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/**
     * Add support for SVG upload
     */
    add_filter('wp_check_filetype_and_ext', function($data, $file, $filename, $mimes) {

        global $wp_version;
        if ($wp_version !== '4.7.1') {
            return $data;
        }

        $filetype = wp_check_filetype($filename, $mimes);

        return [
            'ext'             => $filetype['ext'],
            'type'            => $filetype['type'],
            'proper_filename' => $data['proper_filename'],
        ];

    }, 10, 4);

    function cc_mime_types ($mimes)
    {
        $mimes['svg'] = 'image/svg+xml';

        return $mimes;
    }

    add_filter('upload_mimes', 'cc_mime_types');

    function fix_svg ()
    {
        echo '<style type="text/css">
.attachment-266x266, .thumbnail img {
        width: 100% !important;
        height: auto !important;
}
</style>';
    }

    add_action('admin_head', 'fix_svg');