fix the virtual keyboard causes the E and F to be triggered (#7604)

[DevelopMan303]

It seems when the octave up/down shortcut is pressed along with a note, this issue appears. It also shows up on Windows.
My solution is to stop all the pressed notes after changing the octave, as key repeat will trigger the changed note. With this, it worked on on Ubuntu.
(BTW: my first pull request :-) )

[mkruselj]

That is a venerable attempt, but... I am not sure I would consider turning all notes off if you only change octaves a good UX... no other virtual keyboard I know of works like that...

Also, not all reports of this issue mention using octave offset keys, so this would only be a partial solution.

[baconpaul]

But the fact that this fixes it tells us a lot

Namely a key is getting misinterpreted as a note and as an octave shift

I wonder if our key map is doing both and the answer is if you do an octave shift don’t do a key action and vice versa

[DevelopMan303]

Thanks for your feedback. I agree, this may be a lite simplistic approach. I may find an optimization.
For me it looks there is an issue with the octave shift. Likely, the NoteOff is provided to the octave-shifted note.

[mkruselj]

If you press a normal note and hold it, but then shift the octave, the key you are holding is not going to be triggering the same note you're holding. That's why when you release that key, it doesn't send the correct note off.