From 46ca03e59d52ec8f1d26340ded8a5f6b92448eb1 Mon Sep 17 00:00:00 2001
From: Nicolas Grekas <nicolas.grekas@gmail.com>
Date: Tue, 5 Jul 2022 10:32:33 +0200
Subject: [PATCH] [VarExporter] Fix accessing readonly properties by reference

---
 .../Component/VarExporter/Hydrator.php        |  8 ++---
 .../VarExporter/Internal/Hydrator.php         | 36 ++++++++++++++-----
 2 files changed, 31 insertions(+), 13 deletions(-)

diff --git a/src/Symfony/Component/VarExporter/Hydrator.php b/src/Symfony/Component/VarExporter/Hydrator.php
index 0827481778b1e..b568e43502844 100644
--- a/src/Symfony/Component/VarExporter/Hydrator.php
+++ b/src/Symfony/Component/VarExporter/Hydrator.php
@@ -61,15 +61,15 @@ public static function hydrate(object $instance, array $properties = [], array $
             $propertyScopes = InternalHydrator::$propertyScopes[$class] ??= InternalHydrator::getPropertyScopes($class);
 
             foreach ($properties as $name => &$value) {
-                [$scope, $name] = $propertyScopes[$name] ?? [$class, $name];
-                $scopedProperties[$scope][$name] = &$value;
+                [$scope, $name, $readonlyScope] = $propertyScopes[$name] ?? [$class, $name, $class];
+                $scopedProperties[$readonlyScope ?? $scope][$name] = &$value;
             }
             unset($value);
         }
 
-        foreach ($scopedProperties as $class => $properties) {
+        foreach ($scopedProperties as $scope => $properties) {
             if ($properties) {
-                (InternalHydrator::$simpleHydrators[$class] ??= InternalHydrator::getSimpleHydrator($class))($properties, $instance);
+                (InternalHydrator::$simpleHydrators[$scope] ??= InternalHydrator::getSimpleHydrator($scope))($properties, $instance);
             }
         }
 
diff --git a/src/Symfony/Component/VarExporter/Internal/Hydrator.php b/src/Symfony/Component/VarExporter/Internal/Hydrator.php
index 221d04f234664..a1eac3d9e15a8 100644
--- a/src/Symfony/Component/VarExporter/Internal/Hydrator.php
+++ b/src/Symfony/Component/VarExporter/Internal/Hydrator.php
@@ -155,28 +155,35 @@ public static function getHydrator($class)
 
     public static function getSimpleHydrator($class)
     {
-        $baseHydrator = self::$simpleHydrators['stdClass'] ??= static function ($properties, $object) {
+        $baseHydrator = self::$simpleHydrators['stdClass'] ??= (function ($properties, $object) {
+            $readonly = (array) $this;
+
             foreach ($properties as $name => &$value) {
-                $object->$name = &$value;
+                $object->$name = $value;
+
+                if (!($readonly[$name] ?? false)) {
+                    $object->$name = &$value;
+                }
             }
-        };
+        })->bindTo(new \stdClass());
 
         switch ($class) {
             case 'stdClass':
                 return $baseHydrator;
 
             case 'ErrorException':
-                return $baseHydrator->bindTo(null, new class() extends \ErrorException {
+                return $baseHydrator->bindTo(new \stdClass(), new class() extends \ErrorException {
                 });
 
             case 'TypeError':
-                return $baseHydrator->bindTo(null, new class() extends \Error {
+                return $baseHydrator->bindTo(new \stdClass(), new class() extends \Error {
                 });
 
             case 'SplObjectStorage':
                 return static function ($properties, $object) {
                     foreach ($properties as $name => &$value) {
                         if ("\0" !== $name) {
+                            $object->$name = $value;
                             $object->$name = &$value;
                             continue;
                         }
@@ -202,6 +209,7 @@ public static function getSimpleHydrator($class)
                         if ("\0" === $name) {
                             $constructor($object, $value);
                         } else {
+                            $object->$name = $value;
                             $object->$name = &$value;
                         }
                     }
@@ -209,7 +217,14 @@ public static function getSimpleHydrator($class)
         }
 
         if (!$classReflector->isInternal()) {
-            return $baseHydrator->bindTo(null, $class);
+            $readonly = new \stdClass();
+            foreach ($classReflector->getProperties(\ReflectionProperty::IS_READONLY) as $propertyReflector) {
+                if ($class === $propertyReflector->class) {
+                    $readonly->{$propertyReflector->name} = true;
+                }
+            }
+
+            return $baseHydrator->bindTo($readonly, $class);
         }
 
         if ($classReflector->name !== $class) {
@@ -232,6 +247,7 @@ public static function getSimpleHydrator($class)
                 if ($setValue = $propertySetters[$name] ?? null) {
                     $setValue($object, $value);
                 } else {
+                    $object->$name = $value;
                     $object->$name = &$value;
                 }
             }
@@ -252,10 +268,10 @@ public static function getPropertyScopes($class)
             $name = $property->name;
 
             if (\ReflectionProperty::IS_PRIVATE & $flags) {
-                $propertyScopes["\0$class\0$name"] = $propertyScopes[$name] = [$class, $name];
+                $propertyScopes["\0$class\0$name"] = $propertyScopes[$name] = [$class, $name, $flags & \ReflectionProperty::IS_READONLY ? $class : null];
                 continue;
             }
-            $propertyScopes[$name] = [$flags & \ReflectionProperty::IS_READONLY ? $property->class : $class, $name];
+            $propertyScopes[$name] = [$class, $name, $flags & \ReflectionProperty::IS_READONLY ? $property->class : null];
 
             if (\ReflectionProperty::IS_PROTECTED & $flags) {
                 $propertyScopes["\0*\0$name"] = $propertyScopes[$name];
@@ -268,7 +284,9 @@ public static function getPropertyScopes($class)
             foreach ($r->getProperties(\ReflectionProperty::IS_PRIVATE) as $property) {
                 if (!$property->isStatic()) {
                     $name = $property->name;
-                    $propertyScopes["\0$class\0$name"] = [$class, $name];
+                    $readonlyScope = $property->isReadOnly() ? $class : null;
+                    $propertyScopes["\0$class\0$name"] = [$class, $name, $readonlyScope];
+                    $propertyScopes[$name] ??= [$class, $name, $readonlyScope];
                 }
             }
         }