Re: Final volta bracket closed unexpectedly

[Thomas Morley]

Am Mo., 15. Feb. 2021 um 09:35 Uhr schrieb Jonas Hahnfeld via
bug-lilypond <bug-lilypond@gnu.org>:
>
> Am Sonntag, dem 14.02.2021 um 16:27 -0500 schrieb Dan Eble:
> > As I read Behind Bars, p.237, the bracket for volta 2 should not turn down 
> > at the end in this case.  Either way, it's strange that the outcome depends 
> > on line breaking.  If someone is willing to second this, I am willing to 
> > investigate it.
> > —
> > Dan
> >
> > \version "2.20.0"
> >
> > \layout {
> >   ragged-right = ##t
> > }
> >
> > piece = \fixed c' {
> >   \repeat volta 2 R1 \alternative { R1 R1 }
> >   \repeat volta 2 R1
> > }
> >
> > \new Score \new Staff << \piece >>
> > \new Score \new Staff << \piece { s1*3 \break } >>
>
> Yes, looks strange, especially given that the brackets in the following
> two don't turn down:
> \new Score \new Staff << { \repeat volta 2 R1 \alternative { R1 R1 } R1 } >>
> \new Score \new Staff << { \repeat volta 2 R1 \alternative { R1 R1 } \bar 
> "||" R1 } >>
>
> It turns down with \bar ".|" and \bar "|.", but neither with \bar ".",
> \bar "..", nor \bar "|.|" - weird.
>
> I went to check some scores I have, but both instances I found (Phantom
> of the Opera and Themes from 007) coincide with a line break - but at
> least the not-turning-down matches what LilyPond does in that case.
> I've found another one without line breaks in a custom score, but I
> didn't enter it and I'd have to ask the author what program he used.
> Whatever it was, the output looks visually unpleasant (some text sizes
> don't match), so I'm not sure it should be taken as reference...
>
> Jonas
> _______________________________________________
> bug-lilypond mailing list
> bug-lilypond@gnu.org
> https://lists.gnu.org/mailman/listinfo/bug-lilypond

Currently volta-hooks are allowed only for certain bar-lines.

This is controlled by `allow-volta-hook` from bar-line.scm and
`allowVoltaHook` from property-init.ly, both filling
`volta-bracket-allow-volta-hook-list`.
Defaulting to:
#(pretty-print
  (module-ref (resolve-module '(lily)) 'volta-bracket-allow-volta-hook-list))
->
(":|."
 ".|:"
 "|."
 ":..:"
 ":|.|:"
 ":|.:"
 ".|"
 ":|.S"
 ":|.S-S"
 ":|.S.|:"
 ":|.S.|:-S"
 ":|]"
 ":|][|:")

Here the ".|:"-bar-line is split into "|" at line-end and ".|:" at
line-begin, but the volta-hook is not allowed for "|".

This is the situation, as far as I can tell.
The printed outcome is always the same since 2.12.3, although the
implementation of the whole bar-line-stuff changed somewhere in 2.14.
or 2.16..
I don't remember exactly

No clue how to improve, though.

Cheers,
  Harm