Q:

Unwanted space before Japanese bracket '「' in luatexja

I'm compiling a document with lualatex and luatexja.
If \item is followed by bracket symbol 「, then an unwant space is introduced.

Demo code:
\documentclass{article}
\usepackage{luatexja}

\begin{document}
\begin{itemize}
\item
  「」

  「」

\item
  日本語

  日本語

\item
  english

  english
\end{itemize}
\end{document}

Version:
This is LuaTeX, Version 0.95.0 (TeX Live 2016/Debian) \ProvidesPackage{luatexja-core}[2016/05/15 Core of LuaTeX-ja]
I also tried the version on git LuaTeX-ja OSDN.

A:

This is because there is a glue by \item before 「. Since “character class of a glue” is zero in the standard metric, a half-width space is inserted between a glue and 「.
To solve this issue, we can patch \@item, as in ltjsarticle.cls.
\def\@item[#1]{%
  (...)
    \else
      \clubpenalty \@clubpenalty
      \everypar{}%
    \fi
    \directlua{luatexja.jfmglue.create_beginpar_node()}% <-- !!! add !!!
  }%
  (...)
}

Or, do the same thing using \apptocmd:
\usepackage{etoolbox}
\makeatletter
\patchcmd{\@item}{\everypar{}\fi}
  {\everypar{}\fi\directlua{luatexja.jfmglue.create_beginpar_node()}}{}{}
\makeatother

