keep track of the stage we're at in pairing

This avoids us responding to our own pairing messages, as well
as ignoring any out of order messages that might be received somehow.

Assistant/Pairing/Network.hs

@@ -47,8 +47,8 @@ multicastAddress (IPv6Addr _) = "ff02::1"
  - but it allows new network interfaces to be used as they come up.
  - On the other hand, the expensive DNS lookups are cached.
  -}
-multicastPairMsg :: Maybe Int -> Secret -> PairStage -> PairData -> IO ()
-multicastPairMsg repeats secret stage pairdata = go M.empty repeats
+multicastPairMsg :: Maybe Int -> Secret -> PairData -> PairStage -> IO ()
+multicastPairMsg repeats secret pairdata stage = go M.empty repeats
 	where
 		go _ (Just 0) = noop
 		go cache n = do
@@ -73,13 +73,14 @@ multicastPairMsg repeats secret stage pairdata = go M.empty repeats
 		mkmsg addr = PairMsg $
 			mkVerifiable (stage, pairdata, addr) secret
 
-startSending :: DaemonStatusHandle -> PairingInProgress -> IO () -> IO ()
-startSending dstatus pip sender = do
-	tid <- forkIO sender
-	let pip' = pip { inProgressThreadId = Just tid }
+startSending :: DaemonStatusHandle -> PairingInProgress -> PairStage -> (PairStage -> IO ()) -> IO ()
+startSending dstatus pip stage sender = void $ forkIO $ do
+	tid <- myThreadId
+	let pip' = pip { inProgressPairStage = stage, inProgressThreadId = Just tid }
 	oldpip <- modifyDaemonStatus dstatus $
 		\s -> (s { pairingInProgress = Just pip' }, pairingInProgress s)
 	maybe noop stopold oldpip
+	sender stage
 	where
 		stopold = maybe noop killThread . inProgressThreadId