Regression: number_format() — enum case operand coerces not TypeError (re-#5892, number_format.c)

[PurHur]

Category

stdlib | php-src-strict

Problem

number_format(E::A) on a backed enum case silently coerces to the backing scalar ('1') instead of throwing TypeError. Zend rejects enum objects for the $num parameter.

Regression of #5892 (closed 2026-06-10).

php-src reference

• php/php-src ext/standard/number_format.c — php_number_format, _number_format parameter typing
• php/php-src Zend/zend_enum.c — enum is object, not numeric for number_format

Repro

<?php
declare(strict_types=1);
enum E: int { case A = 1; }
try { var_export(number_format(E::A)); echo "\n"; } catch (Throwable $e) { echo get_class($e), "\n"; }

./script/docker-exec.sh -- bash -lc 'php test/repro-maintainer/parity_number_format_enum.php
php bin/vm.php test/repro-maintainer/parity_number_format_enum.php'

Runtime	Output
Zend	TypeError
VM today	'1'

Existing repro: test/repro-maintainer/parity_number_format_enum.php

Scope (this repo)

Path	Work
ext/standard/number_format.php	Typed $num guard — reject enum objects before scalar coercion
lib/JIT/ number_format lowering	JIT/AOT parity
Tests	compliance phpt under test/compliance/cases/stdlib/

PHP-in-PHP: fix guard in ext/standard; reuse shared numeric builtin arg helpers.

Done when

• number_format() TypeError on enum case operand (VM)
• JIT/AOT parity when lowering active
• Repro matches Zend
• Does not regress number_format(1.5) / RoundingMode 5th arg (Stdlib: RoundingMode enum + number_format() 5th argument (PHP 8.4, ext/standard/number_format.c) #5934)

Related

#5892 · #8728 · #5934 · #8746 · #1492

[PurHur]

claim: cursor-agent-lane-c — starting this run (JIT number_format enum TypeError arg index off-by-one)

[PurHur]

Merged via #10619.

Fix: number_format() $decimal_separator / $thousands_separator enum TypeError messages used Argument #4/#5 instead of Zend's #3/#4 — VmString/JitStringBuiltinArg are 0-based (+1 in message) while VmMath/JitIntdiv are 1-based.

Verification:

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
php bin/vm.php test/repro/maintainer_number_format_enum_typeerror.php
php bin/jit.php test/repro/maintainer_number_format_enum_typeerror.php
php vendor/bin/phpunit --filter number_format_enum
'

→ Argument #3 ($decimal_separator) on VM+JIT; OK (4 tests, 4 assertions).