Handle nil cases.

lib/pleroma/web/activity_pub/activity_pub.ex

@@ -164,8 +164,8 @@ defp restrict_recent(query, _) do
       where: activity.id > ^since
   end
 
-  defp restrict_blocked(query, %{"blocking_user" => user}) do
-    blocks = user.info["blocks"] || []
+  defp restrict_blocked(query, %{"blocking_user" => %User{info: info}}) do
+    blocks = info["blocks"] || []
     from activity in query,
       where: fragment("not (?->>'actor' = ANY(?))", activity.data, ^blocks)
   end

test/web/activity_pub/activity_pub_test.exs

@@ -100,6 +100,11 @@ test "doesn't return blocked activities" do
 
     assert Enum.member?(activities, activity_two)
     assert Enum.member?(activities, activity_one)
+
+    activities = ActivityPub.fetch_activities([], %{"blocking_user" => nil})
+
+    assert Enum.member?(activities, activity_two)
+    assert Enum.member?(activities, activity_one)
   end
 
   describe "public fetch activities" do