PRUnichar str[CHAR_BUFFER_SIZE]; PRUnichar* pstr = SubstituteChars(mDisplayUnicode, aString, aLength, str, CHAR_BUFFER_SIZE, &aLength); if (!pstr) return 0;
nsFontWinSubstitute::GetWidth(HDC aDC, const PRUnichar* aString,  PRUint32 aLength){  PRUnichar str[CHAR_BUFFER_SIZE];  PRUnichar* pstr = SubstituteChars(mDisplayUnicode,                           aString, aLength, str, CHAR_BUFFER_SIZE, &aLength);  if (!pstr) return 0;  SIZE size;  ::GetTextExtentPoint32W(aDC, pstr, aLength, &size);  if (pstr != str) {    delete[] pstr;  }  return size.cx;}