> > It's a unix domain socket. . .
> 
> I see.  I recalled that I've surveyed the sockname behavior for unix
> domain socket some years ago to emulate it on SysV, though I cannot
> find the results any more, unfortunately.
> 
> Yes, that would be the problem since 4.3BSD.  Returning garbage is bug
> and should be filed as PR.
> I think the FreeBSD behavior, returning zero size sockaddr, is not the
> right thing.  The sa_family and sa_len member should be filled.

Sorry about the earlier message.
I was getting the Mozilla bug confused with our internal tracking
system.  It's not clear that the mozilla bug was applicable.

Anyways, I opened a PR kern/10698 with the sample code. . . .