[Serializer] Fix deserializing nested arrays of objects with mixed keys

[HypeMC]

Q	A
Branch?	5.4
Bug fix?	yes
New feature?	no
Deprecations?	no
Tickets	Fix #50675
License	MIT
Doc PR	-

Currently an error is thrown when trying to deserialize the following nested array of objects:

use Symfony\Component\PropertyInfo\Extractor\PhpDocExtractor;
use Symfony\Component\Serializer\Encoder\JsonEncoder;
use Symfony\Component\Serializer\Normalizer\ArrayDenormalizer;
use Symfony\Component\Serializer\Normalizer\ObjectNormalizer;
use Symfony\Component\Serializer\Serializer;

$serializer = new Serializer([
    new ObjectNormalizer(null, null, null, new PhpDocExtractor()),
    new ArrayDenormalizer(),
], ['json' => new JsonEncoder()]);

class Outer
{
    /**
     * @var array<int|string, Inner>
     */
    public array $inners;
}

class Inner
{
    public string $name;
}

$serializer->deserialize('{"inners": {"1": {"name": "One"}, "two": {"name": "Two"}}}', Outer::class, 'json');

Fatal error: Uncaught Symfony\Component\Serializer\Exception\NotNormalizableValueException:
The type of the key "two" must be "int" ("string" given).

The same happens when using generics, e.g. ArrayCollection<Inner>.

[nicolas-grekas]

Can you check the follow patch please?

diff --git a/src/Symfony/Component/Serializer/Normalizer/ArrayDenormalizer.php b/src/Symfony/Component/Serializer/Normalizer/ArrayDenormalizer.php
index 05d8b79d1a..dfd023a437 100644
--- a/src/Symfony/Component/Serializer/Normalizer/ArrayDenormalizer.php
+++ b/src/Symfony/Component/Serializer/Normalizer/ArrayDenormalizer.php
@@ -49,9 +49,7 @@ class ArrayDenormalizer implements ContextAwareDenormalizerInterface, Denormaliz
 
         $type = substr($type, 0, -2);
 
-        $builtinTypes = array_map(static function (Type $keyType) {
-            return $keyType->getBuiltinType();
-        }, \is_array($keyType = $context['key_type'] ?? []) ? $keyType : [$keyType]);
+        $builtinTypes = array_map(static function ($keyType) { return $keyType->getBuiltinType(); }, (array) ($context['key_type'] ?? []));
 
         foreach ($data as $key => $value) {
             $subContext = $context;
@@ -109,20 +107,12 @@ class ArrayDenormalizer implements ContextAwareDenormalizerInterface, Denormaliz
      */
     private function validateKeyType(array $builtinTypes, $key, string $path): void
     {
         if (!$builtinTypes) {
             return;
         }
 
-        $unexpectedDataType = true;
         foreach ($builtinTypes as $builtinType) {
             if (('is_'.$builtinType)($key)) {
-                $unexpectedDataType = false;
-                break;
+                return;
             }
         }
 
-        if ($unexpectedDataType) {
-            throw NotNormalizableValueException::createForUnexpectedDataType(sprintf('The type of the key "%s" must be "%s" ("%s" given).', $key, implode('", "', $builtinTypes), get_debug_type($key)), $key, $builtinTypes, $path, true);
-        }
+        throw NotNormalizableValueException::createForUnexpectedDataType(sprintf('The type of the key "%s" must be "%s" ("%s" given).', $key, implode('", "', $builtinTypes), get_debug_type($key)), $key, $builtinTypes, $path, true);
     }
 }
diff --git a/src/Symfony/Component/Serializer/composer.json b/src/Symfony/Component/Serializer/composer.json
index 1b9537f8f8..11e67a8a7e 100644
--- a/src/Symfony/Component/Serializer/composer.json
+++ b/src/Symfony/Component/Serializer/composer.json
@@ -34,7 +34,7 @@
         "symfony/http-kernel": "^4.4|^5.0|^6.0",
         "symfony/mime": "^4.4|^5.0|^6.0",
         "symfony/property-access": "^5.4|^6.0",
-        "symfony/property-info": "^5.4.24|^6.0",
+        "symfony/property-info": "^5.4.24|^6.2.11",
         "symfony/uid": "^5.3|^6.0",
         "symfony/validator": "^4.4|^5.0|^6.0",
         "symfony/var-dumper": "^4.4|^5.0|^6.0",
@@ -47,7 +47,7 @@
         "phpdocumentor/type-resolver": "<1.4.0",
         "symfony/dependency-injection": "<4.4",
         "symfony/property-access": "<5.4",
-        "symfony/property-info": "<5.4.24",
+        "symfony/property-info": "<5.4.24|>=6,<6.2.11",
         "symfony/uid": "<5.3",
         "symfony/yaml": "<4.4"
     },

[HypeMC]

Can you check the follow patch please?

@nicolas-grekas The following part won't work:

-        $builtinTypes = array_map(static function (Type $keyType) {
-            return $keyType->getBuiltinType();
-        }, \is_array($keyType = $context['key_type'] ?? []) ? $keyType : [$keyType]);
+        $builtinTypes = array_map(static function ($keyType) { return $keyType->getBuiltinType(); }, (array) ($context['key_type'] ?? []));

$context['key_type'] is not a scalar but an instance of \Symfony\Component\PropertyInfo\Type.

[nicolas-grekas]

Thank you @HypeMC.