[patch] disallow requesting org.freedesktop.DBus

[Havoc Pennington]

John (J5) Palmieri wrote:
> Before this patch you could request org.freedesktop.DBus without an
> error being raised.  You wouldn't actually own it but D-Bus would return
> PRIMARY_OWNER.  This specifically errors out with a detailed error
> message if you try to request the name.
>

I might put this check a little further up in the function, below the 
check that names starting with ':' aren't owned; it's an analogous check 
that bus-managed/internal names can't be owned. The INVALID_ARGS error 
might even be appropriate.

A similar check could make sense for release_service; it looks like 
NON_EXISTENT would currently be returned, but NOT_OWNER would be better.

Havoc