[#775] Ensure session cookies are kept across FunctionalTest requests

Two fixes

1. Keep cookies with no Max-Age set across FunctionalTest requests
No Max-Age means keep for the browser session. Without this fix
using FunctionalTest without a maxAge in config file will lose
session cookies on every request.

2. Add timestamp to new session even if we had no old session.
The timestamp was never set the first time the session cookie
was created, so the first session cookie always got discarded.

framework/src/play/mvc/Scope.java

@@ -198,7 +198,13 @@ static Session restore() {
                         // Just restored. Nothing changed. No cookie-expire.
                         session.changed = false;
                     }
+                } else {
+                    // no previous cookie to restore; but we may have to set the timestamp in the new cookie
+                    if (COOKIE_EXPIRE != null) {
+                        session.put(TS_KEY, System.currentTimeMillis() + (Time.parseDuration(COOKIE_EXPIRE) * 1000));
+                    }
                 }
+
                 return session;
             } catch (Exception e) {
                 throw new UnexpectedException("Corrupted HTTP session from " + Http.Request.current().remoteAddress, e);

framework/src/play/test/FunctionalTest.java

@@ -280,7 +280,9 @@ public InvocationContext getInvocationContext() {
                 savedCookies = new HashMap<String, Http.Cookie>();
             }
             for(Map.Entry<String,Http.Cookie> e : response.cookies.entrySet()) {
-                if(e.getValue().maxAge != null && e.getValue().maxAge > 0) {
+                // If Max-Age is unset, browsers discard on exit; if
+                // 0, they discard immediately.
+                if(e.getValue().maxAge == null || e.getValue().maxAge > 0) {
                     savedCookies.put(e.getKey(), e.getValue());
                 }
             }