n00b: signals with an extensible message

[Tim Hockin]

Hey there,

I'm finally getting around to adding dbus support to some tools, and
I'm not sure how to do the payload.

What I have is a data structure.  It has about 10 fields (all numeric,
a mix of sizes and signedness) right now, but I know it will grow in
the future (new fields, not modifying or removing old ones).  I want
to send signals which carry the equivalent of this data structure.
What I don't know is how to do this safely through DBUS.

What happens if the server is newer and has more fields than the
client knows about?

What happens if the server is older and has less fields than the
client knows about?

Is there a canonical answer to this?

Thanks!

Tim