toc, \with-link and `bookpart-level-page-numbering'

[Thomas Morley]

Hi,

please consider the following code:

\version "2.25.13"

\paper {
  print-first-page-number = ##t
  bookpart-level-page-numbering = ##t
}

\book {
  \bookpart { \markuplist \table-of-contents }
  \bookpart {
    \paper { page-number-type = #'roman-upper }
    \tocItem \markup "Text"
    \markup { Lorem ipsum dolor sit amet. }
  }
  \bookpart {
    \tocItem \markup "Music"
    { b }
  }
}

Imho, there are two issues here
a) the intern links of the toc are all not working correctly, more
precisely, they all point to page 1 of the resulting pdf.
b) I'd prefer if the toc would print the page-number as formated in
the bookparts, i.e. for "Text" as roman capital.

`bookpart-level-page-numbering' was implemented with

commit 4e2ebc31eb79319c6914fe5e5c1836d5e873d3ee
Author: Jean Abou Samra <jean@abou-samra.fr>
Date:   Tue Aug 9 10:23:37 2022 +0200

    Add bookpart-level-page-numbering paper variable

    If bookpart-level-page-numbering is set to #t, bookparts have
    independent sequences of page numbers.  This can be useful if
    publishing a set of instrumental parts that are joint in a single
    book, perhaps with a common introduction, but intended to be used
    separately. Furthermore, setting this variable only for the first
    bookpart in conjunction with page-number-type can be used to number
    pages in the introductory material with separate numbering and in
    roman numbers, which is common practice.

    Fixes #6396

If I understand correctly (and my cc-knowledge is more or less zero)
the change in paper-book.cc overrides the real page-number, meaning
\with-link only sees the new value.
I found no workaround...

How about implementing some logic like current-page-number vs
internal-page-number like we have with currentBarNumber and
internalBarNumber?
The page-number in toc could then be printed as current-page-number
but point to internal-page-number.

Thanks,
  Harm

P.S. I didn't write about formating the toc (the second point above),
worth another thread...