Using "custom" LaTex commands generates extra spacing in bullet lists

[tvatter]

I'm trying to use custom LaTeX commands defined via \newcommand in bullet lists (e.g., custom math symbols or colors). However, when using such commands in Quarto, extra spacing is added when rendering the PDF. See below a MWE.qmd, where the included LaTeX header only contains \newcommand\donothing[1]{#1}:

---
title: "MWE"
format: 
    pdf:
        include-in-header: header.tex
---

No extra spacing:

* foo
* bar

Using `\newcommand\donothing[1]{#1}` creates extra spacing:

* \donothing{foo}
* bar

Adding text after `\donothing` suppresses the extra spacing:

* \donothing{foo} LOL
* bar

This stays true when the text following the extra spacing is commented out:

* \donothing{foo} <!-- LOL -->
* bar

What am I doing wrong? Is there an easy solution that I'm missing?

[cscheid]

You can try `\donothing{foo}`{=latex}, which is Pandoc's syntax for a RawInline node. You might also find the keep-tex: true YAML option useful for debugging intermediate .tex code.

[remlapmot]

Using `\donothing{foo}`{=latex} seems to be a good fix.

For a reason I cannot explain, the original code causes Pandoc to omit a \tightlist from the itemize environment, which causes the extra spacing. Whereas with this, and the other methods found, the itemize environment is given a \tightlist. To see this, rendering the original version with keep-tex: true, the .tex file shows

\begin{itemize}
\item
  \donothing{foo}
\item
  bar
\end{itemize}

Whereas, rendering with keep-tex: true and using `\donothing{foo}`{=latex}, the .tex file shows

\begin{itemize}
\tightlist
\item
  \donothing{foo}
\item
  bar
\end{itemize}