Situation: A website member (registered but not logged in) receives an email containing a link to a page that's accessible only to logged-in members. They click on the link and get the WP-Members login page. They log in, but are not automatically redirected to the page they originally requested.
I've played with add_filter( 'wpmem_login_redirect', fn) and it works fine for known addresses, but I can't find that original email link in memory. I had hoped to find it in HTTP_REFERER but that contains only the URL of the login page itself! And it's not stored in a cookie.
Is there a hook I can use to set the redirect URI immediately after the plugin code actives and before that initially requested URI is lost?