Regression: array_multisort() inline non-empty array literal — by-ref Error not Zend success (ext/standard/array.c) #12017

Category

stdlib · php-src-strict

Problem

array_multisort() with an inline non-empty array literal must succeed like Zend — php-src copies/sorts ephemeral arrays for inline operands. This compiler rejects the call:

Error: array_multisort(): Argument #1 ($param1) cannot be passed by reference

Related #9362 (empty [] literal) but distinct: non-empty [1,2] and multi-array array_multisort([1,2], [2,1]) also fail on VM while Zend prints ok.

php-src reference

• php/php-src ext/standard/array.c — php_array_multisort, inline array materialization for by-ref variadic args
• php/php-src Zend/zend_compile.c — send-by-ref lowering for function calls

PHP implementation today

• ext/standard/array_multisort.php, compiler by-ref actualization for variadic builtins

Repro

• test/repro/maintainer_gap_array_multisort_inline_array_flags.php
• test/repro/maintainer_gap_array_multisort_two_inline_arrays.php

./script/docker-exec.sh -- php test/repro/maintainer_gap_array_multisort_inline_array_flags.php   # Zend: ok
./script/docker-exec.sh -- php bin/vm.php test/repro/maintainer_gap_array_multisort_inline_array_flags.php  # VM: Error

Implementation hints (PHP-in-PHP)

• Materialize inline array operands into temporaries with by-ref slots before invoking array_multisort (same fix pattern as Stdlib: array_multisort() inline empty array literal must return true not by-ref Error (ext/standard/array.c) #9362 / array_walk closure args)
• Preserve existing variable-arg path ($a = [1,2]; array_multisort($a, …))
• VM + JIT/AOT agree when both in scope

Done when

• Both repro scripts print ok on VM
• sort([1,2]) / ksort([1=>2]) still correctly reject by-ref Error (only array_multisort is special)
• Targeted compliance guard committed

Refs #1492, #9362, #9076.