Fix visibility of MIDI controller automation tracks across saves.

Fix some inaccurate/misleading comments that led to said bug.

Gracefully handle the "impossible" case where we can't figure out a state ID
for an automation track, instead of crashing.

3 files changed, 16 insertions, 7 deletions

diff --git a/gtk2_ardour/automation_time_axis.cc b/gtk2_ardour/automation_time_axis.cc
index 61c5d28e19..5a6bf5dbbe 100644
--- a/gtk2_ardour/automation_time_axis.cc
+++ b/gtk2_ardour/automation_time_axis.cc
@@ -23,6 +23,7 @@
 #include <boost/algorithm/string.hpp>
 #include <boost/lexical_cast.hpp>
 
+#include "pbd/error.h"
 #include "pbd/memento_command.h"
 #include "pbd/stacktrace.h"
 
@@ -876,15 +877,17 @@ AutomationTimeAxisView::lines () const
 string
 AutomationTimeAxisView::state_id() const
 {
-	if (_control) {
+	if (_automatable != _route && _control) {
 		return string_compose ("automation %1", _control->id().to_s());
-	} else {
-		assert (_parameter);
+	} else if (_parameter) {
 		return string_compose ("automation %1 %2/%3/%4", 
 				       _route->id(), 
 				       _parameter.type(),
 				       _parameter.id(),
 				       (int) _parameter.channel());
+	} else {
+		error << "Automation time axis has no state ID" << endmsg;
+		return "";
 	}
 }
 
diff --git a/gtk2_ardour/automation_time_axis.h b/gtk2_ardour/automation_time_axis.h
index 6db4bd4e64..156a5701e3 100644
--- a/gtk2_ardour/automation_time_axis.h
+++ b/gtk2_ardour/automation_time_axis.h
@@ -123,13 +123,17 @@ class AutomationTimeAxisView : public TimeAxisView {
 	static void what_has_visible_automation (const boost::shared_ptr<ARDOUR::Automatable>& automatable, std::set<Evoral::Parameter>& visible);
 
   protected:
+	/* Note that for MIDI controller "automation" (in regions), all of these
+	   may be set.  In this case, _automatable is likely _route so the
+	   controller will send immediate events out the route's MIDI port. */
+
 	/** parent route */
 	boost::shared_ptr<ARDOUR::Route> _route;
-	/** control; 0 if we are editing region-based automation */
+	/** control */
 	boost::shared_ptr<ARDOUR::AutomationControl> _control;
-	/** control owner; may be _route, or 0 if we are editing region-based automation */
+	/** control owner; may be _route, something else (e.g. a pan control), or NULL */
 	boost::shared_ptr<ARDOUR::Automatable> _automatable;
-	/** controller owner; 0 if we are editing region-based automation */
+	/** controller owner */
 	boost::shared_ptr<AutomationController> _controller;
 	Evoral::Parameter _parameter;
 
diff --git a/gtk2_ardour/midi_time_axis.cc b/gtk2_ardour/midi_time_axis.cc
index 4d55f2e8e1..5f19e0e2a5 100644
--- a/gtk2_ardour/midi_time_axis.cc
+++ b/gtk2_ardour/midi_time_axis.cc
@@ -1303,7 +1303,9 @@ MidiTimeAxisView::create_automation_child (const Evoral::Parameter& param, bool
 		 * since it will have been set visible by default.
 		 */
 
-		if (existing->second->set_marked_for_display (show) && !no_redraw) {
+		existing->second->set_marked_for_display (show);
+
+		if (!no_redraw) {
 			request_redraw ();
 		}