wp_replace_insecure_home_url

WordPress Version: 5.7

/**
 * Replaces insecure HTTP URLs to the site in the given content, if configured to do so.
 *
 * This function replaces all occurrences of the HTTP version of the site's URL with its HTTPS counterpart, if
 * determined via {@see wp_should_replace_insecure_home_url()}.
 *
 * @since 5.7.0
 *
 * @param string $content Content to replace URLs in.
 * @return string Filtered content.
 */
function wp_replace_insecure_home_url($content)
{
    if (!wp_should_replace_insecure_home_url()) {
        return $content;
    }
    $https_url = home_url('', 'https');
    $http_url = str_replace('https://', 'http://', $https_url);
    // Also replace potentially escaped URL.
    $escaped_https_url = str_replace('/', '\/', $https_url);
    $escaped_http_url = str_replace('/', '\/', $http_url);
    return str_replace(array($http_url, $escaped_http_url), array($https_url, $escaped_https_url), $content);
}