[XeTeX] \meaning on a \csname \let to a character

[David Carlisle]

In a similar thread ,\meaning or \show  on a mathchardef'ed character
such as \sumop

in xetex gives

\sumop=\XeTeXmathchar"202211

in luatex

\sumop=\Umathchar"1"00"002211.

the luatex version looks distinctly odd but is legal input.

With the xetex version if you input it

! Bad math class (2105873).
<to be read again>
                   $
l.15 $\XeTeXmathchar"202211$

It needs to be input as \XeTeXmathcharnum (or to use the 3 number
version as in luatex)

This means that if you write the \meaning out to a file and later read
it back  (or you use \scantokens or similar processing) you have to
fix up the input which isn't impossibly difficult but unexpected (and
makes it harder to work with both engines)

Perhaps this is changed in the development version already? If not,
any chance it could be?

Thanks,

David