Cache info about non-existant resources in org.apache.myfaces.application.ResourceHandlerImpl.createResource()

The existent resources are cached in the public Resource createResource(String resourceName, String libraryName, String contentType) method,
which is good, but the information about resources, which are not existent ( deriveResourceMeta(loader, resourceName, libraryName, localePrefix) returned null ) is not cached.
Thus at the next requests for the same resource the same resource lookup operations will happen, which may be expensive.
In my case, for example (Tomcat + Spring + MyFaces + Tomahawk), for every html tag, lookup on the file system and in all classpaths (including ~30 jars) is performed (and failing), which de-gradates response time by factor of 25!