Created attachment 158990 [details] [review]
gtk2perl_menu_detach_func() free the detach func after called

I believe the detach func in gtk_menu_attach_to_widget() is only called once and that whatever closure etc is there can be freed immediately after the detach.

The benefit would be to immediately release anything captured by a closure in that detach func, as opposed to waiting until the next attach_to_widget(), which of course might be either a long time or perhaps never.