From 976e03c15ccc0f2939507a06eea02a8bfb439e57 Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Sun, 16 Apr 2017 23:48:49 +0200
Subject: [PATCH] Fix crashes with empty route-lists e.g. mute_release w/o
 routes

---
 libs/ardour/ardour/utils.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libs/ardour/ardour/utils.h b/libs/ardour/ardour/utils.h
index cc6e5044ce..b06f7f17a8 100644
--- a/libs/ardour/ardour/utils.h
+++ b/libs/ardour/ardour/utils.h
@@ -178,6 +178,7 @@ LIBARDOUR_API uint32_t how_many_dsp_threads ();
 
 template<typename T> boost::shared_ptr<ControlList> route_list_to_control_list (boost::shared_ptr<RouteList> rl, boost::shared_ptr<T> (Stripable::*get_control)() const) {
 	boost::shared_ptr<ControlList> cl (new ControlList);
+	if (!rl) { return cl; }
 	for (RouteList::const_iterator r = rl->begin(); r != rl->end(); ++r) {
 		boost::shared_ptr<AutomationControl> ac = ((*r).get()->*get_control)();
 		if (ac) {