Infinite recursion when data provider provides recursive array

[ptomulik]

Q	A
PHPUnit version	>=10.0.0
PHP version	8.2.13
Installation Method	Composer / PHAR

Summary

When @dataProvider method tries to return recursive array, it always fails with SEGFAULT.

Current behavior

Segmentation fault.

How to reproduce

<?php declare(strict_types=1);

use PHPUnit\Framework\TestCase;

final class RecursiveArrayTest extends TestCase {
    public static function provideRecursiveArray(): iterable {
        $array = [];
        $array[0] = &$array;
        yield [$array];
    }

    /**
     * @dataProvider provideRecursiveArray
     */
    public function testRecursiveArray(array $array): void {
        $this->assertTrue(true);
    }
}

ptomulik@tea:$ vendor/bin/phpunit tests/RecursiveArrayTest.php 
PHPUnit 10.0.0 by Sebastian Bergmann and contributors.

Runtime:       PHP 8.2.13

Segmentation fault

Expected behavior

The test should pass

[sebastianbergmann]

You are testing with PHPUnit 10.0.0 which is not supported anymore. Do you encounter the same issue with PHPUnit 10.5.2?

[ptomulik]

You are testing with PHPUnit 10.0.0 which is not supported anymore. Do you encounter the same issue with PHPUnit 10.5.2?

10.0 is the first version having this bug (9.6 seems working fine). From my experiments, it looks like all the versions >=10.0 are vulnerable.

[ptomulik]

ptomulik@tea:$ vendor/bin/phpunit tests/RecursiveArrayTest.php 
PHPUnit 10.5.2 by Sebastian Bergmann and contributors.

Runtime:       PHP 8.2.13

Segmentation fault

[sebastianbergmann]

This happens in TestCase::registerMockObjectsFromTestArguments().

We do not need this code anymore in PHPUnit 11 as data providers must be static in PHPUnit 11 and therefore can no longer create mock objects. So in PHPUnit 11 this problem will be gone.

As for PHPUnit 10, I do not considers recursive arrays important enough (IMO, they are an edge case) to spend time on fixing the implementation of TestCase::registerMockObjectsFromTestArguments(). I would consider a pull request that addresses this, of course, but I will not invest time in debugging this myself.

[ptomulik]

See #5615