Re: layout.cc: do not draw empty boxes (issue 6450113)

[graham]

http://codereview.appspot.com/6450113/diff/8003/scm/fret-diagrams.scm
File scm/fret-diagrams.scm (right):

http://codereview.appspot.com/6450113/diff/8003/scm/fret-diagrams.scm#newcode642
scm/fret-diagrams.scm:642: (corner1
from the context, I gather than corner1 is not guaranteed to be
lower-left or upper-right?  Could we get a comment stating that -- the
fact that corner1 and corner2 will be bottom-left and top-right, but not
necessarily in that order?

http://codereview.appspot.com/6450113/