I once talked with a gent that used to run that route regularly. I would imagine Qatar's national carrier has renewed interested in such things these days.
I am aware of US restrictions that once forced Cuban carriers to take a circuitous route to Canada, not unlike the South Africa overflight embargo of years gone by when their national airline flew 747SP's.
While not fitting the parameters of your example, there are a few South American countries that restrict foreign aircraft to specific corridors.