Braces are incorrectly escaped in LaTeX package class options

[rrthomas]

Explain the problem.

When I provide the following in a YAML block:

geometry:
  - papersize={12in,12in}

The braces are escaped in LaTeX, which causes LaTeX to fail. I can work around this particular case by using paperwidth and paperheight, but there will be cases for which there isn't a workaround.

I'm not sure if this issue is related to #9262, but the solution there doesn't work for this case.

Minimal example:

Markdown input:

---
geometry:
  - papersize={12in,12in}
---

Hello.

pandoc invocation:

$ pandoc --standalone foo.md --output=foo.tex
$ grep geometry foo.tex
\usepackage[papersize=\{12in,12in\}]{geometry}

Pandoc version?

3.6.4.

Thanks for pandoc!

[bpj]

You need to mark it explicitly as raw LaTeX or it will be parsed as Markdown:

---
geometry:
  - |
      ```{=latex}
      papersize={12in,12in}
      ```
---

(NB: I may have got the indentation wrong above!)

You can also put it in the metadata or variables section of a defaults file, in which case it is parsed as raw text rather than Markdown, so no extra markup is needed in that case.

[rrthomas]

Thanks! It's not obvious that a LaTeX setting in a YAML block would be parsed as Markdown; is there something I missed in the docs?

[jgm]

Yes: https://pandoc.org/MANUAL.html#extension-yaml_metadata_block
"Metadata will be taken from the fields of the YAML object and added to any existing document metadata. Metadata can contain lists and objects (nested arbitrarily), but all string scalars will be interpreted as Markdown."

You can also put it in the metadata or variables section of a defaults file, in which case it is parsed as raw text rather than Markdown, so no extra markup is needed in that case.

To correct this a bit: in variables it will come through in the output just as written.
But in metadata it will be interpreted as plain text, which means that [ will still be escaped in LaTeX.

[rrthomas]

Many thanks for the pointer, and apologies for the already-covered question (and non-issue!).