fix crash at session close/exit if a midi-control-surface is used

[ardour.git] / libs / ardour / session_midi.cc

diff --git a/libs/ardour/session_midi.cc b/libs/ardour/session_midi.cc
index 639ea399d317a9983c5b456b75f2de393ce1d19a..47c7bd4c4037d60aa327366bd84057adbd86e667 100644 (file)
--- a/libs/ardour/session_midi.cc
+++ b/libs/ardour/session_midi.cc
@@ -597,6 +597,7 @@ Session::send_song_position_pointer (framepos_t)
 int
 Session::start_midi_thread ()
 {
+       if (midi_control_ui) { return 0; }
        midi_control_ui = new MidiControlUI (*this);
        midi_control_ui->run ();
        return 0;