Fenced inline code not rendered properly at start of line

[elenlefoll]

I have:

• searched the issue tracker for similar issues
• installed the latest version of Quarto CLI
• formatted my issue following the Bug Reports guide

Bug description

Fenced inline code does not render properly when at the start of a line.

Steps to reproduce

---
title: "Issue with fenced inline code at beginning of line"
date: last-modified
---

For teaching materials explaining how to use insert inline code, I would like to display source code demonstrating how to use inline code in the rendered version of a Quarto document. Here's an example below:

``` markdown
## Inline code demo

`{{r}} nrow(penguins)` penguins are included in the amazing `penguins` dataset. 
On average these penguins weigh `{{r}} mean(penguins$body_mass, na.rm = TRUE)` grams, although the lightest weighs `{{r}} min(penguins$body_mass, na.rm = TRUE)` g and the heaviest `{{r}} max(penguins$body_mass, na.rm = TRUE)` g.
```

When the paragraph above is rendered, the inline code snippets are all correctly rendered as fenced code except the first one that retains its double curly brackets (see screenshot).

The workaround I have found is to add an empty character at the start of the paragraph, but this is less than ideal.

``` markdown
## Example fenced inline code that should be fenced

 `{{r}} nrow(penguins)` penguins are included in this amazing dataset. 
On average they weigh `{{r}} mean(penguins$body_mass, na.rm = TRUE)` grams, though the lightest weighs `{{r}} min(penguins$body_mass, na.rm = TRUE)` g and the heighiest weighs `{{r}} max(penguins$body_mass, na.rm = TRUE)` g.
```

Actual behavior

Inline code snippets are correctly rendered except those that are at the start of a line which retain its double curly brackets.

Expected behavior

All inline code snippets should be rendered with {r}.

Your environment

• IDE: RStudio Version 2026.01.1+403 (2026.01.1+403)
• MacOS Sequoia 15.4.1 (24E263)

Quarto check output

Quarto 1.9.30
[✓] Checking environment information...
Quarto cache location: /Users/lefoll/Library/Caches/quarto
[✓] Checking versions of quarto binary dependencies...
Pandoc version 3.8.3: OK
Dart Sass version 1.87.0: OK
Deno version 2.4.5: OK
Typst version 0.14.2: OK
[✓] Checking versions of quarto dependencies......OK
[✓] Checking Quarto installation......OK
Version: 1.9.30
Path: /Applications/quarto/bin

[✓] Checking tools....................OK
TinyTeX: v2025.11
Chromium: (not installed)
Chrome Headless Shell: (not installed)
VeraPDF: (not installed)

[✓] Checking LaTeX....................OK
Using: TinyTex
Path: /Users/lefoll/Library/TinyTeX/bin/universal-darwin
Version: 2025

[✓] Checking Chrome Headless....................OK
Using: Chrome found on system
Path: /Applications/Google Chrome.app/Contents/MacOS/Google Chrome
Source: MacOS known location

[✓] Checking basic markdown render....OK

[✓] Checking R installation...........OK
Version: 4.5.2
Path: /Library/Frameworks/R.framework/Resources
LibPaths:
- /Library/Frameworks/R.framework/Versions/4.5-arm64/Resources/library
knitr: 1.51
rmarkdown: 2.30

[✓] Checking Knitr engine render......OK

[✓] Checking Python 3 installation....OK
Version: 3.12.8 (Conda)
Path: /Users/lefoll/miniconda3/bin/python
Jupyter: (None)

  Jupyter is not available in this Python installation.
  Install with conda install jupyter

[✓] Checking Julia installation...

[mcanouil]

Important

Accessibility: To improve accessibility, please add alternative text to your screenshots. This helps all users, including those using screen readers, to understand the context of the images. A brief description can make a big difference! See Good Alt Text, Bad Alt Text — Making Your Content Perceivable.

[mcanouil]

To be clear by "rendered properly" you mean {{r}} is rendered as-is instead of {r}, in other words, the inline code escaping remains, correct?

Input	Output
--- format: html engine: markdown --- `` `{{python}} nrow(penguins)` `` ``` `{{python}} nrow(penguins)` ```

[elenlefoll]

Yes, that is what I mean. The expected behaviour is that the double curly brackets should not remain on rendering.

[elenlefoll]

Important

Accessibility: To improve accessibility, please add alternative text to your screenshots. This helps all users, including those using screen readers, to understand the context of the images. A brief description can make a big difference! See Good Alt Text, Bad Alt Text — Making Your Content Perceivable.

Alt-text added ✅

[cscheid]

I think this is a regression from #14162.

[cscheid]

Huh, this not a regression! It's a coincidence that I recently touched this code, and it has a bug we hadn't caught so far.

[elenlefoll]

I think this is a regression from #14162.

I'm not sure I'm interpreting your comment correctly, but I should point out that I've been aware of this issue for many months (more like at least a year). I just never got round to reporting it because I thought my workaround was okay, but my students have started to notice the problem, too. (typed before I saw your next post - sorry)

[cscheid]

@elenlefoll I recently made a change to the buggy code, and since you're running the 1.9.30 release candidate, I spoke too soon, assuming my change was to blame and it was a regression. It's "just" a regular bug, though! We're on it.

[cscheid]

PR is up. I'm a little reluctant to merge this for 1.9. It's a long-standing bug that wasn't caused by one of our 1.9 changes and we're in release-candidate mode. Typically, this would mean we would keep the fix into 1.10 to avoid thrashing.

[elenlefoll]

I understand. Thanks a lot for looking into this so quickly!