-    ToFieldChild,
+    Article, Category, Child, ChildNullableParent, ChildStringPrimaryKeyParent,
+    City, Country, District, First, Parent, ParentStringPrimaryKey, Record,
+    Relation, Reporter, School, Student, Third, ToFieldChild,
 )
 
 
@@ -549,6 +549,16 @@ class ManyToOneTests(TestCase):
         self.assertEqual(child.parent, parent)
         self.assertEqual(child.parent_id, parent.name)
 
+    def test_save_fk_after_parent_with_non_numeric_pk_set_on_child(self):
+        parent = ParentStringPrimaryKey()
+        child = ChildStringPrimaryKeyParent(parent=parent)
+        child.parent.name = 'jeff'
+        parent.save()
+        child.save()
+        child.refresh_from_db()
+        self.assertEqual(child.parent, parent)
+        self.assertEqual(child.parent_id, parent.name)
+
     def test_fk_to_bigautofield(self):
         ch = City.objects.create(name='Chicago')
         District.objects.create(city=ch, name='Far South')