add test for same named subclass in different apps

src/polymorphic/tests/deletion/migrations/0001_initial.py

@@ -1,4 +1,4 @@
-# Generated by Django 4.2 on 2026-01-12 11:07
+# Generated by Django 4.2 on 2026-01-12 13:15
 
 from decimal import Decimal
 from django.conf import settings

src/polymorphic/tests/examples/views/migrations/0001_initial.py

@@ -1,4 +1,4 @@
-# Generated by Django 4.2 on 2026-01-12 11:07
+# Generated by Django 4.2 on 2026-01-12 13:15
 
 from django.db import migrations, models
 import django.db.models.deletion

src/polymorphic/tests/migrations/0001_initial.py

@@ -1,4 +1,4 @@
-# Generated by Django 4.2 on 2026-01-12 11:07
+# Generated by Django 4.2 on 2026-01-12 13:15
 
 from django.conf import settings
 from django.db import migrations, models
@@ -14,8 +14,8 @@ class Migration(migrations.Migration):
     initial = True
 
     dependencies = [
-        ('auth', '0012_alter_user_first_name_max_length'),
         ('contenttypes', '0002_remove_content_type_name'),
+        ('auth', '0012_alter_user_first_name_max_length'),
     ]
 
     operations = [

src/polymorphic/tests/other/migrations/0001_initial.py

@@ -0,0 +1,27 @@
+# Generated by Django 4.2 on 2026-01-12 13:15
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+        ('tests', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='UserProfile',
+            fields=[
+                ('participant', models.OneToOneField(on_delete=django.db.models.deletion.CASCADE, parent_link=True, primary_key=True, related_name='other_userprofile', serialize=False, to='tests.participant')),
+                ('name', models.CharField(max_length=100)),
+            ],
+            options={
+                'abstract': False,
+            },
+            bases=('tests.participant',),
+        ),
+    ]

src/polymorphic/tests/other/models.py

@@ -0,0 +1,12 @@
+from polymorphic.tests.models import Participant
+from django.db import models
+
+
+class UserProfile(Participant):
+    participant = models.OneToOneField(
+        Participant, parent_link=True, on_delete=models.CASCADE, related_name="other_userprofile"
+    )
+    name = models.CharField(max_length=100)
+
+    def __str__(self):
+        return self.name

src/polymorphic/tests/other/test_cross_apps.py

@@ -0,0 +1,21 @@
+from django.test import TestCase
+from django.core.exceptions import FieldError
+
+
+class TestCrossAppSubclasses(TestCase):
+    def test_samename_different_app_subclasses(self):
+        from polymorphic.tests.other.models import UserProfile as OtherUserProfile
+        from polymorphic.tests.models import Participant, UserProfile
+
+        p1 = Participant.objects.create()
+        p2 = UserProfile.objects.create(name="userprofile1")
+        p3 = OtherUserProfile.objects.create(name="otheruserprofile1")
+
+        assert set(Participant.objects.all()) == {p1, p2, p3}
+
+        with self.assertRaises(FieldError):
+            Participant.objects.filter(UserProfile___name="otheruserprofile1")
+
+        assert set(Participant.objects.filter(other__UserProfile___name="otheruserprofile1")) == {
+            p3
+        }

src/polymorphic/tests/settings.py

@@ -107,6 +107,7 @@ INSTALLED_APPS = (
     "polymorphic",
     "polymorphic.tests",
     "polymorphic.tests.deletion",
+    "polymorphic.tests.other",
     "polymorphic.tests.test_migrations",
     "polymorphic.tests.examples.views",
 )

uv.lock

@@ -868,11 +868,11 @@ wheels = [
 
 [[package]]
 name = "identify"
-version = "2.6.15"
+version = "2.6.16"
 source = { registry = "https://pypi.org/simple" }
-sdist = { url = "https://files.pythonhosted.org/packages/ff/e7/685de97986c916a6d93b3876139e00eef26ad5bbbd61925d670ae8013449/identify-2.6.15.tar.gz", hash = "sha256:e4f4864b96c6557ef2a1e1c951771838f4edc9df3a72ec7118b338801b11c7bf", size = 99311, upload-time = "2025-10-02T17:43:40.631Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/5b/8d/e8b97e6bd3fb6fb271346f7981362f1e04d6a7463abd0de79e1fda17c067/identify-2.6.16.tar.gz", hash = "sha256:846857203b5511bbe94d5a352a48ef2359532bc8f6727b5544077a0dcfb24980", size = 99360, upload-time = "2026-01-12T18:58:58.201Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/0f/1c/e5fd8f973d4f375adb21565739498e2e9a1e54c858a97b9a8ccfdc81da9b/identify-2.6.15-py2.py3-none-any.whl", hash = "sha256:1181ef7608e00704db228516541eb83a88a9f94433a8c80bb9b5bd54b1d81757", size = 99183, upload-time = "2025-10-02T17:43:39.137Z" },
+    { url = "https://files.pythonhosted.org/packages/b8/58/40fbbcefeda82364720eba5cf2270f98496bdfa19ea75b4cccae79c698e6/identify-2.6.16-py2.py3-none-any.whl", hash = "sha256:391ee4d77741d994189522896270b787aed8670389bfd60f326d677d64a6dfb0", size = 99202, upload-time = "2026-01-12T18:58:56.627Z" },
 ]
 
 [[package]]