Impossible to pop up a menu at pointer from ::drag-data-received
For example, adding gtk_menu_popup_at_pointer (GTK_MENU (gtk_menu_new ()), NULL)
to drag_data_received
in tests/testtreednd.c will result in the following:
(testtreednd:29893): Gtk-WARNING **: 12:39:32.460: no trigger event for menu popup
(testtreednd:29893): Gtk-CRITICAL **: 12:39:32.460: gtk_menu_popup_at_rect: assertion 'GDK_IS_SURFACE (rect_surface)' failed