diff --git a/src/App/PropertyFile.cpp b/src/App/PropertyFile.cpp
index 1a38e36dab..4e27331f51 100644
--- a/src/App/PropertyFile.cpp
+++ b/src/App/PropertyFile.cpp
@@ -516,7 +516,7 @@ void PropertyFileIncluded::RestoreDocFile(Base::Reader &reader)
 
 Property *PropertyFileIncluded::Copy(void) const
 {
-    PropertyFileIncluded *prop = new PropertyFileIncluded();
+    std::unique_ptr<PropertyFileIncluded> prop(new PropertyFileIncluded());
 
     // remember the base name
     prop->_BaseFileName = _BaseFileName;
@@ -556,7 +556,7 @@ Property *PropertyFileIncluded::Copy(void) const
         newName.setPermissions(Base::FileInfo::ReadWrite);
     }
 
-    return prop;
+    return prop.release();
 }
 
 void PropertyFileIncluded::Paste(const Property &from)
diff --git a/src/Gui/DlgPreferencesImp.cpp b/src/Gui/DlgPreferencesImp.cpp
index a1b74d3438..f7868d5a49 100644
--- a/src/Gui/DlgPreferencesImp.cpp
+++ b/src/Gui/DlgPreferencesImp.cpp
@@ -79,7 +79,8 @@ DlgPreferencesImp::DlgPreferencesImp(QWidget* parent, Qt::WindowFlags fl)
  */
 DlgPreferencesImp::~DlgPreferencesImp()
 {
-  // no need to delete child widgets, Qt does it all for us
+    // no need to delete child widgets, Qt does it all for us
+    delete ui;
 }
 
 void DlgPreferencesImp::setupPages()
diff --git a/src/Gui/DlgProjectUtility.cpp b/src/Gui/DlgProjectUtility.cpp
index b5ffc4919e..66887dccfd 100644
--- a/src/Gui/DlgProjectUtility.cpp
+++ b/src/Gui/DlgProjectUtility.cpp
@@ -122,6 +122,7 @@ DlgProjectUtility::DlgProjectUtility(QWidget* parent, Qt::WindowFlags fl)
 DlgProjectUtility::~DlgProjectUtility()
 {
   // no need to delete child widgets, Qt does it all for us
+    delete ui;
 }
 
 void DlgProjectUtility::on_extractButton_clicked()
diff --git a/src/Gui/View3DInventorExamples.cpp b/src/Gui/View3DInventorExamples.cpp
index 53cfacebab..af70857964 100644
--- a/src/Gui/View3DInventorExamples.cpp
+++ b/src/Gui/View3DInventorExamples.cpp
@@ -407,6 +407,8 @@ timersensorcallback(void * data, SoSensor *)
 
 void AnimationTexture(SoSeparator * root)
 {
+  // Scene graph
+  if ( root == NULL ) return; // Shouldn't happen.
 
   // Generate a julia set to use as a texturemap
   julia(cr, ci, 2.5, texturewidth, textureheight, 4, bitmap, 64);
@@ -425,8 +427,6 @@ void AnimationTexture(SoSeparator * root)
   texturetimer->setInterval(0.05);
   texturetimer->schedule();
 
-  // Scene graph
-  if ( root == NULL ) return; // Shouldn't happen.
   root->ref(); // prevent from being deleted because of the still running timer sensor
 //  SoSeparator * root = new SoSeparator;
 //  root->ref();
diff --git a/src/Gui/ViewProviderBuilder.cpp b/src/Gui/ViewProviderBuilder.cpp
index 66dde49e31..99385a814a 100644
--- a/src/Gui/ViewProviderBuilder.cpp
+++ b/src/Gui/ViewProviderBuilder.cpp
@@ -101,21 +101,20 @@ ViewProviderColorBuilder::~ViewProviderColorBuilder()
 {
 }
 
-void ViewProviderColorBuilder::buildNodes(const App::Property* prop, std::vector<SoNode*>&) const
+void ViewProviderColorBuilder::buildNodes(const App::Property* prop, std::vector<SoNode*>& node) const
 {
     const App::PropertyColorList* color = static_cast<const App::PropertyColorList*>(prop);
     const std::vector<App::Color>& val = color->getValues();
     unsigned long i=0;
 
     SoMaterial* material = new SoMaterial();
-    material->enableNotify(false);
-    material->diffuseColor.deleteValues(0);
     material->diffuseColor.setNum(val.size());
 
+    SbColor* colors = material->diffuseColor.startEditing();
     for (std::vector<App::Color>::const_iterator it = val.begin(); it != val.end(); ++it) {
-        material->diffuseColor.set1Value(i++, SbColor(it->r, it->g, it->b));
+        colors[i].setValue(it->r, it->g, it->b);
+        i++;
     }
-
-    material->enableNotify(true);
-    material->touch();
+    material->diffuseColor.finishEditing();
+    node.push_back(material);
 }
diff --git a/src/Main/FreeCADGuiPy.cpp b/src/Main/FreeCADGuiPy.cpp
index fb6b769797..547c190f4a 100644
--- a/src/Main/FreeCADGuiPy.cpp
+++ b/src/Main/FreeCADGuiPy.cpp
@@ -260,6 +260,7 @@ QWidget* setupMainWindow()
         Base::PyGILStateLocker lock;
         PyObject* input = PySys_GetObject("stdin");
         Gui::MainWindow *mw = new Gui::MainWindow();
+        mw->setAttribute(Qt::WA_DeleteOnClose);
         hasMainWindow = true;
 
         QIcon icon = qApp->windowIcon();
diff --git a/src/Mod/Image/Gui/ImageOrientationDialog.cpp b/src/Mod/Image/Gui/ImageOrientationDialog.cpp
index b09d4df113..f51a2e2f03 100644
--- a/src/Mod/Image/Gui/ImageOrientationDialog.cpp
+++ b/src/Mod/Image/Gui/ImageOrientationDialog.cpp
@@ -52,7 +52,7 @@ ImageOrientationDialog::ImageOrientationDialog()
 
 ImageOrientationDialog::~ImageOrientationDialog()
 {
-
+    delete ui;
 }
 
 void ImageOrientationDialog::accept()
diff --git a/src/Mod/Import/App/dxf.cpp b/src/Mod/Import/App/dxf.cpp
index 597a4390b6..2468e6ec29 100644
--- a/src/Mod/Import/App/dxf.cpp
+++ b/src/Mod/Import/App/dxf.cpp
@@ -57,6 +57,10 @@ m_layerName("none")
 CDxfWrite::~CDxfWrite()
 {
     delete m_ofs;
+    delete m_ssBlock;
+    delete m_ssBlkRecord;
+    delete m_ssEntity;
+    delete m_ssLayer;
 }
 
 void CDxfWrite::init(void)
diff --git a/src/Mod/Mesh/Gui/DlgSettingsImportExportImp.cpp b/src/Mod/Mesh/Gui/DlgSettingsImportExportImp.cpp
index d8f43df43b..2168b6de94 100644
--- a/src/Mod/Mesh/Gui/DlgSettingsImportExportImp.cpp
+++ b/src/Mod/Mesh/Gui/DlgSettingsImportExportImp.cpp
@@ -40,6 +40,7 @@ DlgSettingsImportExport::DlgSettingsImportExport(QWidget* parent)
 DlgSettingsImportExport::~DlgSettingsImportExport()
 {
     // no need to delete child widgets, Qt does it all for us
+    delete ui;
 }
 
 void DlgSettingsImportExport::saveSettings()
diff --git a/src/Mod/Part/Gui/TaskDimension.cpp b/src/Mod/Part/Gui/TaskDimension.cpp
index 8c244733cb..ecb71f1af7 100644
--- a/src/Mod/Part/Gui/TaskDimension.cpp
+++ b/src/Mod/Part/Gui/TaskDimension.cpp
@@ -994,6 +994,7 @@ void PartGui::goDimensionAngularNoTask(const VectorAdapter &vector1Adapter, cons
   }
   
   DimensionAngular *dimension = new DimensionAngular();
+  dimension->ref();
   dimension->matrix.setValue(dimSys);
   dimension->radius.setValue(radius);
   dimension->angle.setValue(static_cast<float>(displayAngle));
@@ -1001,10 +1002,9 @@ void PartGui::goDimensionAngularNoTask(const VectorAdapter &vector1Adapter, cons
   dimension->dColor.setValue(SbColor(0.0, 0.0, 1.0));
   
   Gui::View3DInventorViewer *viewer = getViewer();
-  if (!viewer)
-    return;
-  
-  viewer->addDimension3d(dimension);
+  if (viewer)
+    viewer->addDimension3d(dimension);
+  dimension->unref();
 }
 
 SO_KIT_SOURCE(PartGui::DimensionAngular);
@@ -1058,6 +1058,7 @@ void PartGui::DimensionAngular::setupDimension()
 
   //color
   SoMaterial *material = new SoMaterial;
+  material->ref();
   material->diffuseColor.connectFrom(&dColor);
 
   //dimension arrows.
@@ -1110,22 +1111,21 @@ void PartGui::DimensionAngular::setupDimension()
   coordinates->point.connectFrom(&arcEngine->points);
   
   SoLineSet *lineSet = new SoLineSet();
+  lineSet->ref();
   lineSet->vertexProperty.setValue(coordinates);
   lineSet->numVertices.connectFrom(&arcEngine->pointCount);
   lineSet->startIndex.setValue(0);
   
   SoSeparator *arcSep = static_cast<SoSeparator *>(getPart("arcSep", true));
-  if (!arcSep)
-    return;
-  arcSep->addChild(material);
-  arcSep->addChild(lineSet);
+  if (arcSep) {
+    arcSep->addChild(material);
+    arcSep->addChild(lineSet);
+  }
 
   //text
   SoSeparator *textSep = static_cast<SoSeparator *>(getPart("textSep", true));
-  if (!textSep)
-      return;
-
-  textSep->addChild(material);
+  if (textSep)
+    textSep->addChild(material);
 
   SoCalculator *textVecCalc = new SoCalculator();
   textVecCalc->a.connectFrom(&angle);
@@ -1158,6 +1158,9 @@ void PartGui::DimensionAngular::setupDimension()
   SoResetTransform *rTrans = new SoResetTransform;
   rTrans->whatToReset = SoResetTransform::BBOX;
   textSep->addChild(rTrans);
+
+  lineSet->unref();
+  material->unref();
 }
 
 SO_ENGINE_SOURCE(PartGui::ArcEngine);
diff --git a/src/Mod/Part/Gui/ViewProviderReference.cpp b/src/Mod/Part/Gui/ViewProviderReference.cpp
index 59a74758d5..f6d1e359c1 100644
--- a/src/Mod/Part/Gui/ViewProviderReference.cpp
+++ b/src/Mod/Part/Gui/ViewProviderReference.cpp
@@ -241,9 +241,9 @@ void ViewProviderPartReference::attach(App::DocumentObject *pcFeat)
     ViewProviderGeometryObject::attach(pcFeat);
 
     SoGroup* pcNormalRoot = new SoGroup();
-    SoGroup* pcFlatRoot = new SoGroup();
-    SoGroup* pcWireframeRoot = new SoGroup();
-    SoGroup* pcPointsRoot = new SoGroup();
+    //SoGroup* pcFlatRoot = new SoGroup();
+    //SoGroup* pcWireframeRoot = new SoGroup();
+    //SoGroup* pcPointsRoot = new SoGroup();
 
     // enable two-side rendering
     pShapeHints->vertexOrdering = SoShapeHints::COUNTERCLOCKWISE;
@@ -256,15 +256,15 @@ void ViewProviderPartReference::attach(App::DocumentObject *pcFeat)
     pcNormalRoot->addChild(VertexRoot);
 
     // just faces with no edges or points
-    pcFlatRoot->addChild(pShapeHints);
-    pcFlatRoot->addChild(FaceRoot);
+    //pcFlatRoot->addChild(pShapeHints);
+    //pcFlatRoot->addChild(FaceRoot);
 
     // only edges
-    pcWireframeRoot->addChild(EdgeRoot);
-    pcWireframeRoot->addChild(VertexRoot);
+    //pcWireframeRoot->addChild(EdgeRoot);
+    //pcWireframeRoot->addChild(VertexRoot);
 
     // normal viewing with edges and points
-    pcPointsRoot->addChild(VertexRoot);
+    //pcPointsRoot->addChild(VertexRoot);
 
     // putting all together with the switch
     addDisplayMaskMode(pcNormalRoot, "Reference");
diff --git a/src/Mod/Path/Gui/DlgProcessorChooser.cpp b/src/Mod/Path/Gui/DlgProcessorChooser.cpp
index 62a473a887..94465348c7 100644
--- a/src/Mod/Path/Gui/DlgProcessorChooser.cpp
+++ b/src/Mod/Path/Gui/DlgProcessorChooser.cpp
@@ -58,6 +58,7 @@ DlgProcessorChooser::DlgProcessorChooser(std::vector<std::string> &scriptnames,
 
 DlgProcessorChooser::~DlgProcessorChooser()
 {
+    delete ui;
 }
 
 std::string DlgProcessorChooser::getProcessor()
diff --git a/src/Mod/ReverseEngineering/App/ApproxSurface.cpp b/src/Mod/ReverseEngineering/App/ApproxSurface.cpp
index e7ea0c8d90..62379037ad 100644
--- a/src/Mod/ReverseEngineering/App/ApproxSurface.cpp
+++ b/src/Mod/ReverseEngineering/App/ApproxSurface.cpp
@@ -865,7 +865,7 @@ void BSplineParameterCorrection::DoParameterCorrection(int iIter)
         fMaxScalar = 1.0;
         fMaxDiff   = 0.0;
 
-        Geom_BSplineSurface* pclBSplineSurf = new Geom_BSplineSurface(_vCtrlPntsOfSurf,
+        Handle(Geom_BSplineSurface) pclBSplineSurf = new Geom_BSplineSurface(_vCtrlPntsOfSurf,
                                                     _vUKnots, _vVKnots, _vUMults, _vVMults, _usUOrder-1, _usVOrder-1);
 
         for (int ii=_pvcPoints->Lower();ii <=_pvcPoints->Upper();ii++) {
diff --git a/src/Mod/Robot/Gui/CommandTrajectory.cpp b/src/Mod/Robot/Gui/CommandTrajectory.cpp
index 76adc1ccb7..eef291a0c8 100644
--- a/src/Mod/Robot/Gui/CommandTrajectory.cpp
+++ b/src/Mod/Robot/Gui/CommandTrajectory.cpp
@@ -226,17 +226,16 @@ CmdRobotSetDefaultOrientation::CmdRobotSetDefaultOrientation()
 void CmdRobotSetDefaultOrientation::activated(int)
 {
     // create placement dialog 
-    Gui::Dialog::Placement *Dlg = new Gui::Dialog::Placement();
+    Gui::Dialog::Placement Dlg;
     Base::Placement place;
-    Dlg->setPlacement(place);
-    if(Dlg->exec() == QDialog::Accepted ){
-        place = Dlg->getPlacement();
+    Dlg.setPlacement(place);
+    if (Dlg.exec() == QDialog::Accepted ){
+        place = Dlg.getPlacement();
         Base::Rotation rot = place.getRotation();
         Base::Vector3d disp = place.getPosition();
         doCommand(Doc,"_DefOrientation = FreeCAD.Rotation(%f,%f,%f,%f)",rot[0],rot[1],rot[2],rot[3]);
         doCommand(Doc,"_DefDisplacement = FreeCAD.Vector(%f,%f,%f)",disp[0],disp[1],disp[2]);
     }
-      
 }
 
 bool CmdRobotSetDefaultOrientation::isActive(void)
diff --git a/src/Mod/Robot/Gui/TaskRobot6Axis.cpp b/src/Mod/Robot/Gui/TaskRobot6Axis.cpp
index 080653bbe3..8e3326cc62 100644
--- a/src/Mod/Robot/Gui/TaskRobot6Axis.cpp
+++ b/src/Mod/Robot/Gui/TaskRobot6Axis.cpp
@@ -117,10 +117,10 @@ void TaskRobot6Axis::setRobot(Robot::RobotObject *pcRobotObject)
 
 void TaskRobot6Axis::createPlacementDlg(void)
 {
-    Gui::Dialog::Placement *plc = new Gui::Dialog::Placement();
-    plc->setPlacement(pcRobot->Tool.getValue());
-    if(plc->exec()==QDialog::Accepted)
-        pcRobot->Tool.setValue(plc->getPlacement());
+    Gui::Dialog::Placement plc;
+    plc.setPlacement(pcRobot->Tool.getValue());
+    if (plc.exec()==QDialog::Accepted)
+        pcRobot->Tool.setValue(plc.getPlacement());
     viewTool(pcRobot->Tool.getValue());
 }
 
diff --git a/src/Mod/Robot/Gui/TaskTrajectoryDressUpParameter.cpp b/src/Mod/Robot/Gui/TaskTrajectoryDressUpParameter.cpp
index c519ee4957..e515562a12 100644
--- a/src/Mod/Robot/Gui/TaskTrajectoryDressUpParameter.cpp
+++ b/src/Mod/Robot/Gui/TaskTrajectoryDressUpParameter.cpp
@@ -93,10 +93,10 @@ void TaskTrajectoryDressUpParameter::writeValues(void)
 
 void TaskTrajectoryDressUpParameter::createPlacementDlg(void)
 {
-    Gui::Dialog::Placement *plc = new Gui::Dialog::Placement();
-    plc->setPlacement(PosAdd);
-    if(plc->exec()==QDialog::Accepted){
-        PosAdd = plc->getPlacement();
+    Gui::Dialog::Placement plc;
+    plc.setPlacement(PosAdd);
+    if (plc.exec() == QDialog::Accepted) {
+        PosAdd = plc.getPlacement();
         viewPlacement();
     }
 
diff --git a/src/Mod/Robot/Gui/ViewProviderRobotObject.cpp b/src/Mod/Robot/Gui/ViewProviderRobotObject.cpp
index ffc97ecf35..78d7ac5d11 100644
--- a/src/Mod/Robot/Gui/ViewProviderRobotObject.cpp
+++ b/src/Mod/Robot/Gui/ViewProviderRobotObject.cpp
@@ -60,13 +60,13 @@ ViewProviderRobotObject::ViewProviderRobotObject()
 {
     ADD_PROPERTY(Manipulator,(0));   
 
-	pcRobotRoot = new Gui::SoFCSelection();
+    pcRobotRoot = new Gui::SoFCSelection();
     pcRobotRoot->highlightMode = Gui::SoFCSelection::OFF;
     //pcRobotRoot->selectionMode = Gui::SoFCSelection::SEL_OFF;
     //pcRobotRoot->style = Gui::SoFCSelection::BOX;
     pcRobotRoot->ref();
 
-	pcSimpleRoot = new Gui::SoFCSelection();
+    pcSimpleRoot = new Gui::SoFCSelection();
     pcSimpleRoot->highlightMode = Gui::SoFCSelection::OFF;
     //pcSimpleRoot->selectionMode = Gui::SoFCSelection::SEL_OFF;
     pcSimpleRoot->ref();
@@ -82,6 +82,14 @@ ViewProviderRobotObject::ViewProviderRobotObject()
     Axis1Node = Axis2Node = Axis3Node = Axis4Node = Axis5Node = Axis6Node = 0;
 }
 
+ViewProviderRobotObject::~ViewProviderRobotObject()
+{
+    pcRobotRoot->unref();
+    pcSimpleRoot->unref();
+    pcOffRoot->unref();
+    pcTcpRoot->unref();
+}
+
 void ViewProviderRobotObject::setDragger()
 {
     assert(pcDragger==0);
@@ -98,23 +106,13 @@ void ViewProviderRobotObject::setDragger()
                    SbVec3f(150,150,150)
                    );
     pcDragger->setMotionMatrix(M);
-
-
 }
+
 void ViewProviderRobotObject::resetDragger()
 {
     assert(pcDragger);
     pcTcpRoot->removeAllChildren();
     pcDragger = 0;
-
- }
-
-ViewProviderRobotObject::~ViewProviderRobotObject()
-{
-    pcRobotRoot->unref();
-    pcSimpleRoot->unref();
-    pcOffRoot->unref();
-
 }
 
 void ViewProviderRobotObject::attach(App::DocumentObject *pcObj)
@@ -135,8 +133,6 @@ void ViewProviderRobotObject::attach(App::DocumentObject *pcObj)
 
     addDisplayMaskMode(pcOffRoot, "Off");
     pcOffRoot->addChild(pcTcpRoot);
-
-
 }
 
 void ViewProviderRobotObject::setDisplayMode(const char* ModeName)
diff --git a/src/Mod/Sketcher/App/SketchObject.cpp b/src/Mod/Sketcher/App/SketchObject.cpp
index 6482ba9ae3..3d7aa28677 100644
--- a/src/Mod/Sketcher/App/SketchObject.cpp
+++ b/src/Mod/Sketcher/App/SketchObject.cpp
@@ -4865,8 +4865,7 @@ bool SketchObject::increaseBSplineDegree(int GeoId, int degreeincrement /*= 1*/)
 
     const Handle(Geom_BSplineCurve) curve = Handle(Geom_BSplineCurve)::DownCast(bsp->handle());
 
-    Part::GeomBSplineCurve *bspline = new Part::GeomBSplineCurve(curve);
-
+    std::unique_ptr<Part::GeomBSplineCurve> bspline(new Part::GeomBSplineCurve(curve));
 
     try {
         int cdegree = bspline->getDegree();
@@ -4882,7 +4881,7 @@ bool SketchObject::increaseBSplineDegree(int GeoId, int degreeincrement /*= 1*/)
 
     std::vector< Part::Geometry * > newVals(vals);
 
-    newVals[GeoId] = bspline;
+    newVals[GeoId] = bspline.release();
 
     Geometry.setValues(newVals);
     Constraints.acceptGeometry(getCompleteGeometry());
diff --git a/src/Mod/Sketcher/Gui/SketchMirrorDialog.cpp b/src/Mod/Sketcher/Gui/SketchMirrorDialog.cpp
index 86013e0966..041d263472 100644
--- a/src/Mod/Sketcher/Gui/SketchMirrorDialog.cpp
+++ b/src/Mod/Sketcher/Gui/SketchMirrorDialog.cpp
@@ -49,7 +49,7 @@ SketchMirrorDialog::SketchMirrorDialog(void)
 
 SketchMirrorDialog::~SketchMirrorDialog()
 {
-
+    delete ui;
 }
 
 void SketchMirrorDialog::accept()
diff --git a/src/Mod/Sketcher/Gui/SketchOrientationDialog.cpp b/src/Mod/Sketcher/Gui/SketchOrientationDialog.cpp
index df0a025830..3b4f86e731 100644
--- a/src/Mod/Sketcher/Gui/SketchOrientationDialog.cpp
+++ b/src/Mod/Sketcher/Gui/SketchOrientationDialog.cpp
@@ -52,7 +52,7 @@ SketchOrientationDialog::SketchOrientationDialog(void)
 
 SketchOrientationDialog::~SketchOrientationDialog()
 {
-
+    delete ui;
 }
 
 void SketchOrientationDialog::accept()
diff --git a/src/Mod/Sketcher/Gui/SketchRectangularArrayDialog.cpp b/src/Mod/Sketcher/Gui/SketchRectangularArrayDialog.cpp
index d00cfa9021..cc37c5f59c 100644
--- a/src/Mod/Sketcher/Gui/SketchRectangularArrayDialog.cpp
+++ b/src/Mod/Sketcher/Gui/SketchRectangularArrayDialog.cpp
@@ -53,7 +53,7 @@ SketchRectangularArrayDialog::SketchRectangularArrayDialog(void)
 
 SketchRectangularArrayDialog::~SketchRectangularArrayDialog()
 {
-
+    delete ui;
 }
 
 void SketchRectangularArrayDialog::accept()
diff --git a/src/Mod/Sketcher/Gui/SketcherRegularPolygonDialog.cpp b/src/Mod/Sketcher/Gui/SketcherRegularPolygonDialog.cpp
index c1b8d92a7f..bf7dc3ef88 100644
--- a/src/Mod/Sketcher/Gui/SketcherRegularPolygonDialog.cpp
+++ b/src/Mod/Sketcher/Gui/SketcherRegularPolygonDialog.cpp
@@ -49,7 +49,7 @@ SketcherRegularPolygonDialog::SketcherRegularPolygonDialog(void)
 
 SketcherRegularPolygonDialog::~SketcherRegularPolygonDialog()
 {
-
+    delete ui;
 }
 
 void SketcherRegularPolygonDialog::accept()