Wrong title in revealjs when including a code block

[m-guggenmos]

Bug description

If the following two conditions are met, the title of a revealjs presentation is erroneously set to the heading of the first slide:

1. Using _quarto.yml to define the title
2. Including a block of code in one of the slides

Steps to reproduce

_quarto.yml

project:
  output-dir: _slides
  render:
    - test.qmd

title: "My title"
author: "John Doe"

format: revealjs

test.qmd

## First slide heading

```{python}

```

Expected behavior

The title on the title slide is "My title".

Actual behavior

The title on the title slide is "First slide heading".

Your environment

• VSCode version 1.80.1
• Quarto Extension v1.90.0
• OS: Ubuntu Linux

Quarto check output

[✓] Checking versions of quarto binary dependencies...
      Pandoc version 3.1.6: OK
      Dart Sass version 1.55.0: OK
      Deno version 1.33.4: OK
[✓] Checking versions of quarto dependencies......OK
[✓] Checking Quarto installation......OK
      Version: 1.4.251
      Path: /opt/quarto/bin

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

[✓] Checking Python 3 installation....OK
      Version: 3.10.12
      Path: /usr/bin/python3
      Jupyter: 5.3.1
      Kernels: python3

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

[✓] Checking R installation...........OK
      Version: 4.2.3
      Path: /usr/lib/R
      LibPaths:
        - ~/R
        - /usr/local/lib/R/site-library
        - /usr/lib/R/site-library
        - /usr/lib/R/library
      knitr: 1.42
      rmarkdown: 2.20

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

[cderv]

Thanks for the report. I can reproduce in a specific situation.

• It happens with Jupyter engine and not knitr engine

• It is not link to revealjs and it will also happen with format: html

• _quarto.yml

title: "My title"
author: "John Doe"

format: html

• index.qmd

## First slide heading

Some content

```{python}
1 + 1
```

title is correctly identified in the metadata

Starting python3 kernel...Done

Executing 'index.ipynb'
  Cell 1/1: ''...Done

pandoc 
  to: html
  output-file: index.html
  standalone: true
  section-divs: true
  html-math-method: mathjax
  wrap: none
  default-image-extension: png
  
metadata
  document-css: false
  link-citations: true
  date-format: long
  lang: en
  title: My title
  author: John Doe
  
Output created: index.html

but indeed the document move the ## as title, and overwrite it.

To me, this is a duplicated (or at least a variation) of

• First heading transformed to title when dynamic python content #5363

@dragonstyle I am assigning you on this as this is probably website related.
@cscheid I remember some discussion (but can't find it) about .qmd document for Jupyter with no title, and first header being used. So maybe you know where to look...

It seems here, we should at least consider the global title meta before using the ## as the title of the document.

[knuesel]

I think I have a fix for this but it requires a bit more work (just a note to avoid duplicating efforts).

[mcanouil]

Thank you @knuesel for letting us know and your future contribution!

[dragonstyle]

This is actually not fixed in the referenced commit (it is more specifically a project title being present and should be dealt with separately).