added checks to avoid segfaults when closing the application

git-svn-id: https://lmms.svn.sf.net/svnroot/lmms/trunk/lmms@269 0778d3d1-df1d-0410-868b-ea421aaaa00d

include/song_editor.h

@@ -296,6 +296,8 @@ private:
 
 	track * m_automation_track;
 
+	bool m_destroyed;
+
 
 
 	enum ACTIONS

src/core/note.cpp

@@ -226,7 +226,7 @@ void note::saveSettings( QDomDocument & _doc, QDomElement & _this )
 	_this.setAttribute( "pan", m_panning );
 	_this.setAttribute( "len", m_length );
 	_this.setAttribute( "pos", m_pos );
-	if( m_length > 0 )
+	if( m_length > 0 && m_detuning )
 	{
 		m_detuning->saveSettings( _doc, _this, "detuning" );
 	}

src/core/song_editor.cpp

@@ -113,7 +113,8 @@ songEditor::songEditor( engine * _engine ) :
 	m_trackToPlay( NULL ),
 	m_patternToPlay( NULL ),
 	m_loopPattern( FALSE ),
-	m_scrollBack( FALSE )
+	m_scrollBack( FALSE ),
+	m_destroyed( FALSE )
 {
 	setWindowTitle( tr( "Song-Editor" ) );
 	setWindowIcon( embed::getIconPixmap( "songeditor" ) );
@@ -446,6 +447,7 @@ songEditor::songEditor( engine * _engine ) :
 songEditor::~songEditor()
 {
 	delete m_automation_track;
+	m_destroyed = TRUE;
 }
 
 
@@ -1199,6 +1201,10 @@ void songEditor::updateTimeLinePosition( void )
 
 void songEditor::stop( void )
 {
+	if( m_destroyed )
+	{
+		return;
+	}
 	m_actions.push_back( ACT_STOP_PLAY );
 #ifdef QT4
 	m_playButton->setIcon( embed::getIconPixmap( "play" ) );