Wrong resolution of relative namespace in PHP 8.4

[jlherren]

Serializable Closure Version

2.0.3

PHP Version

8.4.4 on Linux / 8.4.5 on Windows

Description

Usages of relative namespaces get serialized to a wrong absolute namespace in PHP 8.4. It worked correctly in PHP 8.2.

Steps To Reproduce

Example code:

<?php

namespace MyApp\Cache;

class CacheFactory {
    public function getCache() {
        return 'cache';
    }
}

namespace MyApp;

use Laravel\SerializableClosure\SerializableClosure;

require_once __DIR__ . '/vendor/autoload.php';

// The name 'Cache' is relative to the 'MyApp' namespace.
$closure = function (Cache\CacheFactory $cacheFactory) {
    return $cacheFactory->getCache();
};

$serialized = serialize(new SerializableClosure($closure));

echo "Serialized: $serialized\n";

$closure = unserialize($serialized)->getClosure();

echo 'Received: ', $closure(new Cache\CacheFactory()), "\n";

Output in PHP 8.2:

Serialized: O:47:"Laravel\SerializableClosure\SerializableClosure":1:{s:12:"serializable";O:46:"Laravel\SerializableClosure\Serializers\Native":5:{s:3:"use";a:0:{}s:8:"function";s:92:"function (\MyApp\Cache\CacheFactory $cacheFactory) {
    return $cacheFactory->getCache();
}";s:5:"scope";N;s:4:"this";N;s:4:"self";s:32:"00000000000000020000000000000000";}}
Received: cache

Note how in the closure, the name Cache was not imported via use and thus resolves relatively to MyApp to mean \MyApp\Cache. However, with PHP 8.4, this fails and outputs the following:

Serialized: O:47:"Laravel\SerializableClosure\SerializableClosure":1:{s:12:"serializable";O:46:"Laravel\SerializableClosure\Serializers\Native":5:{s:3:"use";a:0:{}s:8:"function";s:86:"function (\Cache\CacheFactory $cacheFactory) {
    return $cacheFactory->getCache();
}";s:5:"scope";N;s:4:"this";N;s:4:"self";s:32:"00000000000000020000000000000000";}}
Received: PHP Fatal error:  Uncaught TypeError: {closure:laravel-serializable-closure://function (\Cache\CacheFactory $cacheFactory) {
    return $cacheFactory->getCache();
}:2}(): Argument #1 ($cacheFactory) must be of type Cache\CacheFactory, MyApp\Cache\CacheFactory given, called in C:\<snip>\b.php on line 27 and defined in laravel-serializable-closure://function (\Cache\CacheFactory $cacheFactory) {
    return $cacheFactory->getCache();
}:2

The name Cache was resolved to mean \Cache for some reason, which obviously does not work.

[jlherren]

Well, turns out it's a bug in PHP 8.4, see php/php-src#18070

[TimWolla]

Relatedly, the resolving of use statements is already broken with PHP 8.3 and earlier, because it doesn't correctly handle namespace blocks. Consider this example:

<?php

namespace {

	use Foo as CacheFactory;

	require_once __DIR__ . '/vendor/autoload.php';
}

namespace MyApp\Cache {

	class CacheFactory
	{
		public function getCache()
		{
			return 'cache';
		}
	}
}

namespace MyApp {

	use MyApp\Cache\CacheFactory;
	use Laravel\SerializableClosure\SerializableClosure;

	// The name 'Cache' is relative to the 'MyApp' namespace.
	$closure = function (CacheFactory $cacheFactory) {
		return $cacheFactory->getCache();
	};

	$serialized = serialize(new SerializableClosure($closure));

	echo "Serialized: $serialized\n";

	$closure = unserialize($serialized)->getClosure();

	echo 'Received: ', $closure(new Cache\CacheFactory()), "\n";
}

namespace {
	use Bar as CacheFactory;
}

Running on PHP 8.3 this results in:

Serialized: O:47:"Laravel\SerializableClosure\SerializableClosure":1:{s:12:"serializable";O:46:"Laravel\SerializableClosure\Serializers\Native":5:{s:3:"use";a:0:{}s:8:"function";s:70:"function (\Bar $cacheFactory) {
                return $cacheFactory->getCache();
        }";s:5:"scope";N;s:4:"this";N;s:4:"self";s:32:"00000000000000020000000000000000";}}
Received: PHP Fatal error:  Uncaught TypeError: {closure}(): Argument #1 ($cacheFactory) must be of type Bar, MyApp\Cache\CacheFactory given, called in /tmp/serializable-closure/test.php on line 37 and defined in laravel-serializable-closure://function (\Bar $cacheFactory) {
                return $cacheFactory->getCache();
        }:2
Stack trace:
#0 /tmp/serializable-closure/test.php(37): {closure}()
#1 {main}
  thrown in laravel-serializable-closure://function (\Bar $cacheFactory) {
                return $cacheFactory->getCache();
        } on line 2

CacheFactory is resolved to Bar, which is incorrect.

[github-actions]

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Thank you!

[jlherren]

I started working on this, see jlherren/serializable-closure@2.x...fix-namespaces

It now parses namespace declarations (braced and unbraced) and no longer relies on getNamespaceName(). All existing tests are passing. However, this will definitely need a bunch of additional tests to make sure it works correctly.