From b3261d7e478bd492d4d6dd0bd737886c1aa38ab7 Mon Sep 17 00:00:00 2001
From: Marina Glancy <marina@moodle.com>
Date: Wed, 21 Apr 2021 11:49:57 +0200
Subject: [PATCH] MDL-71390 core: raise max_input_vars requirement for Moodle
 3.11

---
 admin/environment.xml |  2 ++
 lang/en/admin.php     |  2 ++
 lib/upgradelib.php    | 24 ++++++++++++++++++++++++
 3 files changed, 28 insertions(+)

diff --git a/admin/environment.xml b/admin/environment.xml
index 3a71aef8e67..495db2b5079 100644
--- a/admin/environment.xml
+++ b/admin/environment.xml
@@ -3527,6 +3527,8 @@
           <ON_CHECK message="sixtyfourbitswarning" />
         </FEEDBACK>
       </CUSTOM_CHECK>
+      <CUSTOM_CHECK file="lib/upgradelib.php" function="check_max_input_vars" level="optional">
+      </CUSTOM_CHECK>
     </CUSTOM_CHECKS>
   </MOODLE>
 </COMPATIBILITY_MATRIX>
diff --git a/lang/en/admin.php b/lang/en/admin.php
index 503eb448971..0a813d6fe6a 100644
--- a/lang/en/admin.php
+++ b/lang/en/admin.php
@@ -1050,6 +1050,8 @@ $string['sessioncookiepath'] = 'Cookie path';
 $string['sessionhandling'] = 'Session handling';
 $string['sessiontimeout'] = 'Timeout';
 $string['settingfileuploads'] = 'File uploading is required for normal operation, please enable it in PHP configuration.';
+$string['settingmaxinputvars'] = 'PHP setting max_input_vars is recommended to be at least 5000.';
+$string['settingmaxinputvarsrequired'] = 'PHP setting max_input_vars must be at least 5000.';
 $string['settingmemorylimit'] = 'Insufficient memory detected, please set higher memory limit in PHP settings.';
 $string['settingsafemode'] = 'Moodle is not fully compatible with safe mode, please ask server administrator to turn it off. Running Moodle under safe mode is not supported, please expect various problems if you do so.';
 $string['setupsearchengine'] = 'Setup search engine';
diff --git a/lib/upgradelib.php b/lib/upgradelib.php
index ed5f775ae13..180164f414c 100644
--- a/lib/upgradelib.php
+++ b/lib/upgradelib.php
@@ -2717,3 +2717,27 @@ function upgrade_find_theme_location($themename) {
 
     return $dir;
 }
+
+/**
+ * Environment check for the php setting max_input_vars
+ *
+ * @param environment_results $result
+ * @return environment_results|null
+ */
+function check_max_input_vars(environment_results $result) {
+    $max = (int)ini_get('max_input_vars');
+    if ($max < 5000) {
+        $result->setInfo('max_input_vars');
+        $result->setStatus(false);
+        if (PHP_VERSION_ID >= 80000) {
+            // For PHP8 this check is required.
+            $result->setLevel('required');
+            $result->setFeedbackStr('settingmaxinputvarsrequired');
+        } else {
+            // For PHP7 this check is optional (recommended).
+            $result->setFeedbackStr('settingmaxinputvars');
+        }
+        return $result;
+    }
+    return null;
+}