TYPO3 Hotfix for missing "filterUnits" attribute in the new SvgSanitizer (https://github.com/darylldoyle/svg-sanitizer/pull/41)

AllowedAttributes.php

<?php

declare(strict_types=1);

namespace Vendor\ExtensionName\SvgSanitizer;

use enshrined\svgSanitize\data\AllowedAttributes as OriginalAllowedAttributes;

/**
 * Class AllowedAttributes
 * @package Vendor\ExtensionName\SvgSanitizer
 */
class AllowedAttributes extends OriginalAllowedAttributes
{
    /**
     * getAttributes
     *
     * @return array
     */
    public static function getAttributes(): array
    {
        $allowedAttributes = parent::getAttributes();

        $additionalAllowedAttributes = [
            'filterUnits'
        ];

        return array_merge($allowedAttributes, $additionalAllowedAttributes);
    }
}

ext_localconf.php

<?php
defined('TYPO3_MODE') or die();

if (TYPO3_MODE === 'BE') {
    $GLOBALS['TYPO3_CONF_VARS']['SYS']['Objects'][\TYPO3\CMS\Core\Resource\Security\SvgSanitizer::class] = [
        'className' => Vendor\ExtensionName\SvgSanitizer\SvgSanitizer::class
    ];
}

SvgSanitizer.php

<?php

declare(strict_types=1);

namespace Vendor\ExtensionName\SvgSanitizer;

use enshrined\svgSanitize\Sanitizer;
use TYPO3\CMS\Core\Resource\Security\SvgSanitizer as OriginalSvgSanitizer;
use TYPO3\CMS\Core\Utility\GeneralUtility;

/**
 * SvgSanitizer
 * @package Vendor\ExtensionName\SvgSanitizer
 */
class SvgSanitizer extends OriginalSvgSanitizer
{
    /**
     * @param string $svg
     *
     * @return string
     * @throws \BadFunctionCallException
     */
    public function sanitizeContent(string $svg): string
    {
        $sanitizer = new Sanitizer();

        /** @var AllowedAttributes $allowedAttributes */
        $allowedAttributes = GeneralUtility::makeInstance(AllowedAttributes::class);
        $sanitizer->setAllowedAttrs($allowedAttributes);

        $sanitizer->removeRemoteReferences(true);
        return $sanitizer->sanitize($svg) ?: '';
    }
}