I have a theory that some google xmpp servers don't send prsense for xa
clients, while others do. Seeing some weird lack of presence messages
sometimes there.
This should help prevent git-annex clients receiving messages that
were intended for normal clients they're sharing the account with.
Changed XMPP protocol use to always send chat messages directed at the
specific client, as the negative priority blocks less directed messages.
I decided to use the fallback push mode from the beginning for XMPP, since
while it uses some ugly branches, it avoids the possibility of a normal
push failing, and needing to pull and re-push. Due to the overhead of XMPP,
and the difficulty of building such a chain of actions due to the async
implementation, this seemed reasonable.
It seems to work great!
Maybe the spec allows it, but broadcasting self-directed presence info to
all buddies is just insane.
I had to bring back the IQ messages for self-pairing, while still using
directed presence for other pairing. Ugly.
Testing between Google Talk and prosody, the directed IQ messages
were not received. Google Talk probably only relays them between
clients using the same account.
I first tried even more directed presence, with each client JID being sent
a separate presence, but that didn't work on Google Talk, particularly
it was ignored when one client sent it to another client using the same
account.
So, presence directed at the user@host of the client to pair with. Tested
working between Google Talk and prosody (in both directions), as well
as between two clients with the same account on Google Talk, and
two clients with the same account on prosody.
Only problem with this form of directed presence is that if I also use it
for git pushes, more clients than are interested in a push's data will
receive it. So I may need some better approach, or a hybrid between
directed IQ and directed presence.
Amusingly, I am not really using xmpp ping for pairing. I forgot to put in
the ping tag! And when I did, it stopped working, on Google Talk. Seems
it handles client to client pings, at least using the same JID, without
actually sending them to the end client. My mistake avoided this,
and seems to work, so I've left it as-is for now, with just the git-annex
tag in an IQ message. Also tested on prosody.
Adjust build deps to ensure that only a fixed version of the library will
be used.
Also, removed the bound thread stuff, which I now think was (probably)
a red herring.
