problem to code page-numbers

[Thomas Morley]

Hi,

I'm trying to put out a \book, affecting the page-numbers in a certain way.
Ofcourse this should happen under certain conditions.

Look at the minimal example below.
All I try to affect is the `counter', if the page is the last of the bookpart.
I had expected that the counter would get up to 3 (starting at 1 and
two bookparts having a last page)
Instead it goes up to 9.

No idea why it's called nine times.

\version "2.19.24"

#(define counter 1)

#(define (test layout props arg)

    (if (chain-assoc-get 'page:is-bookpart-last-page props #f)
        (set! counter (1+ counter)))

    (newline) (format #t "I'm called ~a. time" counter)

    (interpret-markup layout props arg))

\paper {
  print-first-page-number = ##t
  oddHeaderMarkup = \markup
  \fill-line { \on-the-fly #test \fromproperty #'page:page-number-string }
  evenHeaderMarkup = \markup
  \fill-line { \on-the-fly #test \fromproperty #'page:page-number-string }
}

\book {
  \bookpart { \repeat unfold 3 { d''1 \pageBreak } }
  \bookpart { \repeat unfold 4 { e''1 \pageBreak } }
}


Any hints?




Cheers,
  Harm