utf8_toUtf8(const ENCODING *UNUSED_P(enc),            const char **fromP, const char *fromLim,            char **toP, const char *toLim){  char *to;  const char *from;  const char *fromLimInitial = fromLim;  /* Avoid copying partial characters. */  align_limit_to_full_utf8_characters(*fromP, &fromLim);  for (to = *toP, from = *fromP; (from < fromLim) && (to < toLim); from++, to++)    *to = *from;  *fromP = from;  *toP = to;  if (fromLim < fromLimInitial)    return XML_CONVERT_INPUT_INCOMPLETE;  else if ((to == toLim) && (from < fromLim))    // <===== Bug is here. In case (to == toLim), it's possible that    //        from is still pointing to partial character. For example,    //        a character with 3 bytes (A, B, C) and form is pointing to C.    //        It means only A and B is copied to output buffer. Next    //        scanning will start with C which could be considered as invalid    //        byte and got dropped. After this, only "AB" is kept in memory    //        and thus it will lead to invalid continuation byte.    return XML_CONVERT_OUTPUT_EXHAUSTED;  else    return XML_CONVERT_COMPLETED;}