From 7764ab58598fdcc7bb5a760959e94cf6f7e6a956 Mon Sep 17 00:00:00 2001
From: aler9 <46489434+aler9@users.noreply.github.com>
Date: Wed, 9 Dec 2020 21:46:07 +0100
Subject: [PATCH] ServerConn: allow empty headers in responses

---
 serverconn.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/serverconn.go b/serverconn.go
index 3333a1e5..b903b58f 100644
--- a/serverconn.go
+++ b/serverconn.go
@@ -70,6 +70,9 @@ func (sc *ServerConn) backgroundRead(
 		res, err := onRequest(req)
 
 		// add cseq to response
+		if res.Header == nil {
+			res.Header = base.Header{}
+		}
 		res.Header["CSeq"] = cseq
 
 		sc.nconn.SetWriteDeadline(time.Now().Add(sc.s.conf.WriteTimeout))