From ff515c05c36825f28c547bc50694e203182708cb Mon Sep 17 00:00:00 2001
From: Mark Felder <feld@feld.me>
Date: Wed, 27 Dec 2023 22:28:41 -0500
Subject: [PATCH] Prevent requeuing Remote Fetcher jobs that exceed thread
 depth

---
 changelog.d/handle_object_fetch_failures.change   |  2 --
 lib/pleroma/object/fetcher.ex                     |  2 +-
 lib/pleroma/workers/remote_fetcher_worker.ex      |  3 +++
 test/pleroma/object/fetcher_test.exs              |  3 +--
 .../workers/remote_fetcher_worker_test.exs        | 15 +++++++++++++++
 5 files changed, 20 insertions(+), 5 deletions(-)
 delete mode 100644 changelog.d/handle_object_fetch_failures.change

diff --git a/changelog.d/handle_object_fetch_failures.change b/changelog.d/handle_object_fetch_failures.change
deleted file mode 100644
index 0b1dda38d..000000000
--- a/changelog.d/handle_object_fetch_failures.change
+++ /dev/null
@@ -1,2 +0,0 @@
-Remote object fetch failures will prevent the object fetch job from retrying if the object has been deleted or the fetch was denied with a 403 due to instance block behavior with authorized_fetch enabled.
-Skip fetching objects from unreachable instances.
diff --git a/lib/pleroma/object/fetcher.ex b/lib/pleroma/object/fetcher.ex
index edaf8c62d..e2d0908d3 100644
--- a/lib/pleroma/object/fetcher.ex
+++ b/lib/pleroma/object/fetcher.ex
@@ -153,7 +153,7 @@ def fetch_object_from_id(id, options \\ []) do
     else
       {:allowed_depth, false} = e ->
         log_fetch_error(id, e)
-        {:error, "Max thread distance exceeded."}
+        {:error, :allowed_depth}
 
       {:scheme, false} ->
         {:error, "URI Scheme Invalid"}
diff --git a/lib/pleroma/workers/remote_fetcher_worker.ex b/lib/pleroma/workers/remote_fetcher_worker.ex
index 1120a3e4e..0816d5737 100644
--- a/lib/pleroma/workers/remote_fetcher_worker.ex
+++ b/lib/pleroma/workers/remote_fetcher_worker.ex
@@ -21,6 +21,9 @@ def perform(%Job{args: %{"op" => "fetch_remote", "id" => id} = args}) do
         {:error, :not_found} ->
           {:cancel, :not_found}
 
+        {:error, :allowed_depth} ->
+          {:cancel, :allowed_depth}
+
         _ ->
           :error
       end
diff --git a/test/pleroma/object/fetcher_test.exs b/test/pleroma/object/fetcher_test.exs
index 55902ba49..6a919e6ef 100644
--- a/test/pleroma/object/fetcher_test.exs
+++ b/test/pleroma/object/fetcher_test.exs
@@ -205,8 +205,7 @@ test "it works when fetching the OP actor errors out" do
     test "it returns thread depth exceeded error if thread depth is exceeded" do
       clear_config([:instance, :federation_incoming_replies_max_depth], 0)
 
-      assert {:error, "Max thread distance exceeded."} =
-               Fetcher.fetch_object_from_id(@ap_id, depth: 1)
+      assert {:error, :allowed_depth} = Fetcher.fetch_object_from_id(@ap_id, depth: 1)
     end
 
     test "it fetches object if max thread depth is restricted to 0 and depth is not specified" do
diff --git a/test/pleroma/workers/remote_fetcher_worker_test.exs b/test/pleroma/workers/remote_fetcher_worker_test.exs
index d8cb52f52..df7d77ea0 100644
--- a/test/pleroma/workers/remote_fetcher_worker_test.exs
+++ b/test/pleroma/workers/remote_fetcher_worker_test.exs
@@ -13,6 +13,7 @@ defmodule Pleroma.Workers.RemoteFetcherWorkerTest do
   @deleted_object_two "https://deleted-410.example.com/"
   @unauthorized_object "https://unauthorized.example.com/"
   @unreachable_object "https://unreachable.example.com/"
+  @depth_object "https://depth.example.com/"
 
   describe "it does not" do
     setup do
@@ -31,6 +32,11 @@ defmodule Pleroma.Workers.RemoteFetcherWorkerTest do
           %Tesla.Env{
             status: 403
           }
+
+        %{method: :get, url: @depth_object} ->
+          %Tesla.Env{
+            status: 200
+          }
       end)
     end
 
@@ -63,5 +69,14 @@ test "fetch an unreachable instance" do
                  args: %{"op" => "fetch_remote", "id" => @unreachable_object}
                })
     end
+
+    test "requeue an object that exceeded depth" do
+      clear_config([:instance, :federation_incoming_replies_max_depth], 0)
+
+      assert {:cancel, _} =
+               RemoteFetcherWorker.perform(%Oban.Job{
+                 args: %{"op" => "fetch_remote", "id" => @depth_object, "depth" => 1}
+               })
+    end
   end
 end