[luatex] 'Out by one' error (?) in \csname messages

[Heiko Oberdiek]

On 06.06.2014 17:46, luigi scarso wrote:
> 
> On Fri, Jun 6, 2014 at 5:33 PM, Joseph Wright
> <joseph.wright at morningstar2.co.uk
> <mailto:joseph.wright at morningstar2.co.uk>> wrote:
> 
>         \csname\csname\endcsname
> 
>     leads to the error
> 
>         ! Missing \endcsname inserted.
>         <to be read again>
>         \^^@csnam\^^@endcsnam
>         l.1 \csname\csname\endcsname
> 
>     which looks like some form of 'out by one' issue.

> I have the same with pdftex

> ! Missing \endcsname inserted.
> <to be read again> 
>                    \csname\endcsname
> l.2 \csname\csname\endcsname

I think, Joseph is referring to the messed up error message in LuaTeX.

The error itself is correct. Usually `\csname\endcsname` is an undefined
command becoming `\relax` which breaks the first `\csname`.

Yours sincerely
  Heiko Oberdiek