App/Gui: fix memory leaks:

+ add function to cleanup units and quantities in debug build
+ fix reference leak in PropertyVector::getPyPathValue()
+ fix reference leak in PropertyPlacement::getPyPathValue()
+ in InterpreterSingleton::init() use a static std::vector<wchar_t*> instead of a C array
  to free memory at program end
+ in MainWindow::closeEvent() explicitly delete all task watchers
+ in ReportOutputObserver constructor pass parent to QObject
+ in PropertyEditor destructor explicitly delete QItemEditorFactory

src/App/Application.cpp

@@ -340,7 +340,6 @@ Application::Application(std::map<std::string,std::string> &mConfig)
 
     // Translate module
     PyObject* pTranslateModule = (new Base::Translate)->module().ptr();
-    Py_INCREF(pTranslateModule);
     PyModule_AddObject(pAppModule, "Qt", pTranslateModule);
 
     //insert Units module
@@ -1499,6 +1498,23 @@ int Application::_argc;
 char ** Application::_argv;
 
 
+void Application::cleanupUnits()
+{
+    try {
+        Base::PyGILStateLocker lock;
+        Py::Module mod (Py::Module("FreeCAD").getAttr("Units").ptr());
+
+        Py::List attr(mod.dir());
+        for (Py::List::iterator it = attr.begin(); it != attr.end(); ++it) {
+            mod.delAttr(Py::String(*it));
+        }
+    }
+    catch (Py::Exception& e) {
+        Base::PyGILStateLocker lock;
+        e.clear();
+    }
+}
+
 void Application::destruct(void)
 {
     // saving system parameter
@@ -1529,6 +1545,11 @@ void Application::destruct(void)
     _pcSysParamMngr = 0;
     _pcUserParamMngr = 0;
 
+#ifdef FC_DEBUG
+    // Do this only in debug mode for memory leak checkers
+    cleanupUnits();
+#endif
+
     // not initialized or double destruct!
     assert(_pcSingleton);
     delete _pcSingleton;

src/App/Application.h

@@ -458,6 +458,8 @@ private:
     /// Destructor
     virtual ~Application();
 
+    static void cleanupUnits();
+
     /** @name member for parameter */
     //@{
     static ParameterManager *_pcSysParamMngr;

src/App/PropertyGeo.cpp

@@ -225,11 +225,11 @@ bool PropertyVector::getPyPathValue(const ObjectIdentifier &path, Py::Object &re
 
     std::string p = path.getSubPathStr();
     if (p == ".x") {
-        res = new QuantityPy(new Quantity(getValue().x,unit));
+        res = Py::asObject(new QuantityPy(new Quantity(getValue().x,unit)));
     } else if(p == ".y") {
-        res = new QuantityPy(new Quantity(getValue().y,unit));
+        res = Py::asObject(new QuantityPy(new Quantity(getValue().y,unit)));
     } else if(p == ".z") {
-        res = new QuantityPy(new Quantity(getValue().z,unit));
+        res = Py::asObject(new QuantityPy(new Quantity(getValue().z,unit)));
     } else
         return false;
     return true;
@@ -678,13 +678,13 @@ bool PropertyPlacement::getPyPathValue(const ObjectIdentifier &path, Py::Object
     if (p == ".Rotation.Angle") {
         Base::Vector3d axis; double angle;
         _cPos.getRotation().getValue(axis,angle);
-        res = new QuantityPy(new Quantity(Base::toDegrees(angle),Unit::Angle));
+        res = Py::asObject(new QuantityPy(new Quantity(Base::toDegrees(angle),Unit::Angle)));
     } else if (p == ".Base.x") {
-        res = new QuantityPy(new Quantity(_cPos.getPosition().x,Unit::Length));
+        res = Py::asObject(new QuantityPy(new Quantity(_cPos.getPosition().x,Unit::Length)));
     } else if (p == ".Base.y") {
-        res = new QuantityPy(new Quantity(_cPos.getPosition().y,Unit::Length));
+        res = Py::asObject(new QuantityPy(new Quantity(_cPos.getPosition().y,Unit::Length)));
     } else if (p == ".Base.z") {
-        res = new QuantityPy(new Quantity(_cPos.getPosition().z,Unit::Length));
+        res = Py::asObject(new QuantityPy(new Quantity(_cPos.getPosition().z,Unit::Length)));
     } else
         return false;
     return true;

src/Base/Interpreter.cpp

@@ -587,7 +587,7 @@ const char* InterpreterSingleton::init(int argc,char *argv[])
 
 #if PY_MAJOR_VERSION >= 3
         size_t size = argc;
-        wchar_t **_argv = new wchar_t*[size];
+        static std::vector<wchar_t *> _argv(size);
         for (int i = 0; i < argc; i++) {
 #if PY_MINOR_VERSION >= 5
             _argv[i] = Py_DecodeLocale(argv[i],NULL);
@@ -595,7 +595,7 @@ const char* InterpreterSingleton::init(int argc,char *argv[])
             _argv[i] = _Py_char2wchar(argv[i],NULL);
 #endif
         }
-        PySys_SetArgv(argc, _argv);
+        PySys_SetArgv(argc, _argv.data());
 #else
         PySys_SetArgv(argc, argv);
 #endif

src/Gui/Application.cpp

@@ -450,7 +450,6 @@ Application::Application(bool GUIenabled)
 
         // PySide additions
         PySideUicModule* pySide = new PySideUicModule();
-        Py_INCREF(pySide->module().ptr());
         PyModule_AddObject(module, "PySideUic", pySide->module().ptr());
 
         ExpressionBindingPy::init_type();

src/Gui/MainWindow.cpp

@@ -1193,6 +1193,10 @@ void MainWindow::closeEvent (QCloseEvent * e)
             (*it)->hide();
             (*it)->deleteLater();
         }
+
+        if (Workbench* wb = WorkbenchManager::instance()->active())
+            wb->removeTaskWatcher();
+
         d->activityTimer->stop();
         saveWindowSettings();
         delete d->assistant;

src/Gui/ReportView.cpp

@@ -240,6 +240,7 @@ private:
  */
 
 ReportOutputObserver::ReportOutputObserver(ReportOutput *report)
+  : QObject(report)
 {
     this->reportView = report;
 }

src/Gui/propertyeditor/PropertyEditor.cpp

@@ -83,6 +83,9 @@ PropertyEditor::PropertyEditor(QWidget *parent)
 
 PropertyEditor::~PropertyEditor()
 {
+    QItemEditorFactory* f = delegate->itemEditorFactory();
+    delegate->setItemEditorFactory(nullptr);
+    delete f;
 }
 
 void PropertyEditor::setAutomaticExpand(bool v)