Fix: saved views do not return to default display fields after setting and then removing (#9168)

src/documents/serialisers.py

@@ -1147,6 +1147,15 @@ class SavedViewSerializer(OwnedObjectSerializer):
         if "user" in validated_data:
             # backwards compatibility
             validated_data["owner"] = validated_data.pop("user")
+        if (
+            "display_fields" in validated_data
+            and isinstance(
+                validated_data["display_fields"],
+                list,
+            )
+            and len(validated_data["display_fields"]) == 0
+        ):
+            validated_data["display_fields"] = None
         super().update(instance, validated_data)
         if rules_data is not None:
             SavedViewFilterRule.objects.filter(saved_view=instance).delete()

src/documents/tests/test_api_documents.py

@@ -1815,6 +1815,19 @@ class TestDocumentApi(DirectoriesMixin, DocumentConsumeDelayMixin, APITestCase):
         )
         self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
 
+        # empty display fields treated as none
+        response = self.client.patch(
+            f"/api/saved_views/{v1.id}/",
+            {
+                "display_fields": [],
+            },
+            format="json",
+        )
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+
+        v1.refresh_from_db()
+        self.assertEqual(v1.display_fields, None)
+
     def test_saved_view_display_customfields(self):
         """
         GIVEN: