sS betterAutoUnindent(S s) {
  int n = betterGetIndent(s);
  if (n == 0) ret s;
  L<S> l = toLines(s);
  for (int i = 0; i < l(l); i++)
    l.set(i, substring(l.get(i), n));
  ret fromLines(l);
}

Began life as a copy of #1002853