Fix issue #5409. (#5413)

Fix multiple uninitialized reads.

src/core/Song.cpp

@@ -69,6 +69,7 @@ Song::Song() :
 	m_oldTicksPerBar( DefaultTicksPerBar ),
 	m_masterVolumeModel( 100, 0, 200, this, tr( "Master volume" ) ),
 	m_masterPitchModel( 0, -12, 12, this, tr( "Master pitch" ) ),
+	m_nLoadingTrack( 0 ),
 	m_fileName(),
 	m_oldFileName(),
 	m_modified( false ),
@@ -79,6 +80,7 @@ Song::Song() :
 	m_renderBetweenMarkers( false ),
 	m_playing( false ),
 	m_paused( false ),
+	m_savingProject( false ),
 	m_loadingProject( false ),
 	m_isCancelled( false ),
 	m_playMode( Mode_None ),

src/core/StepRecorder.cpp

@@ -32,7 +32,8 @@ const int REMOVE_RELEASED_NOTE_TIME_THRESHOLD_MS = 70;
 
 StepRecorder::StepRecorder(PianoRoll& pianoRoll, StepRecorderWidget& stepRecorderWidget):
 	m_pianoRoll(pianoRoll),
-	m_stepRecorderWidget(stepRecorderWidget)
+	m_stepRecorderWidget(stepRecorderWidget),
+	m_pattern(nullptr)
 {
 	m_stepRecorderWidget.hide();
 }

src/gui/editors/PianoRoll.cpp

@@ -152,6 +152,8 @@ PianoRoll::PianoRoll() :
 	m_zoomingModel(),
 	m_quantizeModel(),
 	m_noteLenModel(),
+	m_scaleModel(),
+	m_chordModel(),
 	m_pattern( NULL ),
 	m_currentPosition(),
 	m_recording( false ),