Regression: SplDoublyLinkedList::add(null) TypeError — Zend E_DEPRECATED soft coerce (ext/spl/spl_dllist.c)

[PurHur]

Category

Regression: · php-src-strict · SPL soft-null

Problem

SplDoublyLinkedList::add(null, $v) under non-strict types must emit E_DEPRECATED ("Passing null to parameter #1 ($index) of type int is deprecated") and insert at index 0. VM throws TypeError.

Sibling: offsetSet(null) already appends without DEP (#31731); add uses Z_PARAM_LONG and soft-deprecates.

Probed 2026-08-17 — host Zend PHP 8.2+ vs php bin/vm.php.

Repro	Zend 8.2+	VM (2026-08-17)
$l->add(null, 'x') after one push	E_DEPRECATED + insert at 0	TypeError Argument #1 ($index)

php-src reference

• php/php-src ext/spl/spl_dllist.c — zim_SplDoublyLinkedList_add / Z_PARAM_LONG

PHP implementation target

• ext/spl/SplDoublyLinkedListBuiltin.php — soft-null via VmMath::parseZParamLongBuiltinArgForFrame (or shared coerceIndex DEP path)

Repro

./script/docker-exec.sh -- bash -lc 'php bin/vm.php test/repro/maintainer_gap_dllist_add_null.php'

Done when

• VM (+ JIT when covered) emits E_DEPRECATED #1 ($index) and inserts at 0
• Unit/repro guard; php-src-strict; no php-compiler-strict shortcut

[PurHur]

claim: PHP Compiler STD Lib Advanced — batch (issues #31803, #31804, #31805, #31806, #31807); starting with #31803 SplDoublyLinkedList::add(null)

[PurHur]

Merged via #31808

Verification: VM/JIT repro → E_DEPRECATED #1 ($index) + count=2 top0=x; Issue31803DllistAddNullSoftTest OK (2 tests).