Fix for feathered fix: also handle case beam_multiplicity is empt

This happens for input/regression/beam-quarter.ly

diff --git a/lily/beam.cc b/lily/beam.cc
index 0d83aefb77da09a97a9b0e38cdfc732464ba4a37..79bc076f212165339bb73497aa04d78dbc967d52 100644 (file)
--- a/lily/beam.cc
+++ b/lily/beam.cc
@@ -1149,7 +1149,8 @@ Beam::calc_stem_y (Grob *me, Grob *stem, Grob **common,
   Slice beam_slice (french
                    ? where_are_the_whole_beams (beaming)
                    : Stem::beam_multiplicity (stem));
-
+  if (beam_slice.is_empty ())
+    beam_slice = Slice (0,0);
   Interval beam_multiplicity(beam_slice[LEFT],
                             beam_slice[RIGHT]);