ugly slurs at \break

[Atte André Jensen]

One of the things that still troubles me is how to make un-ugly slurs 
with lily, esp when the slur is over a linebreak. The tools I use are 
height, attachment and sometimes extra-offset. Are there other (better) 
ways to go about this?

The included (constructed) .ly shows two problematic slurs from 1st to 
2nd and from 2nd to 3rd system. I think the slur should end high before 
the line break and continue high on the next system. As it it now it 
looks like two seperate slurs + it clashes with the treble clef both in 
2nd and 3rd system.

Another thing. I often find that \once sometimes doesn't work. In the 
example the uncommented lines starting with \once doesn't work... Why? 
Me? A bug?

--- begin lily ---
\version "2.1.0"

upperOne = \notes\relative c' {
    \slurUp
    \once \property Voice.Slur \set #'attachment = #'(stem . stem)
    \once \property Voice.Slur \set #'height-limit = #'15
    |  c16 ( d e f g a b c d e f g a e a, e
    \translator Staff = lower
    | a, e a, e a,4 ) r
    \once \property Voice.Slur \set #'attachment = #'(stem . note)
    \once \property Voice.Slur \set #'height-limit = #'3
    a16 ( e' a e'\break
    \translator Staff = upper
    | a e' a c e g a b c cis d dis e4 )
    \once \property Voice.Slur \set #'attachment = #'(stem . note)
    \once \property Voice.Slur \set #'height-limit = #'2
    | c,,2  ( g''4 c,)
    \translator Staff = lower
%    \once \property Voice.Slur \set #'attachment = #'(note . stem)
%    \once \property Voice.Slur \set #'height-limit = #'60
    \property Voice.Slur \set #'attachment = #'(note . stem)
    \property Voice.Slur \set #'height-limit = #'8
    | r8 e,,16 ( gis a c
    \translator Staff = upper
    e gis b d des b c cis d dis \break
    | e c gis e fis4 ) r4 c16 c c c
    | c' c c c c, c c c c' c' c c c, c, c c
}

lowerOne = \notes\relative c {
}

\score {
    \context PianoStaff <<
        \context Staff = upper <<
            \context Voice = one \upperOne
        >>
        \context Staff = lower <<
            \clef bass
            \context Voice = one \lowerOne
        >>
    >>
    \paper { }
    \midi { }
}
--- end lily ---



--
peace, love & harmony
Atte

http://www.atte.dk