From 2bd232c982f1978d71363d25973a7af82a71c8ef Mon Sep 17 00:00:00 2001
From: Nicolas Viennot <nicolas@viennot.biz>
Date: Sat, 5 Oct 2019 04:11:32 -0400
Subject: [PATCH] Avoid disconnection warning if fin packet is received

---
 tmate-daemon-decoder.c |  1 +
 tmate-websocket.c      | 10 +++++++++-
 tmate.h                |  1 +
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/tmate-daemon-decoder.c b/tmate-daemon-decoder.c
index 3b2a63d3..c984b710 100644
--- a/tmate-daemon-decoder.c
+++ b/tmate-daemon-decoder.c
@@ -404,6 +404,7 @@ static void tmate_write_copy_mode(__unused struct tmate_session *session,
 static void tmate_fin(__unused struct tmate_session *session,
 		      __unused struct tmate_unpacker *uk)
 {
+	session->fin_received = true;
 	request_server_termination();
 }
 
diff --git a/tmate-websocket.c b/tmate-websocket.c
index 259d3025..26d61fbf 100644
--- a/tmate-websocket.c
+++ b/tmate-websocket.c
@@ -342,8 +342,16 @@ static void on_websocket_encoder_write(void *userdata, struct evbuffer *buffer)
 
 static void on_websocket_event_default(__unused struct tmate_session *session, short events)
 {
-	if (events & BEV_EVENT_EOF)
+	if (events & BEV_EVENT_EOF) {
+		if (session->fin_received) {
+			/*
+			 * This is expected. The websocket will close the
+			 * connection upon receiving the fin message.
+			 */
+			exit(0);
+		}
 		tmate_fatal("Connection to websocket server closed");
+	}
 
 	if (events & BEV_EVENT_ERROR)
 		tmate_fatal("Connection to websocket server error: %s",
diff --git a/tmate.h b/tmate.h
index 6284b0c8..6e1b9761 100644
--- a/tmate.h
+++ b/tmate.h
@@ -246,6 +246,7 @@ struct tmate_session {
 	const char *client_version;
 	int client_protocol_version;
 	struct event ev_notify_timer;
+	bool fin_received;
 
 	int websocket_fd;
 	struct bufferevent *bev_websocket;