[php-src] Issue #12455: Namespace prefixes reused incorrectly

Issue: https://github.com/php/php-src/issues/12455 Author: InvisibleSmiley ### Description The following code: ```php <?php $doc = new DOMDocument(); $element = $doc->createElementNS('http://test', 'a:x'); $doc->appendChild($element); $element1 = $doc->createElementNS('http://test', 'b:y'); $element->appendChild($element1); $element1->appendChild($doc->createElementNS('http://test', 'b:z')); echo $doc->saveXml(); $xpath = new DOMXPath($doc); $xpath->registerNodeNamespaces = true; $xpath->registerNamespace('b', 'http://test'); $elements = $xpath->query('//b:z'); foreach ($elements as $e) { var_dump($e->nodeName); } $elements = $xpath->query('//*[name()="b:z"]'); echo $elements->length; ``` Resulted in this output: ``` <?xml version="1.0"?> <a:x xmlns:a="http://test"><b:y xmlns:b="http://test"><a:z/></b:y></a:x> string(3) "a:z" 0 ``` But I expected this output instead: ``` <?xml version="1.0"?> <a:x xmlns:a="http://test"><b:y xmlns:b="http://test"><b:z/></b:y></a:x> string(3) "b:z" 1 ``` Likely caused by the fix for bug #67440: append_node of a DOMDocumentFragment does not reconcile namespaces https://github.com/php/php-src/commit/b1d8e240e688cae810c83b364772bf140ac45f42 Broken since: 8.1.21 / 8.2.8 Last known good: 8.1.20 / 8.2.7 I think the following is relevant in this context, explaining why XML C14N explicitly excluded XML namespace prefix rewriting: https://datatracker.ietf.org/doc/html/rfc3076#section-4.4 ### PHP Version PHP 8.1.24 ### Operating System MacOS Ventura 13.6