Algernon's Syster implementation not working with zeros

Programming
6

In Syster.cpp, there’s a function named keyToChar() that translates USB HID keycode values to ASCII. That function needs to special-case Key_0, but currently does not. It is defined as a weak function, however, so you should be able to override it by including the following in your sketch:

const char keyToChar(Key key) {
  if (key.getFlags() != 0)
    return 0;

  switch (key.getKeyCode()) {
  case Key_A.getKeyCode() ... Key_Z.getKeyCode():
    return 'a' + (key.getKeyCode() - Key_A.getKeyCode());
  case Key_1.getKeyCode() ... Key_9.getKeyCode():
    return '1' + (key.getKeyCode() - Key_1.getKeyCode());
  case Key_0.getKeyCode():
    return '0';
  }

  return 0;
}