From 9e7fbc20ff3cb2cb204cdb9c635c3a6ff00229ec Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Fri, 30 Jul 2010 19:00:22 -0600
Subject: [PATCH] Fix #6352 (Viewing preferences gives error)

---
 src/calibre/gui2/ui.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/calibre/gui2/ui.py b/src/calibre/gui2/ui.py
index 6507689f42..1109a001c8 100644
--- a/src/calibre/gui2/ui.py
+++ b/src/calibre/gui2/ui.py
@@ -373,8 +373,9 @@ class Main(MainWindow, MainWindowMixin, DeviceMixin, # {{{
 
         d.exec_()
         self.content_server = d.server
-        self.content_server.state_callback = \
-            Dispatcher(self.content_server_state_changed)
+        if self.content_server is not None:
+            self.content_server.state_callback = \
+                Dispatcher(self.content_server_state_changed)
         self.content_server.state_callback(self.content_server.is_running)
 
         if d.result() == d.Accepted: