From 69c15729f2209b2d4ecbc95794b02bebc2b62807 Mon Sep 17 00:00:00 2001
From: Carl Hetherington <carl@carlh.net>
Date: Sat, 13 Nov 2010 22:50:03 +0000
Subject: [PATCH] Fix crash on closedown.

git-svn-id: svn://localhost/ardour2/branches/3.0@8022 d708f5d6-7413-0410-9779-e7cbd77b26cf
---
 libs/ardour/port.cc | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/libs/ardour/port.cc b/libs/ardour/port.cc
index 4ae9b03c3b..55481faa64 100644
--- a/libs/ardour/port.cc
+++ b/libs/ardour/port.cc
@@ -63,7 +63,9 @@ Port::Port (std::string const & n, DataType t, Flags f)
 /** Port destructor */
 Port::~Port ()
 {
-	jack_port_unregister (_engine->jack (), _jack_port);
+	if (_engine->jack ()) {
+		jack_port_unregister (_engine->jack (), _jack_port);
+	}
 }
 
 /** @return true if this port is connected to anything */