Folded sidebar does not work well with nojs

[ehuss]

Problem

If javascript is disabled, and the book has folding enabled, then the sidebar navigation works poorly with the collapsed chapters. In essence, if the active page is inside a folded group, it does not appear in the sidebar.

Here, the active page is inside one of the collapsed groups.

Steps

Have a book with folding enabled:

[output.html.fold]
enable = true
level = 0

Load the page without javascript, and try to navigate in the sidebar.

Possible Solution(s)

I'm wondering if the nojs iframe should completely disable folding?

Notes

No response

Version

mdbook v0.4.52 and mdbook v0.5.0-alpha.1