Missing error handling in the RegisterAdvertisement

I noticed that RegisterAdvertisement calls may succeed while internally failing.

Example of *logged* error:
daemon.err bluetoothd[1104]: Failed to add advertisement: Busy (0x0a)
(I'm still debugging that).

Forward-trace to consider:
register_advertisement()
client_create()
client_proxy_added()
parse_advertisement()
add_adv_callback()
add_client_complete()

Explanation:
add_client_complete() may fail and:
1) It doesn't propagate error up
2) Its reply sent using g_dbus_send_message doesn't reach caller

Could someone look at this problem and see if/how it can be fixed,
please? I don't have required BlueZ knowledge & experience to fix
this.

-- 
Rafał