In makesockaddr(), the current implementation does not do any decoding of AF_UNIX addresses in the abstract namespace in the struct sockaddr_un to bytes direction, i.e. system to python direction, but does encode a string or bytes object to struct sockaddr_un in the reverse direction, in getsockaddrarg(). This is not correct.

So the patch does more than fixing the type of the addresses as it also fixes this in a non backward compatible way. Maybe this should be indicated in Misc/NEWS.