Stdlib: array_rand() on enum case arrays materializes backing scalars (ext/standard/array.c)

[PurHur]

Category

stdlib · php-src-strict

Problem

array_rand() on an array of enum case objects must return a key whose element remains an enum object. VM indexes the array and materializes the backing scalar (int/string) instead of preserving the enum case.

Verified 2026-06-16: Zend PHP 8.2 vs php bin/vm.php.

php-src reference

• php/php-src ext/standard/array.c — php_array_rand
• php/php-src Zend/zend_enum.c — enum object storage in arrays

Repro

test/repro/maintainer_gap_array_rand_enum.php

php test/repro/maintainer_gap_array_rand_enum.php
php bin/vm.php test/repro/maintainer_gap_array_rand_enum.php

	Zend	VM (wrong)
get_debug_type($arr[array_rand($arr)])	E	int
$value instanceof E	true	false

enum E: int { case A = 1; case B = 2; }
$arr = [E::A, E::B, E::A];
$key = array_rand($arr);
$value = $arr[$key]; // Zend: E::A|E::B; VM: 1|2

Scope (PHP-in-PHP)

Path	Work
ext/standard/array_rand.php	Stop enum→scalar coercion when returning elements / building result
lib/VM/ArrayOps.php (if shared)	Preserve enum objects in array access paths used by array_rand
lib/JIT/Builtin/Standard/ArrayRand.php	JIT parity when in scope
Tests	test/compliance/cases/stdlib/array_rand_enum.phpt

Done when

• VM: array_rand() on enum case arrays returns keys mapping to enum objects (same as Zend)
• array_rand($arr, $num) multi-pick parity when applicable
• Targeted PHPUnit/compliance guard green

Related

#5554 array_slice/reverse · #5586 array_pop/splice · #1492