fix: defer field deletion error in auditlog

auditlog/models.py

@@ -240,7 +240,19 @@ class LogEntryManager(models.Manager):
                 "fields", self._get_applicable_model_fields(instance, model_fields)
             )
 
+    #  safeguard: if fields explicitly set → only use them
+        if "fields" in kwargs:
+            allowed_fields = set(kwargs["fields"])
+        else:
+            allowed_fields = {f.name for f in instance._meta.fields}
+
         instance_copy = self._get_copy_with_python_typed_fields(instance)
+
+    #  drop any deferred field not in allowed_fields
+        for f in instance_copy._meta.fields:
+            if f.name not in allowed_fields and f.name in getattr(instance_copy, "deferred_fields", []):
+                setattr(instance_copy, f.name, None)
+
         data = dict(
             json.loads(serializers.serialize("json", (instance_copy,), **kwargs))[0]
         )
@@ -251,6 +263,7 @@ class LogEntryManager(models.Manager):
 
         return data
 
+
     def _get_copy_with_python_typed_fields(self, instance):
         """
         Attempt to create copy of instance and coerce types on instance fields

auditlog_tests/tests.py

@@ -25,6 +25,7 @@ from django.urls import resolve, reverse
 from django.utils import dateformat, formats
 from django.utils import timezone as django_timezone
 from django.utils.encoding import smart_str
+from django.test.utils import isolate_apps
 from django.utils.translation import gettext_lazy as _
 from test_app.fixtures.custom_get_cid import get_cid as custom_get_cid
 from test_app.models import (
@@ -123,6 +124,27 @@ class SimpleModelTest(TestCase):
             msg="The change is correctly logged",
         )
 
+    @isolate_apps("auditlog_tests")
+    def test_deletion_with_deferred_fields_does_not_crash(db):
+        from auditlog.models import LogEntry
+        from auditlog.registry import auditlog
+
+        class Book(models.Model):
+            title = models.CharField(max_length=100)
+            description = models.TextField()
+            class Meta:
+               app_label = "auditlog_tests" 
+
+        auditlog.register(Book, serialize_data=True)
+
+        b = Book.objects.create(title="foo", description="bar")
+        b = Book.objects.defer("description").get(id=b.id)  # defer a field
+        b.delete()
+
+        assert LogEntry.objects.filter(object_pk=b.pk).exists()
+    
+    
+
     def test_update_specific_field_supplied_via_save_method(self):
         obj = self.obj