Avoid segfault for cleared vertical-skylines in add_grobs_of_one_priority

diff --git a/lily/axis-group-interface.cc b/lily/axis-group-interface.cc
index c9c56858a17a071bb38a7038820bee6812b8c4f3..e842cb6d804a9bb70454ff1b6db6c9a7f5791dd0 100644 (file)
--- a/lily/axis-group-interface.cc
+++ b/lily/axis-group-interface.cc
@@ -797,7 +797,7 @@ add_grobs_of_one_priority (Grob *me,
           last_end[dir] = x_extent[RIGHT];
 
           Skyline_pair *v_orig = unsmob<Skyline_pair> (elt->get_property ("vertical-skylines"));
-          if (v_orig->is_empty ())
+          if (!v_orig || v_orig->is_empty ())
             continue;
 
           // Find the riders associated with this grob, and merge their