[luatex] \mathchardef (again)

[David Carlisle]

Hi,

the last few releases have had some iterations in the handling of
\mathchar tokens, but unfortunately it's still broken in 0.89.2, the
latex format and core packages such as amsmath and bm really need to
be able to interrogate the \meaning of symbols and
\meaning on a \mathchar is currently not usable.

\mathchardef\alpha="010B % plain tex definintion
\show\alpha

\bye

produces

 \alpha=\Umathchar"0"00"00010B.


whereas the equivalent \Umathchar should be

 \alpha=\Umathchar"0"01"00000B.

Presumably the internal mathchar to Umathchar conversion is showing
fam =0 and appending the fam digits to the character slot?

David