fix Activity.get_by_id

lib/pleroma/activity.ex

@@ -150,11 +150,18 @@ def get_by_ap_id_with_object(ap_id) do
     )
   end
 
+  @spec get_by_id(String.t()) :: Activity.t() | nil
   def get_by_id(id) do
+    case Pleroma.FlakeId.is_flake_id?(id) do
+      true ->
         Activity
         |> where([a], a.id == ^id)
         |> restrict_deactivated_users()
         |> Repo.one()
+
+      _ ->
+        nil
+    end
   end
 
   def get_by_id_with_object(id) do

test/web/mastodon_api/mastodon_api_controller_test.exs

@@ -2864,6 +2864,15 @@ test "returns empty object when id invalid", %{conn: conn} do
 
       assert response == %{}
     end
+
+    test "returns empty object when id isn't FlakeID", %{conn: conn} do
+      response =
+        conn
+        |> get("/api/v1/statuses/3ebbadd1-eb14-4e20-8118/card")
+        |> json_response(200)
+
+      assert response == %{}
+    end
   end
 
   test "bookmarks" do