Book 404 page does not include book navbar preventing navigation

[cderv]

Discussed in #9988

^{Originally posted by meierluk June 13, 2024}

Description

It would be nice if a custom 404.qmd would automatically inherit all the properties of the corresponding book project, i.e., render with the navbar etc. (as seems to have been the case with bookdown).

---

From #9988 (comment)

If I use the (only-slightly edited) book template, I get this 404.html, compare with the standard book layout.

The source is available on github.com/meierluk/quarto-test/.

[cderv]

I can confirm that this is same issue as others we have. The commit which breaks this is ff820aa with the change regarding sidebar

• sidebar with single sidebar entry gets shown across entire website #5689

Same cause than

• Sidebar not displayed if no Quarto document #9242
• Sidebar not loading properly in new version, works in old version #9728

which were supposed to be solved by

• Correctly detect a global sidebar and not a specific page sidebar #9741

But it was not a good fix as it broke complex website

So still ongoing work at

• Correctly detect a global sidebar and not a specific page sidebar  #9966

Our global sidebar logic seems to be broken, and only pages identified in sidebars gets one.