\textarab with faulty optional parameter

[pcdi]

If you call \textarab{} with empty brackets (\textarab[]{some text}) or with an unknown option (\textarab[foo]{some text}), it will yield the following error message:

Undefined control sequence.
<write> ...\ not defined, defaulting to \@ax@mode 
                                                  \on@line .^^J
l.7 \textarab[foo]{some text}

and consequently abort the compilation process.

I think the bug is on line 321 of arabxetex.sty for \textarabic{} and parallel passages for the other languages, which is

\PackageWarning{arabxetex}{Mode \@tempa\ not defined, defaulting to \@ax@mode}%

where I think should be

\PackageWarning{arabxetex}{Mode \@tempa\ not defined, defaulting to \ax@mode}%

that is, no @ in front of the \ax@mode. Removing the @ will throw the warning but let the document compile nonetheless with the default \ax@mode, as I see it.