Il problema nasce caricando hyperref. Il seguente codice non compila.
`\documentclass[a4paper]{article}
\usepackage[latin1]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[italian]{babel}
\usepackage[]{MinionPro}
\makeatletter
\catcode`\'=12
\def\qu@te{'}
\catcode`'=\active
\begingroup
\obeylines\obeyspaces%
\gdef\@resetactivechars{%
\def^^M{\@activechar@info{EOL}\space}%
\def {\@activechar@info{space}\space}%
}%
\endgroup
\protected\def'{\relax
\ifmmode
\expandafter^\expandafter\bgroup\expandafter\prim@s
\else
\expandafter\futurelet\expandafter\@let@token\expandafter\qu@t@
\fi}
\def\qu@t@{%
\ifx'\@let@token
\qu@te\qu@te\expandafter\@gobble
\else
{}\qu@te{}\penalty\@M\hskip\expandafter\z@skip
\fi}
\scantokens\expandafter{%
\expandafter\def\expandafter\pr@m@s\expandafter{\pr@m@s}}
\makeatother
\usepackage{hyperref}
\begin{document}
%%====================================
\section{L'arte tipografica}
%%====================================
\end{document}`
L’errore riportato è:
`! Missing } inserted.`
togliendo l’apostrofo dal titolo, invece, tutto fila liscio. 😕
Ciao
Ivan