* Documentation/topdocs/INSTALL.texi (Top): update versions.

[lilypond.git] / lily / note-collision.cc

diff --git a/lily/note-collision.cc b/lily/note-collision.cc
index a3f18ab0026be756ee22c60280ea201afd0bd428..24a9a532cfdd28492e097cc4e1f5399ea087f539 100644 (file)
--- a/lily/note-collision.cc
+++ b/lily/note-collision.cc
@@ -354,7 +354,14 @@ Note_collision_interface::get_clash_groups (Grob *me)
     {
       Grob *se = elements[i];
       if (Note_column::has_interface (se))
-       clash_groups[Note_column::dir (se)].push_back (se);
+       {
+         if (!Note_column::dir (se))
+           {
+             se->programming_error ("note-column has no direction");
+           }
+         else
+           clash_groups[Note_column::dir (se)].push_back (se);
+       }
     }
 
   Direction d = UP;