Doc: Clarified how to use clip-systems option

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

diff --git a/lily/note-column.cc b/lily/note-column.cc
index 760e37dc1956c045d51d3250bee9fad5269ee73b..91a7690697e338a8fe054808d2aabc9c4401b19d 100644 (file)
--- a/lily/note-column.cc
+++ b/lily/note-column.cc
@@ -1,7 +1,7 @@
 /*
   This file is part of LilyPond, the GNU music typesetter.
 
-  Copyright (C) 1997--2014 Han-Wen Nienhuys <hanwen@xs4all.nl>
+  Copyright (C) 1997--2015 Han-Wen Nienhuys <hanwen@xs4all.nl>
 
   LilyPond is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -43,7 +43,7 @@ using namespace std;
 bool
 Note_column::has_rests (Grob *me)
 {
-  return Grob::unsmob (me->get_object ("rest"));
+  return Grob::is_smob (me->get_object ("rest"));
 }
 
 bool
@@ -107,7 +107,10 @@ Note_column::dir (Grob *me)
         return (Direction)sign (head_positions_interval (me).center ());
     }
 
-  programming_error ("note column without heads and stem");
+  if (has_interface (me))
+    programming_error ("Note_column without heads and stem");
+  else
+    programming_error ("dir() given grob without Note_column interface");
   return CENTER;
 }
 
@@ -138,7 +141,7 @@ Note_column::add_head (Grob *me, Grob *h)
     }
   else if (Note_head::has_interface (h))
     {
-      if (Grob::unsmob (me->get_object ("rest")))
+      if (Grob::is_smob (me->get_object ("rest")))
         both = true;
       Pointer_group_interface::add_grob (me, ly_symbol2scm ("note-heads"), h);
     }
@@ -164,7 +167,7 @@ Note_column::first_head (Grob *me)
 Interval
 Note_column::calc_main_extent (Grob *me)
 {
-    Grob *main_head;
+    Grob *main_head = 0;
     if (get_stem (me))
         main_head = first_head (me);
     else