From c61353ae417ca5fe1957de4fc7813b98e958d176 Mon Sep 17 00:00:00 2001
From: Ryan Wyllie <ryan@moodle.com>
Date: Tue, 6 Nov 2018 14:03:11 +0800
Subject: [PATCH] MDL-63303 message: fix mark_all_conversation_messages_as_read
 ext func

---
 message/externallib.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/message/externallib.php b/message/externallib.php
index 0c9c0559007..65ccda6c316 100644
--- a/message/externallib.php
+++ b/message/externallib.php
@@ -3196,7 +3196,7 @@ class core_message_external extends external_api {
      * @since 3.6
      */
     public static function mark_all_conversation_messages_as_read_returns() {
-        return new external_warnings();
+        return null;
     }
 
     /**