From 2548ba926aaca6be25ae5e26cbe0c55271edfedd Mon Sep 17 00:00:00 2001
From: Mouse Reeve <mousereeve@riseup.net>
Date: Sat, 13 Mar 2021 07:15:30 -0800
Subject: [PATCH] Fixes error when receiving Undo for unknown boost

---
 bookwyrm/activitypub/verbs.py      |  3 +++
 bookwyrm/tests/views/test_inbox.py | 17 +++++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/bookwyrm/activitypub/verbs.py b/bookwyrm/activitypub/verbs.py
index cd7a757b..1788dda7 100644
--- a/bookwyrm/activitypub/verbs.py
+++ b/bookwyrm/activitypub/verbs.py
@@ -70,6 +70,9 @@ class Undo(Verb):
         if self.object.type == "Follow":
             model = apps.get_model("bookwyrm.UserFollows")
         obj = self.object.to_model(model=model, save=False, allow_create=False)
+        if not obj:
+            # if we don't have the object, we can't undo it. happens a lot with boosts
+            return
         obj.delete()
 
 
diff --git a/bookwyrm/tests/views/test_inbox.py b/bookwyrm/tests/views/test_inbox.py
index cab50892..d43018db 100644
--- a/bookwyrm/tests/views/test_inbox.py
+++ b/bookwyrm/tests/views/test_inbox.py
@@ -563,6 +563,23 @@ class Inbox(TestCase):
         }
         views.inbox.activity_task(activity)
 
+    def test_handle_unboost_unknown_boost(self):
+        """ undo a boost """
+        activity = {
+            "type": "Undo",
+            "actor": "hi",
+            "id": "bleh",
+            "to": ["https://www.w3.org/ns/activitystreams#public"],
+            "cc": ["https://example.com/user/mouse/followers"],
+            "object": {
+                "type": "Announce",
+                "id": "http://fake.com/unknown/boost",
+                "actor": self.remote_user.remote_id,
+                "object": self.status.remote_id,
+            },
+        }
+        views.inbox.activity_task(activity)
+
     def test_handle_add_book_to_shelf(self):
         """ shelving a book """
         work = models.Work.objects.create(title="work title")