Regression: SimpleXMLElement::addChild/addAttribute(null) TypeError — Zend Deprecated + ValueError empty (ext/simplexml/sxe.c)

[PurHur]

Category

Regression: · php-src-strict · SimpleXMLElement addChild/addAttribute null name

Problem

Passing null for $qualifiedName on Zend soft-deprecates null-to-string then throws ValueError: … Argument #1 ($qualifiedName) cannot be empty. VM hard-TypeErrors (must be of type string) with no deprecation.

Same soft-null class as open #31514 / #31530 (SimpleXMLElement ctor / xpath).

Probed 2026-08-16 — host Zend PHP 8.2.32 vs php bin/vm.php.

Repro	Zend 8.2+	VM (2026-08-16)
$x->addChild(null)	Deprecated + ValueError: … cannot be empty	TypeError: … must be of type string
$x->addAttribute(null, 'v')	Deprecated + ValueError: … cannot be empty	TypeError: … must be of type string

php-src reference

• php/php-src ext/simplexml/sxe.c — zim_SimpleXMLElement_addChild / addAttribute null→string soft coerce then empty-name ValueError
• php/php-src ext/simplexml/simplexml.stub.php — addChild(string $qualifiedName, …) / addAttribute(string $qualifiedName, …)

PHP implementation target

• ext/simplexml/SimpleXmlElementAddChild.php + SimpleXmlElementAddAttribute.php — under php-src-strict, soft-deprecate null then empty-name ValueError (reuse shared string-arg coerce helpers)
• No new runtime/*.c

Repro

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

Done when

• addChild(null) / addAttribute(null, …) emit Zend deprecation then ValueError: … cannot be empty
• Targeted compliance/PHPUnit guard
• php-src-strict; no php-compiler-strict shortcut

[PurHur]

claim: PHP Compiler Ext — DOM & XML — starting this run

[PurHur]

Merged via PR #31561.

Fix: Soft-null $qualifiedName on SimpleXMLElement::addChild / addAttribute via VmString::stringBuiltinArgForFrame(..., false) (php-src sxe.c); empty name still throws ValueError: … cannot be empty. JIT addChild(null) emits DEP then the same ValueError.

Verification:

./script/docker-exec.sh -- bash -lc 'php bin/vm.php test/repro/maintainer_gap_simplexml_addchild_addattribute_null.php'
# DEP:…Passing null… deprecated
# addChild ValueError: … cannot be empty
# DEP:…Passing null… deprecated
# addAttribute ValueError: … cannot be empty

./script/docker-exec.sh -- bash -lc 'php bin/jit.php test/repro/maintainer_gap_simplexml_addchild_addattribute_null.php'
# same

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && vendor/bin/phpunit test/compliance/SimplexmlAddChildAddAttributeNullSoft31554VMTest.php test/compliance/SimplexmlAddChildAddAttributeNullSoft31554JITTest.php'
# OK (1 test) ×2 (run separately)