Luatex has changed mathcode to allow a larger numeric range however
changing TeX primitives without giving them new names seems suspect and
in this particular case, since \mathcode has changed but \mathchardef
has not the essential link between these two commands has been broken.
This has come to light (again) due to a latex bug report that the core
tools latex package bm is broken in lualatex
http://www.latex-project.org/cgi-bin/ltxbugs2html?pr=tools/4188
Searching with google suggests that several other packages notably
amsmath are similarly broken but workarounds have been provided on an ad
hoc basis.
Can this change be reversed and TeX primitives _not_ be changed in
incompatible ways.
\documentclass{article}
\mathchardef\matha\mathcode`a
\showthe\matha
\stop
produces
> 29025.
l.4 \showthe\matha
on systems compatible with TeX
on lulatex it produces:
$ lualatex bm99
This is LuaTeX, Version beta-0.70.1-2012042619 (rev 4277)
restricted \write18 enabled.
(./bm99.tex
LaTeX2e <2011/06/27>
LuaTeX adaptation of babel <v3.8l-luatex-1.4> and hyphenation patterns
for engl
ish, dumylang, nohyphenation, loaded.
(/usr/share/texmf-dist/tex/latex/base/article.cls
Document Class: article 2007/10/19 v1.4h Standard LaTeX document class
(/usr/share/texmf-dist/tex/latex/base/size10.clo))
! Invalid math code.
l.3 \mathchardef\matha\mathcode`a
David
