From 7ee3b2c516590bae918532ba406960ef2bf426db Mon Sep 17 00:00:00 2001
From: Ad Schellevis <ad@opnsense.org>
Date: Wed, 19 Nov 2025 15:50:00 +0100
Subject: [PATCH] Config - ditch isArraySequential() in favor of the new
 array_is_list() introduced in PHP 8.1. closes
 https://github.com/opnsense/core/pull/9424

This impacts $config usage in legacy code, a before and after comparison of the $config output shows no difference on a larger config file.
As mentioned by @swhite2, the performance of the internal check is much better than the one we're replacing now.

closes https://github.com/opnsense/core/pull/9424
---
 .../mvc/app/library/OPNsense/Core/Config.php       | 14 ++------------
 1 file changed, 2 insertions(+), 12 deletions(-)

diff --git a/src/opnsense/mvc/app/library/OPNsense/Core/Config.php b/src/opnsense/mvc/app/library/OPNsense/Core/Config.php
index 037694c209..1e3dbf3d76 100644
--- a/src/opnsense/mvc/app/library/OPNsense/Core/Config.php
+++ b/src/opnsense/mvc/app/library/OPNsense/Core/Config.php
@@ -86,16 +86,6 @@ class Config extends Singleton
         return $this->statusIsValid;
     }
 
-    /**
-     * check if array is a sequential type.
-     * @param &array $arrayData array structure to check
-     * @return bool
-     */
-    private function isArraySequential(&$arrayData)
-    {
-        return is_array($arrayData) && ctype_digit(implode('', array_keys($arrayData)));
-    }
-
     /**
      * serialize xml to array structure (backwards compatibility mode)
      * @param null|array $forceList force specific tags to be contained in a list.
@@ -128,7 +118,7 @@ class Config extends Singleton
                     $old_content = $result[$xmlNodeName];
                     // check if array content is associative, move items to new list
                     // (handles first item of specific type)
-                    if (!$this->isArraySequential($old_content)) {
+                    if (!is_array($old_content) || !array_is_list($old_content)) {
                         $result[$xmlNodeName] = array();
                         $result[$xmlNodeName][] = $old_content;
                     }
@@ -253,7 +243,7 @@ class Config extends Singleton
             } elseif (is_numeric($itemKey)) {
                 // recurring tag (content), use parent tagname.
                 $childNode = $node->addChild($parentTagName);
-            } elseif ($this->isArraySequential($itemValue)) {
+            } elseif (is_array($itemValue) && array_is_list($itemValue)) {
                 // recurring tag, skip placeholder.
                 $childNode = $node;
             } else {