From 9104f4f33ea69408bee5c3f6dc768d865c925cff Mon Sep 17 00:00:00 2001
From: Pratik Bhujel <prateekbhujelpb@gmail.com>
Date: Fri, 23 Oct 2026 08:36:30 +0545
Subject: [PATCH] Add regression test for GH-21824

---
 ext/standard/tests/serialize/gh21824.phpt | 24 +++++++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 ext/standard/tests/serialize/gh21824.phpt

diff --git a/ext/standard/tests/serialize/gh21824.phpt b/ext/standard/tests/serialize/gh21824.phpt
new file mode 100644
index 000000000000..90de1482bd66
--- /dev/null
+++ b/ext/standard/tests/serialize/gh21824.phpt
@@ -0,0 +1,24 @@
+--TEST--
+GH-21824 (Crash in unserialize() with destructor reentry)
+--ENV--
+USE_ZEND_ALLOC=0
+--FILE--
+<?php
+class Trigger {
+    public function __destruct() {
+        unserialize('i:1;');
+    }
+}
+
+$payload = 'a:1019:{';
+for ($i = 0; $i < 1017; $i++) {
+    $payload .= "i:$i;s:1:\"A\";";
+}
+$payload .= 'i:1017;O:7:"Trigger":0:{}';
+$payload .= 'i:1017;i:0;}';
+
+unserialize($payload);
+echo "Done\n";
+?>
+--EXPECT--
+Done