getMicPositionName defaults to channel 0 when index is greater than the number of channels

[d.healey]

If I have a sample map with 3 mic positions; close, decca, hall.

When I call getMicPositionName() and pass 3 as the index (a channel that is not present in this sample map) the function returns close.

This is very annoying because I end up purging/loading the wrong channel.

I think it would be better if the function returns undefined. Then I can just check with isDefined() and ignore it.

The problem line is here

@Christoph-Hart Should I make a pull request?

As an alternative I can of course run a check with getNumMicPositions().