[BUG][App Compat] REAPER, Studio One, and Bitwig Studio crash when receiving certain messages using WinMM

[Psychlist1972]

Release Customer Preview 1, Canary 27788

App crashes after key-up on notes recorded from Montage M. Testing additional instruments and apps, but wanted to get this documented in case others run into it.

[Psychlist1972]

Testing so far:

MIDI 1.0 device using old class driver: works
MIDI 1.0 device using new class driver: works
MIDI 2.0 device using new class driver: crashes the apps.

This is likely something related to translation. Maybe our in-box build did not pick up the correct version of libmidi2. Too early to tell.

[Psychlist1972]

I believe we have this discovered. It wasn't related to MIDI 2.0, but to the montage sending lots of active sensing messages. We had some incorrect single-byte-message handling in wdmaud2.drv.

Validating that now.

[Psychlist1972]

Quick update on this: we had some incorrect logic in handling incoming messages for WinMM/MME client applications. We're getting this fixed and will have those fixes in a future Canary release.

[Psychlist1972]

There was message corruption based on handling in the WinMM shim of certain notes under 3 bytes in length, under some conditions. Unfortunately, those conditions were very common (active sensing, clock, etc.). There will be a fix in the code base, soon, but unsure yet when that will move to Canary. I'll update here as I have more info.