if (!mXftFont && !GetXftFont()) return NS_ERROR_NOT_AVAILABLE;
NS_PRECONDITION(mXftFont, "FindFont should not return bad fonts");
nsFontXftCustom::SetFT_FaceCharmap(void){    if (!mXftFont && !GetXftFont())            return NS_ERROR_NOT_AVAILABLE;    if (mFT_Face)        return NS_OK;    mFT_Face = XftLockFace(mXftFont);    NS_ENSURE_TRUE(mFT_Face != nsnull, NS_ERROR_UNEXPECTED);    // Select FT_Encoding to use for custom narrow fonts in     // glyph index look-up with FT_Get_Char_Index succeeds.            if (FT_Select_Charmap (mFT_Face, mFontInfo->mFT_Encoding))        return NS_ERROR_UNEXPECTED;    return NS_OK;}