Looking at the code on Windows calling GetMIDIData on Windows returns
the number of bytes read, and also for external MIDI.  If I read it
correctly for Linux it does not return anything in particular, and
possibly zero.  I suspect this may be a bug.  Code in
OOps/mididevice.c (btw should this be in InOut?).

Can someone else take a look?  This is true in both 4 nd 5

==John ffitch