Regression: substr_compare(..., null) $offset TypeError — Zend DEP+coerce (ext/standard/string.c)

[PurHur]

Category

stdlib · php-src-strict · null→int DEP · pillar 4

Problem

substr_compare($haystack, $needle, null) must emit E_DEPRECATED for passing null to int $offset, coerce to 0, and return the comparison result. VM/JIT throw TypeError: … Argument #3 ($offset) must be of type int, null given with no deprecation.

Probed 2026-08-09 @ dd181e4f49 vs container Zend 8.2.32. VM and JIT agree (both wrong).

Repro	Zend 8.2+	VM / JIT
substr_compare('abc', 'b', null)	DEP then -1	TypeError on $offset

php-src reference

• php/php-src ext/standard/string.c — PHP_FUNCTION(substr_compare)
• php/php-src ext/standard/string.stub.php — substr_compare(string $haystack, string $needle, int $offset, …)

PHP implementation target

• ext/standard substr_compare / shared int-arg null DEP+coerce helper (same pattern as siblings for strspn/strcspn/range null args)
• PHP-in-PHP; no new runtime/*.c logic

Repro

./script/docker-exec.sh -- bash -lc 'cat > /tmp/substr_compare_null.php <<\"PHP\"
<?php
error_reporting(E_ALL);
set_error_handler(static function (int $no, string $str): bool {
    echo \"WARN: $str\n\";
    return true;
});
try {
    var_export(substr_compare(\"abc\", \"b\", null));
    echo \"\n\";
} catch (Throwable $e) {
    echo get_class($e), \": \", $e->getMessage(), \"\n\";
}
PHP
php /tmp/substr_compare_null.php; php bin/vm.php /tmp/substr_compare_null.php; php bin/jit.php /tmp/substr_compare_null.php'

Done when

• VM + JIT: null $offset → DEP + coerce to 0 + same return as Zend
• Compliance .phpt under test/compliance/cases/stdlib/
• php-src-strict; no php-compiler-strict shortcut

[PurHur]

claim: PHP Compiler STD Lib — starting this run

Pillar probe (pre-claim):

• php script/bootstrap-inventory.php --check: red — stale docs/bootstrap-inventory.md construct-flag drift on lib/JIT/InstancePropertyVisibilityJitGuard.php (not a stdlib blocker for this issue)
• ./script/release-readiness.sh --json: still running at claim time; will note first fail if any
• Target: Regression: substr_compare(..., null) $offset TypeError — Zend DEP+coerce (ext/standard/string.c) #29504 substr_compare(..., null) $offset TypeError → Zend DEP+coerce (php-src-strict)

[PurHur]

Merged in #29520

Verification (local Docker):

• VM/JIT: substr_compare('abc','b',null) → E_DEPRECATED parameter Stdlib: ceil, floor, intval and expanded PHPT specs #3 ($offset) + -1
• AOT: ./phpc build of test/repro/issue_29504_substr_compare_null_offset_aot.php → DEP + -1
• vendor/bin/phpunit --filter SubstrCompareNullOffset → OK (2)

php-src-strict via shared Z_PARAM_LONG soft-null helpers (VmMath / JitChr), no new C.