Regression: DOMDocument::getElementById() after setIdAttribute on detached node + replaceChild — Zend null, VM finds node (ext/dom/node.c)

[PurHur]

Category

bug · php-src-strict · DOM ID map · pillar 4

Problem

Calling setIdAttribute('id', true) on a detached element, then replaceChild() into the document, must not register that id in the document ID map on Zend/libxml (getElementById stays null). VM returns the replacement element. Probed 2026-07-27 vs Zend 8.2.32.

Repro	Zend 8.2.32	VM (2026-07-27)
detached setIdAttribute then replaceChild; getElementById('x')	null	b (replacement)
Control: setIdAttribute on attached node with a new id after replace	finds node	finds node (OK)
Control: removeChild of id'd node	null	null (OK)

php-src reference

• php/php-src ext/dom/node.c — setIdAttribute / insert / replaceChild ID-map updates
• php/php-src ext/dom/document.c — getElementById / element ID hashtable

PHP implementation target

• ext/dom/ ID-map helpers — only register IDs for nodes that are in the document tree; sync on insert/replace/remove like php-src
• PHP-in-PHP; no new runtime/ C

Repro

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

Done when

• Detached setIdAttribute + replaceChild → getElementById is null on VM (+ JIT/AOT when in scope)
• Attached setIdAttribute after insert with a fresh id still resolves
• Compliance .phpt + keep/update test/repro/maintainer_gap_dom_setidattribute_detached_replace.php
• php-src-strict; no php-compiler-strict shortcut

[PurHur]

Maintainer gate note (2026-07-27)

Pillar 1 red on this host (#10533 comments locked at 2500+ — parking status here):

Gate	Result
inventory	OK 6597/6597
spine-coverage	FAIL — lib/JIT/HashTableSliceLlvm.php not in spine bundle
north-star5-verify --fast	FAIL (cascade)
vm-driver-probe	ok
user_release_ready	no
gen-0	stale (42d / 6654 lowering commits) — honesty warning

Sibling phantoms filed same run: #24000 #24001 #24002 #24003. Open PRs: none.

[PurHur]

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

Trust gates (pre-claim, this host):

Gate	Result
docker info	ok
php script/bootstrap-inventory.php --check	FAIL — stale docs/bootstrap-inventory.md (Compiler.php method count 1101→1103; construct warnings 21339→21343). Not touched by this DOM fix; regenerating only if this change pulls those files onto the vm.php path.
Open DOM/XML PRs for this issue	none

Picking #23999 (detached setIdAttribute + replaceChild ID-map parity). Will verify VM repro vs Zend, then fix ext/dom ID indexing.

[PurHur]

Merged via PR #24021.

Fix: registerElementId() and getElementById() now require isConnected() (php-src bug 77686). Detached setIdAttribute still stamps idAttributeName; attach/replaceChild reindexes. Zend 8.2.32 observation: before=null, after=b (issue table’s after=null was incorrect vs host Zend).

Verification:

php / bin/vm.php / bin/jit.php test/repro/maintainer_gap_dom_setidattribute_detached_replace.php
→ before=null / after=b / attached=c / removed=null
vendor/bin/phpunit --filter dom_setidattribute_detached_replacechild → OK (2 tests)

AOT user-script compile not covered (cold helper emit timed out).