Fix handling of models with UUID primary keys in reference index

wagtail/signal_handlers.py

@@ -72,7 +72,7 @@ def update_reference_index_on_save(instance, **kwargs):
         return
 
     update_reference_index_task.enqueue(
-        instance._meta.app_label, instance._meta.model_name, instance.pk
+        instance._meta.app_label, instance._meta.model_name, str(instance.pk)
     )
 
 

wagtail/test/testapp/migrations/0047_advertwithcustomuuidprimarykey_page.py

@@ -0,0 +1,25 @@
+# Generated by Django 5.1.5 on 2025-02-13 01:36
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("tests", "0046_alter_custom_rendition_to_unique_constraint"),
+        ("wagtailcore", "0094_alter_page_locale"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="advertwithcustomuuidprimarykey",
+            name="page",
+            field=models.ForeignKey(
+                blank=True,
+                null=True,
+                on_delete=django.db.models.deletion.SET_NULL,
+                to="wagtailcore.page",
+            ),
+        ),
+    ]

wagtail/test/testapp/models.py

@@ -1010,10 +1010,12 @@ class AdvertWithCustomUUIDPrimaryKey(ClusterableModel):
     advert_id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
     url = models.URLField(null=True, blank=True)
     text = models.CharField(max_length=255)
+    page = models.ForeignKey(Page, null=True, blank=True, on_delete=models.SET_NULL)
 
     panels = [
         FieldPanel("url"),
         FieldPanel("text"),
+        FieldPanel("page"),
     ]
 
     def __str__(self):

wagtail/tests/test_reference_index.py

@@ -250,6 +250,19 @@ class TestCreateOrUpdateForObject(TestCase):
         refs = ReferenceIndex.get_references_to(content_type)
         self.assertEqual(refs.count(), 0)
 
+    def test_model_with_uuid_primary_key(self):
+        refs = ReferenceIndex.get_references_to(self.event_page)
+        self.assertEqual(refs.count(), 0)
+
+        with self.captureOnCommitCallbacks(execute=True):
+            AdvertWithCustomUUIDPrimaryKey.objects.create(
+                text="An advertisement",
+                page=self.event_page,
+            )
+
+        refs = ReferenceIndex.get_references_to(self.event_page)
+        self.assertEqual(refs.count(), 1)
+
     def test_rebuild_references_index_no_verbosity(self):
         stdout = StringIO()
         management.call_command(