breadcrumbs only appear if title set in topmatter

[machow]

Bug description

The docs on breadcrumbs mention they will be displayed by default. It appears that when title: is not set in the top-matter, then they are not displayed.

Note that in this issue I'll refer to three possible meanings of title:

1. _quarto.yml sidebar text: title
2. qmd topmatter title
3. qmd header title

Currently, quarto requires (2) to be set. When this happens, (1) gets shown if set. Otherwise, (2) gets shown.

Steps to reproduce

_quarto.qmd

project:
  type: website

website:
  sidebar:
    - contents:
      - section: "Tutorials"
        contents:
          - text: Tutorial sidebar title
            href: tutorials.qmd

tutorial.qmd

---
# uncomment below to see breadcrumbs say "Tutorial sidebar title"
# title: Tutorial topmatter title
---

# Tutorial qmd first header

abc

Expected behavior

breacrumb for tutorial page should say "Tutorial sidebar title".

Actual behavior

No breadcrumb shown

Your environment

mac osx

Quarto check output

Quarto 1.5.56
[✓] Checking versions of quarto binary dependencies...
      Pandoc version 3.2.0: OK
      Dart Sass version 1.70.0: OK
      Deno version 1.41.0: OK
      Typst version 0.11.0: OK
[✓] Checking versions of quarto dependencies......OK
[✓] Checking Quarto installation......OK
      Version: 1.5.56
      Path: /Applications/quarto/bin

[✓] Checking tools....................OK
      TinyTeX: (not installed)
      Chromium: (not installed)

[✓] Checking LaTeX....................OK
      Tex:  (not detected)

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

[✓] Checking Python 3 installation....OK
      Version: 3.9.5
      Path: /Users/machow/.pyenv/versions/3.9.5/bin/python3
      Jupyter: 5.3.1
      Kernels: <removed>

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

[✓] Checking R installation...........OK
      Version: 4.1.2
      Path: /Library/Frameworks/R.framework/Resources
      LibPaths:
        - /Library/Frameworks/R.framework/Versions/4.1-arm64/Resources/library
      knitr: 1.39
      rmarkdown: 2.14

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

[cscheid]

Thanks. We've had similar bugs in the past, so this tracks.

Can you just confirm to me that you're not using both title: and a Header of level 1? It's not perfectly clear from your tutorial.qmd.

[machow]

The example uses both, but I think the bug is that the breadcrumb only works if title: is set. quartodoc unfortunately sets title via the h1 header (#), but I'm guessing that will need to change as a separate quartodoc issue 😭

[mcanouil]

@machow As a side note, I think quartodoc should set title as it is safer and more reliable in Quarto. h1 are no title by default. Quarto promotes the first header to title in some conditions/context.

[machow]

That makes sense, and I'll switch it over!

[cscheid]

Quarto's HTML is itself not identical depending on whether the title is specified on title: vs on an H1 header. That's a Quarto bug by itself, and it seems to be the cause of this bug.