[Crash] MIKMIDICommand.m - Line 73 +[MIKMIDICommand commandsWithMIDIPacket:] + 73

[taovo]

Hi I has crash issue in this line. Could you please help me check it. Thank you so much. I just happen on iOS 14.

[armadsen]

Hi! The screenshot you posted really doesn't have enough information in it to say much of anything about the crash by itself. Can you tell me more about the circumstances behind the crash?

[taovo]

Thank you for quick response @armadsen. I got it from our firebase system. I saw it just happen on iOS 14 (especially 14.4.2). it just came out recently and i still haven't replayed it on my device.

[ahmaniea]

Hi. We have also received crash reports with the same stack trace. The only additional info I can give is that it seems to occur also with macOS 10.16.0 and 11.4.0.

[makaGeorge]

Hi,

I've also experienced this crash but in a very special circumstance: I have an older MIDI interface and when I connect it to the output of one of my synths, before the connection is fully made I get a few calls to this function where the standardLength variable is -1. It seems that it makes its way into the MIDIPacketListAdd function and causes the crash.

Am I right in guessing standardLength should never be -1?

From what I've seen I only get this in this specific case... maybe its a corrupted message as the cable is not fully connected.

BTW this is on Mac Catalyst.

I've added a condition just to check this:

if (standardLength == -1) {
NSLog(@"STANDARDLENGHT -1");
standardLength = inputPacket->length;
}

now the crash doesn't happen but I'm not really sure this is any good...

[monosG]

A System Message (MIKMIDICommandTypeSystemMessage) results in standardLength being -1. You can reproduce the crash by sending a message with status byte 0xFF (Reset command) to the library. Some footswitches seem to be sending those messages, for example.