voku / simple_html_dom

    protected function createDOMDocument(string $html, $libXMLExtraOptions = null): \DOMDocument

    {

        // Remove content before <!DOCTYPE.*> because otherwise the DOMDocument can not handle the input.

        if (\stripos($html, '<!DOCTYPE') !== false) {

            /** @noinspection NestedPositiveIfStatementsInspection */

            if (

                \preg_match('/(^.*?)<!(?:DOCTYPE)(?: [^>]*)?>/sui', $html, $matches_before_doctype)

                &&

                \trim($matches_before_doctype[1])

            ) {

                $html = \str_replace($matches_before_doctype[1], '', $html);

            }

        }

        if ($this->keepBrokenHtml) {

            $html = $this->keepBrokenHtml(\trim($html));

            $this->isDOMDocumentCreatedWithFakeEndScript = true;

        }

        if (\stripos($html, '</html>') !== false) {

            /** @noinspection NestedPositiveIfStatementsInspection */

            if (

                \preg_match('/<\/html>(.*?)/suiU', $html, $matches_after_html)

                &&

                \trim($matches_after_html[1])

            ) {

                $html = \str_replace($matches_after_html[0], $matches_after_html[1] . '</html>', $html);

            }

        }

        if (\strpos($html, '<script') !== false) {

            $this->html5FallbackForScriptTags($html);