store Python attributes of all extension types in one dict

src/App/ExtensionContainerPyImp.cpp

@@ -112,6 +112,30 @@ int ExtensionContainerPy::PyInit(PyObject* /*args*/, PyObject* /*kwd*/)
 
 PyObject *ExtensionContainerPy::getCustomAttributes(const char* attr) const
 {
+    if (Base::streq(attr, "__dict__")) {
+        PyObject* dict = PyDict_New();
+        PyObject* props = PropertyContainerPy::getCustomAttributes("__dict__");
+        if (props && PyDict_Check(props)) {
+            PyDict_Merge(dict, props, 0);
+            Py_DECREF(props);
+        }
+
+        ExtensionContainer::ExtensionIterator it = this->getExtensionContainerPtr()->extensionBegin();
+        for (; it != this->getExtensionContainerPtr()->extensionEnd(); ++it) {
+            // The PyTypeObject is shared by all instances of this type and therefore
+            // we have to add new methods only once.
+            PyObject* obj = (*it).second->getExtensionPyObject();
+            PyTypeObject *tp = Py_TYPE(obj);
+            if (tp && tp->tp_dict) {
+                Py_XINCREF(tp->tp_dict);
+                PyDict_Merge(dict, tp->tp_dict, 0);
+                Py_XDECREF(tp->tp_dict);
+            }
+            Py_DECREF(obj);
+        }
+
+        return dict;
+    }
     // Search for the method called 'attr' in the extensions. If the search with
     // Py_FindMethod is successful then a PyCFunction_New instance is returned
     // with the PyObject pointer of the extension to make sure the method will