clarify notifyNetMessagerRestart

Assistant/NetMessager.hs

@@ -29,6 +29,10 @@ notifyNetMessagerRestart :: Assistant ()
 notifyNetMessagerRestart =
 	flip writeSV () <<~ (netMessagerRestart . netMessager)
 
+{- This can be used to get an early indication if the network has
+ - changed, to immediately restart a connection. However, that is not
+ - available on all systems, so clients also need to deal with
+ - restarting dropped connections in the usual way. -}
 waitNetMessagerRestart :: Assistant ()
 waitNetMessagerRestart = readSV <<~ (netMessagerRestart . netMessager)
 

Assistant/Threads/NetWatcher.hs

@@ -39,7 +39,11 @@ netWatcherThread = thread noop
  - network connection changes, but it also ensures that
  - any networked remotes that may have not been routable for a
  - while (despite the local network staying up), are synced with
- - periodically. -}
+ - periodically.
+ -
+ - Note that it does not call notifyNetMessagerRestart, because
+ - it doesn't know that the network has changed.
+ -}
 netWatcherFallbackThread :: NamedThread
 netWatcherFallbackThread = namedThread "NetWatcherFallback" $
 	runEvery (Seconds 3600) <~> handleConnection