X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fmusic-wrapper-iterator.cc;h=e208d135f5c75bf63973866b8815695263f4499c;hb=1badb0e2d9c97ad6f5c63bba3272348a684ac7a7;hp=e89896ce663652bca52800985e9ecdf487eeedc4;hpb=25190a4637753e6439c445d2d4fe9323b7945d32;p=lilypond.git

diff --git a/lily/music-wrapper-iterator.cc b/lily/music-wrapper-iterator.cc
index e89896ce66..e208d135f5 100644
--- a/lily/music-wrapper-iterator.cc
+++ b/lily/music-wrapper-iterator.cc
@@ -1,9 +1,20 @@
 /*
-  music-wrapper-iterator.cc -- implement Music_wrapper_iterator
+  This file is part of LilyPond, the GNU music typesetter.
 
-  source file of the GNU LilyPond music typesetter
+  Copyright (C) 1998--2012 Han-Wen Nienhuys <hanwen@xs4all.nl>
 
-  (c) 1998--2006 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
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  LilyPond is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 #include "music-wrapper-iterator.hh"
@@ -18,7 +29,8 @@ Music_wrapper_iterator::Music_wrapper_iterator ()
 void
 Music_wrapper_iterator::do_quit ()
 {
-  child_iter_->quit ();
+  if (child_iter_)
+    child_iter_->quit ();
 }
 
 void
@@ -40,7 +52,9 @@ Music_wrapper_iterator::construct_children ()
 {
   Music *my_music = get_music ();
   Music *child = unsmob_music (my_music->get_property ("element"));
-  child_iter_ = unsmob_iterator (get_iterator (child));
+  child_iter_ = (child)
+                ? unsmob_iterator (get_iterator (child))
+                : 0;
 }
 
 bool
@@ -52,13 +66,17 @@ Music_wrapper_iterator::ok () const
 void
 Music_wrapper_iterator::process (Moment m)
 {
-  child_iter_->process (m);
+  if (child_iter_)
+    child_iter_->process (m);
 }
 
 Moment
 Music_wrapper_iterator::pending_moment () const
 {
-  return child_iter_->pending_moment ();
+  if (child_iter_)
+    return child_iter_->pending_moment ();
+  else
+    return Music_iterator::pending_moment ();
 }
 
 IMPLEMENT_CTOR_CALLBACK (Music_wrapper_iterator);
@@ -66,5 +84,5 @@ IMPLEMENT_CTOR_CALLBACK (Music_wrapper_iterator);
 bool
 Music_wrapper_iterator::run_always () const
 {
-  return child_iter_->run_always ();
+  return (child_iter_ && child_iter_->run_always ());
 }