Allows slurs to break at barlines.

lily/slur.cc

 /*
   This file is part of LilyPond, the GNU music typesetter.
 
   Copyright (C) 1996--2012 Han-Wen Nienhuys <hanwen@xs4all.nl>
   Jan Nieuwenhuizen <janneke@gnu.org>
 
   LilyPond is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
@@ skipping 30 matching lines @@
 #include "slur-scoring.hh"
 #include "separation-item.hh"
 #include "unpure-pure-container.hh"
 #include "international.hh"
 
 MAKE_SCHEME_CALLBACK (Slur, calc_direction, 1)
 SCM
 Slur::calc_direction (SCM smob)
 {
   Grob *me = unsmob_grob (smob);
-  extract_grob_set (me, "note-columns", encompasses);
+  vector<Grob *> encompasses;
+  extract_grob_set (me, "note-columns", ro_encompasses);
+  encompasses.insert (encompasses.end (), ro_encompasses.begin (), ro_encompasses.end ());
+  if (Grob *other_half = unsmob_grob (me->get_object ("other-half")))
+    {
+      extract_grob_set (other_half, "note-columns", oh_encompasses);
+      encompasses.insert (encompasses.end (), oh_encompasses.begin (), oh_encompasses.end ());
+    }
 
   if (encompasses.empty ())
     {
       me->suicide ();
       return SCM_BOOL_F;
     }
 
   Direction d = DOWN;
   for (vsize i = 0; i < encompasses.size (); i++)
     {
@@ skipping 502 matching lines @@
                "height-limit "
                "inspect-quants "
                "inspect-index "
                "line-thickness "
                "note-columns "
                "positions "
                "ratio "
                "thickness "
               );