Stdlib: array_chunk() rejects inline empty array literal — must return [] (ext/standard/array.c)

[PurHur]

Category

stdlib | php-src-strict

Problem

array_chunk([], $size, $preserve_keys) with an inline empty array literal throws LogicException ("first argument must be an array"). Zend returns array().

A variable holding [] works ($a = []; array_chunk($a, 2) is fine), so the bug is in compile-time literal lowering / builtin arg materialization for empty Expr_Array.

php-src reference

• php/php-src ext/standard/array.c — php_array_chunk early return on empty input
• php/php-src Zend/zend_operators.c — empty array handling

Repro

test/repro/maintainer_gap_array_chunk_empty_literal.php:

<?php
var_export(array_chunk([], 2, true));
echo "\n";

php test/repro/maintainer_gap_array_chunk_empty_literal.php          # Zend: array ()
php bin/vm.php test/repro/maintainer_gap_array_chunk_empty_literal.php  # VM: LogicException

Control (must stay green):

$a = [];
var_export(array_chunk($a, 2, true));

Engine	Inline []	$a = []
Zend PHP 8.4+	array()	array()
This compiler VM	LogicException	array()

Scope

Module	Path
Compiler	empty array literal → VM array value for builtin calls
VM builtin	ext/standard/array_chunk.php type guard should accept empty arrays
JIT/AOT	same literal lowering path
Tests	test/compliance/cases/stdlib/array_chunk_empty_literal.phpt

Done when

• Inline array_chunk([], …) returns [] on VM
• Non-empty literal and variable forms unchanged
• No regression on other builtins taking inline [] (audit array_pad, array_merge, …)

Related

• Stdlib: array_splice() negative offset + replacement array mis-binds arguments (ext/standard/array.c) #9329 array_splice mis-bind · literal-arg family Regression: builtin calls with null literal arguments mis-bind parameters (array_column/array_search/in_array, ext/standard/array.c) #9305 · Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492

[PurHur]

claim: PHP Compiler STD Lib — starting this run

[PurHur]

Unclaiming: inline empty array literal repro already green on master. Issue appears stale.

[PurHur]

claim: cursor-agent-lane-b — starting this run

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claim: cursor-agent-lane-b — starting this run

[PurHur]

claim released: repro green on master — inline array_chunk([], 2, true) returns array() on VM matching Zend; no code change needed.

[PurHur]

claim: cursor-agent-lane-b — starting this run

[PurHur]

claim: cursor-agent-lane-b — starting this run

[PurHur]

claim released: inline array_chunk([], …) and array_reduce([], …) already match Zend on master — repro scripts pass on VM without code changes. Pivoting to bootstrap inventory drift.

[PurHur]

unclaim: stale claim (>7 days, no open PR). Returning to implementation-ready pool for the next worker.

[PurHur]

claim: PHP Compiler STD Lib — starting this run

Prior #20073 released (mis-scoped soft-null vs #20007). Trust: bootstrap-selfhost-link OK; inventory OK 5441/5441.