From 025cf18714d5514ef89c871a7d7642a04062015b Mon Sep 17 00:00:00 2001
From: wmayer <wmayer@users.sourceforge.net>
Date: Thu, 10 Nov 2016 23:57:41 +0100
Subject: [PATCH] do not allow to delete properties in FeaturePythonPyT

---
 src/App/FeaturePythonPyImp.h   | 2 +-
 src/App/FeaturePythonPyImp.inl | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/App/FeaturePythonPyImp.h b/src/App/FeaturePythonPyImp.h
index a9ab3a352902..4e72f013df2c 100644
--- a/src/App/FeaturePythonPyImp.h
+++ b/src/App/FeaturePythonPyImp.h
@@ -24,7 +24,7 @@
 #define APP_FEATUREPYTHONPYIMP_H
 
 #include <Base/BaseClass.h>
-#include <Base/PyObjectBase.h>
+#include <App/PropertyContainerPy.h>
 
 namespace App
 {
diff --git a/src/App/FeaturePythonPyImp.inl b/src/App/FeaturePythonPyImp.inl
index 3c021d7946dc..a71e47606686 100644
--- a/src/App/FeaturePythonPyImp.inl
+++ b/src/App/FeaturePythonPyImp.inl
@@ -113,6 +113,12 @@ int FeaturePythonPyT<FeaturePyT>::__setattr(PyObject *obj, char *attr, PyObject
 template<class FeaturePyT>
 int FeaturePythonPyT<FeaturePyT>::_setattr(char *attr, PyObject *value)
 {
+    App::Property *prop = FeaturePyT::getPropertyContainerPtr()->getPropertyByName(attr);
+    if (prop && !value) {
+        PyErr_Format(PyExc_AttributeError, "Cannot delete attribute: '%s'", attr);
+        return -1;
+    }
+
     int returnValue = FeaturePyT::_setattr(attr, value);
     if (returnValue == -1) {
         PyObject* dict_item = value;