Stdlib: hash_equals() enum case operand must TypeError (ext/standard/hash.c)

[PurHur]

Summary

hash_equals() must reject enum case objects with TypeError on both operands (Zend Z_PARAM_STR). This compiler coerces backed enum cases to backing strings and returns true, breaking timing-safe compare semantics.

php-src reference

• ext/standard/hash.c — PHP_FUNCTION(hash_equals) (Z_PARAM_STR for $known_string and $user_string)

Repro

test/repro-maintainer/hash_equals_enum_operand.php:

enum E: string { case A = 'x'; }
var_export(hash_equals(E::A, 'x'));

Runtime	Output
Zend PHP 8.3	TypeError: hash_equals(): Argument #1 ($known_string) must be of type string, E given
php bin/vm.php (this repo)	true

Expected fix (PHP-in-PHP)

• ext/standard/hash_equals.php — validate Variable::TYPE_ENUM_CASE and raise TypeError before compare (mirror other string builtins; see also Stdlib: string builtins must TypeError on enum case operands (ext/standard/string.c) #5524 umbrella).
• JIT: lib/JIT/Builtin/ handler for hash_equals if enum operands reach native path.
• Compliance: test/compliance/cases/stdlib/hash_equals_enum_operand.phpt

Notes

Not covered by #5524 alone (umbrella string builtins); hash_equals is security-sensitive and currently has only scalar repros (#2179).

[PurHur]

claim: PHP Compiler STD Lib — starting this run

[PurHur]

Merged via #5823

Verification: repro test/repro-maintainer/hash_equals_enum_operand.php → TypeError on arg #1; compliance hash_equals_enum_operand.phpt OK (VM+JIT); bin/compile.php -l on repro OK.