From 27a6dbeeb6e4cc027596887c0176487deaeaf1ab Mon Sep 17 00:00:00 2001
From: Michael Milette <michael.milette@tngconsulting.ca>
Date: Mon, 27 Jan 2020 23:42:35 -0500
Subject: [PATCH] MDL-67554 oauth2: New filtered language tags for additional
 parameters.

This adds support for new language tags in OAuth2's
"Additional Parameters Included in a Login Request"
field. Available tags include:

Tags            Example value
-----------------------------
{lang}          fr
{LANG}          FR
{language}      fr_ca
{LANGUAGE}      FR_CA
{lan-guage}     fr-ca
{LAN-GUAGE}     FR-CA
---
 lib/classes/oauth2/client.php | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/lib/classes/oauth2/client.php b/lib/classes/oauth2/client.php
index 905a751ce41..6369636355f 100644
--- a/lib/classes/oauth2/client.php
+++ b/lib/classes/oauth2/client.php
@@ -126,6 +126,20 @@ class client extends \oauth2_client {
             return [];
         }
         $result = [];
+
+        // Replace the language tag if it appears in the string.
+        $lang = current_language();
+        $tags = ["{lang}", "{LANG}", "{language}", "{LANGUAGE}", '{lan-guage}', '{LAN-GUAGE}'];
+        $langcode = [
+            strtolower(substr($lang, 0, 2)),
+            strtoupper(substr($lang, 0, 2)),
+            strtolower($lang),
+            strtoupper($lang),
+            str_replace('_', '-', strtolower($lang)),
+            str_replace('_', '-', strtoupper($lang)),
+        ];
+        $params = str_replace($tags, $langcode, $params);
+
         parse_str($params, $result);
         return $result;
     }