sS ellipsisToRegexp_generic(S s, S replacementForEllipsis) {
  int i = 0;
  new StringBuffer buf;
  while (i < l(s)) {
    int j = smartIndexOf(s, "...", i);
    buf.append(regexpQuote(substring(s, i, j)));
    if (j >= l(s)) break;
    buf.append(replacementForEllipsis);
    i = j+3;
  }
  ret str(buf);
}

Began life as a copy of #1024108