From d9ee9a0d3fefc6a30482467165097343432eb4c8 Mon Sep 17 00:00:00 2001
From: Brad Fitzpatrick <bradfitz@tailscale.com>
Date: Mon, 12 Apr 2021 10:33:50 -0700
Subject: [PATCH] ipn: set BackendServer's notify earlier; don't require Start

We've been slowly making Start less special and making IPN a
multi-connection "watch" bus of changes, but this Start specialness
had remained.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
---
 ipn/message.go | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/ipn/message.go b/ipn/message.go
index 9a8a327f1..fe3df7d67 100644
--- a/ipn/message.go
+++ b/ipn/message.go
@@ -94,11 +94,13 @@ type BackendServer struct {
 }
 
 func NewBackendServer(logf logger.Logf, b Backend, sendNotifyMsg func(b []byte)) *BackendServer {
-	return &BackendServer{
+	bs := &BackendServer{
 		logf:          logf,
 		b:             b,
 		sendNotifyMsg: sendNotifyMsg,
 	}
+	b.SetNotifyCallback(bs.send)
+	return bs
 }
 
 func (bs *BackendServer) send(n Notify) {
@@ -188,7 +190,6 @@ func (bs *BackendServer) GotCommand(ctx context.Context, cmd *Command) error {
 		bs.GotQuit = true
 		return errors.New("Quit command received")
 	} else if c := cmd.Start; c != nil {
-		bs.b.SetNotifyCallback(bs.send)
 		opts := c.Opts
 		return bs.b.Start(opts)
 	} else if c := cmd.StartLoginInteractive; c != nil {