emergency() hangs with no response, also fails to recognise landing

[ceperman]

emergency() waits for a response when the Tello appears not return one, so it hangs.

Also emergency() should recognise that the drone will have landed - difficult not to with the motors switched off - but does not flag it. This causes end() to attempt to land the drone when it has already landed (see issue "end() throws exception if drone has already landed through mishap").

I have modified my version of Tello emergency() thus:

self.send_command_without_return("emergency")
self.is_flying = False

Update
I realised this could be model/firmware related. I have a basic Tello, firmware 01.04.92.01 (the latest for this model I believe).

[M4GNV5]

The manual describes the drone to return ok or error after sending emergency.

I adjusted the code to the behaviour you describe, but wasnt able to test it just yet.