disconnect from a Controllable when it is destroyed

git-svn-id: svn://localhost/ardour2/branches/3.0@12938 d708f5d6-7413-0410-9779-e7cbd77b26cf

2 files changed, 17 insertions, 2 deletions

diff --git a/libs/surfaces/generic_midi/midicontrollable.cc b/libs/surfaces/generic_midi/midicontrollable.cc
index d39886e0fc..a6d0b1c5ac 100644
--- a/libs/surfaces/generic_midi/midicontrollable.cc
+++ b/libs/surfaces/generic_midi/midicontrollable.cc
@@ -30,6 +30,7 @@
 #include "midi++/channel.h"
 
 #include "ardour/automation_control.h"
+#include "ardour/midi_ui.h"
 #include "ardour/utils.h"
 
 #include "midicontrollable.h"
@@ -76,7 +77,7 @@ MIDIControllable::MIDIControllable (GenericMidiControlProtocol* s, Port& p, Cont
 
 MIDIControllable::~MIDIControllable ()
 {
-	drop_external_control ();
+	drop_controllable ();
 }
 
 int
@@ -111,6 +112,7 @@ MIDIControllable::drop_external_control ()
 void
 MIDIControllable::set_controllable (Controllable* c)
 {
+	drop_controllable ();
 	controllable = c;
 }
 
@@ -198,11 +200,22 @@ MIDIControllable::lookup_controllable()
 	}
 
 	controllable = c.get();
+	controllable->Destroyed.connect (controllable_death_connection, MISSING_INVALIDATOR,
+					 boost::bind (&MIDIControllable::drop_controllable, this), 
+					 MidiControlUI::instance());
 
 	return 0;
 }
 
 void
+MIDIControllable::drop_controllable ()
+{
+	drop_external_control ();
+	controllable_death_connection.disconnect ();
+	controllable = 0;
+}
+
+void
 MIDIControllable::midi_sense_note (Parser &, EventTwoBytes *msg, bool /*is_on*/)
 {
 	if (!controllable) { 
diff --git a/libs/surfaces/generic_midi/midicontrollable.h b/libs/surfaces/generic_midi/midicontrollable.h
index 571f71edfe..ff4411a9ca 100644
--- a/libs/surfaces/generic_midi/midicontrollable.h
+++ b/libs/surfaces/generic_midi/midicontrollable.h
@@ -107,6 +107,7 @@ class MIDIControllable : public PBD::Stateful
 	int              midi_msg_id;      /* controller ID or note number */
 	PBD::ScopedConnection midi_sense_connection[2];
 	PBD::ScopedConnection midi_learn_connection;
+        PBD::ScopedConnection controllable_death_connection;
 	/** the type of MIDI message that is used for this control */
 	MIDI::eventType  control_type;
 	MIDI::byte       control_additional;
@@ -118,7 +119,8 @@ class MIDIControllable : public PBD::Stateful
 	bool            _bank_relative;
 
         int lookup_controllable();
-	
+        void drop_controllable();
+
 	void midi_receiver (MIDI::Parser &p, MIDI::byte *, size_t);
 	void midi_sense_note (MIDI::Parser &, MIDI::EventTwoBytes *, bool is_on);
 	void midi_sense_note_on (MIDI::Parser &p, MIDI::EventTwoBytes *tb);