`\if@hyper@item` it not reset after an item with optional argument

This leads to wrong destination names (and so can affect autoref), but the links should be okay, so not a serious problem.

see also https://tex.stackexchange.com/q/586551/2388

\documentclass[11pt]{article}
\usepackage{hyperref}
\usepackage{xpatch}
\begin{document}

\newcounter{test}
Some text \makeatletter
\begin{enumerate}
\item   \if@hyper@item true \else false \fi
 \refstepcounter{test}\label{a}
\item[a] \if@hyper@item true \else false \fi 
 \refstepcounter{test}\label{b}
\end{enumerate}

\xpatchcmd\@item{\ignorespaces}{\@hyper@itemfalse\ignorespaces}{}{\fail}

\begin{enumerate}
\item   \if@hyper@item true \else false \fi
\refstepcounter{test}\label{c}
\item[a] \if@hyper@item true \else false \fi
\refstepcounter{test}\label{d}
\end{enumerate}

\end{document}

\newlabel{a}{{1}{1}{}{test.1}{}}
\newlabel{b}{{2}{1}{}{Item.2}{}}
\newlabel{c}{{3}{1}{}{test.3}{}}
\newlabel{d}{{4}{1}{}{test.4}{}}

Start by compiling the minimal document from the issue and inspect the behavior of \if@hyper@item around \item and \item[a]. Use the @item entry point and compare the generated .aux labels for a, b, c, and d. Done means the state is reset after an optional item argument so later destinations no longer receive the wrong name.