Stdlib: array_fill_keys() nested array keys — Array-to-string warning + 'Array' key missing (ext/standard/array.c)

[PurHur]

Summary

array_fill_keys() with a nested array as a key element must emit Zend's E_WARNING: Array to string conversion and use the string key "Array". VM throws Error: Object of class array could not be converted to string (wrong exception class/message).

Repro

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

Call	Zend PHP 8.2	VM today
array_fill_keys([[[1]]], 1)	warning + array('Array' => 1)	Error ❌

php-src reference

• php/php-src ext/standard/array.c — php_array_fill_keys, _zval_get_string_func array branch

Implementation (PHP-in-PHP)

• ext/standard/VmArray.php — array key coercion: warn via frame helper, use literal "Array" key (same as ext/standard/array_combine / php-src _array_to_string)
• Do not route through object __toString path

Done when (php-src-strict)

• Repro: warning + array('Array' => 1) on VM
• Scalar keys unchanged

Verification

./script/docker-exec.sh -- php bin/vm.php test/repro/maintainer_gap_array_fill_keys_array_key.php

Related: #8779, #1492

[PurHur]

claim: cursor-agent-lane-a — starting this run (lane A queue empty for non-stdlib language; lowest open failing lane-A issue)

[PurHur]

Merged via #10862

Fix: nested inline array literal call args now wire outermost array to array_fill_keys(); array key operands emit Zend warning + "Array" key (VM + JIT).

Verify:

./script/docker-exec.sh -- bash -lc 'php bin/vm.php test/repro/maintainer_gap_array_fill_keys_array_key.php'
# array ( 'Array' => 1, )
vendor/bin/phpunit --filter array_fill_keys_array_key  # OK (2 tests)