1.7.12: minimumVerticalExtent and HariKariStaffContext

[Hans Forbrich]

(Suse 8.0 + w/ Lilypond 1.7.12)

I have a score with StaffGroup:  Guitar (ChordNames) + Solo staff &
lyrics + SA staff & lyrics + TB lyrics & staff + PianoStaff

On the second system, Solo, SA & TB are "HariKari'd" but Guitar has a
single chord.  That chord is dangling up in the middle of the page,
almost independent of any music.  As Solo, SA, TB come in the Chordnames
approach closer to the system and when all three vocals are visible, the
whole system has a very pleasing effect.

In some systems, I have Piano +  Solo only, SA only or TB only.
Interestingly the further up the StaffGroup, the larger the displayed
gap between the PianoStaff and the active vocal.

I have been playing with the minimumVerticalExtent for Staff, Lyrics and
ChordNames with good success when all staves are visible, but less
success for systems with HariKari'd  staves.  It almost appears that a
spot is maintained even when the associated staff or chord is suppressed
- even when minimumVerticalExtent = ( 0 . 0 ).  Or possibly the spacing
for lyrics is maintained even when there are no associated notes.

Am I missing something or using the wrong overrides?

TIA
/Hans