From d21bc7f1e66e897a4acef27ca363e6bbeb606485 Mon Sep 17 00:00:00 2001
From: Ilija Tovilo <ilija.tovilo@me.com>
Date: Fri, 6 Sep 2024 12:31:06 +0200
Subject: [PATCH] Disallow enums in ArrayObject

Closes GH-15775
---
 UPGRADING                           |  4 ++++
 ext/spl/spl_array.c                 |  6 ++++++
 ext/spl/tests/ArrayObject_enum.phpt | 15 +++++++++++++++
 3 files changed, 25 insertions(+)
 create mode 100644 ext/spl/tests/ArrayObject_enum.phpt

diff --git a/UPGRADING b/UPGRADING
index 88f66696cb4..c9c9468a3bd 100644
--- a/UPGRADING
+++ b/UPGRADING
@@ -19,6 +19,10 @@ PHP 8.5 UPGRADE NOTES
 1. Backward Incompatible Changes
 ========================================
 
+- SPL:
+  . ArrayObject no longer accepts enums, as modifying the $name or $value
+    properties can break engine assumptions.
+
 ========================================
 2. New Features
 ========================================
diff --git a/ext/spl/spl_array.c b/ext/spl/spl_array.c
index 0be317c173e..ffe8178afa7 100644
--- a/ext/spl/spl_array.c
+++ b/ext/spl/spl_array.c
@@ -970,6 +970,12 @@ static void spl_array_set_array(zval *object, spl_array_object *intern, zval *ar
 					ZSTR_VAL(Z_OBJCE_P(array)->name), ZSTR_VAL(intern->std.ce->name));
 				return;
 			}
+			if (UNEXPECTED(Z_OBJCE_P(array)->ce_flags & ZEND_ACC_ENUM)) {
+				zend_throw_exception_ex(spl_ce_InvalidArgumentException, 0,
+					"Enums are not compatible with %s",
+					ZSTR_VAL(intern->std.ce->name));
+				return;
+			}
 			zval_ptr_dtor(&intern->array);
 			ZVAL_COPY(&intern->array, array);
 		}
diff --git a/ext/spl/tests/ArrayObject_enum.phpt b/ext/spl/tests/ArrayObject_enum.phpt
new file mode 100644
index 00000000000..906c89b54df
--- /dev/null
+++ b/ext/spl/tests/ArrayObject_enum.phpt
@@ -0,0 +1,15 @@
+--TEST--
+Enums are not compatible with ArrayObject
+--FILE--
+<?php
+
+enum Foo {
+    case Bar;
+}
+
+new ArrayObject(Foo::Bar);
+
+?>
+--EXPECTF--
+Fatal error: Uncaught InvalidArgumentException: Enums are not compatible with ArrayObject in %s:%d
+%a