musescore/MuseScore — pull request #1124 by MarcSabatella (2014-08-12 14:16:04+00:00)
Title: fix #14353: lyrics and staff spacers don't work with hide empty staves

Fixes calculation of system height. I thought maybe spacers up and/or fret diagrams would have a similar issue, but they don't - the bbox() calculation already accounts for those.