duplicate child item being created

[iplayfast]

While debugging https://forum.freecadweb.org/viewtopic.php?f=8&t=47669 bug #3 I determined that it was caused by part-o-magic.

Start fresh session
Create New Document
Select Part Design Workbench
At this point you can create a body. Go ahead and create the body.
Go to the part design menu and select Involute Gear
click ok
If you switch back to the model, you will see you've got two involute gears with a body.
You will see an error like
5.69e-07 Tree.cpp(293): [TreeView] duplicate child item Unnamed#Body.InvoluteGear
0.00100885 Tree.cpp(293): [ComboView] duplicate child item Unnamed#Body.InvoluteGear