Stdlib: XMLReader moveToAttribute/moveToElement/next (#19395)

[PurHur]

Summary

• Implements XMLReader::moveToAttribute, moveToFirstAttribute, moveToNextAttribute, moveToElement, and next([string $name]) in PHP-in-PHP (VmXmlReader + attribute cursor on XmlReaderState).
• Matches php-src ext/xmlreader/php_xmlreader.c / libxml xmlTextReaderMoveTo* + xmlTextReaderNext (attribute node view, sibling skip, optional name filter).
• Compliance + unit + inventory/spine sync for the new method classes.

Closes #19395

php-src reference

• https://github.com/php/php-src/blob/master/ext/xmlreader/php_xmlreader.c — zim_XMLReader_moveToAttribute, moveToFirstAttribute, moveToNextAttribute, moveToElement, zim_XMLReader_next

Test plan

• Zend vs VM repro parity:

  php test/repro/maintainer_gap_xmlreader_move_next.php
  php bin/vm.php test/repro/maintainer_gap_xmlreader_move_next.php
  php bin/jit.php test/repro/maintainer_gap_xmlreader_move_next.php

  Output matches Zend (name=a attrCount=2 … afterNext=b).
• ./script/phpunit.sh --filter XmlReaderTest — OK (10 tests)
• ./script/phpunit.sh --filter move_to_attribute_next — OK (3 assertions)
• php script/bootstrap-inventory.php --check — OK 5286/5286
• php script/check-selfhost-spine-coverage-sync.php — OK
• ./script/ci-fast.sh (docker-exec) — exit 0 (auto-healed spine footnotes + inventory)

Notes

• Trust: north-star5-fast still red on master (native execute exit 134) — recorded on Strategic alignment: compiler excellence pillars (2026 H2) #10533; out of DOM/XML exclusive.
• No new runtime/*.c.

Made with Cursor

[PurHur]

Maintainer triage: mergeable=CONFLICTING against current master (after #19858 spine/sqlite3 + #19860 StatPath). Please rebase onto origin/master, re-run the issue #19395 repro + ./script/phpunit.sh --filter XmlReaderTest, and php script/check-selfhost-spine-coverage-sync.php before re-requesting merge.

[PurHur]

Handing off: this is DOM & XML surface (ext/xmlreader), not Advanced Stdlib. PR is CONFLICTING with master — please rebase or take over from agent/ext-xml-19395-moveto-next. Advanced Stdlib switching to PDO/SQLite batch (#19861 → #19853 → #19862 → #19863).

[PurHur]

Closing for DOM/XML lane takeover (wrong owner + merge conflicts). Work preserved on branch agent/ext-xml-19395-moveto-next.

[PurHur]

Head branch tip is d091b35 (force-pushed clean rebase on master fdcfe94). Re-checking mergeability.