Re: \incipit sometimes returns programming error

[Thomas Morley]

Am Do., 26. Mai 2022 um 17:36 Uhr schrieb Jean Abou Samra <jean@abou-samra.fr>:
>
>
>
> Le 26/05/2022 à 17:12, Thomas Morley a écrit :
> > Hi,
> >
> > consider:
> >
> > \score {
> >    \new Staff \with { instrumentName = "" }  { \incipit { c'1. } R1 }
> >    \layout {
> >      indent = 5\cm
> >      incipit-width = 3\cm
> >    }
> > }
> >
> > with recent versions it returns:
> > programming error: Loose column does not have right side to attach to.
> >
> > First bad comit is:
> > commit 8ae26d8330c603d249fec5953a887de9fbcbe31c
> > Author: Dan Eble <nine.fierce.ballads@gmail.com>
> > Date:   Thu Mar 10 20:08:31 2022 -0500
> >
> >      Refactor BarLine engraving
> >      [...]
> >
> > Dan?
> >
> >
> > The example above can be fixed by inserting an explicit \bar "" at end
> > of incipit-music.
> >
> >
> > Cheers,
> >    Harm
>
>
> That looks like an old bug uncovered to me. \incipit
> uses a MensuralStaff, and indeed I can reproduce it
> with
>
> \version "2.23.10"
>
> \new MensuralStaff {
>    c'1.
> }
>
>
> The definition of MensuralStaff contains measureBarType = "",
> and this also triggers the bug:
>
> \version "2.23.10"
>
> \new Staff \with {
>    measureBarType = ""
> } {
>    c'1.
> }
>
> which is an instance of our old
>
> https://gitlab.com/lilypond/lilypond/-/issues/4084
>
> I can't tell why the commit "Refactor BarLine engraving" had that
> effect (and I'm not investigating). Dan, any thoughts? Should
> MensuralStaff simply be changed to have measureBarType = ##f
> (instead of "")?
>
> Jean
>
>
>
Currently I'm testing LSR-upgrade to current master, anticipating the
next stable. In the past doing so served me well as soon as the next
stable is actually out and updating LSR is really a TODO-NOW.
I stumbled upon a handful snippets (I may post about them, if I don't
find my way), one of them is incipit.ly,
https://lsr.di.unimi.it/LSR/Item?id=582
It works fine with 2.22. and before, I wonder why #4084 raises its
head now and not before.

Wouldn't it be a possibility to just change  our `incipit':
$ git diff
diff --git a/ly/property-init.ly b/ly/property-init.ly
index f8e6ee37be..c0605757be 100644
--- a/ly/property-init.ly
+++ b/ly/property-init.ly
@@ -323,6 +323,7 @@ incipit =
                 \override InstrumentName.self-alignment-X = #align-x
                 \override InstrumentName.self-alignment-Y = #align-y
                 instrumentName = #instrument-name
+                measureBarType = ##f
               }
               {
                 $incipit-music

At least it fixes the here reported bug.

Thanks,
  Harm