From a47cacfcc6213674ac5e8b40474f5a513c4e99e9 Mon Sep 17 00:00:00 2001
From: Paul Davis <paul@linuxaudiosystems.com>
Date: Wed, 3 Dec 2014 13:31:49 -0500
Subject: [PATCH] add signal to indicate absence of removal of scene change
 from Location

---
 libs/ardour/ardour/location.h | 5 +++--
 libs/ardour/location.cc       | 9 ++++++---
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/libs/ardour/ardour/location.h b/libs/ardour/ardour/location.h
index 7a6832eb2d..6b1f89dab3 100644
--- a/libs/ardour/ardour/location.h
+++ b/libs/ardour/ardour/location.h
@@ -144,8 +144,9 @@ class LIBARDOUR_API Location : public SessionHandleRef, public PBD::StatefulDest
 	void set_position_lock_style (PositionLockStyle ps);
 	void recompute_frames_from_bbt ();
 
-	static PBD::Signal0<void> scene_changed;
-
+	static PBD::Signal0<void> scene_changed; /* for use by backend scene change management, class level */
+        PBD::Signal0<void> SceneChangeChanged;   /* for use by objects interested in this object */
+        
   private:
 	std::string        _name;
 	framepos_t         _start;
diff --git a/libs/ardour/location.cc b/libs/ardour/location.cc
index 73978ae15c..9d7e7c3e57 100644
--- a/libs/ardour/location.cc
+++ b/libs/ardour/location.cc
@@ -759,9 +759,12 @@ Location::unlock ()
 void
 Location::set_scene_change (boost::shared_ptr<SceneChange>  sc)
 {
-	_scene_change = sc;
-
-	scene_changed (); /* EMIT SIGNAL */
+        if (_scene_change != sc) {
+                _scene_change = sc;
+                
+                scene_changed (); /* EMIT SIGNAL */
+                SceneChangeChanged (); /* EMIT SIGNAL */
+        }
 }
 
 /*---------------------------------------------------------------------- */