BIM: Added delay to ifc viewprovider drag and drop - fixes #15259

src/Mod/BIM/nativeifc/ifc_viewproviders.py

@@ -315,12 +315,20 @@ class ifc_vp_object:
     def dropObject(self, vobj, incoming_object):
         """Add an object to the view provider by d&d"""
 
-        from nativeifc import ifc_tools  # lazy import
+        from PySide import QtCore  # lazy import
+        self.incoming_object = incoming_object
+        # delay the action to prevent the object to be deleted
+        # before the end of the drop
+        QtCore.QTimer.singleShot(100, self.onDrop)
 
-        parent = vobj.Object
-        ifc_tools.aggregate(incoming_object, parent)
-        if self.hasChildren(parent):
-            self.expandChildren(parent)
+    def onDrop(self):
+        """Delayed action to be taken when dropping an object"""
+
+        from nativeifc import ifc_tools  # lazy import
+        ifc_tools.aggregate(self.incoming_object, self.Object)
+        if self.hasChildren(self.Object):
+            self.expandChildren(self.Object)
+        del self.incoming_object
 
     def activate(self):
         """Marks this container as active"""