If a server-side method wrapped with the GLib bindings receives a message marked
with the noreply flag, a reply is sent anyway.
This then confuses the client as there is no pending reply for the message reply
that arrives, so it sends back an error (AccessDenied specifically).
glib bindings should do this, but it should not confuse the client if it gets
an error or reply without a pending reply, so robustness against that is
another bug to fix.
(The bus sending accessdenied is correct I think, but the sender of the reply
should just ignore this error)
I missed this earlier bug when filing bug 19441, which is now fixed.
*** This bug has been marked as a duplicate of bug 19441 ***