Drop unknown Delete message

activitypub.py

@@ -479,7 +479,9 @@ class MicroblogPubBackend(Backend):
         question = create.get_object()
         if question.has_type(ap.ActivityType.QUESTION):
             now = datetime.now(timezone.utc)
-            dt = parser.parse(question.closed or question.endTime).astimezone(timezone.utc)
+            dt = parser.parse(question.closed or question.endTime).astimezone(
+                timezone.utc
+            )
             minutes = int((dt - now).total_seconds() / 60)
             Tasks.fetch_remote_question(create.id, minutes)
 

app.py

@@ -1817,7 +1817,7 @@ def inbox():
             "failed to verify request, trying to verify the payload by fetching the remote"
         )
         try:
-            data = get_backend().fetch_iri(data["id"])
+            remote_data = get_backend().fetch_iri(data["id"])
         except ActivityGoneError:
             # XXX Mastodon sends Delete activities that are not dereferencable, it's the actor url with #delete
             # appended, so an `ActivityGoneError` kind of ensure it's "legit"
@@ -1831,6 +1831,11 @@ def inbox():
         except Exception:
             logger.exception(f"failed to fetch remote for payload {data!r}")
 
+            # Friendica does not returns a 410, but a 302 that redirect to an HTML page
+            if ap._has_type(data["type"], ActivityType.DELETE):
+                logger.info(f"received a Delete for an unknown actor {data!r}, drop it")
+                return Response(status=201)
+
             # Track/store the payload for analysis
             ip, geoip = _get_ip()
 
@@ -1856,6 +1861,9 @@ def inbox():
                     }
                 ),
             )
+
+        # We fetched the remote data successfully
+        data = remote_data
     print(data)
     activity = ap.parse_activity(data)
     logger.debug(f"inbox activity={activity}/{data}")