Fix crash when changing automation mode for MIDI track control automation.

Also some work towards tolerating automation controls with no automation list,
towards actually doing something for these cases, though not required just to
fix this crash (MidiTrack::set_parameter_automation_state() avoids those
paths).

1 files changed, 10 insertions, 5 deletions

diff --git a/libs/ardour/automatable.cc b/libs/ardour/automatable.cc
index 7669f22df1..8629722889 100644
--- a/libs/ardour/automatable.cc
+++ b/libs/ardour/automatable.cc
@@ -137,16 +137,20 @@ Automatable::add_control(boost::shared_ptr<Evoral::Control> ac)
 	Evoral::Parameter param = ac->parameter();
 
 	boost::shared_ptr<AutomationList> al = boost::dynamic_pointer_cast<AutomationList> (ac->list ());
-	assert (al);
 
-	al->automation_state_changed.connect_same_thread (
-		_list_connections, boost::bind (&Automatable::automation_list_automation_state_changed, this, ac->parameter(), _1)
-		);
+	if (al) {
+		al->automation_state_changed.connect_same_thread (
+			_list_connections,
+			boost::bind (&Automatable::automation_list_automation_state_changed,
+			             this, ac->parameter(), _1));
+	}
 
 	ControlSet::add_control (ac);
 	_can_automate_list.insert (param);
 
-	automation_list_automation_state_changed (param, al->automation_state ()); // sync everything up
+	if (al) {
+		automation_list_automation_state_changed (param, al->automation_state ()); // sync everything up
+	}
 }
 
 string
@@ -394,6 +398,7 @@ Automatable::control_factory(const Evoral::Parameter& param)
 		MidiTrack* mt = dynamic_cast<MidiTrack*>(this);
 		if (mt) {
 			control = new MidiTrack::MidiControl(mt, param);
+			list.reset();  // No list, this is region "automation"
 		} else {
 			warning << "MidiCCAutomation for non-MidiTrack" << endl;
 		}