1 files changed, 37 insertions, 5 deletions
diff --git a/lib/pleroma/web/activity_pub/mrf/force_mentions_in_content.ex b/lib/pleroma/web/activity_pub/mrf/force_mentions_in_content.ex
index c9b022cf8..255910b2f 100644
--- a/lib/pleroma/web/activity_pub/mrf/force_mentions_in_content.ex
+++ b/lib/pleroma/web/activity_pub/mrf/force_mentions_in_content.ex
@@ -3,6 +3,8 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 
 defmodule Pleroma.Web.ActivityPub.MRF.ForceMentionsInContent do
+  require Pleroma.Constants
+
   alias Pleroma.Formatter
   alias Pleroma.Object
   alias Pleroma.User
@@ -58,9 +60,25 @@ defmodule Pleroma.Web.ActivityPub.MRF.ForceMentionsInContent do
 
   defp sort_replied_user(users, _), do: users
 
+  # Drop constants and the actor's own AP ID
+  defp clean_recipients(recipients, object) do
+    Enum.reject(recipients, fn ap_id ->
+      ap_id in [
+        object["object"]["actor"],
+        Pleroma.Constants.as_public(),
+        Pleroma.Web.ActivityPub.Utils.as_local_public()
+      ]
+    end)
+  end
+
   @impl true
-  def filter(%{"type" => "Create", "object" => %{"type" => "Note", "to" => to}} = object)
-      when is_list(to) do
+  def filter(
+        %{
+          "type" => "Create",
+          "object" => %{"type" => "Note", "to" => to, "inReplyTo" => in_reply_to}
+        } = object
+      )
+      when is_list(to) and is_binary(in_reply_to) do
     # image-only posts from pleroma apparently reach this MRF without the content field
     content = object["object"]["content"] || ""
 
@@ -69,6 +87,7 @@ defmodule Pleroma.Web.ActivityPub.MRF.ForceMentionsInContent do
 
     mention_users =
       to
+      |> clean_recipients(object)
       |> Enum.map(&User.get_cached_by_ap_id/1)
       |> Enum.reject(&is_nil/1)
       |> sort_replied_user(replied_to_user)
@@ -84,10 +103,23 @@ defmodule Pleroma.Web.ActivityPub.MRF.ForceMentionsInContent do
         end
       end)
 
-    content =
+    recipients_inline =
       if added_mentions != "",
-        do: "<span class=\"recipients-inline\">#{added_mentions}</span>" <> content,
-        else: content
+        do: "<span class=\"recipients-inline\">#{added_mentions}</span>",
+        else: ""
+
+    content =
+      cond do
+        # For Markdown posts, insert the mentions inside the first <p> tag
+        recipients_inline != "" && String.starts_with?(content, "<p>") ->
+          "<p>" <> recipients_inline <> String.trim_leading(content, "<p>")
+
+        recipients_inline != "" ->
+          recipients_inline <> content
+
+        true ->
+          content
+      end
 
     {:ok, put_in(object["object"]["content"], content)}
   end