SturdyRefs and boot-comm (hangs)

This program prints

<Promise>

and then hangs, consuming 100% CPU:

def seedVatAuthor := <elang:interp.seedVatAuthor>
def seedVat := seedVatAuthor(<unsafe>)
def sr := seedVat("introducer.onTheAir(); makeSturdyRef.temp(42)")[0]
println(sr)
when (sr) -> {
	println(`resolved: $sr`)
	interp.continueAtTop()
}
interp.blockAtTop()


SturdyRefs are not PassByProxy, but BootRefHandler doesn't know how to
send them, so it pretends they are:

            //XXX For now, if it isn't passable over boot comm, treat it as
            // if it was PassByProxy.
//            T.fail("Not passable over boot-comm: " +
//                   ClassDesc.simpleSig(arg.getClass()));
//            return null; //make compiler happy
            BootRefHandler handler = new BootRefHandler(src, arg);
            return handler.myResolver.getProxy();

But in the constructor, only PassByProxy objects get an identity:

        Object optIdentity = null;
        if (Ref.isPassByProxy(target)) {
            optIdentity = new BootRefIdentity(target);
        }
        myResolver = new EProxyResolver(this, optIdentity);

This causes a <Promise> to be sent. The receiver calls
<Promise>.__whenMoreResolved, but when the SturdyRef tries to send
itself back in the reply, it gets turned into a promise again, so the
receiver calls __whenMoreResolved again, forever.


-- 
Dr Thomas Leonard
GPG: 9242 9807 C985 3C07 44A6  8B9A AE07 8280 59A5 3CC1
GPG: DA98 25AE CAD0 8975 7CDA  BD8E 0713 3F96 CA74 D8BA