[XeTeX] New version of xetex

[Stefan Solbrig]

>> That is reasonable.  I will follow your suggestion. Something like  
>> this?
>>
>> \edef\XeTeXVersionNumber{{\expandafter\@gobble\XeTeXrevision}
>> \ifnum\XeTeXVersionNumber<99992
>>  <old xetex code>
>> \else
>>  <new xetex code>
>> \fi
>
> Not sure about that snippet, but I usually use the more generic:
>
> \ifdim\number\XeTeXversion\XeTeXrevision in<0.99992in


For five-digit revsion numbers, they are equivalent,
but if \XeTeXrevision will contain a digit more,
the latter code might fail in certain cases
due to rounding in TeX's fixed point arithmetic.
(See example below, which yields
"ifdim not less"   and  "ifnum less".)

\newcount\myversion\myversion=0
\edef\myrevision{.999991}

\ifdim\number\myversion\myrevision in < 0.999992 in
ifdim less\message{^^Jifdim less^^J}\else
ifdim not less\message{^^Jifdim not less^^J}\fi

\def\mygobble#1{}
\edef\myrevno{\expandafter\mygobble\myrevision}

\ifnum\myrevno < 999992
ifnum less\message{^^Jifnum less^^J}\else
ifnum not less\message{^^Jifnum not less^^J}\fi

best,
Stefan