3 files changed, 30 insertions, 20 deletions
diff --git a/tests/admin_views/admin.py b/tests/admin_views/admin.py
index 4dcf40b610..2493c309ce 100644
--- a/tests/admin_views/admin.py
+++ b/tests/admin_views/admin.py
@@ -36,8 +36,8 @@ from .models import (Article, Chapter, Child, Parent, Picture, Widget,
     FilteredManager, EmptyModelHidden, EmptyModelVisible, EmptyModelMixin,
     State, City, Restaurant, Worker, ParentWithDependentChildren,
     DependentChild, StumpJoke, FieldOverridePost, FunkyTag,
-    ReferencedByParent, ChildOfReferer, M2MReference, ReferencedByInline,
-    InlineReference, InlineReferer, Ingredient)
+    ReferencedByParent, ChildOfReferer, ReferencedByInline,
+    InlineReference, InlineReferer, Recipe, Ingredient, NotReferenced)
 
 
 def callable_year(dt_value):
@@ -901,7 +901,6 @@ site.register(Worker, WorkerAdmin)
 site.register(FunkyTag, FunkyTagAdmin)
 site.register(ReferencedByParent)
 site.register(ChildOfReferer)
-site.register(M2MReference)
 site.register(ReferencedByInline)
 site.register(InlineReferer, InlineRefererAdmin)
 
@@ -940,7 +939,9 @@ site.register(EmptyModelHidden, EmptyModelHiddenAdmin)
 site.register(EmptyModelVisible, EmptyModelVisibleAdmin)
 site.register(EmptyModelMixin, EmptyModelMixinAdmin)
 site.register(StumpJoke)
+site.register(Recipe)
 site.register(Ingredient)
+site.register(NotReferenced)
 
 # Register core models we need in our tests
 from django.contrib.auth.models import User, Group
diff --git a/tests/admin_views/models.py b/tests/admin_views/models.py
index 97be6dc340..5101ea5463 100644
--- a/tests/admin_views/models.py
+++ b/tests/admin_views/models.py
@@ -827,28 +827,28 @@ class Worker(models.Model):
 
 # Models for #23329
 class ReferencedByParent(models.Model):
-    pass
+    name = models.CharField(max_length=20, unique=True)
 
 
 class ParentWithFK(models.Model):
-    fk = models.ForeignKey(ReferencedByParent)
+    fk = models.ForeignKey(
+        ReferencedByParent, to_field='name', related_name='hidden+',
+    )
 
 
 class ChildOfReferer(ParentWithFK):
     pass
 
 
-class M2MReference(models.Model):
-    ref = models.ManyToManyField('self')
-
-
 # Models for #23431
 class ReferencedByInline(models.Model):
-    pass
+    name = models.CharField(max_length=20, unique=True)
 
 
 class InlineReference(models.Model):
-    fk = models.ForeignKey(ReferencedByInline, related_name='hidden+')
+    fk = models.ForeignKey(
+        ReferencedByInline, to_field='name', related_name='hidden+',
+    )
 
 
 class InlineReferer(models.Model):
@@ -857,9 +857,14 @@ class InlineReferer(models.Model):
 
 # Models for #23604
 class Recipe(models.Model):
-    name = models.CharField(max_length=20)
+    pass
 
 
 class Ingredient(models.Model):
-    name = models.CharField(max_length=20)
-    recipes = models.ManyToManyField('Recipe', related_name='ingredients')
+    recipes = models.ManyToManyField(Recipe)
+
+
+# Model for #23839
+class NotReferenced(models.Model):
+    # Don't point any FK at this model.
+    pass
diff --git a/tests/admin_views/tests.py b/tests/admin_views/tests.py
index 3d1c5eb7c8..e6077f26af 100644
--- a/tests/admin_views/tests.py
+++ b/tests/admin_views/tests.py
@@ -612,26 +612,30 @@ class AdminViewBasicTest(AdminViewBasicTestCase):
             self.assertEqual(response.status_code, 400)
             self.assertEqual(len(calls), 1)
 
-        # Specifying a field referenced by another model should be allowed.
-        response = self.client.get("/test_admin/admin/admin_views/section/", {TO_FIELD_VAR: 'id'})
+        # #23839 - Primary key should always be allowed, even if the referenced model isn't registered.
+        response = self.client.get("/test_admin/admin/admin_views/notreferenced/", {TO_FIELD_VAR: 'id'})
         self.assertEqual(response.status_code, 200)
 
         # Specifying a field referenced by another model though a m2m should be allowed.
-        response = self.client.get("/test_admin/admin/admin_views/m2mreference/", {TO_FIELD_VAR: 'id'})
+        # XXX: We're not testing against a non-primary key field since the admin doesn't
+        # support it yet, ref #23862
+        response = self.client.get("/test_admin/admin/admin_views/recipe/", {TO_FIELD_VAR: 'id'})
         self.assertEqual(response.status_code, 200)
 
-        # #23604 - Specifying the pk of this model should be allowed when this model defines a m2m relationship
+        # #23604 - Specifying a field referenced through a reverse m2m relationship should be allowed.
+        # XXX: We're not testing against a non-primary key field since the admin doesn't
+        # support it yet, ref #23862
         response = self.client.get("/test_admin/admin/admin_views/ingredient/", {TO_FIELD_VAR: 'id'})
         self.assertEqual(response.status_code, 200)
 
         # #23329 - Specifying a field that is not referred by any other model directly registered
         # to this admin site but registered through inheritance should be allowed.
-        response = self.client.get("/test_admin/admin/admin_views/referencedbyparent/", {TO_FIELD_VAR: 'id'})
+        response = self.client.get("/test_admin/admin/admin_views/referencedbyparent/", {TO_FIELD_VAR: 'name'})
         self.assertEqual(response.status_code, 200)
 
         # #23431 - Specifying a field that is only referred to by a inline of a registered
         # model should be allowed.
-        response = self.client.get("/test_admin/admin/admin_views/referencedbyinline/", {TO_FIELD_VAR: 'id'})
+        response = self.client.get("/test_admin/admin/admin_views/referencedbyinline/", {TO_FIELD_VAR: 'name'})
         self.assertEqual(response.status_code, 200)
 
         # We also want to prevent the add and change view from leaking a