Two-pass page layout sometimes stretches too much.

[Arvid Grøtting]

>> (Please disregard this line.  No, Gmane; I'm not top-posting.)

\version "2.11.5"

\paper {
  ragged-last-bottom = ##f
  texidoc = "
Two-pass page layout sometimes stretches too much.

When run without a tweak file, three pages of 3 + 3 + 2 systems are created.
After two-pass space tweaking, I get five pages of 2 + 1 + 1 + 2 + 1 systems.

I haven't been able to reproduce this without lyrics.

Reproduce thus:

lilypond two-pass.ly # three pages now

lilypond -b null -d dump-tweaks two-pass.ly 
lilypond two-pass.ly # five pages
"
}

foo = \relative c'' {
  \repeat unfold 32 { c4 d e c }
  \bar "|."
}

baz = \lyricmode {
  \repeat unfold 32 {
    Two -- pass pro -- blem?
  }
}

\includePageLayoutFile

\score {

  \context Score <<
    \new Staff <<     
      \scoreTweak "twopassTweaks"
      \foo 
    >> 
    \addlyrics { \baz }
    \new Staff << \foo >>
    \addlyrics { \baz }
    \new Staff << \foo >>
    \addlyrics { \baz }
    \new Staff << \foo >>
    \addlyrics { \baz }
  >>
  \layout {
    #(define tweak-key "twopassTweaks")
  }
 }