Doc: minor edits to tweaks.itely for LM

[lilypond.git] / lily / align-interface.cc

diff --git a/lily/align-interface.cc b/lily/align-interface.cc
index f090cfd1e037b224e68d083f8ba578b210ff63b2..f27316bb278535ff049b3d736bebb9e2effb7025 100644 (file)
--- a/lily/align-interface.cc
+++ b/lily/align-interface.cc
@@ -1,7 +1,7 @@
 /*
   This file is part of LilyPond, the GNU music typesetter.
 
-  Copyright (C) 2000--2009 Han-Wen Nienhuys <hanwen@xs4all.nl>
+  Copyright (C) 2000--2010 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
@@ -240,9 +240,13 @@ void
 Align_interface::align_elements_to_ideal_distances (Grob *me)
 {
   System *sys = me->get_system ();
-  Page_layout_problem layout (NULL, SCM_EOL, scm_list_1 (sys->self_scm ()));
-
-  layout.solution (true);
+  if (sys)
+    {
+      Page_layout_problem layout (NULL, SCM_EOL, scm_list_1 (sys->self_scm ()));
+      layout.solution (true);
+    }
+  else
+    programming_error ("vertical alignment called before line breaking");
 }
 
 void