[gnote] Avoid a crash in a race condition when deleting a note.

[Hubert Figuière <hub src gnome org>]

commit 3e0ec405997bcc9aa5523a7705a2b2c6bae3528e
Author: Hubert Figuiere <hub figuiere net>
Date:   Tue Jun 30 03:32:09 2009 -0400

    Avoid a crash in a race condition when deleting a note.
    Closes #587395.

 src/notewindow.cpp |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)
---
diff --git a/src/notewindow.cpp b/src/notewindow.cpp
index f7598e1..2159618 100644
--- a/src/notewindow.cpp
+++ b/src/notewindow.cpp
@@ -194,7 +194,9 @@ namespace gnote {
   NoteWindow::~NoteWindow()
   {
     delete m_global_keys;
+    m_global_keys = NULL;
     delete m_mark_set_timeout;
+    m_mark_set_timeout = NULL;
     Preferences::obj().remove_notify(m_gconf_notify);
   }
 
@@ -293,7 +295,9 @@ namespace gnote {
   void NoteWindow::on_selection_mark_set(const Gtk::TextIter&, const Glib::RefPtr<Gtk::TextMark>&)
   {
     // FIXME: Process in a timeout due to GTK+ bug #172050.
-    m_mark_set_timeout->reset(0);
+    if(m_mark_set_timeout) {
+      m_mark_set_timeout->reset(0);
+    }
   }
 
   void NoteWindow::update_link_button_sensitivity()