FacetRootsObserver throws RepositoryException when having comma separated uuids in the hippo:docbase of hippofacnav:facetnavigation

According to wiki [1], it's possible to use two (comma separated) uuids in the hippo:docbase of hippofacnav:facetnavigation node.

That works, however on each login an error is logged [2] because of invalid UUID in FacetRootsObserver, possibly introduced in CMS7-5004.

[1] https://wiki.onehippo.com/display/CMS7/Faceted+Navigation+Configuration
[2]
[INFO] [talledLocalContainer] 26.10.2011 10:16:42 ERROR [org.hippoecm.frontend.FacetRootsObserver.start():90] Failure to subscribe to facet root nodes
[INFO] [talledLocalContainer] javax.jcr.RepositoryException: Invalid UUID: e0d80795-1153-4a4c-bf0c-97b6814df7a4,e2f7fa7-8078-4f3b-a80a-9cfc6a1f1e97
[INFO] [talledLocalContainer] at org.apache.jackrabbit.core.SessionImpl.getNodeByUUID(SessionImpl.java:738)
[INFO] [talledLocalContainer] at org.hippoecm.repository.decorating.SessionDecorator.getNodeByUUID(SessionDecorator.j
va:167)
[INFO] [talledLocalContainer] at org.hippoecm.repository.decorating.checked.SessionDecorator.getNodeByUUID(SessionDec
rator.java:188)
[INFO] [talledLocalContainer] at org.hippoecm.frontend.FacetRootsObserver.start(FacetRootsObserver.java:85)
[INFO] [talledLocalContainer] at org.hippoecm.frontend.FacetRootsObserver.subscribe(FacetRootsObserver.java:124)
[INFO] [talledLocalContainer] at org.hippoecm.frontend.JcrObservationManager$JcrListener.subscribe(JcrObservationMana
er.java:383)
....