[lltx] [luatex] fontspec prevents hyphenation

[Khaled Hosny]

On Sun, Nov 28, 2010 at 12:05:01PM +0100, Taco Hoekwater wrote:
> Hi,
> 
> On 11/22/2010 01:22 PM, Taco Hoekwater wrote:
> >>
> >>Would you be so kind to fix this?
> >
> >The problematic case seems to be: a combination of a non-letter in one
> >font, followed by a letter in another font. LuaTeX does not consider
> >that a valid word start. I will add an item to the tracker database.
> 
> That was a bad analysis. The bug is not in luatex at all, it is a bug
> in fontspec.  Some input like
> 
>   (\emph{hyphenation})
> 
> in fontspec produces the following low-level node list
> 
>   ( \/ h y p h e n a t i o n \/ )
> 
> and the "\/ h" combination is not a valid word start (the second italic
> correction is fine, the first one is the problem).
> 
> In this, luatex is compatible with TeX itself, you can try
> 
>   \showhyphens{(\/hyphenation\/)}
> 
> in plain TeX to see the thing happening (same lack of hyphenation).
> 
> Closing the luatex tracker item,

It seems deeper than fontspec, either in luaotfload or something deeper
inside latex. This gives the same result:

\documentclass{article}
\usepackage{luaotfload}
\usepackage[EU2]{fontenc}
\usepackage[width=2cm]{geometry}

\begin{document}
An intere\textit{st}ing word.

An intere{\itshape st}ing word
\end{document}

-- 
 Khaled Hosny
 Arabic localiser and member of Arabeyes.org team
 Free font developer