in saml-authentication-server/src/main/java/jetbrains/buildServer/auth/saml/plugin/SamlAuthenticationScheme.java [198:206]
private static String getRedirectUrl(HttpServletRequest request) {
HttpSession session = request.getSession();
if (session == null) {
return request.getContextPath() + "/";
}
String url = (String) session.getAttribute("URL_KEY");
session.removeAttribute("URL_KEY");
return url != null ? url : request.getContextPath() + "/";
}