There is an infinite loop in DefaultRestoreViewSupport.handlePrefixMapping when there is an empty prefix. There was a similar issue reported in MyFaces-2891 however the algorithm was not
updated in DefaultrestoreViewSupport.
I've made the same fix in DefaultRestoreViewSupport as was made in DefaultViewHandlerSupport.handlePrefixMapping in MyFaces-2891.
I'll attach a diff showing my changes. If a sample application is needed I can also provide that as it's a very simple application.