fix(django): Fix 404 Handler handler being labeled as "generic ASGI r…

…equest"

sentry_sdk/integrations/django/__init__.py

@@ -4,6 +4,7 @@
 import sys
 import threading
 import weakref
+from importlib import import_module
 
 from sentry_sdk._types import TYPE_CHECKING
 from sentry_sdk.consts import OP, SPANDATA
@@ -32,6 +33,8 @@
     from django import VERSION as DJANGO_VERSION
     from django.conf import settings as django_settings
     from django.core import signals
+    from django.urls.exceptions import Resolver404
+    from django.conf import settings
 
     try:
         from django.urls import resolve
@@ -370,6 +373,15 @@ def _set_transaction_name_and_source(scope, transaction_style, request):
             transaction_name,
             source=source,
         )
+    except Resolver404:
+        urlconf = import_module(settings.ROOT_URLCONF)
+        # This exception only gets thrown when transaction_style is `function_name`
+        # So we don't check here what style is configured
+        if hasattr(urlconf, "handler404"):
+            handler = getattr(urlconf, "handler404")
+            scope.transaction = transaction_from_function(
+                getattr(handler, "view_class", handler)
+            )
     except Exception:
         pass