+ avoid throwing exceptions in property editor if not needed

src/Gui/propertyeditor/PropertyItem.cpp

@@ -83,27 +83,27 @@ void PropertyItem::reset()
 void PropertyItem::setPropertyData(const std::vector<App::Property*>& items)
 {
     //if we have a single property we can bind it for expression handling
-    if(items.size() == 1) {
-
+    if (items.size() == 1) {
         const App::Property& p = *items.front();
-        
+
         try {
-            if(!(p.getContainer()->isReadOnly(&p))) {
-
+            // Check for 'DocumentObject' as parent because otherwise 'ObjectIdentifier' raises an exception
+            App::DocumentObject * docObj = Base::freecad_dynamic_cast<App::DocumentObject>(p.getContainer());
+            if (docObj && !docObj->isReadOnly(&p)) {
                 App::ObjectIdentifier id(p);
                 std::vector<App::ObjectIdentifier> paths;
                 p.getPaths(paths);
-                
+
                 //there may be no paths available in this property (for example an empty constraint list)
-                if(id.getProperty() && !paths.empty())
+                if (id.getProperty() && !paths.empty())
                     bind(id);
-
             }
         }
         //it may happen that setting properties is not possible
-        catch(...) {}; 
+        catch (...) {
+        }
     }
-    
+
     propertyItems = items;
     updateData();
     this->initialize();