switch to directed presence for pair requests

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.

1 files changed, 3 insertions, 3 deletions

diff --git a/doc/design/assistant/xmpp.mdwn b/doc/design/assistant/xmpp.mdwn
index 6cfcbf56c..9410b3e7c 100644
--- a/doc/design/assistant/xmpp.mdwn
+++ b/doc/design/assistant/xmpp.mdwn
@@ -40,9 +40,9 @@ To indicate it's pushed changes to a git repo with a given UUID, a client uses:
 Multiple UUIDs can be listed when multiple clients were pushed. If the
 git repo does not have a git-annex UUID, an empty string is used.
 
-For pairing over XMPP, git-annex uses IQ messages, also containing a 
-git-annex tag. The id attribute of the iq tag contains the pairing
-information.
+For pairing, a directed presence message is sent, also using the git-annex tag:
+
+	<git-annex xmlns='git-annex' pairing="PairReq uuid" />
 
 ### security