login redirect processing

app/services/session.js

@@ -53,7 +53,16 @@ class SessionService {
     return async (req, res, next) => {
       if (options.requireLogin && !req.user) {
         req.session.loginReturnTo = req.url;
-        return res.redirect(options.loginUri);
+        this.log.info('redirecting to login', { returnTo: req.url });
+        return new Promise((resolve, reject) => {
+          req.session.save(async (err) => {
+            if (err) {
+              return reject(err);
+            }
+            res.redirect(options.loginUri);
+            return resolve();
+          });
+        });
       }
       if (options.requireAdmin && (!req.user || !req.user.flags.isAdmin)) {
         return next(new SiteError(403, 'Administrator privileges are required'));