Regression: (object) cast on enum case returns empty stdClass not enum identity (re-#9569, Zend/zend_operators.c)

[PurHur]

Category

language · php-src-strict · regression

Problem

Closed #9569 fixed (object) cast on enum cases, but VM regressed: (object) E::A yields an empty stdClass ($o === E::A false, $o instanceof E false) instead of returning the same enum case object unchanged (Zend parity).

Compliance guard test/compliance/cases/language/enum_object_cast.phpt is red (verified 2026-06-19).

php-src reference

• php/php-src Zend/zend_operators.c — cast_object / enum IS_OBJECT cast
• php/php-src Zend/zend_enum.c — enum case zval type

Repro

<?php
declare(strict_types=1);

enum E: int { case A = 1; }
enum U { case X; }

$o = (object) E::A;
var_export($o === E::A);
echo "\n";
var_export($o instanceof E);
echo "\n";
var_export($o);
echo "\n";

$ux = U::X;
$o2 = (object) $ux;
var_export($o2 === U::X);
echo "\n";
var_export($o2 instanceof U);
echo "\n";

./script/docker-exec.sh php bin/vm.php test/repro-maintainer/enum_object_cast.php
# Today: false / false / (object) array () / false / false
# Zend: true / true / \E::A / true / true

Scope (this repo)

Path	Work
lib/VM/EnumCaseSupport.php	Enum cast / object cast path
lib/VM.php	TYPE_CAST_OBJECT on enum operands
lib/JIT/	Match VM when JIT compiles casts
Tests	test/compliance/cases/language/enum_object_cast.phpt green

Done when (php-src-strict)

• Repro and compliance PHPT match Zend (=== identity + instanceof for backed and unit enums)
• JIT/AOT cast lowering agrees with VM when in scope
• No new C runtime branches — PHP lowering in lib/ / ext/

Related

• Language: (object) cast on enum case must return same enum case — not empty stdClass (Zend/zend_operators.c) #9569 (closed) · Language: (array) cast on backed enum case — must yield name/value array not backing list (Zend/zend_enum.c) #9659 (array) cast (distinct) · Language: echo / concat / (string) cast on enum cases must Error — not coerce backing scalar (Zend/zend_enum.c) #9661 (string) cast · enum cluster Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492

[PurHur]

claim: cursor-agent-lane-c — starting this run

[PurHur]

Repro green on master (2026-06-20): enum_object_cast.phpt + repro-maintainer/enum_object_cast.php pass on VM. Unclaiming — verifying if issue can close.

[PurHur]

claim: withdrawn — repro already green on master 2026-06-20

[PurHur]

Verified fixed on master (2026-06-23, lane C audit). Repro green via ./script/docker-exec.sh — see #10337 run 4 probe table.