The SLOTs of dev-java/rhino-1.7.2 and its revisions are 1.6 now. However, I think it should be 1.7. Reproducible: Always
Do you happen to have an example of where rhino-1.7.x isn't backward-compatible to rhino-1.6.x? Otherwise changing SLOT only causes work with no benefit.
I'm sorry for the delay in my response. AFAIK Rhino 1.7 has no changes which break existing Java or JavaScript code.