-Mm flag & ctrl7 midi channels - out of range errors

[boonier]

Observed on Csound version 6.18 (double samples) Oct 20 2022

So when I was testing out the -Mm flag to enable access to multiple ports it looks like the ctrlN family of opcodes won't accept a midi channel greater than 1-16. This would also affect other midi input opcodes I think.

Can confirm that the error is being sent in here:

csound/Opcodes/midiops2.c

Lines 326 to 329 in a1580f9

	else if (UNLIKELY((chan=(int32_t) *p->ichan-1) < 0 || chan > 15)) {
	return csound->InitError(csound,
	Str("illegal midi channel")); /* gab-A2 (chan number fix)*/
	}

More background info here:
https://forum.csound.com/t/how-to-make-use-of-mm-flag-for-multiple-input-ports/1281?u=boonier
https://discord.com/channels/784849854270537790/786239959342121021/1133325632982499378

Cheers