Fix cookie updates

syncmonitor/cookie.py

@@ -70,6 +70,11 @@ class SyncreplCookie:
     def update(self, cookie):
         "Merge the two cookies, incorporating all CSNs into this one"
         updated = False
+        if cookie is None:
+            updated = bool(self)
+            self._csnset = {}
+            return updated
+
         if isinstance(cookie, __class__):
             for sid, csn in cookie._csnset.items():
                 if sid not in self._csnset or self._csnset[sid] < csn:

syncmonitor/environment.py

@@ -263,5 +263,5 @@ class SyncreplEnvironment:
         else:  # a cookie reset happened, recreate environment cookie
             self.cookie = SyncreplCookie()
             for uri, provider in self.providers.items():
-                cookie.update(provider.cookie)
+                self.cookie.update(provider.cookie)
             self.cookie_updated(self.cookie)