[XeTeX] Discretionary hyphens don't work in paragraphed footnotes

[Philip Taylor]

Zdenek Wagner wrote:

> I have no time to look deep into it but does anybody know what is the
> definition of \- if these packages is used? Isn't is possible that it is
> a fragile macro? I remember one thing from Phil Taylor's tutorial held
> on EuroTeX'92 in Prague. He said that the most frequent error is wrong
> timing of expansion. Is it possible that \- is redefined in such a way
> that it disappears somewhere during expansion of \footnote before t is
> typeset?

More than possible :-(  Why /does/ LaTeX have to meddle so ?!

\-::macro:->\x at protect \-\protect \-

Try :

% !TeX Program=XeLaTeX
\documentclass[a4paper]{article}
\usepackage{fontspec}
\usepackage[para]{footmisc}
\begin{document}
\def \-{\discretionary {}{}{}}
\footnote{XXXXXXXXXXXXXX just a few normal words to fill up the line
  up to my x x x hy\-phe\-n\nobreak a\-te\-me }
\end{document}

** Phil.