--- modules/session/mod_session.c	2012-12-03 11:33:42.000000000 -0500
+++ modules/session/mod_session.c	2013-07-26 10:58:49.104384950 -0400
@@ -447,4 +447,5 @@
             if (override) {
                 z->encoded = override;
+		z->dirty = 1;
                 session_identity_decode(r, z);
             }
@@ -453,5 +454,6 @@
         /* save away the session, and we're done */
         /* when unset or on error, we've complained to the log */
-        ap_session_save(r, z);
+        if (z->dirty)
+            ap_session_save(r, z);
 
         r = r->next;