Description:
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Native DOMDocument's method saveHTML() creates paired tag from picture/video source element, but according to https://www.w3.org/TR/2011/WD-html5-author-20110809/the-source-element.html it should be unpaired element. It works well with another unpaired elements like meta, img, br, hr, … . But it filed with source ( https://developer.mozilla.org/en-US/docs/Web/HTML/Element/source ) .




Test script:
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<?php

const ELEMENT_NAME = 'source'; // meta / img / br / hr

$document = new DOMDocument( '1.0', 'UTF-8' );
$element = $document->createElement(ELEMENT_NAME);
$document->appendChild($element);
echo $document->saveHTML(); // writes '<source></source>' but according to https://www.w3.org/TR/2011/WD-html5-author-20110809/the-source-element.html it should be '<source>'


Expected result:
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<source>

Actual result:
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<source></source>