https://codereview.appspot.com/576090043/diff/569740045/lily/staff-symbol.cc File lily/staff-symbol.cc (right):
https://codereview.appspot.com/576090043/diff/569740045/lily/staff-symbol.cc#newcode116 lily/staff-symbol.cc:116: return ly_scm2floatvector (line_positions); The suggested patch to expose internal_line_count() as line_count() bypasses this branch. line_count() should have the same branches as line_positions() but call scm_ilength() (I think) in this branch, and internal_line_count() in the other branch. Another thing is that it should return the type vsize, so you would need to take care to clip the values you get from Guile to >= 0. It isn't a lot of code, but it's the kind of thing that could easily get out of sync with line_positions() when later contributors come by. It's not something I'd want to commit myself, but if you are interested in doing it, I'm willing to say the L-word once it's ready. https://codereview.appspot.com/576090043/