micro:bit freezes when playing `music.play([None])`

[microbit-carlos]

Duplicating the issue here as it affect V2 as well:

• music hangs when playing None bbcmicrobit/micropython#776

The program

from microbit import *
import music

music.play([None])

hangs the microbit

[dpgeorge]

Using None in a tune was intended to be a "rest", ie no sound for a period. But this was never documented and instead "r" and "R" are supported and documented characters for inserting a "rest".

Using None as a rest is actually broken, as seen by the above example (you can still use ctrl-C to stop it, but the rest goes for a very long time).

I suggest we just completely remove support for None in tunes. It never worked and was never documented. That will then fix this issue.

[microbit-carlos]

Thanks Damien! I wasn't aware of the None rest either, sounds good 👍
Just for curiosity, do we know that it was always broken, or has it been broken from a specific point in time?

[dpgeorge]

Just for curiosity, do we know that it was always broken, or has it been broken from a specific point in time?

As far as I can tell, this "rest" feature was broken since commit (on micro:bit v1) 0189136af557bc2c8514935f7351bcaafe32c47f done in Nov 2015, which first allowed music to be played in the background. So I think it's safe to assume this feature was never used.

[dpgeorge]

Fixed by d2130d8 (support for None as a rest is removed).