Unhandled exception thrown when decreasing Groove number to a nonexistent value

[TakuikaNinja]

Specifically decreasing the Groove number in a module with no Grooves created throws an unhandled exception. Increasing the number doesn't do anything. I don't recall this occurring in previous versions.

Version: 0.5.2 on wine (dn-famitracker-bin AUR package)

Reproduction steps:

1. In a new module, switch from Speed to Groove mode without creating a new Groove.
2. Decrease the Groove number.

Screenshot:

MiniDump:
MiniDump_20250830-1722-v0_5_2_17.dmp.zip

[henrikvilhelmberglund]

It is because of the recent fix that recalls groove settings when changing frames during playback. To be honest I forgot you could even set a groove that way.

It doesn't crash in earlier versions but is a bit weird there too, it starts at groove 6, then you press the down arrow and it changes to groove 0 which doesn't exist and doesn't do anything (until you add a groove).

If you add a groove first and then switch using the button it works the same way as in earlier versions.

Maybe this is better:

1. Start at groove 0 when you press Speed (right now it's linked to the speed number which seems like a bad idea)
2. Have a default groove at 0 with for example 2 1 2 1 aka 150bpm since the crash happens because there's not a real groove with data.