From f1f44069ae525fd21127e5ceccc61016c12f4427 Mon Sep 17 00:00:00 2001
From: "Haelwenn (lanodan) Monnier" <contact@hacktivis.me>
Date: Fri, 11 Sep 2020 19:58:58 +0200
Subject: [PATCH] Fetcher: Correctly return MRF reject reason

---
 lib/pleroma/object/fetcher.ex                |  4 ++--
 lib/pleroma/web/activity_pub/activity_pub.ex |  4 ++--
 test/object/fetcher_test.exs                 | 25 +++++++++++++++-----
 3 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/lib/pleroma/object/fetcher.ex b/lib/pleroma/object/fetcher.ex
index 1de2ce6c3..24dc7cb95 100644
--- a/lib/pleroma/object/fetcher.ex
+++ b/lib/pleroma/object/fetcher.ex
@@ -98,8 +98,8 @@ def fetch_object_from_id(id, options \\ []) do
       {:containment, _} ->
         {:error, "Object containment failed."}
 
-      {:transmogrifier, {:error, {:reject, nil}}} ->
-        {:reject, nil}
+      {:transmogrifier, {:error, {:reject, e}}} ->
+        {:reject, e}
 
       {:transmogrifier, _} = e ->
         {:error, e}
diff --git a/lib/pleroma/web/activity_pub/activity_pub.ex b/lib/pleroma/web/activity_pub/activity_pub.ex
index 66a9f78a3..b2205bff7 100644
--- a/lib/pleroma/web/activity_pub/activity_pub.ex
+++ b/lib/pleroma/web/activity_pub/activity_pub.ex
@@ -154,8 +154,8 @@ def insert(map, local \\ true, fake \\ false, bypass_actor_check \\ false) when
       {:remote_limit_pass, _} ->
         {:error, :remote_limit}
 
-      {:reject, reason} ->
-        {:error, reason}
+      {:reject, _} = e ->
+        {:error, e}
     end
   end
 
diff --git a/test/object/fetcher_test.exs b/test/object/fetcher_test.exs
index 16cfa7f5c..3173ee31c 100644
--- a/test/object/fetcher_test.exs
+++ b/test/object/fetcher_test.exs
@@ -6,10 +6,13 @@ defmodule Pleroma.Object.FetcherTest do
   use Pleroma.DataCase
 
   alias Pleroma.Activity
+  alias Pleroma.Config
   alias Pleroma.Object
   alias Pleroma.Object.Fetcher
-  import Tesla.Mock
+
+  import ExUnit.CaptureLog
   import Mock
+  import Tesla.Mock
 
   setup do
     mock(fn
@@ -71,20 +74,20 @@ test "it works when fetching the OP actor errors out" do
     setup do: clear_config([:instance, :federation_incoming_replies_max_depth])
 
     test "it returns thread depth exceeded error if thread depth is exceeded" do
-      Pleroma.Config.put([:instance, :federation_incoming_replies_max_depth], 0)
+      Config.put([:instance, :federation_incoming_replies_max_depth], 0)
 
       assert {:error, "Max thread distance exceeded."} =
                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
-      Pleroma.Config.put([:instance, :federation_incoming_replies_max_depth], 0)
+      Config.put([:instance, :federation_incoming_replies_max_depth], 0)
 
       assert {:ok, _} = Fetcher.fetch_object_from_id(@ap_id)
     end
 
     test "it fetches object if requested depth does not exceed max thread depth" do
-      Pleroma.Config.put([:instance, :federation_incoming_replies_max_depth], 10)
+      Config.put([:instance, :federation_incoming_replies_max_depth], 10)
 
       assert {:ok, _} = Fetcher.fetch_object_from_id(@ap_id, depth: 10)
     end
@@ -120,6 +123,16 @@ test "it fetches an object" do
 
       assert object == object_again
     end
+
+    test "Return MRF reason when fetched status is rejected by one" do
+      clear_config([:mrf_keyword, :reject], ["yeah"])
+      clear_config([:mrf, :policies], [Pleroma.Web.ActivityPub.MRF.KeywordPolicy])
+
+      assert {:reject, "[KeywordPolicy] Matches with rejected keyword"} ==
+               Fetcher.fetch_object_from_id(
+                 "http://mastodon.example.org/@admin/99541947525187367"
+               )
+    end
   end
 
   describe "implementation quirks" do
@@ -212,7 +225,7 @@ test "it can refetch pruned objects" do
                    Pleroma.Signature,
                    [:passthrough],
                    [] do
-      Pleroma.Config.put([:activitypub, :sign_object_fetches], true)
+      Config.put([:activitypub, :sign_object_fetches], true)
 
       Fetcher.fetch_object_from_id("http://mastodon.example.org/@admin/99541947525187367")
 
@@ -223,7 +236,7 @@ test "it can refetch pruned objects" do
                    Pleroma.Signature,
                    [:passthrough],
                    [] do
-      Pleroma.Config.put([:activitypub, :sign_object_fetches], false)
+      Config.put([:activitypub, :sign_object_fetches], false)
 
       Fetcher.fetch_object_from_id("http://mastodon.example.org/@admin/99541947525187367")