1.6 Typst CSL problems with character escaping

[cscheid]

See #11364 (comment)

[gordonwoodhull]

To be clear, this isn't a regression; this is something that happens with any path specified in metadata, and csl is a new feature for Typst in Quarto 1.6 / bbcf429

Prior to that commit, I can produce the same bug for bibliography by renaming literatur.bib to _literatur.bib

Oddly, using a pandoc-native raw block in the metadata

bibliography: '`Str "_literatur.bib"`{=pandoc-native}'

still produces the same backslashing error, but using a Typst raw block works:

bibliography: '`_literatur.bib`{=typst}'

It's even worse if I rename the file _literatur_.bib:

bibliography: _literatur_.bib

produces

#bibliography("#emph[literatur];.bib")

[cscheid]

Huh, this is a Pandoc "bug", or at least surprising behavior.

Edit: It's also independent of formats, happening in typst, latex, html, and native.

test.md

---
csl: _literatur_.bib
---

## Hello.
```

```
$ touch _literatur_.bib
$ pandoc -f markdown -t typst test.md -o out.pdf --citeproc
File literatur.bib not found in resource path
```

Note `literatur` instead of `_literatur_`.

```
$ touch literatur.bib
$ pandoc -f markdown -t typst test.md -o out.pdf --citeproc
CiteprocXMLError: Missing root element
```

[cscheid]

Searching on the Pandoc repo brings me to this discussion, where we eventually find my own comment about the issue. My interpretation of JGM's comments is he doesn't consider this a bug, and the recommendation is to wrap paths. Because of YAML syntax, this ends up eventually becoming very ugly, and requiring something like '`_bibliography_.bib`'.

At the risk of adding another Quarto-vs-Pandoc inconsistency, I think this is another reason for Quarto to do a schema-directed translation from Quarto's YAML to Pandoc's YAML, where we find

csl: _bibliography_.bib

and convert it to a safe YAML entry, however ugly it is. (I still need to understand why the pandoc-native technique doesn't work...)

[cderv]

I just wanted to add that csl: field is an alias to bibliographystyle: in Typst, and this is to specify the styling of the bibliography, not to pass the bib file itself. bibliographystyle is undocumented variable in Pandoc's Manual to pass built-in styling, and csl is the usual way to set style with Pandoc citeproc which is now supported with typst.

So passing a bib file to csl will lead to other bug. Just wanted to clarify the reprex above.

Now, I wanted to share that I don't have the issue on windows 🤔

• CSL from the web

   curl -o _chicago.csl https://www.zotero.org/styles/chicago-fullnote-bibliography

• bib file created using knitr knitr::write_bib("knitr", file = "_references.bib") in R for convenience.
  content being

   @Manual{R-knitr,
     title = {knitr: A General-Purpose Package for Dynamic Report Generation in R},
     author = {Yihui Xie},
     year = {2025},
     note = {R package version 1.49.4},
     url = {https://yihui.org/knitr/},
   }

• Markdown content

   ---
   title: "test"
   format: typst
   bibliography: _references.bib
   csl: _chicago.csl
   keep-typ: true
   ---
   
   See @R-knitr
   
   Bib: {{< meta bibliography >}}  
   
   Bib: {{< meta csl >}}

I don't get an error

and I get the following content

See #cite(<R-knitr>, form: "prose")

Bib: \_references.bib

Bib: \_chicago.csl

 
  
#set bibliography(style: "\_chicago.csl") 


#bibliography("\_references.bib")

Not sure why it works on my side 🤔

[cderv]

Definitely a windows difference that using \ works... 🤷 I can see the error on linux. So odd...

Reproducible example is also with user's repo

gh repo clone produnis/minimal_examples
cd minimal_examples
git checkout quartotypstcsl2
quarto render template.qmd

I wanted to understand why it was not a problem for me

[cderv]

(I still need to understand why the pandoc-native technique doesn't work...)

Regarding, I think it does not work, because we are trying to avoid escaping in the Writer and no in the Reader

So using Typst raw inline works correctly, but pandoc-native trick has no effect on the Writer. It only prevent the YAML field to be parsed as Markdown at reading time.

❯ pandoc -f native -t typst
Str "_literatur.bib"
^Z
\_literatur.bib

We do need raw inline here.

[cderv]

so maybe we can enforce this for known field that should have any markdown in them.
bibliography and csl are among them I would say. We could enforce Raw inline for those from Lua.

Otherwise, we could do this only for some known set of characters that would be escaped by writes

• if _ in bibliography, then we wrap the Meta as Raw Inline. Otherwise, we do not.

The former seems safer, and ok to do even if this is a strong rule difference from Quarto compared to pandoc in this case.