If an interface is added and removed on the same mailoop iteration,
ObjectManager would try to send InterfacesAdded signal while running the
idler because the interface was added to data->added list.
This is easily reproduced by forcing an error path in a plugin
registration, like on sap_server_register(), resulting in the following
error:
==11795== Invalid read of size 4
==11795== at 0x496F592: dbus_message_iter_append_basic (dbus-message.c:2598)
==11795== by 0x117B39: append_interface (object.c:554)
==11795== by 0x48955E7: g_slist_foreach (gslist.c:840)
==11795== by 0x11923B: process_changes (object.c:592)
==11795== by 0x11956D: generic_unregister (object.c:980)
==11795== by 0x4973BAC: _dbus_object_tree_unregister_and_unlock (dbus-object-tree.c:516)
==11795== by 0x4965240: dbus_connection_unregister_object_path (dbus-connection.c:5776)
==11795== by 0x1178A5: object_path_unref (object.c:1219)
==11795== by 0x118517: g_dbus_unregister_interface (object.c:1344)
==11795== by 0x19AF5B: sap_exit (sap.c:385)
==11795== by 0x13E9E2: sap_server_register (server.c:1428)
==11795== by 0x13C092: sap_server_probe (manager.c:44)
With this patch we don't send the InterfacesAdded signal, removing it
from data->added while unregistering.
return TRUE;
}
+ /*
+ * Interface being removed was just added, on the same mainloop
+ * iteration? Don't send any signal
+ */
+ if (g_slist_find(data->added, iface)) {
+ data->added = g_slist_remove(data->added, iface);
+ g_free(iface->name);
+ g_free(iface);
+ return TRUE;
+ }
+
data->removed = g_slist_prepend(data->removed, iface->name);
g_free(iface);