Comment #54 on issue 2801 by [email protected]: Patch: Approximates
cross-staff slurs in VerticalAxisGroup vertical-skylines.
http://code.google.com/p/lilypond/issues/detail?id=2801
I agree that this is likely what's happening, but I can't figure out why.
The problem is that it is impossible to recreate outside of the regtests (I
tried -fkeep-inline-functions, applying different patches, etc. but to no
avail).
My guess is that somewhere in the slur-scoring code, using pure heights and
pure offsets is leading to inconsistent results. They have never been used
this far downstream before, so I'm guessing that they may be freed up
earlier. But at least the inconsistency is consistent - I'm getting
4.9456964833876 whenever it does go off track.
