Stdlib: fputcsv() — enclosure/escape edge cases + ValueError parity (ext/standard/file.c) #4530

Category

stdlib

Problem

fputcsv() is implemented for basic cases but does not match Zend for empty enclosure (ValueError) and empty escape character (PHP 8.4+ rules), multi-byte separators, or TypeError vs LogicException on bad handle types.

VM path: ext/standard/fputcsv.php + VmFs; defaults separator=',', enclosure='"', escape='\\' with no validation.

php-src reference

• php/php-src ext/standard/file.c — PHP_FUNCTION(fputcsv) (_php_fputcsv)
• PHP 8.4: empty $escape allowed only when $enclosure is non-empty one-byte string; otherwise ValueError

Repro

Save as test/repro-maintainer/fputcsv_escape.php:

<?php
$fp = fopen('php://memory', 'r+');
foreach ([
    ['escape' => ''],
    ['enclosure' => ''],
] as $case) {
    try {
        fputcsv($fp, ['a'], ',', $case['enclosure'] ?? '"', $case['escape'] ?? '\\');
        echo "no throw\n";
    } catch (Throwable $e) {
        echo get_class($e), ': ', $e->getMessage(), "\n";
    }
}

php test/repro-maintainer/fputcsv_escape.php
./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && php bin/vm.php test/repro-maintainer/fputcsv_escape.php'

Expected on PHP 8.4+ (Zend, document exact message from php -v in Docker)

Record actual message strings in the compliance PHPT header when implementing.

Actual (this compiler)

Often no throw or LogicException on bad handle type instead of TypeError.

Scope

• ext/standard/fputcsv.php, ext/standard/VmFs.php
• lib/JIT/Builtin/ fputcsv lowering if present
• test/compliance/cases/stdlib/fputcsv_escape.phpt, fputcsv_bad_handle.phpt

Done when

• Repro exception class + message match Zend for empty escape/enclosure on VM
• Normal 5-arg calls still write RFC4180-style CSV like Zend
• ./script/ci-fast.sh --filter fputcsv green

Links

• Stdlib: fputcsv() — VM + LLVM JIT/AOT #1193 baseline fputcsv implementation