From 96e991d08f94a7da04a9bb6fe2eb55968013759d Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Sat, 23 Mar 2019 15:52:36 +0100
Subject: [PATCH] Clean out session-global controllables

This isn't strictly speaking needed, there are only a handful of
users (most notably generic-midi ctrl surface, and Selection)
---
 libs/ardour/session.cc | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index 2c00fbbd80..d6753c50d9 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -680,6 +680,14 @@ Session::destroy ()
 
 	Port::PortDrop (); /* EMIT SIGNAL */
 
+	{
+		Glib::Threads::Mutex::Lock lm (controllables_lock);
+		for (Controllables::iterator i = controllables.begin(); i != controllables.end(); ++i) {
+			(*i)->DropReferences (); /* EMIT SIGNAL */
+		}
+		controllables.clear ();
+	}
+
 	/* clear history so that no references to objects are held any more */
 
 	_history.clear ();
@@ -864,6 +872,10 @@ Session::destroy ()
 
 	DEBUG_TRACE (DEBUG::Destruction, "Session::destroy() done\n");
 
+#ifndef NDEBUG
+	Controllable::dump_registry ();
+#endif
+
 	BOOST_SHOW_POINTERS ();
 }