From f04efab52fd05cbd1b25280ae54423fc7b12e267 Mon Sep 17 00:00:00 2001
From: David Justice <david@devigned.com>
Date: Wed, 1 Aug 2018 09:14:34 -0700
Subject: [PATCH] add read from link.rx when sending a detach to eliminate
 deadlock on send

---
 client.go | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/client.go b/client.go
index 4a4e62c5..d1bf9c16 100644
--- a/client.go
+++ b/client.go
@@ -1307,13 +1307,24 @@ func (l *link) muxDetach() {
 		Closed: true,
 		Error:  detachError,
 	}
-	select {
-	case l.session.tx <- fr:
-	case <-l.session.done:
-		if l.err == nil {
-			l.err = l.session.err
+
+Loop:
+	for {
+		select {
+		case l.session.tx <- fr:
+			// after sending the detach frame, break the read loop
+			break Loop
+		case fr := <-l.rx:
+			// discard incoming frames to avoid blocking session.mux
+			if fr, ok := fr.(*performDetach); ok && fr.Closed {
+				l.detachReceived = true
+			}
+		case <-l.session.done:
+			if l.err == nil {
+				l.err = l.session.err
+			}
+			return
 		}
-		return
 	}
 
 	// don't wait for remote to detach when already