[texinfo.tex version 2023-08-13.14]
Please consider the attached files. If I say
```
luatex foo.texinfo
```
the `@tex` environment within this file works just fine, and file
`foo.lua` is correctly loaded. However, saying
```
luatex bar.texinfo
```
which includes file `bar.itexi`, I get an error:
```
(./bar.itexi[\directlua]:1: ')' expected near '@'.
l.5 dofile(kpse.find_file("bar.lua")) }
```
AFAICS, there is a problem with the handling of underscores in
included files that contain a `@tex` environment, having the wrong
catcode.
Werner
\input texinfo
@tex
\ifx\luatexversion\thisisundefined
\else
\directlua{
dofile(kpse.find_file("foobar.lua")) }
\fi
@end tex
foobar
@bye
local foo = "bar"
\input texinfo
@include bar.itexi
foobar
@bye
@tex
\ifx\luatexversion\thisisundefined
\else
\directlua{
dofile(kpse.find_file("bar.lua")) }
\fi
@end tex
local foo = "bar"
