Re: weird error writing a tablature which uses a custom tuning

[Thomas Morley]

Am Di., 24. Sept. 2024 um 01:04 Uhr schrieb Federico Bruni <fede@inventati.org>:
>
> Hi folks
>
> I've just come across a really weird error.
> I'll try to make a minimal example tomorrow, but maybe you can give me
> some hints.
> The piece I'm writing is copyrighted but I can send it privately to
> anyone who wants to help to debug this weird error. It uses a custom
> guitar tuning.
>
> I'm entering a music and suddenly whatever note I write after this:
>
> \acciaccatura a'8\3 b\3 g' b,\3( a\3)
>
> will produce the following error:
>
> Drawing systems...
> /app/dev/share/lilypond/2.25.19/ly/init.ly:66:2: error: Guile signaled
> an error for the expression beginning here
> #
>  (let ((book-handler (if (defined? 'default-toplevel-book-handler)
> In procedure ly:item-break-dir: Wrong type argument in position 1
> (expecting Item): ()
>
>
>
>
> And here's the verbose output running the official LilyPond binaries:
>
> /var/home/fede/.local/lilypond/lilypond-2.25.19/share/lilypond/2.25.19/ly/init.ly:66:2:
> error: Guile signaled an error for the expression beginning here
> #
>  (let ((book-handler (if (defined? 'default-toplevel-book-handler)
>
> In ice-9/boot-9.scm:
>   1755:12 15 (with-exception-handler _ _ #:unwind? _ # _)
> In unknown file:
>           14 (apply-smob/0 #<thunk 7f838110d300>)
> In
> /home/lily/lilypond-2.25.19/release/binaries/lilypond/build/out/share/lilypond/current/scm/lily/lily.scm:
>   1070:16 13 (lilypond-main _)
>    1099:4 12 (lilypond-all ("The-Pelican.ly"))
> In srfi/srfi-1.scm:
>     634:9 11 (for-each #<procedure 7f8381f68f30 at /home/lily/lilyp?> ?)
> In
> /home/lily/lilypond-2.25.19/release/binaries/lilypond/build/out/share/lilypond/current/scm/lily/lily.scm:
>    1111:9 10 (_ "The-Pelican.ly")
> In ice-9/boot-9.scm:
>   1749:15 9 (with-exception-handler #<procedure 7f8381f68f00 at ic?> ?)
> In unknown file:
>            8 (ly:parse-file "The-Pelican.ly")
> In ice-9/boot-9.scm:
>   1755:12 7 (with-exception-handler _ _ #:unwind? _ # _)
> In unknown file:
>            6 (apply-smob/0 #<thunk 7f83824388c0>)
>            5 (ly:book-process #<Book> #< Output_def> #< Output_def> #)
>            4 (ly:optimal-breaking #<Paper_book>)
> In
> /home/lily/lilypond-2.25.19/release/binaries/lilypond/build/out/share/lilypond/current/scm/lily/tablature.scm:
>    205:36 3 (tab-note-head::handle-ties #<Grob TabNoteHead >)
> In unknown file:
>            2 (ly:item-break-dir ())
> In ice-9/boot-9.scm:
>   1676:22 1 (raise-exception _ #:continuable? _)
> In unknown file:
>            0 (apply-smob/1 #<exception-handler 7f83824388a0> #<&comp?>)
> In procedure ly:item-break-dir: Wrong type argument in position 1
> (expecting Item): ()
>
>
>
>

Hi Federico,

commit 23a3778f2ed6a12b2e41026d3e6646f7177f0a29
Author: Thomas Morley <thomasmorley65@gmail.com>
Date:   Fri Jul 26 23:39:37 2024 +0200

    Rewrite handling of tied tab note heads

    If a tab note head is right bound of a tie (or has a repeat tie)
    and a spanner starts, always print it parenthesized.
    If a Tie is split, print the tied tab note head due to the
    settings of tied-properties.
    Same for a tied tab note holding a `RepeatTie`.

    This was already intended by the first implementation
    by 3417b5edd0596f128bc5faca6c600c3b11915709
    Though, using break-visibility for a note head made no sense.

    dcafb42fa6c1cf234a8916ec221a2b006d3582b9 deleted break-visibility,
    but introduced a regression.

    This patch rewrites most of the functionality:
    - extend the engraver, port it to scheme
    - introduce a new context-property tabFullNotation
    - introduce new sub-properties ties/repeat-tied, for
      TabNoteHead.details.tied-properties.
      Delete TabNoteHead.details.repeat-tied-properties.
    - Move functionality from (Repeat)Tie.after-line-breaking to
      TabNoteHead.after-line-breaking.
    - Extend tab-note-head interface
    - Adjust hide/showSplitTiedTabNotes

    Closes #6733


may have introduced the problem.
Though its hard to diagnose/fix without MWE.

As an experiment, try to change in tablature.scm the lines
         (nmpc (ly:grob-object pc 'left-neighbor))
         (at-line-begin? (positive? (ly:item-break-dir nmpc)))
to
         (nmpc (ly:grob-object pc 'left-neighbor #f))
         (at-line-begin? (and nmpc (positive? (ly:item-break-dir nmpc))))

Cheers,
  Harm