gUserDefinedConverter->Convert(aSrc, &aSrcLen, aDest, &aDestLen);
for (PRUint32 i = 0; i < aSrcLen; i++) { aDest[i] = '?'; }
nsFontGTKUserDefined::Convert(const PRUnichar* aSrc, PRInt32 aSrcLen,  char* aDest, PRInt32 aDestLen){  if (aSrcLen > aDestLen) {    aSrcLen = aDestLen;  }  gUserDefinedConverter->Convert(aSrc, &aSrcLen, aDest, &aDestLen);  return aSrcLen;}