Handle empty binding username claim configurations

auth/oidc/classes/form/binding_username_claim.php

@@ -116,7 +116,7 @@ protected function definition() {
         $mform->addElement(
                 'select',
                 'bindingusernameclaim',
-                auth_oidc_config_name_in_form('binding_username_claim'),
+                auth_oidc_config_name_in_form('beingusernameclaim'),
                 $bindingusernameoptions
         );
         $mform->setDefault('bindingusernameclaim', 'auto');

auth/oidc/classes/loginflow/base.php

@@ -731,6 +731,10 @@ protected function get_oidc_username_from_token_claim(jwt $idtoken, string $bind
 
         if (empty($bindingusernameclaim)) {
             $bindingusernameclaim = get_config('auth_oidc', 'bindingusernameclaim');
+            if (empty($bindingusernameclaim)) {
+                $bindingusernameclaim = 'auto';
+                set_config('bindingusernameclaim', $bindingusernameclaim, 'auth_oidc');
+            }
         }
 
         switch ($bindingusernameclaim) {

auth/oidc/db/install.php

@@ -0,0 +1,35 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Plugin installation script.
+ *
+ * @package auth_oidc
+ * @author Lai Wei <[email protected]>
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ * @copyright (C) 2014 onwards Microsoft, Inc. (http://microsoft.com/)
+ */
+
+/**
+ * Installation script.
+ */
+function xmldb_auth_oidc_install() {
+    // Set the default value for the bindingusernameclaim setting.
+    $bindingusernameclaimconfig = get_config('auth_oidc', 'bindingusernameclaim');
+    if (empty($bindingusernameclaimconfig)) {
+        set_config('bindingusernameclaim', 'auto', 'auth_oidc');
+    }
+}

auth/oidc/db/upgrade.php

@@ -504,5 +504,16 @@ function xmldb_auth_oidc_upgrade($oldversion) {
         upgrade_plugin_savepoint(true, 2023100921, 'auth', 'oidc');
     }
 
+    if ($oldversion < 2023100926) {
+        // Set the default value for the bindingusernameclaim setting.
+        $bindingusernameclaimconfig = get_config('auth_oidc', 'bindingusernameclaim');
+        if (empty($bindingusernameclaimconfig)) {
+            set_config('bindingusernameclaim', 'auto', 'auth_oidc');
+        }
+
+        // Oidc savepoint reached.
+        upgrade_plugin_savepoint(true, 2023100926, 'auth', 'oidc');
+    }
+
     return true;
 }

auth/oidc/lang/en/auth_oidc.php

@@ -404,7 +404,7 @@
 <div class="existing_claims">{$a}</div>';
 $string['binding_username_auto'] = 'Choose automatically';
 $string['binding_username_custom'] = 'Custom';
-$string['binding_username_claim'] = 'Binding username claim';
+$string['bindingusernameclaim'] = 'Binding username claim';
 $string['customclaimname'] = 'Custom claim name';
 $string['customclaimname_description'] = 'This field is used only when the <b>Binding Username Claim</b> setting is set to <b>Custom</b>.';
 $string['binding_username_claim_help_ms_no_user_sync'] = 'The options for non Microsoft IdPs include:

auth/oidc/version.php

@@ -25,7 +25,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$plugin->version = 2023100925;
+$plugin->version = 2023100926;
 $plugin->requires = 2023100900;
 $plugin->release = '4.3.6';
 $plugin->component = 'auth_oidc';