Max media attachment count

Signed-off-by: marcin mikołajczak <git@mkljczk.pl>

lib/pleroma/web/common_api/activity_draft.ex

@@ -112,7 +112,12 @@ defmodule Pleroma.Web.CommonAPI.ActivityDraft do
 
   defp attachments(%{params: params} = draft) do
     attachments = Utils.attachments_from_ids(params)
-    %__MODULE__{draft | attachments: attachments}
+    draft = %__MODULE__{draft | attachments: attachments}
+
+    case Utils.validate_attachments_count(attachments) do
+      :ok -> draft
+      {:error, message} -> add_error(draft, message)
+    end
   end
 
   defp in_reply_to(%{params: %{in_reply_to_status_id: ""}} = draft), do: draft

lib/pleroma/web/common_api/utils.ex

@@ -492,4 +492,19 @@ defmodule Pleroma.Web.CommonAPI.Utils do
       {:error, dgettext("errors", "The status is over the character limit")}
     end
   end
+
+  def validate_attachments_count([] = _attachments) do
+    :ok
+  end
+
+  def validate_attachments_count(attachments) do
+    limit = Config.get([:instance, :max_media_attachments])
+    count = length(attachments)
+
+    if count <= limit do
+      :ok
+    else
+      {:error, dgettext("errors", "Too many attachments")}
+    end
+  end
 end