From 18e3906099903ea18f0e0e71f3e315234811a5fb Mon Sep 17 00:00:00 2001
From: "Alexander M. Turek" <me@derrabus.de>
Date: Mon, 12 Feb 2024 11:10:17 +0100
Subject: [PATCH] [VarDumper] Fix serialization of stubs with null or
 uninitialized values

---
 Cloner/Internal/NoDefault.php | 25 +++++++++++++++++
 Cloner/Stub.php               | 15 +++++++---
 Tests/Cloner/StubTest.php     | 53 +++++++++++++++++++++++++++++++++++
 3 files changed, 89 insertions(+), 4 deletions(-)
 create mode 100644 Cloner/Internal/NoDefault.php
 create mode 100644 Tests/Cloner/StubTest.php

diff --git a/Cloner/Internal/NoDefault.php b/Cloner/Internal/NoDefault.php
new file mode 100644
index 00000000..ed9db988
--- /dev/null
+++ b/Cloner/Internal/NoDefault.php
@@ -0,0 +1,25 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\VarDumper\Cloner\Internal;
+
+/**
+ * Flags a typed property that has no default value.
+ *
+ * This dummy object is used to distinguish a property with a default value of null
+ * from a property that is uninitialized by default.
+ *
+ * @internal
+ */
+enum NoDefault
+{
+    case NoDefault;
+}
diff --git a/Cloner/Stub.php b/Cloner/Stub.php
index 0c2a4b9d..a377d2b9 100644
--- a/Cloner/Stub.php
+++ b/Cloner/Stub.php
@@ -11,6 +11,8 @@
 
 namespace Symfony\Component\VarDumper\Cloner;
 
+use Symfony\Component\VarDumper\Cloner\Internal\NoDefault;
+
 /**
  * Represents the main properties of a PHP variable.
  *
@@ -50,15 +52,20 @@ public function __sleep(): array
         $properties = [];
 
         if (!isset(self::$defaultProperties[$c = static::class])) {
-            self::$defaultProperties[$c] = get_class_vars($c);
+            $reflection = new \ReflectionClass($c);
+            self::$defaultProperties[$c] = [];
+
+            foreach ($reflection->getProperties() as $p) {
+                if ($p->isStatic()) {
+                    continue;
+                }
 
-            foreach ((new \ReflectionClass($c))->getStaticProperties() as $k => $v) {
-                unset(self::$defaultProperties[$c][$k]);
+                self::$defaultProperties[$c][$p->name] = $p->hasDefaultValue() ? $p->getDefaultValue() : ($p->hasType() ? NoDefault::NoDefault : null);
             }
         }
 
         foreach (self::$defaultProperties[$c] as $k => $v) {
-            if ($this->$k !== $v) {
+            if (NoDefault::NoDefault === $v || $this->$k !== $v) {
                 $properties[] = $k;
             }
         }
diff --git a/Tests/Cloner/StubTest.php b/Tests/Cloner/StubTest.php
new file mode 100644
index 00000000..dd44aba3
--- /dev/null
+++ b/Tests/Cloner/StubTest.php
@@ -0,0 +1,53 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\VarDumper\Tests\Cloner;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\VarDumper\Cloner\Stub;
+
+final class StubTest extends TestCase
+{
+    public function testUnserializeNullValue()
+    {
+        $stub = new Stub();
+        $stub->value = null;
+
+        $stub = unserialize(serialize($stub));
+
+        self::assertNull($stub->value);
+    }
+
+    public function testUnserializeNullInTypedProperty()
+    {
+        $stub = new MyStub();
+        $stub->myProp = null;
+
+        $stub = unserialize(serialize($stub));
+
+        self::assertNull($stub->myProp);
+    }
+
+    public function testUninitializedStubPropertiesAreLeftUninitialized()
+    {
+        $stub = new MyStub();
+
+        $stub = unserialize(serialize($stub));
+
+        $r = new \ReflectionProperty(MyStub::class, 'myProp');
+        self::assertFalse($r->isInitialized($stub));
+    }
+}
+
+final class MyStub extends Stub
+{
+    public mixed $myProp;
+}