[5.2] 948f3c1 Mention clarification of req.backend_hint and restarts as of 5.2.

[PÃ¥l Hermunn Johansen]

commit 948f3c14fdb14d6bd0977cdb72a771a671379906
Author: Geoff Simmons <geoff at uplex.de>
Date:   Thu Sep 14 10:00:20 2017 +0200

    Mention clarification of req.backend_hint and restarts as of 5.2.

diff --git a/doc/sphinx/whats-new/upgrading-5.2.rst b/doc/sphinx/whats-new/upgrading-5.2.rst
index b28c328..196fcf0 100644
--- a/doc/sphinx/whats-new/upgrading-5.2.rst
+++ b/doc/sphinx/whats-new/upgrading-5.2.rst
@@ -116,6 +116,14 @@ but was still in grace time. Varnish returns the stale cached response
 to the client, and initiates the background fetch to refresh the cache
 object.
 
+``req.backend_hint``
+--------------------
+
+We have clarified what happens to ``req.backend_hint`` on a client
+restart -- it gets reset to the default backend. So you might want to
+make sure that the backend hint gets set the way you want in that
+situation.
+
 XXX: vcl_sub_XXX ...
 ~~~~~~~~~~~~~~~~~~~~