strange formatting with involved `\break`

[Jean Abou Samra]

> Folks,
>
>
> can someone please explain to me why the following code
>
>    {
>      \compressEmptyMeasures
>      c'4 4 4 4 | 4 4 4 4 | 4 4 4 4 | 4 4 4 4 | \break
>      R4*120 | \break
>      c'4 4 4 4 | 4 4 4 4 | 4 4 4 4 | 4 4 4 4 |
>      c'4 4 4 4 | 4 4 4 4 | 4 4 4 4 | 4 4 4 4 |
>      c'4 4 4 4 | 4 4 4 4 | 4 4 4 4 | 4 4 4 4 |
>      c'4 4 4 4 | 4 4 4 4 | 4 4 4 4 | 4 4 4 4 |
>    }
>
> causes such an uneven formatting after the multi-measure?  And is
> there a work-around available?
>
>
>      Werner

Hi,
(Excuse the bad email threading, which will get fixed next time I reply.)

Interesting. The example can be made even more minimal, without
\compressEmptyMeasures:

{
  c'1
  \break
  \repeat unfold 35 { c'1 }
}

This produces the same bad output in 2.20. In 2.18, the output
is still suboptimal, but different (files attached).

A workaround would be

\paper {
  page-breaking = #ly:minimal-breaking
}

Both ly:optimal-page-breaking and ly:page-turn-breaking are faulty;
ly:one-page-breaking is not.

This issue could be related:

https://gitlab.com/lilypond/lilypond/-/issues/5488

Regards,
Jean

mwe-2.18.pdf
Description: Adobe PDF document

mwe-2.20.pdf
Description: Adobe PDF document