Fixed crashes reloading songs having open editors. Previous memleak fixes

 revealed some problems. Installed bool TopWin::deleting(). It is set true when 
 closeEvent() is called in any self-deleting TopWins. Used it to make all such 
 TopWins and their corresponding child canvasses ignore songChanged signals.

24 files changed, 95 insertions, 40 deletions

diff --git a/muse2/muse/app.cpp b/muse2/muse/app.cpp
index 677743b3..50a766dc 100644
--- a/muse2/muse/app.cpp
+++ b/muse2/muse/app.cpp
@@ -1844,7 +1844,7 @@ void MusE::openInScoreEdit(MusEGui::ScoreEdit* destination, MusECore::PartList*
       destination = new MusEGui::ScoreEdit(this, 0, _arranger->cursorValue());
       destination->show();
       toplevels.push_back(destination);
-      connect(destination, SIGNAL(deleted(MusEGui::TopWin*)), SLOT(toplevelDeleted(MusEGui::TopWin*)));
+      connect(destination, SIGNAL(isDeleting(MusEGui::TopWin*)), SLOT(toplevelDeleting(MusEGui::TopWin*)));
       connect(destination, SIGNAL(name_changed()), arrangerView, SLOT(scoreNamingChanged()));
       //connect(muse, SIGNAL(configChanged()), destination, SLOT(config_changed()));
       //commented out by flo, because the ScoreEditor connects to all 
@@ -1882,7 +1882,7 @@ void MusE::startPianoroll(MusECore::PartList* pl, bool showDefaultCtrls)
         pianoroll->addCtrl();
       pianoroll->show();
       toplevels.push_back(pianoroll);
-      connect(pianoroll, SIGNAL(deleted(MusEGui::TopWin*)), SLOT(toplevelDeleted(MusEGui::TopWin*)));
+      connect(pianoroll, SIGNAL(isDeleting(MusEGui::TopWin*)), SLOT(toplevelDeleting(MusEGui::TopWin*)));
       connect(MusEGlobal::muse, SIGNAL(configChanged()), pianoroll, SLOT(configChanged()));
       updateWindowMenu();
       }
@@ -1904,7 +1904,7 @@ void MusE::startListEditor(MusECore::PartList* pl)
       MusEGui::ListEdit* listEditor = new MusEGui::ListEdit(pl);
       listEditor->show();
       toplevels.push_back(listEditor);
-      connect(listEditor, SIGNAL(deleted(MusEGui::TopWin*)), SLOT(toplevelDeleted(MusEGui::TopWin*)));
+      connect(listEditor, SIGNAL(isDeleting(MusEGui::TopWin*)), SLOT(toplevelDeleting(MusEGui::TopWin*)));
       connect(MusEGlobal::muse,SIGNAL(configChanged()), listEditor, SLOT(configChanged()));
       updateWindowMenu();
       }
@@ -1918,7 +1918,7 @@ void MusE::startMasterEditor()
       MusEGui::MasterEdit* masterEditor = new MusEGui::MasterEdit();
       masterEditor->show();
       toplevels.push_back(masterEditor);
-      connect(masterEditor, SIGNAL(deleted(MusEGui::TopWin*)), SLOT(toplevelDeleted(MusEGui::TopWin*)));
+      connect(masterEditor, SIGNAL(isDeleting(MusEGui::TopWin*)), SLOT(toplevelDeleting(MusEGui::TopWin*)));
       updateWindowMenu();
       }
 
@@ -1931,7 +1931,7 @@ void MusE::startLMasterEditor()
       MusEGui::LMaster* lmaster = new MusEGui::LMaster();
       lmaster->show();
       toplevels.push_back(lmaster);
-      connect(lmaster, SIGNAL(deleted(MusEGui::TopWin*)), SLOT(toplevelDeleted(MusEGui::TopWin*)));
+      connect(lmaster, SIGNAL(isDeleting(MusEGui::TopWin*)), SLOT(toplevelDeleting(MusEGui::TopWin*)));
       connect(MusEGlobal::muse, SIGNAL(configChanged()), lmaster, SLOT(configChanged()));
       updateWindowMenu();
       }
@@ -1955,7 +1955,7 @@ void MusE::startDrumEditor(MusECore::PartList* pl, bool showDefaultCtrls)
         drumEditor->addCtrl();
       drumEditor->show();
       toplevels.push_back(drumEditor);
-      connect(drumEditor, SIGNAL(deleted(MusEGui::TopWin*)), SLOT(toplevelDeleted(MusEGui::TopWin*)));
+      connect(drumEditor, SIGNAL(isDeleting(MusEGui::TopWin*)), SLOT(toplevelDeleting(MusEGui::TopWin*)));
       connect(MusEGlobal::muse, SIGNAL(configChanged()), drumEditor, SLOT(configChanged()));
       updateWindowMenu();
       }
@@ -1980,7 +1980,7 @@ void MusE::startWaveEditor(MusECore::PartList* pl)
       waveEditor->show();
       connect(MusEGlobal::muse, SIGNAL(configChanged()), waveEditor, SLOT(configChanged()));
       toplevels.push_back(waveEditor);
-      connect(waveEditor, SIGNAL(deleted(MusEGui::TopWin*)), SLOT(toplevelDeleted(MusEGui::TopWin*)));
+      connect(waveEditor, SIGNAL(isDeleting(MusEGui::TopWin*)), SLOT(toplevelDeleting(MusEGui::TopWin*)));
       updateWindowMenu();
       }
 
@@ -2038,7 +2038,7 @@ void MusE::startClipList(bool checked)
             //clipListEdit = new ClipListEdit();
             clipListEdit = new MusEGui::ClipListEdit(this);
             toplevels.push_back(clipListEdit);
-            connect(clipListEdit, SIGNAL(deleted(MusEGui::TopWin*)), SLOT(toplevelDeleted(MusEGui::TopWin*)));
+            connect(clipListEdit, SIGNAL(isDeleting(MusEGui::TopWin*)), SLOT(toplevelDeleting(MusEGui::TopWin*)));
             }
       clipListEdit->show();
       viewCliplistAction->setChecked(checked);
@@ -2084,10 +2084,10 @@ void MusE::selectProject(QAction* act)
       }
 
 //---------------------------------------------------------
-//   toplevelDeleted
+//   toplevelDeleting
 //---------------------------------------------------------
 
-void MusE::toplevelDeleted(MusEGui::TopWin* tl)
+void MusE::toplevelDeleting(MusEGui::TopWin* tl)
       {
       for (MusEGui::iToplevel i = toplevels.begin(); i != toplevels.end(); ++i) {
             if (*i == tl) {
@@ -2132,19 +2132,17 @@ void MusE::toplevelDeleted(MusEGui::TopWin* tl)
                         case MusEGui::TopWin::TOPLEVELTYPE_LAST_ENTRY: //to avoid a warning
                           break;
                         }
-                  toplevels.erase(i);
+                  toplevels.erase(i);   
                   if (mustUpdateScoreMenus)
                         arrangerView->updateScoreMenus();
                   updateWindowMenu();
                   return;
                   }
             }
-      printf("topLevelDeleted: top level %p not found\n", tl);
+      printf("topLevelDeleting: top level %p not found\n", tl);
       //assert(false);
       }
 
-
-
 //---------------------------------------------------------
 //   kbAccel
 //---------------------------------------------------------
@@ -2750,16 +2748,21 @@ again:
                   case MusEGui::TopWin::MASTER:
                   case MusEGui::TopWin::WAVE:
                   case MusEGui::TopWin::LMASTER:
-                        tl->close();
-                        goto again;
-                  
+                  {  
+                        if(tl->isVisible())   // Don't keep trying to close, only if visible.
+                        {  
+                          if(!tl->close())
+                            printf("MusE::clearSong TopWin did not close!\n");  
+                          goto again;
+                        }  
+                  }
                   case MusEGui::TopWin::TOPLEVELTYPE_LAST_ENTRY: //to avoid a warning
                     break;
                   }
             }
-      microSleep(100000);
+      microSleep(100000);  
       MusEGlobal::song->clear(true, clear_all);
-      microSleep(100000);
+      microSleep(100000);  
       return false;
       }
 
diff --git a/muse2/muse/app.h b/muse2/muse/app.h
index 46e9f99b..27722e9a 100644
--- a/muse2/muse/app.h
+++ b/muse2/muse/app.h
@@ -333,7 +333,7 @@ class MusE : public QMainWindow
       void closeEvent(QCloseEvent*e);
       void loadProjectFile(const QString&);
       void loadProjectFile(const QString&, bool songTemplate, bool loadAll);
-      void toplevelDeleted(MusEGui::TopWin* tl);
+      void toplevelDeleting(MusEGui::TopWin* tl);
       void loadTheme(const QString&);
       void loadStyleSheetFile(const QString&);
       bool seqRestart();
diff --git a/muse2/muse/cliplist/cliplist.cpp b/muse2/muse/cliplist/cliplist.cpp
index a4702137..1055f449 100644
--- a/muse2/muse/cliplist/cliplist.cpp
+++ b/muse2/muse/cliplist/cliplist.cpp
@@ -194,7 +194,7 @@ void ClipListEdit::updateList()
 
 void ClipListEdit::closeEvent(QCloseEvent* e)
       {
-      emit deleted(static_cast<TopWin*>(this));
+      emit isDeleting(static_cast<TopWin*>(this));
       e->accept();
       }
 
diff --git a/muse2/muse/cliplist/cliplist.h b/muse2/muse/cliplist/cliplist.h
index b490663c..0972df97 100644
--- a/muse2/muse/cliplist/cliplist.h
+++ b/muse2/muse/cliplist/cliplist.h
@@ -73,7 +73,7 @@ class ClipListEdit : public TopWin {
       void clicked(QTreeWidgetItem*, int);
 
    signals:
-      void deleted(MusEGui::TopWin*);
+      void isDeleting(MusEGui::TopWin*);
 
    public:
       ClipListEdit(QWidget* parent);
diff --git a/muse2/muse/cobject.cpp b/muse2/muse/cobject.cpp
index b4c6537c..92748268 100644
--- a/muse2/muse/cobject.cpp
+++ b/muse2/muse/cobject.cpp
@@ -50,6 +50,7 @@ bool TopWin::initInited=false;
 TopWin::TopWin(ToplevelType t, QWidget* parent, const char* name, Qt::WindowFlags f)
                  : QMainWindow(parent, f)
 {
+        _isDeleting = false;
 	if (initInited==false)
 		initConfiguration();
 
diff --git a/muse2/muse/cobject.h b/muse2/muse/cobject.h
index c1c45039..309d8424 100644
--- a/muse2/muse/cobject.h
+++ b/muse2/muse/cobject.h
@@ -62,7 +62,8 @@ class TopWin : public QMainWindow
       ToplevelType type() const { return _type; }
       static QString typeName(ToplevelType t);
 
-
+      bool deleting() const { return _isDeleting; }
+      
       virtual void readStatus(MusECore::Xml&);
       virtual void writeStatus(int, MusECore::Xml&) const;
 
@@ -118,6 +119,11 @@ class TopWin : public QMainWindow
       
       QByteArray _savedToolbarState;
       
+      // Set if close has been called on a TopWin having the WA_DeleteOnClose attribute.
+      // The TopWins and any children should ignore any signals such as songChanged
+      //  which may cause a crash while deleting.
+      bool _isDeleting;  
+      
       void initTopwinState();
 
   private slots:
@@ -131,7 +137,7 @@ class TopWin : public QMainWindow
       void shareToolsAndMenu(bool);
       void restoreMainwinState();
       void storeInitialState() const;
-  
+      
       };
 
 
diff --git a/muse2/muse/ctrl/ctrlcanvas.cpp b/muse2/muse/ctrl/ctrlcanvas.cpp
index 486e279a..1a155fc4 100644
--- a/muse2/muse/ctrl/ctrlcanvas.cpp
+++ b/muse2/muse/ctrl/ctrlcanvas.cpp
@@ -468,6 +468,9 @@ void CtrlCanvas::configChanged()
 
 void CtrlCanvas::songChanged(int type)
 {
+  if(editor->deleting())  // Ignore while while deleting to prevent crash.
+    return; 
+  
   //printf("CtrlCanvas::songChanged type:%x\n", type);  
   // Is it simply a midi controller value adjustment? Forget it.
   if(type == SC_MIDI_CONTROLLER)
diff --git a/muse2/muse/ctrl/ctrlcanvas.h b/muse2/muse/ctrl/ctrlcanvas.h
index 815898ac..f9fcb54f 100644
--- a/muse2/muse/ctrl/ctrlcanvas.h
+++ b/muse2/muse/ctrl/ctrlcanvas.h
@@ -176,6 +176,8 @@ class CtrlCanvas : public MusEGui::View {
       void updateItems();
       void updateSelections();
 
+      //virtual void closeEvent(QCloseEvent*);
+      
    private slots:
       void songChanged(int type);
       void configChanged();    
diff --git a/muse2/muse/ctrl/ctrlpanel.cpp b/muse2/muse/ctrl/ctrlpanel.cpp
index 0d981fbd..1889c608 100644
--- a/muse2/muse/ctrl/ctrlpanel.cpp
+++ b/muse2/muse/ctrl/ctrlpanel.cpp
@@ -161,6 +161,9 @@ CtrlPanel::CtrlPanel(QWidget* parent, MidiEditor* e, const char* name)
 
 void CtrlPanel::heartBeat()
 {
+  if(editor->deleting())  // Ignore while while deleting to prevent crash.
+    return;
+  
   inHeartBeat = true;
   
   if(_track && _ctrl && _dnum != -1)
diff --git a/muse2/muse/liste/listedit.cpp b/muse2/muse/liste/listedit.cpp
index eadfa68c..e4837bf9 100644
--- a/muse2/muse/liste/listedit.cpp
+++ b/muse2/muse/liste/listedit.cpp
@@ -183,7 +183,8 @@ static QString midiMetaComment(const MusECore::Event& ev)
 
 void ListEdit::closeEvent(QCloseEvent* e)
       {
-      emit deleted(static_cast<TopWin*>(this));
+      _isDeleting = true;  // Set flag so certain signals like songChanged, which may cause crash during delete, can be ignored.
+      emit isDeleting(static_cast<TopWin*>(this));
       e->accept();
       }
 
@@ -193,6 +194,9 @@ void ListEdit::closeEvent(QCloseEvent* e)
 
 void ListEdit::songChanged(int type)
       {
+      if(_isDeleting)  // Ignore while while deleting to prevent crash.
+        return;
+        
       if (type == 0)
             return;
       if (type & (SC_PART_REMOVED | SC_PART_MODIFIED
diff --git a/muse2/muse/liste/listedit.h b/muse2/muse/liste/listedit.h
index 7548fc86..1c0c1bd9 100644
--- a/muse2/muse/liste/listedit.h
+++ b/muse2/muse/liste/listedit.h
@@ -86,7 +86,7 @@ class ListEdit : public MidiEditor {
       void songChanged(int);
 
    signals:
-      void deleted(MusEGui::TopWin*);
+      void isDeleting(MusEGui::TopWin*);
 
    public:
       ListEdit(MusECore::PartList*);
diff --git a/muse2/muse/master/lmaster.cpp b/muse2/muse/master/lmaster.cpp
index bf31cc91..52b488d0 100644
--- a/muse2/muse/master/lmaster.cpp
+++ b/muse2/muse/master/lmaster.cpp
@@ -122,7 +122,9 @@ namespace MusEGui {
 
 void LMaster::closeEvent(QCloseEvent* e)
       {
-      emit deleted(static_cast<TopWin*>(this));
+      _isDeleting = true;  // Set flag so certain signals like songChanged, which may cause crash during delete, can be ignored.
+      
+      emit isDeleting(static_cast<TopWin*>(this));
       e->accept();
       }
 
@@ -132,6 +134,9 @@ void LMaster::closeEvent(QCloseEvent* e)
 
 void LMaster::songChanged(int type)
       {
+      if(_isDeleting)  // Ignore while while deleting to prevent crash.
+        return;
+      
       if (type & (SC_SIG | SC_TEMPO | SC_KEY ))
             updateList();
       }
diff --git a/muse2/muse/master/lmaster.h b/muse2/muse/master/lmaster.h
index 6bc90019..33b40f30 100644
--- a/muse2/muse/master/lmaster.h
+++ b/muse2/muse/master/lmaster.h
@@ -173,7 +173,7 @@ class LMaster : public MidiEditor {
       void configChanged();
 
    signals:
-      void deleted(MusEGui::TopWin*);
+      void isDeleting(MusEGui::TopWin*);
       void seekTo(int tick);
 
    public:
diff --git a/muse2/muse/master/masteredit.cpp b/muse2/muse/master/masteredit.cpp
index e9d669e1..c3c66008 100644
--- a/muse2/muse/master/masteredit.cpp
+++ b/muse2/muse/master/masteredit.cpp
@@ -59,7 +59,9 @@ int MasterEdit::_rasterInit = 0;
 
 void MasterEdit::closeEvent(QCloseEvent* e)
       {
-      emit deleted(static_cast<TopWin*>(this));
+      _isDeleting = true;  // Set flag so certain signals like songChanged, which may cause crash during delete, can be ignored.
+
+      emit isDeleting(static_cast<TopWin*>(this));
       e->accept();
       }
 
@@ -69,6 +71,9 @@ void MasterEdit::closeEvent(QCloseEvent* e)
 
 void MasterEdit::songChanged(int type)
       {
+      if(_isDeleting)  // Ignore while while deleting to prevent crash.
+        return;
+        
       if (type & SC_TEMPO) {
             int tempo = MusEGlobal::tempomap.tempo(MusEGlobal::song->cpos());
             curTempo->blockSignals(true);
diff --git a/muse2/muse/master/masteredit.h b/muse2/muse/master/masteredit.h
index fdf8dd71..835ca879 100644
--- a/muse2/muse/master/masteredit.h
+++ b/muse2/muse/master/masteredit.h
@@ -91,7 +91,7 @@ class MasterEdit : public MidiEditor {
 //      void tempoChanged(double);
 
    signals:
-      void deleted(MusEGui::TopWin*);
+      void isDeleting(MusEGui::TopWin*);
 
    public:
       MasterEdit();
diff --git a/muse2/muse/midiedit/drumedit.cpp b/muse2/muse/midiedit/drumedit.cpp
index 03580142..19700a4e 100644
--- a/muse2/muse/midiedit/drumedit.cpp
+++ b/muse2/muse/midiedit/drumedit.cpp
@@ -152,6 +152,8 @@ void DrumEdit::setHeaderToolTips()
 
 void DrumEdit::closeEvent(QCloseEvent* e)
       {
+      _isDeleting = true;  // Set flag so certain signals like songChanged, which may cause crash during delete, can be ignored.
+
       QSettings settings("MusE", "MusE-qt");
       //settings.setValue("Drumedit/geometry", saveGeometry());
       settings.setValue("Drumedit/windowState", saveState());
@@ -162,7 +164,7 @@ void DrumEdit::closeEvent(QCloseEvent* e)
       _dlistWidthInit = *it; //There are only 2 values stored in the sizelist, size of dlist widget and dcanvas widget
       it++;
       _dcanvasWidthInit = *it;
-      emit deleted(static_cast<TopWin*>(this));
+      emit isDeleting(static_cast<TopWin*>(this));
       e->accept();
       }
 
@@ -541,6 +543,9 @@ DrumEdit::DrumEdit(MusECore::PartList* pl, QWidget* parent, const char* name, un
 
 void DrumEdit::songChanged1(int bits)
       {
+        if(_isDeleting)  // Ignore while while deleting to prevent crash.
+          return;
+        
         if (bits & SC_SOLO)
         {
             toolbar->setSolo(canvas->track()->solo());
diff --git a/muse2/muse/midiedit/drumedit.h b/muse2/muse/midiedit/drumedit.h
index 1ca6f989..7ad5aabd 100644
--- a/muse2/muse/midiedit/drumedit.h
+++ b/muse2/muse/midiedit/drumedit.h
@@ -137,7 +137,7 @@ class DrumEdit : public MidiEditor {
       
       virtual void updateHScrollRange();
    signals:
-      void deleted(MusEGui::TopWin*);
+      void isDeleting(MusEGui::TopWin*);
 
    public:
       DrumEdit(MusECore::PartList*, QWidget* parent = 0, const char* name = 0, unsigned initPos = MAXINT);
diff --git a/muse2/muse/midiedit/pianoroll.cpp b/muse2/muse/midiedit/pianoroll.cpp
index 82a75f7f..8a7356aa 100644
--- a/muse2/muse/midiedit/pianoroll.cpp
+++ b/muse2/muse/midiedit/pianoroll.cpp
@@ -540,6 +540,8 @@ PianoRoll::PianoRoll(MusECore::PartList* pl, QWidget* parent, const char* name,
 
 void PianoRoll::songChanged1(int bits)
       {
+        if(_isDeleting)  // Ignore while while deleting to prevent crash.
+          return;
         
         if (bits & SC_SOLO)
         {
@@ -815,15 +817,19 @@ void PianoRoll::removeCtrl(CtrlEdit* ctrl)
 
 //---------------------------------------------------------
 //   closeEvent
+//   Save state. 
+//   Disconnect signals which may cause crash due to Qt deferred deletion on close.
 //---------------------------------------------------------
 
 void PianoRoll::closeEvent(QCloseEvent* e)
       {
+      _isDeleting = true;  // Set flag so certain signals like songChanged, which may cause crash during delete, can be ignored.
+
       QSettings settings("MusE", "MusE-qt");
       //settings.setValue("Pianoroll/geometry", saveGeometry());
       settings.setValue("Pianoroll/windowState", saveState());
 
-      emit deleted(static_cast<TopWin*>(this));
+      emit isDeleting(static_cast<TopWin*>(this));
       e->accept();
       }
 
diff --git a/muse2/muse/midiedit/pianoroll.h b/muse2/muse/midiedit/pianoroll.h
index 0b90b1e6..9b73fc1b 100644
--- a/muse2/muse/midiedit/pianoroll.h
+++ b/muse2/muse/midiedit/pianoroll.h
@@ -176,7 +176,7 @@ class PianoRoll : public MidiEditor {
       void updateTrackInfo();
 
    signals:
-      void deleted(MusEGui::TopWin*);
+      void isDeleting(MusEGui::TopWin*);
    
    public slots:
       virtual void updateHScrollRange();
diff --git a/muse2/muse/midiedit/scoreedit.cpp b/muse2/muse/midiedit/scoreedit.cpp
index ab161946..9ddf8fbb 100644
--- a/muse2/muse/midiedit/scoreedit.cpp
+++ b/muse2/muse/midiedit/scoreedit.cpp
@@ -604,6 +604,9 @@ void ScoreEdit::velo_off_box_changed()
 
 void ScoreEdit::song_changed(int flags)
 {
+        if(_isDeleting)  // Ignore while while deleting to prevent crash.
+          return;
+        
 	if (flags & (SC_SELECTION | SC_EVENT_MODIFIED | SC_EVENT_REMOVED))
 	{
 		map<MusECore::Event*, MusECore::Part*> selection=get_events(score_canvas->get_all_parts(),1);
@@ -671,11 +674,13 @@ void ScoreEdit::viewport_height_changed(int height)
 
 void ScoreEdit::closeEvent(QCloseEvent* e)
 {
+        _isDeleting = true;  // Set flag so certain signals like songChanged, which may cause crash during delete, can be ignored.
+        
 	QSettings settings("MusE", "MusE-qt");
 	//settings.setValue("ScoreEdit/geometry", saveGeometry());
 	settings.setValue("ScoreEdit/windowState", saveState());
 
-	emit deleted(static_cast<TopWin*>(this));
+	emit isDeleting(static_cast<TopWin*>(this));
 	e->accept();
 }
 
@@ -1449,6 +1454,9 @@ void ScoreCanvas::fully_recalculate()
 
 void ScoreCanvas::song_changed(int flags)
 {
+        if(parent && parent->deleting())  // Ignore while while deleting to prevent crash.
+          return;
+        
 	if (flags & (SC_PART_MODIFIED | SC_PART_REMOVED | SC_PART_INSERTED | SC_TRACK_REMOVED))
 	{
 		update_parts();
diff --git a/muse2/muse/midiedit/scoreedit.h b/muse2/muse/midiedit/scoreedit.h
index 4e2ecf5d..29ab258e 100644
--- a/muse2/muse/midiedit/scoreedit.h
+++ b/muse2/muse/midiedit/scoreedit.h
@@ -184,7 +184,7 @@ class ScoreEdit : public TopWin
 		void clipboard_changed();
 		
 	signals:
-		void deleted(MusEGui::TopWin*);
+		void isDeleting(MusEGui::TopWin*);
 		void name_changed();
 		void velo_changed(int);
 		void velo_off_changed(int);
diff --git a/muse2/muse/songfile.cpp b/muse2/muse/songfile.cpp
index 033122d7..fbcb23cc 100644
--- a/muse2/muse/songfile.cpp
+++ b/muse2/muse/songfile.cpp
@@ -1296,7 +1296,7 @@ void MusE::readToplevels(MusECore::Xml& xml)
                                 MusEGui::ScoreEdit* score = new MusEGui::ScoreEdit(this, 0, _arranger->cursorValue());
                                 score->show();
                                 toplevels.push_back(score);
-                                connect(score, SIGNAL(deleted(MusEGui::TopWin*)), SLOT(toplevelDeleted(MusEGui::TopWin*)));
+                                connect(score, SIGNAL(isDeleting(MusEGui::TopWin*)), SLOT(toplevelDeleting(MusEGui::TopWin*)));
                                 connect(score, SIGNAL(name_changed()), arrangerView, SLOT(scoreNamingChanged()));
                                 score->readStatus(xml);
                               }
diff --git a/muse2/muse/waveedit/waveedit.cpp b/muse2/muse/waveedit/waveedit.cpp
index 424f0688..8d58cfb3 100644
--- a/muse2/muse/waveedit/waveedit.cpp
+++ b/muse2/muse/waveedit/waveedit.cpp
@@ -64,10 +64,12 @@ namespace MusEGui {
 
 void WaveEdit::closeEvent(QCloseEvent* e)
       {
+      _isDeleting = true;  // Set flag so certain signals like songChanged, which may cause crash during delete, can be ignored.
+      
       QSettings settings("MusE", "MusE-qt");
       //settings.setValue("Waveedit/geometry", saveGeometry());
       settings.setValue("Waveedit/windowState", saveState());
-      emit deleted(static_cast<TopWin*>(this));
+      emit isDeleting(static_cast<TopWin*>(this));
       e->accept();
       }
 
@@ -458,7 +460,9 @@ void WaveEdit::readStatus(MusECore::Xml& xml)
 
 void WaveEdit::songChanged1(int bits)
       {
-        
+        if(_isDeleting)  // Ignore while while deleting to prevent crash.
+          return;
+
         if (bits & SC_SOLO)
         {
           MusECore::WavePart* part = (MusECore::WavePart*)(parts()->begin()->second);
diff --git a/muse2/muse/waveedit/waveedit.h b/muse2/muse/waveedit/waveedit.h
index b40aa93a..85e71a60 100644
--- a/muse2/muse/waveedit/waveedit.h
+++ b/muse2/muse/waveedit/waveedit.h
@@ -94,7 +94,7 @@ class WaveEdit : public MidiEditor {
 
 
    signals:
-      void deleted(MusEGui::TopWin*);
+      void isDeleting(MusEGui::TopWin*);
 
    public:
       WaveEdit(MusECore::PartList*);