Comment 5 for bug 1547864

Urgh. My immediate reaction is “that touchscreen shouldn't be emulating a keyboard, damnit”.

My concern with adding cancellation behaviour is that there'll be no existing client or toolkit that expects it, and we can't make it opt-in (like the opt-in touch cancellation support).

Could we quirk this in either libinput or Mir to not send key-down until we've got a confirmed key-up?