From dce81aecc54b9ed286ec502a2e45f4da6200d056 Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Mon, 26 Nov 2018 03:31:02 +0100
Subject: [PATCH] Prevent deadlock when removing routes w/o engine

---
 libs/ardour/session.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index ae354646b9..f5920f96e4 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -3814,7 +3814,7 @@ Session::remove_routes (boost::shared_ptr<RouteList> routes_to_remove)
 		resort_routes ();
 #endif
 
-	if (_process_graph && !(_state_of_the_state & Deletion)) {
+	if (_process_graph && !(_state_of_the_state & Deletion) && _engine.running()) {
 		_process_graph->clear_other_chain ();
 	}