fix assumption that Session::_mmc != 0

git-svn-id: svn://localhost/ardour2/branches/3.0@7349 d708f5d6-7413-0410-9779-e7cbd77b26cf

1 files changed, 8 insertions, 8 deletions

diff --git a/libs/ardour/session_midi.cc b/libs/ardour/session_midi.cc
index 201c913588..425c12db6c 100644
--- a/libs/ardour/session_midi.cc
+++ b/libs/ardour/session_midi.cc
@@ -230,26 +230,26 @@ Session::set_trace_midi_input (bool yn, MIDI::Port* port)
 		}
 	} else {
 
-		if (_mmc->port()) {
+		if (_mmc && _mmc->port()) {
 			if ((input_parser = _mmc->port()->input()) != 0) {
 				input_parser->trace (yn, &cout, "input: ");
 			}
 		}
 
-		if (_mtc_port && _mtc_port != _mmc->port()) {
+		if (_mtc_port && (!_mmc || (_mtc_port != _mmc->port()))) {
 			if ((input_parser = _mtc_port->input()) != 0) {
 				input_parser->trace (yn, &cout, "input: ");
 			}
 		}
 
-		if (_midi_port && _midi_port != _mmc->port() && _midi_port != _mtc_port  ) {
+		if (_midi_port && (!_mmc || (_midi_port != _mmc->port())) && _midi_port != _mtc_port  ) {
 			if ((input_parser = _midi_port->input()) != 0) {
 				input_parser->trace (yn, &cout, "input: ");
 			}
 		}
 
 		if (_midi_clock_port
-		    && _midi_clock_port != _mmc->port()
+		    && (!_mmc || (_midi_clock_port != _mmc->port()))
 			&& _midi_clock_port != _mtc_port
 			&& _midi_clock_port != _midi_port) {
 			if ((input_parser = _midi_clock_port->input()) != 0) {
@@ -271,7 +271,7 @@ Session::set_trace_midi_output (bool yn, MIDI::Port* port)
 			output_parser->trace (yn, &cout, "output: ");
 		}
 	} else {
-		if (_mmc->port()) {
+		if (_mmc && _mmc->port()) {
 			if ((output_parser = _mmc->port()->output()) != 0) {
 				output_parser->trace (yn, &cout, "output: ");
 			}
@@ -283,7 +283,7 @@ Session::set_trace_midi_output (bool yn, MIDI::Port* port)
 			}
 		}
 
-		if (_midi_port && _midi_port != _mmc->port() && _midi_port != _mtc_port  ) {
+		if (_midi_port && (!_mmc || (_midi_port != _mmc->port())) && _midi_port != _mtc_port  ) {
 			if ((output_parser = _midi_port->output()) != 0) {
 				output_parser->trace (yn, &cout, "output: ");
 			}
@@ -304,7 +304,7 @@ Session::get_trace_midi_input(MIDI::Port *port)
 		}
 	}
 	else {
-		if (_mmc->port()) {
+		if (_mmc && _mmc->port()) {
 			if ((input_parser = _mmc->port()->input()) != 0) {
 				return input_parser->tracing();
 			}
@@ -336,7 +336,7 @@ Session::get_trace_midi_output(MIDI::Port *port)
 		}
 	}
 	else {
-		if (_mmc->port()) {
+		if (_mmc && _mmc->port()) {
 			if ((output_parser = _mmc->port()->output()) != 0) {
 				return output_parser->tracing();
 			}