Prevent requeuing Remote Fetcher jobs that exceed thread depth

changelog.d/handle_object_fetch_failures.change

@@ -1 +1 @@
-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. 
+Remote object fetch failures will prevent the object fetch job from retrying if the object request returns 403, 404, 410, or exceeds the maximum thread depth.

lib/pleroma/object/fetcher.ex

@@ -74,7 +74,7 @@ defmodule Pleroma.Object.Fetcher do
     else
       {:allowed_depth, false} = e ->
         log_fetch_error(id, e)
-        {:error, "Max thread distance exceeded."}
+        {:error, :allowed_depth}
 
       {:containment, reason} = e ->
         log_fetch_error(id, e)

lib/pleroma/workers/remote_fetcher_worker.ex

@@ -21,6 +21,9 @@ defmodule Pleroma.Workers.RemoteFetcherWorker do
         {:error, :not_found} ->
           {:cancel, :not_found}
 
+        {:error, :allowed_depth} ->
+          {:cancel, :allowed_depth}
+
         _ ->
           :error
       end

test/pleroma/object/fetcher_test.exs

@@ -101,8 +101,7 @@ defmodule Pleroma.Object.FetcherTest 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

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 @@ defmodule Pleroma.Workers.RemoteFetcherWorkerTest 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