Positron cannot recognize slides with multiple `column` environment correctly

[DavisVaughan]

Bug description

Transferred from posit-dev/positron#6802

System details:

Positron and OS details:

Positron Version: 2025.03.0 (user setup) build 116
Code - OSS Version: 1.96.0
Commit: 7f0f93873e8b24c9f393bb3586724f4783c5e72c
Date: 2025-03-01T19:05:24.180Z
Electron: 32.2.6
Chromium: 128.0.6613.186
Node.js: 20.18.1
V8: 12.8.374.38-electron.0
OS: Windows_NT x64 10.0.26100

Interpreter details:

R 4.5.0

Describe the issue:

When adding multiple columns environment, Positron cannot recognize later sections. The code chunk cannot be executed, either.

The following codes create a minimal reproducible example: in which the sections after # C do not shown in the OUTLINE, but everything shows well in Rstudio. See the comparison of the screenshots below:

Steps to reproduce the issue:

---
title: "Untitled"
format: html
---

# A

## B

:::: {.columns}

::: {.column width="40%"}
left

::: {.fragment}
body
:::
:::

::: {.column width="30%"}
right
:::

::: {.column width="30%"}
right
:::


::::

## B

:::: {.columns}

::: {.column width="40%"}
left

::: {.fragment}
body
:::
:::

::: {.column width="30%"}
right
:::

::: {.column width="30%"}
right
:::


::::

## B

:::: {.columns}

::: {.column width="40%"}
left

::: {.fragment}
body
:::
:::

::: {.column width="30%"}
right
:::

::: {.column width="30%"}
right
:::


::::

## B

:::: {.columns}

::: {.column width="40%"}
left

::: {.fragment}
body
:::
:::

::: {.column width="30%"}
right
:::

::: {.column width="30%"}
right
:::


::::

## B

:::: {.columns}

::: {.column width="40%"}
left

::: {.fragment}
body
:::
:::

::: {.column width="30%"}
right
:::

::: {.column width="30%"}
right
:::

::::

# C

## D

```{r}
"hello world"
```

Expected or desired behavior:

Make positron show the outline correctly and make the chunks executable.

Steps to reproduce

No response

Actual behavior

No response

Expected behavior

No response

Your environment

No response

[juliasilge]

@sammo3182 you need a bit more whitespace here, and then it will work:

We are noticing that folks may not be aware of the fact that pandoc markdown requires these kinds of empty lines, as specified here:

https://pandoc.org/MANUAL.html

We have quarto-dev/quarto-cli#12255 logged to improve the documentation around this and plan to improve our parsing of markdown. In the meantime, as a workaround, if you see problems like this, check your whitespace usage.

[cderv]

We are noticing that folks may not be aware of the fact that pandoc markdown requires these kinds of empty lines, as specified here: pandoc.org/MANUAL.html

@juliasilge I don't think Pandoc requires empty space after divs inside nested divs

❯ quarto pandoc --to native
::: A
::: B
:::
:::
^Z
[ Div ( "" , [ "A" ] , [] ) [ Div ( "" , [ "B" ] , [] ) [] ]
]

We correctly got two divs.

It does require it before an after main one.

This wouldn't work

Content
::: A
::: B
:::
:::
Content

but this is not Div-specific—it is about the Paragraph / Block definition in Markdown. Before a new block, there needs to be a new empty line.

So the problem is definitely in the Quarto VS Code extension that does not handle nested div the same.