I saw this happen in real life, when syncing to a newly added usb drive.
I think it got scanned twice, and files were doubled in the queue.
This could be optimised a little bit more, to only read from the mvar
once, rather than twice.
This is not perfect, because on loss of connection, we do not currently
immediately detect it and stop the client. It has to time out, and then
the buddy list will clear.
The NetWatcher should detect disconnects too..
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.
Noticed that, At startup or network reconnect, git push messages were sent,
often before presence info has been gathered, so were not sent to any
buddies.
To fix this, keep track of which buddies have seen such messages,
and when new presence is received from a buddy that has not yet seen it,
resend.
This is done only for push initiation messages, so very little data needs
to be stored.
This fixes the issue mentioned in the last commit.
Turns out just collecting UUID of clients behind a XMPP remote is
insufficient (although I should probably still do it for other reasons),
because a single remote repo might be connected via both XMPP and local
pairing. So a way is needed to know when a push was received from any
client using a given XMPP remote over XMPP, as opposed to via ssh.
Make manualPull send push requests over XMPP.
When reconnecting with remotes, those that are XMPP remotes cannot
immediately be pulled from and scanned, so instead maintain a set of
(probably) desynced remotes, and put XMPP remotes on it. (This set could be
used in other ways later, if we can detect we're out of sync with other
types of remotes.)
The merger handles detecting when a XMPP push is received from a desynced
remote, and triggers a scan then, if they have in fact diverged.
This has one known bug: A single XMPP remote can have multiple clients
behind it. When this happens, only the UUID of one client is recorded
as the UUID of the XMPP remote. Pushes from the other XMPP clients will not
trigger a scan. If the client whose UUID is expected responds to the push
request, it'll work, but when that client is offline, we're SOL.
