Arithmetic overflow with fontspec and LuaTeX

Question

I have the following code using this font:

\documentclass{minimal}

\usepackage{lettrine}
\usepackage{fontspec,xunicode}

\newfontfamily\EBLettrineFont{EBGaramondInitialsF2}
\renewcommand{\LettrineFontHook}{\EBLettrineFont}

\begin{document}

\lettrine{T}{his} is a test


\end{document}

It works fine with xelatex, but crashes with lualatex:

! Arithmetic overflow.
\LettrineFont ...\divide \@tempcnta by \@tempcntb 
                                                  \advance \@tempcnta by -99...
l.11 \lettrine{T}{his}
                       is a test
? 

What is wrong?

Answer 1

The lettrine package depends on the font having the character X in order to perform its calculations; and this font, it seems, does not have the character. The lettrine macro in question is \LettrineFont. It constructs a box containing the X in a given font and then measures its height. For this font and this character, LuaTeX reports a box height of 0 pt. A following integer division then fails.

Strictly speaking, the lettrine assumption is fair and the font is at fault for not providing even a minimal set of characters. If you still want to use this font, the easiest way is to modify \LettrineFont to use a character that exists in this font, such as O:

\documentclass{minimal}

\usepackage{lettrine}
\usepackage{fontspec,xunicode}
\usepackage{etoolbox}

\newfontfamily\EBLettrineFont{EBGaramondInitialsF2}
\renewcommand{\LettrineFontHook}{\EBLettrineFont}

\patchcmd{\LettrineFont}{\selectfont X}{\selectfont O}{}{%
  \GenericWarning{}{Patching \protect\LettrineFont\space failed}}

\begin{document}

\lettrine{T}{his} is a test

\end{document}

XeTeX, unlike LuaTeX, returns the height of nonexistent X as 8.10722 pt with this example code, and therefore division by zero does not occur.