[Dev-luatex] additional argument to kpse.find_file?

[Elie Roux]

Hello,

I found that a problem in the mplib package was to find mpost.mem in 
TeXLive: It cant be found with kpse.find_file(). I can't be found 
neither with "kpsewhich --format mem --must-exist mpost.mem", but in 
TeXLive 2008, it can be found with "kpsewhich --format mem --engine 
metapost mpost.mem". The problem is that I can't pass the "engine" 
option to kpse.find_file(). Is it is possible to add it? I think it will 
benefit more packages than only mplib.

Thank you in advance,
-- 
Elie