\documentclass{article}
\begin{document}\small
\begin{enumerate}
\renewcommand{\labelenumi}{(\arabic{enumi})}
\item An item.
\end{enumerate}
\end{document}
TeX is very user-friendly in this case by dropping all white-space
after the opening of the enumerate environment and
skipping over non-text generation code up to the first \item.
Here is a minimal example:
TeX is very user-friendly in this case by dropping all white-space after the opening of the
enumerate
environment and skipping over non-text generation code up to the first\item
.Found by xmllint.