Re: Snippet 960 fails with Ly 2.25

[Thomas Morley]

Am Di., 2. Apr. 2024 um 00:21 Uhr schrieb K. Blum via bug-lilypond
<bug-lilypond@gnu.org>:
>
> Hello,
>
> LSR snippet 960 works alright with LilyPond 2.24.3 and earlier.
> Ly 2.25.1 (and later) aborts with an error message, see below.
> In the docs I haven't found any changes to the functions in use.
> Also tried convert-ly, but it did not change anything from the code.
> Am I missing something or is this a bug?
>
> Snippet 960: https://lsr.di.unimi.it/LSR/Item?id=960
>
> Here is a (not quite) MWE:
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> colorSpan =
> #(define-music-function (y-lower y-upper color)
>     (number? number? color?)
>     #{
>       \once \override HorizontalBracket.stencil =
>       $(lambda (grob)
>          (let* (
>                  (area (ly:horizontal-bracket::print grob))
>                  (X-ext (ly:stencil-extent area X))
>                  (Y-ext (ly:stencil-extent area Y)))
>            (set! Y-ext (cons y-lower y-upper))
>            (ly:grob-set-property! grob 'layer -10)
>            (ly:make-stencil (list 'color color
>                                   (ly:stencil-expr (ly:round-filled-box
> X-ext Y-ext 0))
>                                   X-ext Y-ext))))
>       \once\override HorizontalBracket.Y-offset = #0
>     #})
>
> \score {
>    {
>      \colorSpan #-4 #4 #green
>      c'2\startGroup g' c'\stopGroup r
>    }
>    \layout {
>      \context {
>        \Voice
>        \consists "Horizontal_bracket_engraver"
>      }
>    }
> }
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>
> The error message from Ly 2.25.1 reads:
> -----------------------------------
> Starte lilypond.exe 2.25.1 [mwe.ly]...
> »C:/Users/Flower/AppData/Local/Temp/frescobaldi-0hwxag11/tmp9kixmwyv/mwe.ly«
> wird verarbeitet
> Analysieren...
> Interpretation der Musik...
> Vorverarbeitung der grafischen Elemente...
> Ideale Seitenanzahl wird gefunden...
> Musik wird auf eine Seite angepasst...
> Systeme erstellen...
> C:/Portable/lilypond-2.25.1/share/lilypond/2.25.1/ly/init.ly:64:2:
> Fehler: Guile signaled an error for the expression beginning here
> #
>   (let ((book-handler (if (defined? 'default-toplevel-book-handler)
> In procedure cadddr: Wrong type (expecting pair): ()
> Wurde mit dem Return-Code 1 beendet.
>

Fixed in LSR.
Works now for 2.24 and 2.25

Cheers,
  Harm