 +            principalURI = joinURL(collection, authid)
  
              principal = waitForDeferred(request.locateResource(principalURI))
+             yield principal
+@@ -1173,22 +1270,30 @@
              yield principal
              principal = principal.getResult()
  

+                    d = self.quota(request)
+                    d.addCallback(callback)
+                    return d
 
+                if name == "quota-used-bytes":
+                    def callback(qvalue):
+                        if qvalue is None:

-        yield principalCollections
-
-    principalCollections = deferredGenerator(principalCollections)
+        d = request.locateResource(parentForURL(myURL))
+        d.addCallback(gotParent)
+        return d
 
     def defaultAccessControlList(self):
         """
@@ -1146,11 +1205,14 @@
 
         This implementation returns an empty set.
         """
